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Sodium Hydroxide

PubChem CID
14798
Structure
Sodium Hydroxide_small.png
Sodium Hydroxide__Crystal_Structure.png
Molecular Formula
Synonyms
  • SODIUM HYDROXIDE
  • 1310-73-2
  • Caustic soda
  • Sodium hydrate
  • Aetznatron
Molecular Weight
39.997 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2005-03-26
  • Modify:
    2025-01-18
Description
At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air. It is a manufactured substance. When dissolved in water or neutralized with acid it liberates substantial heat, which may be sufficient to ignite combustible materials. Sodium hydroxide is very corrosive. It is generally used as a solid or a 50% solution. Other common names include caustic soda and lye. Sodium hydroxide is used to manufacture soaps, rayon, paper, explosives, dyestuffs, and petroleum products. It is also used in processing cotton fabric, laundering and bleaching, metal cleaning and processing, oxide coating, electroplating, and electrolytic extracting. It is commonly present in commercial drain and oven cleaners.
Sodium hydroxide solution appears as a colorless liquid. More dense than water. Contact may severely irritate skin, eyes, and mucous membranes. Toxic by ingestion. Corrosive to metals and tissue.
Sodium hydroxide, solid appears as a white solid. Corrosive to metals and tissue. Used in chemical manufacturing, petroleum refining, cleaning compounds, drain cleaners.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Sodium Hydroxide.png

1.2 3D Status

Conformer generation is disallowed since MMFF94s unsupported element, mixture or salt

1.3 Crystal Structures

1 of 3
View All
COD Number
Associated Article
Bleif, H.J.; Dachs, H.. Crystalline modifications and structural phase transitions of Na O H and Na O D. Acta Crystallographica A (24,1968-38,1982) 1982;38:470-476.
Crystal Structure Depiction
Crystal Structure Depiction
Hermann-Mauguin space group symbol
P 1 21/m 1
Hall space group symbol
-P 2yb
Space group number
11
a
3.345 Å
b
3.445 Å
c
6.08 Å
α
90 °
β
109.9 °
γ
90 °
Z
2
Z'
0.5
Component
1 x [Na+] (Sodium ion)
Component
1 x [OH-] (Hydroxide)

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

sodium;hydroxide
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

2.1.2 InChI

InChI=1S/Na.H2O/h;1H2/q+1;/p-1
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 InChIKey

HEMHJVSKTPXQMS-UHFFFAOYSA-M
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.4 SMILES

[OH-].[Na+]
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

HNaO
Computed by PubChem 2.2 (PubChem release 2021.10.14)
NaOH

2.3 Other Identifiers

2.3.1 CAS

1310-73-2
81133-20-2

2.3.2 Deprecated CAS

1418731-95-9, 2319645-49-1, 2391974-94-8, 8012-01-9

2.3.3 European Community (EC) Number

215-185-5

2.3.4 UNII

2.3.5 UN Number

2.3.6 ChEBI ID

2.3.7 ChEMBL ID

2.3.8 DrugBank ID

2.3.9 DSSTox Substance ID

2.3.10 HMDB ID

2.3.11 ICSC Number

2.3.12 KEGG ID

2.3.13 NCI Thesaurus Code

2.3.14 Nikkaji Number

2.3.15 NSC Number

2.3.16 RTECS Number

2.3.17 RXCUI

2.3.18 Wikidata

2.3.19 Wikipedia

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • Caustic Soda
  • Hydroxide, Sodium
  • Soda, Caustic
  • Sodium Hydroxide

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
39.997 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Donor Count
Property Value
1
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Acceptor Count
Property Value
1
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
39.99250893 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
39.99250893 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
1 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
2
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
2
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Isotope Atom Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Atom Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Defined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Undefined Bond Stereocenter Count
Property Value
0
Reference
Computed by PubChem
Property Name
Covalently-Bonded Unit Count
Property Value
2
Reference
Computed by PubChem
Property Name
Compound Is Canonicalized
Property Value
Yes
Reference
Computed by PubChem (release 2021.10.14)

3.2 Experimental Properties

3.2.1 Physical Description

Sodium hydroxide solution appears as a colorless liquid. More dense than water. Contact may severely irritate skin, eyes, and mucous membranes. Toxic by ingestion. Corrosive to metals and tissue.
Sodium hydroxide, solid appears as a white solid. Corrosive to metals and tissue. Used in chemical manufacturing, petroleum refining, cleaning compounds, drain cleaners.
Water or Solvent Wet Solid; Dry Powder; Liquid; Liquid, Other Solid; Other Solid; Pellets or Large Crystals, Liquid, Other Solid; NKRA; Pellets or Large Crystals; Pellets or Large Crystals, Liquid; Dry Powder, Pellets or Large Crystals; Dry Powder, Liquid
White or nearly white pellets, flakes, sticks, fused masses or other forms. Solutions are clear or slightly turbid, colourless or slightly coloured, strongly caustic and hygroscopic and when exposed to the air they absorb carbon dioxide, forming sodium carbonate
Colorless to white, odorless solid (flakes, beads, granular form); [NIOSH] Deliquescent; [CHEMINFO]
WHITE HYGROSCOPIC SOLID IN VARIOUS FORMS.
Colorless to white, odorless solid (flakes, beads, granular form).

3.2.2 Color / Form

White, orthogonal crystals
Haynes, W.M. (ed.) CRC Handbook of Chemistry and Physics. 91st ed. Boca Raton, FL: CRC Press Inc., 2010-2011, p. 4-90
Colorless to white ... solid (flakes, beads, granular form).
NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from, as of Oct 7, 2011: https://www.cdc.gov/niosh/npg/
Brittle, white, translucent crystalline solid
Eggeman T; Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2011). New York, NY: John Wiley & Sons; Sodium Hydroxide. Online Posting Date: 15 April 2011

3.2.3 Odor

... Odorless ...
NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from, as of Oct 7, 2011: https://www.cdc.gov/niosh/npg/

3.2.4 Taste

Detection - the minimum physical intensity detection by a subject where he or she is not required to identify the stimulus but just detect the existence of the stimulus - in water: 8.00X10-3 mol/L.
ASTM; Compilation of Odor and Taste Threshold Values Data p.150 (1978)

3.2.5 Boiling Point

greater than 266 °F at 760 mmHg (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
Very high (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
1388
MSDS
1388 °C
Haynes, W.M. (ed.) CRC Handbook of Chemistry and Physics. 91st ed. Boca Raton, FL: CRC Press Inc., 2010-2011, p. 4-90
2534 °F

3.2.6 Melting Point

604 °F (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
323
MSDS
323 °C
Haynes, W.M. (ed.) CRC Handbook of Chemistry and Physics. 91st ed. Boca Raton, FL: CRC Press Inc., 2010-2011, p. 4-90
318 °C
605 °F

3.2.7 Solubility

111 % (NIOSH, 2024)
easily soluble in cold water, hot water
MSDS
Very soluble in water. Freely soluble in ethanol
1 g dissolves in 7.2 mL absolute alcohol, 4.2 mL methanol; also soluble in glycerol
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485
1 g dissolves in 0.9 mL water, 0.3 mL boiling water
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485
Solubility in water, g/100ml at 20 °C: 109 (very good)
111%

3.2.8 Density

1.5 at 68 °F (USCG, 1999) - Denser than water; will sink
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
2.13 at 68 °F (USCG, 1999) - Denser than water; will sink
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
2.13 g/cu cm 25 °C
Haynes, W.M. (ed.) CRC Handbook of Chemistry and Physics. 91st ed. Boca Raton, FL: CRC Press Inc., 2010-2011, p. 4-90
70-73 % solution: MP 62 °C; Density = 2.0 at 15.5 °C
Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) p.1 (1981)
2.1 g/cm³
2.13

3.2.9 Vapor Pressure

0 mmHg (approx) (NIOSH, 2024)
VP: 1 Pa at 513 °C; 10 Pa at 605 °C; 100 Pa at 722 °C; 1kPa at 874 °C; 10 kPa at 1080 °C; 100 kPa at 1377 °C
Haynes, W.M. (ed.) CRC Handbook of Chemistry and Physics. 91st ed. Boca Raton, FL: CRC Press Inc., 2010-2011, p. 6-90
1.82X10-21 mm Hg at 25 °C /extrapolated/
Ohe S; Computer Aided Data Book of Vapor Pressure. Tokyo, Japan: Data Book Publ. Co. (1976)
0 mmHg (approx)

3.2.10 Stability / Shelf Life

CONTAINERS OF LYE MUST BE TIGHTLY CLOSED TO PREVENT CONVERSION TO SODIUM CARBONATE BY CARBON DIOXIDE OF AIR.
Jones, L.M., et al. Veterinary Pharmacology & Therapeutics. 4th ed. Ames: Iowa State University Press, 1977., p. 867

3.2.11 Autoignition Temperature

Not flammable (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.

3.2.12 Decomposition

When heated to decomposition it emits toxic fumes of /sodium oxide/.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 3254

3.2.13 Viscosity

4.0 cP at 350 °C
General Electric Co; Material Safety Data Sheet MSDS #3 (1984)

3.2.14 Corrosivity

Very corrosive (caustic) to ... aluminum metal in presence of moisture
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485

3.2.15 Heat of Combustion

SRP4: Non-combustible

3.2.16 Heat of Vaporization

175 kJ/mol at 1388 °C
Haynes, W.M. (ed.) CRC Handbook of Chemistry and Physics. 91st ed. Boca Raton, FL: CRC Press Inc., 2010-2011, p. 6-130

3.2.17 pH

Strongly alkaline (1 % solution)
pH of a 0.05% wt/wt solution about 12; 0.5% solution about 13; 5% solution about 14
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485

3.2.18 Surface Tension

At 18 °C: 74.35 dynes/cm (2.72 wt%), 75.85 dynes/cm (5.66 wt%), 83.05 dynes/cm (16.66 wt%), 96.05 dynes/cm (30.56 wt%), 101.05 dynes/cm (35.90 wt%)
Weast, R.C. (ed.) Handbook of Chemistry and Physics. 67th ed. Boca Raton, FL: CRC Press, Inc., 1986-87., p. F-31

3.2.19 Polymerization

SRP4: Not polymerized

3.2.20 Refractive Index

Refractive index at 589.4 nm: 1.433 at 320 °C; 1.421 at 420 °C
Eggeman T; Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2011). New York, NY: John Wiley & Sons; Sodium Hydroxide. Online Posting Date: 15 April 2011

3.2.21 Dissociation Constants

SRP4: Completely dissociated

3.2.22 Other Experimental Properties

5% solution (wt/wt): density: 1.056, FP: -4 °C, BP: 102 °C. 10% solution (wt/wt): density: 1.111, FP: -10 °C, BP: 105 °C. 20% solution (wt/wt): density: 1.222, FP: -26 °C, BP: 110 °C. 30% solution (wt/wt): density: 1.333, FP: 1 °C, CP: 115 °C. 40% solution (wt/wt): density: 1.434, FP: 15 °C, BP: 125 °C. 50% solution (wt/wt): density: 1.530, FP: 12 °C, BP: 140 °C
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485
Rapidly absorbs carbon dioxide and water from air
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485
Deliquescent
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 1146
Heat of Formation: -425.8 kK/mol at 298.15 K (crystal); -191.0 kJ/mol at 298.15 K (gas)
Haynes, W.M. (ed.) CRC Handbook of Chemistry and Physics. 91st ed. Boca Raton, FL: CRC Press Inc., 2010-2011, p. 5-13
Heat of Transition, alpha to beta, J/g = 103.3. Heat of formation from the elements: Alpha form, kJ/mol = 422.46; Beta form, kJ/mol = 426.60. Transition temperature, 299.6 °C.
Eggeman T; Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2011). New York, NY: John Wiley & Sons; Sodium Hydroxide. Online Posting Date: 15 April 2011
Caustic soda reacts with all the mineral acids to form the corresponding salts. It also reacts with weak-acid gases, such as hydrogen sulfide, sulfur dioxide, and carbon dioxide. Caustic soda reacts with amphoteric metals (Al, Zn, Sn) and their oxides to form complex anions such as AlO2(-), ZnO2(-2), SNO2(-2), and H2 (or H2O with oxides). All organic acids also react with sodium hydroxide to form soluble salts. Another common reaction of caustic soda is dehydrochlorination.
Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V1: 1008
For more Other Experimental Properties (Complete) data for SODIUM HYDROXIDE (8 total), please visit the HSDB record page.

3.3 SpringerMaterials Properties

3.4 Chemical Classes

Other Classes -> Bases

3.4.1 Drugs

3.4.1.1 Animal Drugs
Pharmaceuticals -> UK Veterinary Medicines Directorate List
S104 | UKVETMED | UK Veterinary Medicines Directorate's List | DOI:10.5281/zenodo.7802119

3.4.2 Cosmetics

Cosmetics ingredient -> Base; Buffering/pH Adjusting; Conditioning/Emollient; Flavor; Fragrance; Opacifying Agent; Other (Specify); Preservative/Stabilizer; Solvent
Cosmetic ingredients (Sodium Hydroxide) -> CIR (Cosmetic Ingredient Review)
Buffering; Denaturant
S13 | EUCOSMETICS | Combined Inventory of Ingredients Employed in Cosmetic Products (2000) and Revised Inventory (2006) | DOI:10.5281/zenodo.2624118

3.4.3 Food Additives

COLOR OR COLORING ADJUNCT, DOUGH STRENGTHENER, FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, FLOUR TREATING AGENT, FUMIGANT, OXIDIZING OR REDUCING AGENT, PH CONTROL AGENT, PROCESSING AID, WASHING OR SURFACE REMOVAL AGENT -> FDA Substance added to food

3.4.4 Fragrances

Fragrance Ingredient (Sodium hydroxide) -> IFRA transparency List

3.4.5 Pesticides

Herbicides
Active substance -> EU Pesticides database: Not approved

4 Spectral Information

4.1 IR Spectra

4.1.1 ATR-IR Spectra

Instrument Name
Bio-Rad FTS
Technique
ATR-Neat (DuraSamplIR II)
Source of Spectrum
Forensic Spectral Research
Source of Sample
British Drug House Ltd. Poole, England
Copyright
Copyright © 2012-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail

6 Chemical Vendors

7 Drug and Medication Information

7.1 Drug Indication

Used to destroy or kill the nail matrix (matrixectomies).

7.2 FDA National Drug Code Directory

7.3 Drug Labels

Active ingredient and drug

7.4 Therapeutic Uses

Caustics
National Library of Medicine's Medical Subject Headings online file (MeSH, 2011)
Vet: Caustic, dehorning of calves.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485
VET: A 2% solution of soda lye (contains 94% sodium hydroxide) in hot water is used as a disinfectant against many common pathogens, such as those causing fowl cholera and pullorum disease.
Kahn, C.M. (Ed.); The Merck Veterinary Manual 9th ed. Merck & Co. Whitehouse Station, NJ. 2005, p. 2153

8 Food Additives and Ingredients

8.1 Food Additive Classes

JECFA Functional Classes
Food Additives -> ACIDITY_REGULATOR;

8.2 FDA Substances Added to Food

Used for (Technical Effect)
COLOR OR COLORING ADJUNCT, DOUGH STRENGTHENER, FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, FLOUR TREATING AGENT, FUMIGANT, OXIDIZING OR REDUCING AGENT, PH CONTROL AGENT, PROCESSING AID, WASHING OR SURFACE REMOVAL AGENT

8.3 Evaluations of the Joint FAO / WHO Expert Committee on Food Additives - JECFA

Chemical Name
CAUSTIC SODA
Evaluation Year
1965
ADI
NOT LIMITED

9 Agrochemical Information

9.1 Agrochemical Category

Pesticide active substances -> Herbicides

9.2 EU Pesticides Data

Active Substance
sodium hydroxide
Status
Not approved [Reg. (EC) No 1107/2009]
Legislation
2004/129/EC

10 Pharmacology and Biochemistry

10.1 Pharmacodynamics

Sodium Hydroxide 10% forms a strongly alkaline and caustic solution. As a caustic agent, it is used to destroy organic tissue by chemical action.

10.2 MeSH Pharmacological Classification

Caustics
Strong alkaline chemicals that destroy soft body tissues resulting in a deep, penetrating type of burn, in contrast to corrosives, that result in a more superficial type of damage via chemical means or inflammation. Caustics are usually hydroxides of light metals. SODIUM HYDROXIDE and potassium hydroxide are the most widely used caustic agents in industry. Medically, they have been used externally to remove diseased or dead tissues and destroy warts and small tumors. The accidental ingestion of products (household and industrial) containing caustic ingredients results in thousands of injuries per year. (See all compounds classified as Caustics.)

10.3 Absorption, Distribution and Excretion

Absorption
There are no quantitative data for the absorption of sodium hydroxide through the skin. Solutions which contain 50 % sodium hydroxide have been shown to be corrosive and lethal when applied dermally to mice.
ALKALIS PENETRATE SKIN SLOWLY.
Dreisbach, R. H. Handbook of Poisoning. 9th ed. Los Altos, California: Lange Medical Publications, 1977., p. 202
Ammonium hydroxide penetrates fastest, followed by sodium hydroxide, potassium hydroxide, and finally calcium hydroxide.
Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992., p. 433

10.4 Mechanism of Action

Because of its high-level alkalinity, sodium hydroxide in aqueous solution directly causes bond breakage in proteins (especially disulfide bridges). Hair and fingernails are found to be dissolved after 20 hours of direct contact with sodium hydroxide at pH values higher than 9.2. Sodium hydroxide has depilatory effects which have been described after accidental contact with solutions in the workplace. The breakage of bonds in proteins may lead to severe necrosis to the application site. The level of corrosion depends on the period of contact with the tissue, and on the concentration of sodium hydroxide.

11 Use and Manufacturing

11.1 Uses

Cosmetic Ingredient Review Link
CIR ingredient: Sodium Hydroxide
EPA CPDat Chemical and Product Categories
The Chemical and Products Database, a resource for exposure-relevant data on chemicals in consumer products, Scientific Data, volume 5, Article number: 180125 (2018), DOI:10.1038/sdata.2018.125
Sources/Uses
Used to neutralize acids, produce sodium salts, hydrolyze fats to make soaps, and precipitate metals; large amounts are used in petroleum refining, rayon production, and rubber reclaiming; [Merck Index # 8627] Also used in metal cleaning, electroplating, processing cotton fabrics, and bleaching; [ATSDR Medical Management] Used in photography (developing bath); [www.ci.tucson.az.us/arthazards/medium.html] In semiconductor manufacturing, sodium hydroxide is used to develop the pattern in the photoresists and also as a wet echant. [CHS, p. 44-5] Caustic soda is used in hide preparation for leather production; [PMID 21938525]
Merck Index - O'Neil MJ, Heckelman PE, Dobbelaar PH, Roman KJ (eds). The Merck Index, An Encyclopedia of Chemicals, Drugs, and Biologicals, 15th Ed. Cambridge, UK: The Royal Society of Chemistry, 2013. # 8627
Industrial Processes with risk of exposure
Activities with risk of exposure

Textile arts [Category: Hobbies]

Applying metallic patinas [Category: Hobbies]

Both oil base and water base fracturing fluids are being used in the fracturing industry. Water base, which includes alcohol-water mixtures and low strength acids, make up the majority of treating fluids. The common chemicals added to these fluids are polymers for viscosity development, crosslinkers for viscosity enhancement, pH control chemicals, gel breakers for polymer degradation following the treatment, surfactants, clay stabilizers, alcohol, bactericides, fluid loss additives and friction reducer. /Hydraulic fracturing/
Halliburton; Hydraulic Fracturing. Document ID: EPA-HQ-ORD-2010-0674-1634 p.32. Available from, as of October 27, 2011: https://www.regulations.gov/#!documentDetail;D=EPA-HQ-ORD-2010-0674-1634
Hydraulic fracturing uses a specially blended liquid which is pumped into a well under extreme pressure causing cracks in rock formations underground. These cracks in the rock then allow oil and natural gas to flow, increasing resource production. ... Chemical Name: Sodium hydroxide; Chemical Purpose: Adjusts the pH of fluid to maintain the effectiveness of other components, such as crosslinkers; Product Function: pH Adjusting agent.
FracFocus; Chemical Disclosure Registry, Hydraulic Fracturing, How it Works; What Chemicals are Used. Available from, as of October 28, 2011: https://fracfocus.org/chemical-use/what-chemicals-are-used
For sodium hydroxide (USEPA/OPP Pesticide Code: 075603) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./
National Pesticide Information Retrieval System's USEPA/OPP Chemical Ingredients Database on Sodium Hydroxide (1310-73-2). Available from, as of October 10, 2011: https://npirspublic.ceris.purdue.edu/ppis/
In inorganic chemistry, sodium hydroxide is used in the manufacture of sodium salts, for alkaline ore digestion, and for pH regulation.
Kurt C, Bittner J; Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2011). NY, NY: John Wiley & Sons; Sodium Hydroxide. Online Posting Date: July 15, 2006
For more Uses (Complete) data for SODIUM HYDROXIDE (16 total), please visit the HSDB record page.

11.1.1 Use Classification

EPA Safer Chemical Functional Use Classes -> Processing Aids and Additives
Safer Chemical Classes -> Green circle Green circle - The chemical has been verified to be of low concern
Food additives
Fragrance Ingredients
Food Additives -> ACIDITY_REGULATOR; -> JECFA Functional Classes
Hazard Classes and Categories -> Corrosives, Reactive - 1st degree
Cosmetics -> Buffering; Denaturant
S13 | EUCOSMETICS | Combined Inventory of Ingredients Employed in Cosmetic Products (2000) and Revised Inventory (2006) | DOI:10.5281/zenodo.2624118

11.1.2 Industry Uses

  • Density modifier
  • Laboratory chemicals
  • Other (specify)
  • Solvents (for cleaning or degreasing)
  • Solvents (which become part of product formulation or mixture)
  • Plasticizers
  • Oxidizing/reducing agents
  • Ion exchange agent
  • Not Known or Reasonably Ascertainable
  • Adsorbents and absorbents
  • Intermediate
  • Solvent
  • Sealant (barrier)
  • Corrosion inhibitors and anti-scaling agents
  • Stabilizing agent
  • Fuels and fuel additives
  • Thickening agent
  • Anti-scaling agent
  • Intermediates
  • Bleaching agents
  • Adhesives and sealant chemicals
  • Processing aids, specific to petroleum production
  • Process regulators
  • Processing aids not otherwise specified
  • Finishing agents
  • Corrosion inhibitor
  • Abrasives
  • Diluent
  • Leaching agent
  • Sizing agent
  • Ion exchange agents
  • Dye
  • Other
  • Bleaching agent
  • Pigments
  • Solids separation agents
  • Anti-adhesive agents
  • Flotation agent
  • Cleaning agent
  • pH regulating agent
  • Plasticizer
  • Swelling agent
  • Odor agents
  • Surface active agents
  • Plating agents and surface treating agents
  • Processing aids, not otherwise listed
  • Agricultural chemicals (non-pesticidal)
  • Paint additives and coating additives not described by other categories
  • Catalyst
  • Softener and conditioner
  • Viscosity adjustors

11.1.3 Consumer Uses

  • Bleaching agent
  • Other
  • Pigments
  • Processing aids, specific to petroleum production
  • Process regulators
  • Processing aids not otherwise specified
  • Finishing agents
  • Corrosion inhibitor
  • Brightener
  • Plating agents and surface treating agents
  • Processing aids, not otherwise listed
  • Softener and conditioner
  • Paint additives and coating additives not described by other categories
  • Agricultural chemicals (non-pesticidal)
  • Solids separation agents
  • pH regulating agent
  • Cleaning agent
  • Oxidizing agent
  • Ion exchange agent
  • Oxidizing/reducing agents
  • Plasticizers
  • Laboratory chemicals
  • Solvents (for cleaning or degreasing)
  • Other (specify)
  • Fuels and fuel additives
  • Intermediates
  • Adhesives and sealant chemicals
  • Bleaching agents
  • Adsorbents and absorbents
  • Not Known or Reasonably Ascertainable
  • Intermediate
  • Solvent
  • Sealant (barrier)
  • Corrosion inhibitors and anti-scaling agents

11.1.4 Household Products

California Safe Cosmetics Program (CSCP)

Cosmetics product ingredient: Sodium hydroxide

Reason for Listing: Identified with non-cancer endpoints and listed with an inhalation or oral Reference Exposure Level by the California Office of Environmental Health Hazard Assessment under Health and Safety Code section 44360(b)(2)

Potential Health Impacts: Dermatotoxicity, Ocular Toxicity, and Respiratory Toxicity

Product count: 655

Household & Commercial/Institutional Products

Information on 1896 consumer products that contain Sodium hydroxide in the following categories is provided:

• Auto Products

• Commercial / Institutional

• Home Maintenance

• Inside the Home

• Landscaping/Yard

• Personal Care

• Pesticides

• Pet Care

11.2 Methods of Manufacturing

By reacting calcium hydroxide with sodium carbonate; from sodium chloride by electrolysis; from sodium metal and water vapor at low temperature.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485
Sodium hydroxide is produced industrially mainly by the electrolysis of sodium chloride. This yields sodium hydroxide solution, chlorine, and hydrogen in the mass ratios 1:0.88:0.025.
Kurt C, Bittner J; Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2011). New York, NY: John Wiley & Sons; Sodium Hydroxide. Online Posting Date: July 15, 2006
Solid sodium hydroxide (caustic soda) is obtained by evaporating sodium hydroxide solution until the water content is < 0.5 - 1.5 wt%. The most efficient utilization of energy is achieved with multistage equipment.
Kurt C, Bittner J; Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2011). New York, NY: John Wiley & Sons; Sodium Hydroxide. Online Posting Date: July 15, 2006
Causticization of sodium carbonate: A hot, ca. 12% solution of sodium carbonate is mixed with quicklime (CaO). The calcium carbonate that precipitates out is removed and the ca. 12% solution of sodium hydroxide is evaporated in several stages.
Gerhartz, W. (exec ed.). Ullmann's Encyclopedia of Industrial Chemistry. 5th ed.Vol A1: Deerfield Beach, FL: VCH Publishers, 1985 to Present., p. VA24: 349 (1993)
For more Methods of Manufacturing (Complete) data for SODIUM HYDROXIDE (6 total), please visit the HSDB record page.

11.3 Impurities

Major impurities which are normally tested for are sodium chloride, sodium carbonate, sodium sulfate, sodium chlorate, iron, and nickel.
Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V1: 1012 (1991)

11.4 Formulations / Preparations

Solid sodium hydroxide is supplied in the form of flakes, prills, cast blocks, and less commonly as tablets, briquettes, or granules.
Kurt C, Bittner J; Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2011). New York, NY: John Wiley & Sons; Sodium Hydroxide. Online Posting Date: July 15, 2006
Grades: commercial; ground; flake; beads; Food Chemical Codex grade; granulated (60% and 76% Na2O); rayon (low in iron, copper, and manganese); purified by alcohol (sticks, lumps, and drops); reagent; highest purity: CP, USP.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 1146
When kept in tight containers, the usual grades contain 97-98% sodium hydroxide.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485
Anhydrous (Rayon Grade) 99.0% minimum; Rayon Grade: 50% liquid; Regular Grade: 50% liquid, 47.7-51% purity.
Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) p.1 (1981)
For more Formulations/Preparations (Complete) data for SODIUM HYDROXIDE (8 total), please visit the HSDB record page.

11.5 Consumption Patterns

51% IS CONSUMED IN CHEMICAL PROCESSING AND METAL PROCESSING OTHER THAN ALUMINUM; 6% FOR ALUMINUM PROCESSING; 18% IS USED IN PAPER AND PULP MANUFACTURE; 13% IS USED IN THE PETROLEUM, TEXTILE, SOAP, AND FOOD INDUSTRIES; 4% IS USED IN RAYON AND CELLOPHANE PRODUCTION; 8% IS USED IN OTHER APPLICATIONS (1974).
SRI
CHEMICAL PROFILE: Caustic soda. Organic Chemicals, 30%; Inorganic Chemicals, 20%; Pulp & Paper, 20%; Exports, 10%; Soaps and Detergents, 5%; Petroleum, 5%; Textiles, 4%; Alumina, 3%; Other, 3% (1986).
CHEMICAL PROFILE: Caustic Soda, 1986
CHEMICAL PROFILE: Caustic soda. Pulp and paper, 22%; organic chemicals, 20%; inorganic chemicals, 11%; soaps and detergents, 7%; petroleum, 7%; water treatment, 7%; textiles, 5%; alumina, 4%; other, 9%; exports, 8%.
Kavaler AR; Chemical Marketing Reporter 235 (25): 50 (1989)
Direct application, 55% (pulp & paper, 24%; soaps and detergents, 10%; alumina, 6%; petroleum, 7%; textiles, 5%; water treatment, 5%; miscellaneous, 43%); organic chemicals 36% (propylene oxide, 23%; polycarbonates, 5%; ethyleneamines, 3%; epoxy resins, 3%; miscellaneous, 66%); inorganic chemicals, 9% (sodium/calcium hypochlorite, 24%; sulfur-containing compounds, 14%; sodium cyanide, 10%; miscellaneous 52%)
Kavaler AR; Chemical Marketing Reporter, June 1, 1998, p. 37 Chemical Profile: Caustic Soda

11.6 U.S. Production

Aggregated Product Volume

2019: 20,000,000,000 - <30,000,000,000 lb

2018: 20,000,000,000 - <30,000,000,000 lb

2017: 20,000,000,000 - <30,000,000,000 lb

2016: 20,000,000,000 - <30,000,000,000 lb

(1972) 9.27X10+12 GRAMS
SRI
(1975) 8.7X10+12 GRAMS
SRI
(1985) 9.24X10+12 g
Chem Eng News 64(16): 13(1986)
(1990) 24.06 billion lb
Chem & Engineering News 70 (15): 17 (4/13/92)
For more U.S. Production (Complete) data for SODIUM HYDROXIDE (12 total), please visit the HSDB record page.

11.7 U.S. Imports

(1972) 9.53X10+10 GRAMS
SRI
(1975) 9.8X10+10 GRAMS
SRI
(1984) 4.78X10+11 g
BUREAU OF THE CENSUS. U.S. IMPORTS FOR CONSUMPTION AND GENERAL IMPORTS 1984 p.1-351
1996: 540,000 tons
Kavaler AR; Chemical Marketing Reporter, June 1, 1998, p. 37, Chemical Profile: Caustic Soda

11.8 U.S. Exports

(1972) 1.1X10+12 GRAMS
SRI
(1975) 1.00X10+12 GRAMS
SRI
(1984) 1.14X10+12 g
BUREAU OF THE CENSUS. U.S. EXPORTS, SCHEDULE E, 1984 p.2-92
1996: 2 million tons.
Kavaler AR; Chemical Marketing Reporter, June 1, 1998, p. 37, Chemical Profile: Caustic Soda

11.9 General Manufacturing Information

Industry Processing Sectors
  • All other Petroleum and Coal Products Manufacturing
  • Fabricated Metal Product Manufacturing
  • Plastics Product Manufacturing
  • Wood Product Manufacturing
  • Synthetic Dye and Pigment Manufacturing
  • Paper Manufacturing
  • Utilities
  • Plastics Material and Resin Manufacturing
  • Not Known or Reasonably Ascertainable
  • Petrochemical Manufacturing
  • Soap, Cleaning Compound, and Toilet Preparation Manufacturing
  • Synthetic Rubber Manufacturing
  • Primary Metal Manufacturing
  • Construction
  • Oil and Gas Drilling, Extraction, and Support activities
  • All Other Chemical Product and Preparation Manufacturing
  • Textiles, apparel, and leather manufacturing
  • Miscellaneous Manufacturing
  • Wholesale and Retail Trade
  • Organic Fiber Manufacturing
  • Mining (except Oil and Gas) and support activities
  • Food, beverage, and tobacco product manufacturing
  • Petroleum Lubricating Oil and Grease Manufacturing
  • Petroleum Refineries
  • Other (requires additional information)
  • All Other Basic Inorganic Chemical Manufacturing
  • Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing
  • All Other Basic Organic Chemical Manufacturing
  • Agriculture, Forestry, Fishing and Hunting
  • Paint and Coating Manufacturing
EPA TSCA Commercial Activity Status
Sodium hydroxide (Na(OH)): ACTIVE
All U.S. production, except for that in Granger and Green River, WY, is by brine electrolysis.
SRI. 1997 Directory of Chemical Producers -United States of America. Menlo Park, CA: SRI International 1997., p. 892
Chlorine and sodium hydroxide are usually coproduced /by brine electrolysis/ in a ratio of 1 ton of chlorine to 1.1 tons of sodium hydroxide.
SRI. 1998 Directory of Chemical Producers -United States of America. SRI International, Menlo Park, CA. 1998., p. 892
Caustic soda (NaOH) and chlorine are coproducts and consequently caustic soda production has been limited by chlorine demand. Increased demand for caustic soda over that of chlorine will be presumably addressed by a switch to soda ash (sodium carbonate) where possible.
Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V1: 939 (1991)
Produced commercially in two forms: a 50 wt % solution (the most common form) and in the solid (caustic soda) as prills, flakes, or cast shapes.
Gerhartz, W. (exec ed.). Ullmann's Encyclopedia of Industrial Chemistry. 5th ed.Vol A1: Deerfield Beach, FL: VCH Publishers, 1985 to Present., p. VA24: 347 (1993)
For more General Manufacturing Information (Complete) data for SODIUM HYDROXIDE (8 total), please visit the HSDB record page.

11.10 Sampling Procedures

ANALYTE: SODIUM HYDROXIDE; MATRIX: AIR; PROCEDURE: FILTER COLLECTION, EXTRACTION WITH AQUEOUS ACID.
U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual of Analytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present., p. V4 S381-1
Workplace monitoring: Sampling and analysis may be performed by collection of sodium hydroxide in a glass bubble containing hydrochloric acid, followed by subsequent titration.
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 2
Detector tubes certified by NIOSH under 42 CFR part 84 or other direct-reading devices calibrated to measure sodium hydroxide may be used.
Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 2

12 Identification

12.1 Analytic Laboratory Methods

Method: NIOSH 7401, Issue 2; Procedure: acid-base titration; Analyte: hydroxide (alkalinity); Matrix: air; Detection Limit: 0.03 mg/sample (as NaOH).
CDC; NIOSH Manual of Analytical Methods, 4th ed. Alkaline Dusts (1310-73-2). Available from, as of October 12, 2011: https://www.cdc.gov/niosh/docs/2003-154/

12.2 NIOSH Analytical Methods

13 Safety and Hazards

13.1 Hazards Identification

13.1.1 GHS Classification

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Note
Pictograms displayed are for > 99.9% (6903 of 6906) of reports that indicate hazard statements. This chemical does not meet GHS hazard criteria for < 0.1% (3 of 6906) of reports.
Pictogram(s)
Corrosive
Irritant
Signal
Danger
GHS Hazard Statements

H290 (47.3%): May be corrosive to metals [Warning Corrosive to Metals]

H314 (> 99.9%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H315 (36.5%): Causes skin irritation [Warning Skin corrosion/irritation]

H318 (43.8%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H319 (36.7%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

Precautionary Statement Codes

P234, P260, P264, P264+P265, P280, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P351+P338, P305+P354+P338, P316, P317, P321, P332+P317, P337+P317, P362+P364, P363, P390, P405, P406, and P501

(The corresponding statement to each P-code can be found at the GHS Classification page.)

ECHA C&L Notifications Summary

Aggregated GHS information provided per 6906 reports by companies from 76 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 3 of 6906 reports by companies. For more detailed information, please visit ECHA C&L website.

There are 75 notifications provided by 6903 of 6906 reports by companies with hazard statement code(s).

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown.

13.1.2 Hazard Classes and Categories

Met. Corr. 1 (47.3%)

Skin Corr. 1A (> 99.9%)

Eye Dam. 1 (43.8%)

Eye Irrit. 2 (36.7%)

Met. Corr. 1 (100%)

Skin Corr. 1B (100%)

Eye Dam. 1 (100%)

13.1.3 NFPA Hazard Classification

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NFPA 704 Diamond
3-0-1
NFPA Health Rating
3 - Materials that, under emergency conditions, can cause serious or permanent injury.
NFPA Fire Rating
0 - Materials that will not burn under typical fire conditions, including intrinsically noncombustible materials such as concrete, stone, and sand.
NFPA Instability Rating
1 - Materials that in themselves are normally stable but that can become unstable at elevated temperatures and pressures.

13.1.4 EPA Safer Chemical

Chemical: Sodium hydroxide

Green circle Green circle - The chemical has been verified to be of low concern based on experimental and modeled data.

13.1.5 Health Hazards

Causes severe burns of eyes, skin, and mucous membranes. (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
Strong corrosive action on contacted tissues. INHALATION: dust may cause damage to upper respiratory tract and lung itself, producing from mild nose irritation to pneumonitis. INGESTION: severe damage to mucous membranes; severe scar formation or perforation may occur. EYE CONTACT: produces severe damage. (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
ERG 2024, Guide 154 (Sodium hydroxide, solution; Sodium hydroxide, solid)

· TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death.

· Contact with molten substance may cause severe burns to skin and eyes.

· Avoid any skin contact.

· Fire may produce irritating, corrosive and/or toxic gases.

· Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination.

13.1.6 Fire Hazards

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. For electric vehicles or equipment, ERG Guide 147 (lithium ion or sodium ion batteries) or ERG Guide 138 (sodium batteries) should also be consulted. (ERG, 2024)

ERG 2024, Guide 154 (Sodium hydroxide, solution; Sodium hydroxide, solid)

· Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.

· Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.).

· Corrosives in contact with metals may evolve flammable hydrogen gas.

· Containers may explode when heated.

· For electric vehicles or equipment, GUIDE 147 (lithium ion or sodium ion batteries) or GUIDE 138 (sodium batteries) should also be consulted.

Not combustible. Contact with moisture or water may generate sufficient heat to ignite combustible materials. Risk of fire and explosion on contact with incompatible substances. See Chemical Dangers.

13.1.7 Hazards Summary

At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air. It is a manufactured substance. When dissolved in water or neutralized with acid it liberates substantial heat, which may be sufficient to ignite combustible materials. Sodium hydroxide is very corrosive. It is generally used as a solid or a 50% solution. Other common names include caustic soda and lye. Sodium hydroxide is used to manufacture soaps, rayon, paper, explosives, dyestuffs, and petroleum products. It is also used in processing cotton fabric, laundering and bleaching, metal cleaning and processing, oxide coating, electroplating, and electrolytic extracting. It is commonly present in commercial drain and oven cleaners.
Liquid causes second or third degree burns after short contact; [CHRIS] In studies using rabbits, instillation by oral intubation caused within 10 seconds: erosion into the stomach muscle with 12% solutions; perforation with 28% solutions; and no damage with 1% solutions. Application to the skin of a 5% solution caused severe necrosis after 4 hours. Application of a 1% solution to the eyes caused no damage if the eyes were immediately irrigated. [ACGIH] Solutions > 30% are highly corrosive to skin. [Quick CPC] Inhalation of the aerosol can cause pulmonary edema. [ICSC]
ACGIH - Documentation of the TLVs and BEIs, 7th Ed. Cincinnati: ACGIH Worldwide, 2020.
Quick CPC - Forsberg K, Mansdorf SZ. Quick Selection Guide to Chemical Protective Clothing, 5th Ed. Hoboken, NJ: Wiley-Interscience, 2007.

13.1.8 Fire Potential

Not combustible.
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-136

13.1.9 Skin, Eye, and Respiratory Irritations

Liquid or solid sodium hydroxide is a severe skin irritant. It causes second and third degree burns on short contact and is very injurious to the eyes.
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
HAZARD WARNING: The irritating nature of the aerosol on the mucous membranes is presumed to be adequate warning to maintain air concn at tolerable levels.
Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) p.74 (Date)
Irritating to skin, eyes, and respiratory system.
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-136

13.1.10 EPA Hazardous Waste Number

D002; A waste containing sodium hydroxide may (or may not) be characterized a hazardous waste following testing for corrosivity characteristics as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations.

13.2 Safety and Hazard Properties

13.2.1 Flammable Limits

Flammability
Noncombustible Solid, but when in contact with water may generate sufficient heat to ignite combustible materials.

13.2.2 OSHA Standards

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 2 mg/cu m.
29 CFR 1910.1000 (USDOL); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov
Vacated 1989 OSHA PEL Ceiling limit 2 mg/cu m is still enforced in some states.
NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997., p. 371

13.2.3 NIOSH Recommendations

Recommended Exposure Limit: 15 Minute Ceiling Value: 2 mg/cu m.
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)

13.3 First Aid Measures

Inhalation First Aid
Fresh air, rest. Refer immediately for medical attention.
Skin First Aid
Remove contaminated clothes. Rinse skin with plenty of water or shower for at least 15 minutes. Refer immediately for medical attention.
Eye First Aid
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.
Ingestion First Aid
Rinse mouth. Do NOT induce vomiting. If within a few minutes after ingestion, one small glass of water may be given to drink. Refer immediately for medical attention.

13.3.1 First Aid

(Act quickly)

EYES: flush with water at once for at least 15 min.

SKIN: flush with water, then rinse with dilute vinegar (acetic acid).

INGESTION: give water and milk. Do NOT induce vomiting. Call physician at once, even when injury seems to be slight. (USCG, 1999)

U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.

Excerpt from NIOSH Pocket Guide for Sodium hydroxide:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: WATER FLUSH IMMEDIATELY - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024)

ERG 2024, Guide 154 (Sodium hydroxide, solution; Sodium hydroxide, solid)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingestedor inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuouscompressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

(See general first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Water flush immediately - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

13.4 Fire Fighting

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

In case of fire in the surroundings, use appropriate extinguishing media.

13.4.1 Fire Fighting Procedures

Extinguish fire using agent suitable for surrounding fire. Use water spray to keep fire-exposed containers cool.
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-136
If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use "alcohol" foam, dry chemical or carbon dioxide. Keep run-off water out of sewers and water sources.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 823

13.5 Accidental Release Measures

Public Safety: ERG 2024, Guide 154 (Sodium hydroxide, solution; Sodium hydroxide, solid)

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Ventilate closed spaces before entering, but only if properly trained and equipped.

Spill or Leak: ERG 2024, Guide 154 (Sodium hydroxide, solution; Sodium hydroxide, solid)

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.

· Stop leak if you can do it without risk.

· Prevent entry into waterways, sewers, basements or confined areas.

· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.

· DO NOT GET WATER INSIDE CONTAINERS.

13.5.1 Isolation and Evacuation

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Evacuation: ERG 2024, Guide 154 (Sodium hydroxide, solution; Sodium hydroxide, solid)

Immediate precautionary measure

· Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

Spill

· For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.

· For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.

Fire

· If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

13.5.2 Spillage Disposal

Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Sweep spilled substance into covered plastic containers. Carefully collect remainder. Then store and dispose of according to local regulations.

13.5.3 Cleanup Methods

On/in soil (solid): Construct barriers to convert or divert to impervious surface. Promptly shovel into steel containers.
Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) p.2 (1981)
Soil, Liquid: Absorb small amounts of spill with sand, vermiculite or other inert absorbant material; Shovel into steel containers. May also remove material with vacuum equipment.
Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) p.2 (1981)
Environment considerations - Land spill:: Dig a pit, pond, lagoon, or holding area to contain liquid or solid material. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash of cement powder.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 823
Environmental considerations - Water spill: Use natural barriers or oil spill control booms to limit spill travel. Neutralize with dilute acid.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 823
For more Cleanup Methods (Complete) data for SODIUM HYDROXIDE (6 total), please visit the HSDB record page.

13.5.4 Disposal Methods

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.
Following neutralization either at the spill site or at a waste management facility, the resultant sludge can be disposed of in a secure landfill.
Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) p.92 (1981)
SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.
Put into large vessel containing water. Neutralize with HCL /hydrochloric acid/. Discharge into the sewer with sufficient water. Recommendable methods: Neutralization & discharge to sewer. Peer review: Dilute greatly (< pH 9) before discharge. (Peer-review conclusions of an IRPTC expert consultation (May 1985))
United Nations. Treatment and Disposal Methods for Waste Chemicals (IRPTC File). Data Profile Series No. 5. Geneva, Switzerland: United Nations Environmental Programme, Dec. 1985., p. 280

13.5.5 Preventive Measures

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.
Nickel is the preferred metal for handling caustic soda at all concentrations and temperatures. However, the high cost and limited availability of nickel precludes its use for most applications. Mild steel is adequate for almost all caustic-handling applications. Plastics and plastic-lined steel are now available as construction materials. Fiberglass reinforced plastic tanks of Derakane vinyl ester resin are suitable for many applications. Polypropane is commonly used for lining pipe for protection against mechanical damage.
Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984., p. 1:858
Any dilutions of caustic from concentrations greater than 25% should be done cautiously.
Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984., p. 1:849
Personnel protection: Keep upwind. Avoid breathing vapors. ... Avoid bodily contact with the material.
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 823
For more Preventive Measures (Complete) data for SODIUM HYDROXIDE (11 total), please visit the HSDB record page.

13.6 Handling and Storage

13.6.1 Nonfire Spill Response

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

13.6.2 Safe Storage

Separated from food and feedstuffs, strong acids and metals. Store only in original container. Dry. Well closed. Store in an area without drain or sewer access.

13.6.3 Storage Conditions

CONTAINERS SHOULD BE STORED IN ROOMS WITH TRAPPED FLOOR DRAINS TOWARDS WHICH FLOORS SHOULD BE SLANTED. WHERE FLOOR DRAINS ARE NOT PROVIDED, CURBS OR DRAINED GUTTER, COVERED WITH ... GRILL, SHOULD BE CONSTRUCTED @ DOOR OPENINGS.
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 116
Volumetric sodium hydroxide soln used in laboratory must be protected from air to avoid formation of carbonate.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1485
Store in a cool, dry, well-ventilated location. Separate from organic and oxidizing materials, acids, metal powders. Immediately remove and properly dispose of any spilled material.
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 49-136

13.7 Exposure Control and Personal Protection

Protective Clothing: ERG 2024, Guide 154 (Sodium hydroxide, solution; Sodium hydroxide, solid)

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

13.7.2 Permissible Exposure Limit (PEL)

2.0 [mg/m3]
PEL-TWA (8-Hour Time Weighted Average)
2 mg/m³
TWA 2 mg/m3 See Appendix G

13.7.3 Immediately Dangerous to Life or Health (IDLH)

10 mg/m3 [From NPG: Sodium hydroxide] (NIOSH, 2024)
10 mg/m3 (NIOSH, 2024)

10.0 [mg/m3]

Excerpts from Documentation for IDLHs: Human data: Workplace concentrations ranging from 2 to 8 mg/m3 have been associated with irritation of the respiratory system [Ott et al. 1977].

10 mg/cu m
NIOSH. NIOSH Pocket Guide to Chemical Hazards & Other Databases CD-ROM. Department of Health & Human Services, Centers for Disease Prevention & Control. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2005-151 (2005)
10 mg/m³

10 mg/m3

See: 1310732

13.7.4 Threshold Limit Values (TLV)

TLV-Ceiling
2.0 [mg/m3]
Ceiling Limit: 2 mg/cu m.
American Conference of Governmental Industrial Hygienists; 2011 Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices . Cincinnati, OH 2011, p. 53
2 mg/m
TLV-C (Ceiling)
2 mg/m³ [1992]

13.7.5 Emergency Response Planning Guidelines

Emergency Response: ERG 2024, Guide 154 (Sodium hydroxide, solution; Sodium hydroxide, solid)

Small Fire

· Dry chemical, CO2 or water spray.

Large Fire

· Dry chemical, CO2, alcohol-resistant foam or water spray.

· If it can be done safely, move undamaged containers away from the area around the fire.

· Dike runoff from fire control for later disposal.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Do not get water inside containers.

· Cool containers with flooding quantities of water until well after fire is out.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

· ALWAYS stay away from tanks in direct contact with flames.

ERPG-1: 0.5 mg/m3 - one hour exposure limit: 1 = mild transient health effects or objectionable odor [AIHA]

ERPG-2: 5 mg/m3 - one hour exposure limit: 2 = impaired ability to take protective action [AIHA]

ERPG-3: 50 mg/m3 - one hour exposure limit: 3 = life threatening health effects [AIHA]

13.7.6 Other Standards Regulations and Guidelines

Australia: 2 mg/cu m, peak limitation (1990); Federal Republic of Germany: 2 mg/cu m, short-term level 4 mg/cu m, 5 min, 8 times per shift (1990); Sweden: 2 mg/cu m ceiling (1990); United Kingdom: 10 min STEL 2 mg/cu m (1991)
American Conference of Governmental Industrial Hygienists, Inc. Documentation of the Threshold Limit Values and Biological Exposure Indices. 6th ed. Volumes I, II, III. Cincinnati, OH: ACGIH, 1991., p. 1417
Emergency Response Planning Guidlines (ERPGs) for sodium hydroxide:
ERPG
The ERPG-1: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing more than mild, transient adverse health effects or without perceiving a clearly defined objectionable odor.
Maximum Airborne Concentration
0.5 mg/cu m
ERPG
The ERPG-2: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair an individual's ability to take protective action.
Maximum Airborne Concentration
5 mg/cum
ERPG
The ERPG-3: The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing or developing life-threatening health effects.
Maximum Airborne Concentration
50 mg/cu m
American Industrial Hygiene Association. 2010 Emergency Response Planning Guidelines (ERPG) Workplace Environmental Exposure Level (WEEL). American Industrial Hygiene Association Guideline Foundation. Fairfax, VA 2010., p. 26

13.7.7 Inhalation Risk

A harmful concentration of airborne particles can be reached quickly when dispersed.

13.7.8 Effects of Short Term Exposure

The substance is corrosive to the eyes, skin and respiratory tract. Corrosive on ingestion.

13.7.9 Effects of Long Term Exposure

Repeated or prolonged contact with skin may cause dermatitis.

13.7.10 Allowable Tolerances

Residues of sodium hydroxide are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest. Use: neutralizer. Limit: none.
40 CFR 180.910 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov
Residues of sodium hydroxide are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to animals. Use: neutralizer. Limit: none.
40 CFR 180.930 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov

13.7.11 Personal Protective Equipment (PPE)

Wide-brimmed hat; safety goggles with rubber side shields; tight-fitting cotton clothing; rubber gloves under shirt cuffs; rubber boots and apron. (USCG, 1999)
U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.

Excerpt from NIOSH Pocket Guide for Sodium hydroxide:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: DAILY - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

Provide:

• EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.

• QUICK DRENCH - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2024)

Hazards from spills and leaks should be minimized by an adequate supply of water for washing-down. ... Adequate ventilation should be provided in areas where caustic ... soda mist or dust is present. ... For the protection of the eyes, safety goggles should be worn, as well as face shields, if complete face protection is necessary. Eyewash fountains and safety showers must be available at any location where eye and/or skin contact can occur. Protection against mist or dust of this compound can be provided by filter or dust-type respiratory protective equipment. ... Safety shoes ... are recommended.
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 116
Respirator selection: 100 mg/cu m: a) High-efficiency particulate respirator with a full facepiece, b) Supplied air respirator with a full facepiece, helmet, or hood. , c) Self-contained breathing apparatus with a full facepiece. 200 mg/cu m: a) Powered air-purifying respirator with a high-efficiency filter with a full facepiece, or b) Type C SA with a full facepiece operated in pressure-demand or other positive pressure mode or with a full facepiece, helmet, or hood operated in continuous- flow mode. . Escape: a) Dust and mist respirator, except single-use respirators with full facepiece, or b) Self-contained breathing apparatus with a full facepiece.
NIOSH; Pocket Guide to Chemical Hazards p.167 (1981) DHEW (NIOSH) Pub No. 78-210
Sodium hydroxide: Chemical protective clothing composed of natural rubber, neoprene, nitrile, or styrene/butadiene (SBR)-coated fabric is highly recommended, having break through times greater than one hour. Butyl rubber, neoprene and SBR, polyethylene, chlorinated polyurethane, or polyvinyl alcohol may be used but data suggests break through times of approximately an hour or more.
ACGIH; Guidelines Select of Chem Protect Clothing Volume #1 Field Guide p.67 (1983)
Sodium hydroxide, 30-70%: Chemical protective clothing composed of natural rubber, neoprene, nitrile, or polyvinyl chloride (PVC) is highly recommended, having break through times greater than one hour. Butyl rubber, nitrile/PVC, polyethylene, chlorinated polyethylene, or styrene/butadiene coated approximately an hour or more. Some data for polyvinyl alcohol (usually from immersion tests) suggest break through times greater than one hour are not likely.
ACGIH; Guidelines Select of Chem Protect Clothing Volume #1 Field Guide p.67 (1983)
For more Personal Protective Equipment (PPE) (Complete) data for SODIUM HYDROXIDE (12 total), please visit the HSDB record page.

(See personal protection and sanitation codes)

Skin: Prevent skin contact - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: Prevent eye contact - Wear appropriate eye protection to prevent eye contact.

Wash skin: When contaminated

Remove: When wet or contaminated

Change: Daily - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

Provide: Eyewash, Quick drench

13.7.12 Respirator Recommendations

NIOSH/OSHA

Up to 10 mg/m3 :

(APF = 25) Any supplied-air respirator operated in a continuous-flow mode/

(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.

Click here for information on selection of N, R, or P filters.

(APF = 25) Any powered, air-purifying respirator with a high-efficiency particulate filter.

(APF = 50) Any self-contained breathing apparatus with a full facepiece

(APF = 50) Any supplied-air respirator with a full facepiece

Emergency or planned entry into unknown concentrations or IDLH conditions:

(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode

(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:

(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.

Click here for information on selection of N, R, or P filters.

Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

13.7.13 Preventions

Fire Prevention
NO contact with water. NO contact with incompatible materials: See Chemical Dangers
Exposure Prevention
PREVENT DISPERSION OF DUST! AVOID ALL CONTACT! IN ALL CASES CONSULT A DOCTOR!
Inhalation Prevention
Use local exhaust or breathing protection.
Skin Prevention
Protective gloves. Protective clothing.
Eye Prevention
Wear face shield or eye protection in combination with breathing protection.
Ingestion Prevention
Do not eat, drink, or smoke during work.

13.8 Stability and Reactivity

13.8.1 Air and Water Reactions

Slowly absorbs carbon dioxide from the air to give solid products as crusts or precipitates. Water soluble. Dilution with water liberates heat, possibly enough to cause local boiling and spattering.
Soluble in water. Dissolution can liberate enough heat to cause steaming and spattering and ignite adjacent combustible material [Haz. Chem. Data 1966].

13.8.2 Reactive Group

Bases, Strong

Water and Aqueous Solutions

Bases, Strong

13.8.3 Reactivity Alerts

Water-Reactive
13.8.3.1 CSL Reaction Information
1 of 5
CSL No
Reactants/Reagents
METHANOL + 5-METHYLISOXAZOLE + SODIUM HYDROXIDE
Warning Message
potentially explosive
GHS Category
Explosive
Reference Source
User-Reported
Modified Date
7/8/18
Create Date
6/27/17
2 of 5
CSL No
Reactants/Reagents
ACETONITRILE + SODIUM HYDROXIDE
Warning Message
Acetonitrile can be hydrolyzed exothermally in the presence of strong aqueous base, such as NaOH or KOH, starting at ~60oC. The reaction can potentially escalate into a runaway reaction if the generated heat is not removed (such as during a loss of cooling incident).
Reference Source
User-Reported
Modified Date
2/27/18
Create Date
9/1/18
3 of 5
CSL No
Reactants/Reagents
FORMALDEHYDE + SODIUM HYDROXIDE
Warning Message
Formaldehyde, sodium hydroxide hazard
GHS Category
Explosive,Flammable
Functional Group
ALDEHYDE
Reaction Class
oxidation
Additional Information
solutions of organic acid sodium salts that contains residual formaldehyde, as result, they did generate hydrogen gas in a steady fashion, and if stored in a confined space, it would be possible to exceed the lower explosive limit
Reference Source
C&EN
Modified Date
5/31/18
Create Date
2/22/18
4 of 5
CSL No
Reactants/Reagents
Phenol + Formaldehyde + Sodium hydroxide
Warning Message
Reaction with Sodium hydroxide resulted in a runaway reaction and an explosion.
GHS Category
Explosive
Reaction Scale
Not Available
Reference Source
User Reported
Modified Date
04/22/2022
Create Date
04/21/2022
5 of 5
CSL No
Reactants/Reagents
(SP-4-1)-[29H,31H-Phthalocyanine-2,9,16,23-tetracarboxamidato(2-)-κN29,κN30,κN31,κN32]zinc + Zincate(4-), [29H,31H-phthalocyanine-2,9,16,23-tetracarboxylato(6-)-κN29,κN30,κN31,κN32]-, hydrogen (1:4), (SP-4-1)- + Trimellitic anhydride + Urea + Zinc acetate + Ammonium chloride + Ammonium molybdate ((NH4)6Mo7O24) + Sodium hydroxide + Hydrochloric acid
Warning Message
"An explosion accident occurred when synthesizing Zn(II)-2,9,16,23-tetracarboxyphthalocyanine from trimellitic anhydride, urea, and zinc acetate. In this work, we discuss the direct causes of this explosion by investigating the thermal stability of the reaction with differential scanning calorimetry. Furthermore, four factors leading to explosions in closed systems have been summarized, including vessel damage, system volume reduction, increasing temperature, and gas generation. Finally, we propose technical and managerial measures for preventing explosions in a closed system, aiming to help scientific researchers prevent potential explosion accidents in academic laboratories." (abstract of paper)
GHS Category
Explosive,Gas Emitter
Reaction Scale
Medium (up to 100g)
Reference Source
Literature Reference
Modified Date
10/22/2022
Create Date
10/22/2022

13.8.4 Reactivity Profile

SODIUM HYDROXIDE SOLUTION refers to an aqueous solution of sodium hydroxide. Strongly basic. Reacts rapidly and exothermically with organic and inorganic acids, with organic and inorganic acid anhydrides, including oxides of nonmetals such as sulfur dioxide, sulfur trioxide, phosphorus trioxide, phosphorus pentaoxide, and with organic and inorganic acid chlorides. May react explosively with maleic anhydride [MCA Case History 622 1960]. Attacks aluminum and zinc with evolution of hydrogen, a flammable gas. May initiate polymerization in polymerizable organic materials: a violent polymerization results if acetaldehyde contacts alkaline materials such as sodium hydroxide; an extremely violent polymerization results from contact of acrolein with alkaline materials such as sodium hydroxide [Chem. Safety Data Sheet SD-85 1961]. A violent explosion resulted when a quantity of pentol was accidentally brought in contact with a caustic cleaning solution chemically similar to aqueous sodium hydroxide [MCA Case History 363 1964]. Aqueous solutions of reducing sugars other than sucrose, when heated (above 84 °C.), evolve toxic levels of carbon monoxide in the presence of alkalis or alkaline salts, such as sodium phosphate (also potassium hydroxide, sodium hydroxide, calcium hydroxide, etc.) [Bretherick 5th ed. 1995]. Hot and/or concentrated NaOH can cause hydroquinone to decompose exothermically at elevated temperature. (NFPA Pub. 491M, 1975, 385)
SODIUM HYDROXIDE (Caustic Soda) is a strong base. Reacts rapidly and exothermically with acids, both organic and inorganic. Readily absorbs moisture from the air to give caustic semi-solids that attack aluminum and zinc with the evolution of flammable hydrogen gas. Catalyzes the polymerization of acetaldehyde and other polymerizable compounds; these reactions can occur violently, for example, acrolein polymerizes with extreme violence when put in contact with alkaline materials such as sodium hydroxide [Chem. Safety Data Sheet SD-85 1961]. Reacts with great violence with phosphorus pentaoxide when initiated by local heating [Mellor 8 Supp.3:406 1971]. Contact (as a drying agent) with tetrahydrofuran, which often contains peroxides, may be hazardous---explosions have occurred in such a use of the chemically similar potassium hydroxide [NSC Newsletter Chem. Soc. 1967]. Mixing with any of the following substances in a closed container caused the temperature and pressure to increase: glacial acetic acid, acetic anhydride, acrolein, chlorohydrin, chlorosulfonic acid, ethylene cyanohydrin, glyoxal, hydrochloric acid (36%), hydrofluoric acid (48.7%), nitric acid (70%), oleum, propiolactone, sulfuric acid (96%) [NFPA 1991]. Accidental contact between a caustic cleaning solution (probably containing sodium hydroxide) and Pentol caused a violent explosion. [MCA Case History 363(1964)]. Heating with a mixture of methyl alcohol and trichlorobenzene during an attempted synthesis led to a sudden increase in pressure and an explosion [MCA Guide for Safety Appendix 3 1972]. Hot and/or concentrated NaOH can cause hydroquinone to decompose exothermically at elevated temperature. (NFPA Pub. 491M, 1975, 385)

13.8.5 Hazardous Reactivities and Incompatibilities

GENERATES CONSIDERABLE HEAT WHEN ... SOLN IS MIXED WITH ACID.
The Merck Index. 10th ed. Rahway, New Jersey: Merck Co., Inc., 1983., p. 1236
CRUDE HYDROQUINONE WAS PUMPED INTO SODIUM HYDROXIDE STORAGE TANK BY MISTAKE. THE HYDROQUINONE LIQUOR AT 85 °C DECOMP RAPIDLY IN THE PRESENCE OF THE SODIUM HYDROXIDE RESULTING IN OVERFLOW OF TANK & EVOLUTION OF CONSIDERABLE AMOUNT OF HEAT.
National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 491-180
Much heat is evolved when the solid material is dissolved in water. Therefore, cold water and caution must be used for this process.
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 116
Caustic solutions generate heat when further diluted with water. With concentrations of 40% or greater, the heat generated can raise the temperature above the boiling point, resulting in sporadic, dangerous eruptions of the solution.
Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984., p. 1:848
For more Hazardous Reactivities and Incompatibilities (Complete) data for SODIUM HYDROXIDE (32 total), please visit the HSDB record page.

13.9 Transport Information

13.9.1 DOT Emergency Guidelines

/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Fire or Explosion: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. /Sodium hydroxide, bead; Sodium hydroxide, dry; Sodium hydroxide, flake; Sodium hydroxide, granular; Sodium hydroxide, solid; Sodium hydroxide solution/
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Health: TOXIC; inhalation, ingestion, or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. /Sodium hydroxide, bead; Sodium hydroxide, dry; Sodium hydroxide, flake; Sodium hydroxide, granular; Sodium hydroxide, solid; Sodium hydroxide solution/
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas. /Sodium hydroxide, bead; Sodium hydroxide, dry; Sodium hydroxide, flake; Sodium hydroxide, granular; Sodium hydroxide, solid; Sodium hydroxide solution/
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. /Sodium hydroxide, bead; Sodium hydroxide, dry; Sodium hydroxide, flake; Sodium hydroxide, granular; Sodium hydroxide, solid; Sodium hydroxide solution/
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
For more DOT Emergency Guidelines (Complete) data for SODIUM HYDROXIDE (8 total), please visit the HSDB record page.

13.9.2 DOT ID and Guide

13.9.3 Shipping Name / Number DOT/UN/NA/IMO

IMO 8.0; Sodium hydroxide solid; Sodium hydroxide solution
UN 1823; Sodium hydroxide, solid
UN 1824; Sodium hydroxide solution

13.9.4 Standard Transportation Number

49 352 35; Dry
49 352 40; Liquid
49 352 43; 52% Solution

13.9.5 Shipment Methods and Regulations

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./
49 CFR 171.2; U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of November 22, 2011: https://www.ecfr.gov
The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.
International Air Transport Association. Dangerous Goods Regulations. 47th Edition. Montreal, Quebec Canada. 2006., p. 255
The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.
International Maritime Organization. International Maritime Dangerous Goods Code. London, UK. 2004., p. 89

13.9.6 DOT Label

Corrosive

13.9.7 Packaging and Labelling

Do not transport with food and feedstuffs.

13.9.8 EC Classification

Symbol: C; R: 35; S: (1/2)-26-37/39-45

13.9.9 UN Classification

UN Hazard Class: 8; UN Pack Group: II

13.10 Regulatory Information

The Australian Inventory of Industrial Chemicals
Chemical: Sodium hydroxide (Na(OH))
California Safe Cosmetics Program (CSCP) Reportable Ingredient

Hazard Traits - Dermatotoxicity; Ocular Toxicity; Respiratory Toxicity

Authoritative List - OEHHA RELs

Report - if used as a fragrance or flavor ingredient

Status Regulation (EC)
2004/129/EC
REACH Registered Substance
New Zealand EPA Inventory of Chemical Status
Sodium hydroxide: HSNO Approval: HSR001547 Approved with controls
New Zealand EPA Inventory of Chemical Status
Ascarite II: Does not have an individual approval but may be used under an appropriate group standard

13.10.1 Clean Water Act Requirements

Sodium hydroxide is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.
40 CFR 116.4 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov

13.10.2 CERCLA Reportable Quantities

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1000 lb or 454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV.D.3.b).
40 CFR 302.4 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov

13.10.3 FIFRA Requirements

Residues of sodium hydroxide are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest. Use: neutralizer. Limit: none.
40 CFR 180.910 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov
Residues of sodium hydroxide are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to animals. Use: neutralizer. Limit: none.
40 CFR 180.930 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov
The Agency has completed its review of all available information, and has determined that the data are sufficient to support reregistration of products containing sodium hydroxide. ... The Agency therefore finds that products containing sodium hydroxide as an active ingredient are eligible for reregistration. ... Although the Agency has found that certain products containing sodium hydroxide are eligible for registration, it should be understood that the Agency may take appropriate regulatory action, and/or require the submission of additional data to support the registration of products containing sodium hydroxide, if new information comes to the Agency's attention or if the data requirements for reregistration (or the guidelines for generating such data) change.
USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Sodium Hydroxide p.9 (September 1992). Available from, as of October 10, 2011: https://www.epa.gov/pesticides/reregistration/status.htm
As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Sodium hydroxide is found on List D. Case No: 4065; Pesticide type: fungicide, herbicide, antimicrobial; Case Status: RED Approved 09/92; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document .; Active ingredient (AI): sodium hydroxide; Data Call-in (DCI) Date(s): 09/30/92; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.
United States Environmental Protection Agency/ Prevention, Pesticides and Toxic Substances; Status of Pesticides in Registration, Reregistration, and Special Review. (1998) EPA 738-R-98-002, p. 326

13.10.4 FDA Requirements

Substance added directly to human food affirmed as generally recognized as safe (GRAS).
21 CFR 184.1763 (USFDA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov
Sodium hydroxide used as a general purpose food additive in animal drugs, feeds, and related products is generally recognized as safe when used in accordance with good manufacturing or feeding practice.
21 CFR 582.1763 (USFDA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of October 9, 2011: https://www.ecfr.gov

13.11 Other Safety Information

Chemical Assessment

IMAP assessments - Sodium hydroxide (Na(OH)): Environment tier I assessment

IMAP assessments - Sodium hydroxide: Human health tier II assessment

13.11.1 Other Hazardous Reactions

Corrosion is a problem at temperatures above 60 degrees C, therefore, the use of steel for caustic-handling is not recommended at elevated temperatures. Stress cracking may also occur when caustic soda solution concentrations exceed 20% at temperatures in excess of 60 degrees C.
Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984., p. 1:859

13.11.2 History and Incidents

This article reports a chemical burn incident that occurred on August 7th, 2005, when a Matsa typhoon hit Shanghai, China. This is the largest chemical burn incident reported in the literature for 20 years in China, involving 118 alkali burn patients who were rescued by the Burn Department of Shanghai Changhai Hospital independently.The scene of the incident was investigated, and the clinical, emergency and hospitalized data of the patients were summarized.The main injurious chemical was a water solution of sodium hydroxide and ammonium chloride. The 118 victims were mostly young men with 5%TBSA deep thickness burn of both lower extremities, including 31 patients who had additional light coughing. Of 58 patients who were finally hospitalized, 42 patients received surgical treatment. Most of these patients recovered within 1 month. There were no deaths. ...
Ma B et al; Burns. 33 (5): 565-71 (2007)
Over a six-month period, the New Jersey Poison Information System received 61 calls related to exposures to alkaline corrosives. Seven of these calls related to a new oven-cleaner product, oven-cleaner pads. These pads are sealed in a protective plastic wrap and contain lye in excess of 5%. ... Five of the callers sustained injuries from their exposure, and three of these sustained burns, one in the oral cavity and one in the eye. None suffered permanent sequelae, but the potential for such is considerable. The method of application, concn of base, and prolonged exposure to a widely covered area may make this product particularly hazardous. /Alkaline corrosives/
Vilogi J et al; Am J Emerg Med 3 (5): 412-4 (1985)

13.11.3 Special Reports

Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) (1981)
NIOSH; Criteria Document: Sodium Hydroxide (1975) DHEW Pub. NIOSH 76-105

14 Toxicity

14.1 Toxicological Information

14.1.1 RAIS Toxicity Values

Inhalation Acute Reference Concentration (RfCa) (mg/m^3)
0.008
Inhalation Acute Reference Concentration Reference
CALEPA

14.1.2 NIOSH Toxicity Data

14.1.3 Exposure Routes

Serious local effects by all routes of exposure.
inhalation, ingestion, skin and/or eye contact

14.1.4 Symptoms

Inhalation Exposure
Cough. Sore throat. Burning sensation. Shortness of breath.
Skin Exposure
Redness. Pain. Serious skin burns. Blisters.
Eye Exposure
Redness. Pain. Blurred vision. Severe burns.
Ingestion Exposure
Abdominal pain. Burns in mouth and throat. Burning sensation in the throat and chest. Nausea. Vomiting. Shock or collapse.
irritation eyes, skin, mucous membrane; pneumonitis; eye, skin burns; temporary loss of hair

14.1.5 Target Organs

Eyes, skin, respiratory system

14.1.6 Adverse Effects

Dermatotoxin - Skin burns.

Toxic Pneumonitis - Inflammation of the lungs induced by inhalation of metal fumes or toxic gases and vapors.

14.1.7 Acute Effects

14.1.8 Interactions

An experimental study was conducted to investigate the effects of erythropoietin on the acute phase of esophageal burn damage induced by sodium hydroxide. A standard esophageal alkaline burn was produced by the application of 10% sodium hydroxide to the distal esophagus in an in vivo rat model. Fifty-six female rats were allocated into three groups: Group BC (baseline control, n = 8) rats were uninjured and untreated, Group PC (positive control, n = 24) rats were injured but untreated and Group EPO (erythropoietin-treated, n = 24) rats were injured and given subcutaneous erythropoietin (1,000 IU/kg per day), 15 min, 24, and 48 hr after administration of the NaOH solution. Six animals from Group PC and six from Group EPO were killed at 4, 24, 48, and 72 hr after application of NaOH to the esophagus. All of animals in Group BC were killed 4 hr after exposure to 0.9% NaCl. Oxidative damage was assessed by measuring levels of malondialdehyde (MDA) and nitric oxide (NO), and activities of superoxide dismutase (SOD) and catalase (CAT) in homogenized samples of esophageal tissue. Histologic damage to esophageal tissue was scored by a single pathologist blind to groups. MDA levels in the BC and EPO groups were significantly lower than those in the PC group (p < 0.05). CAT and SOD activities, and NO levels in the BC and EPO groups were significantly higher than in the PC group (p < 0.05). Esophageal tissue damage measured at 4, 24, 48, and 72 hr after NaOH application was significantly less in the EPO group than in the PC group (p < 0.05). When administered early after an esophageal burn induced by 10% sodium hydroxide in this rat model, erythropoietin significantly attenuated oxidative damage, as measured by biochemical markers and histologic scoring.
Bakan V et al; Pediatr Surg Int. 26 (2): 195-201 (2010)
SRP4: Interacts with acid salts to form bases.
... Esophageal burns were induced in male rats by the administration of 10% sodium hydroxide. Lipid peroxidation (LPO) products were then measured at the following times: 0, 1, 6, 24, 48 and 72 hr after treatment. Tissue hydroxyproline (HP) concentrations in the injured area were assessed at 14 days after the administration of sodium hydroxide. The groups received either systemic melatonin or normal saline. There were two, non-ischemic, sham control groups treated with or without melatonin. LPO products, malondialdehyde (MDA) and 4-hydroxyalkenal (4-HDA), increased immediately after the administration of sodium hydroxide; this indicates the participation of free radicals in the development of damage. Melatonin diminished the oxidative response and the amount of HP in the late phase of the lesion. Melatonin reduced oxidative damage in the early phase of the esophageal burns induced by sodium hydroxide.
Larios-Arceo F et al; J Pineal Res. 45 (2): 219-23 (2008)
/SRP: Experimental/ The gastric damaging effects of necrotizing concn of sodium hydroxide were strongly reduced by paracetamol. ... Paracetamol might be protective by stimulating the biosynthesis of prostaglandins in the stomach wall.
Van Kolfschoten AA et al; Toxicol Appl Pharmacol 69 (1): 37-42 (1983
For more Interactions (Complete) data for SODIUM HYDROXIDE (6 total), please visit the HSDB record page.

14.1.9 Antidote and Emergency Treatment

/EXPERIMENTAL/ An experimental study was conducted to investigate the effects of erythropoietin on the acute phase of esophageal burn damage induced by sodium hydroxide. A standard esophageal alkaline burn was produced by the application of 10% sodium hydroxide to the distal esophagus in an in vivo rat model. Fifty-six female rats were allocated into three groups: Group BC (baseline control, n = 8) rats were uninjured and untreated, Group PC (positive control, n = 24) rats were injured but untreated and Group EPO (erythropoietin-treated, n = 24) rats were injured and given subcutaneous erythropoietin (1,000 IU/kg per day), 15 min, 24, and 48 hr after administration of the NaOH solution. Six animals from Group PC and six from Group EPO were killed at 4, 24, 48, and 72 hr after application of NaOH to the esophagus. All of animals in Group BC were killed 4 hr after exposure to 0.9% NaCl. Oxidative damage was assessed by measuring levels of malondialdehyde (MDA) and nitric oxide (NO), and activities of superoxide dismutase (SOD) and catalase (CAT) in homogenized samples of esophageal tissue. Histologic damage to esophageal tissue was scored by a single pathologist blind to groups. MDA levels in the BC and EPO groups were significantly lower than those in the PC group (p < 0.05). CAT and SOD activities, and NO levels in the BC and EPO groups were significantly higher than in the PC group (p < 0.05). Esophageal tissue damage measured at 4, 24, 48, and 72 hr after NaOH application was significantly less in the EPO group than in the PC group (p < 0.05). When administered early after an esophageal burn induced by 10% sodium hydroxide in this rat model, erythropoietin significantly attenuated oxidative damage, as measured by biochemical markers and histologic scoring.
Bakan V et al; Pediatr Surg Int. 26 (2): 195-201 (2010)
/EXPERIMENTAL/ ... Esophageal burns were induced in male rats by the administration of 10% sodium hydroxide. Lipid peroxidation (LPO) products were then measured at the following times: 0, 1, 6, 24, 48 and 72 hr after treatment. Tissue hydroxyproline (HP) concentrations in the injured area were assessed at 14 days after the administration of sodium hydroxide. The groups received either systemic melatonin or normal saline. There were two, non-ischemic, sham control groups treated with or without melatonin. LPO products, malondialdehyde (MDA) and 4-hydroxyalkenal (4-HDA), increased immediately after the administration of sodium hydroxide; this indicates the participation of free radicals in the development of damage. Melatonin diminished the oxidative response and the amount of HP in the late phase of the lesion. Melatonin reduced oxidative damage in the early phase of the esophageal burns induced by sodium hydroxide.
Larios-Arceo F et al; J Pineal Res. 45 (2): 219-23 (2008)
When caustic soda comes into contact with the skin it does not usually cause immediate pain, but it does start to cause immediate damage. It fails to coagulate protein which would serve to prevent further penetration. Thus, upon contact with eyes, washing with water must be started within 10 seconds and continued for at least 15 minutes to prevent permanent injury. Following contact with skin, washing with water must be started immediately to prevent corrosive chemical burns.
Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984., p. 1:861
/SRP: Experimental/ Alkali-burned corneas were treated with 2% ascorbic acid. Topical applications and subconjunctival injections were given for 32 days. Treatment with ascorbic acid significantly decreased the incidence of corneal ulcerations and perforations compared to the control group that received the vehicle. These results confirm previous studies and strongly suggest that ascorbic acid presents a potential for use in the alkali-burned human eye.
Pertoutsos G and Pouliguen Y; Ophthalmic Res 16 (4): 185-89 (1984)
For more Antidote and Emergency Treatment (Complete) data for SODIUM HYDROXIDE (11 total), please visit the HSDB record page.

14.1.10 Medical Surveillance

The skin, eyes, and respiratory tract should receive special attention in any placement or periodic examination. NIOSH recommends that workers subject to sodium hydroxide exposure have comprehensive preplacement medical examinations. Medical examinations shall be made available promptly to all workers with signs or symptoms of skin, eye, or upper respiratory tract irritation resulting from exposure to sodium hydoxide.
Sittig M; Handbook of Toxic and Hazardous Chemicals p.606 (1981)

14.1.11 Human Toxicity Excerpts

/HUMAN EXPOSURE STUDIES/ ... Esophageal motor function in 21 children (7.5 +/- 2.9 years) with caustic strictures /was assessed/. /All patients had ingested sodium hydroxide./ Esophageal manometry was performed using a water-infusion system interfaced with a polygraph and displayed on a computer screen. The data were compared with those obtained from 9 healthy children. Radionuclide transit was determined by studying deglutition of a single bolus of (99m)Tc-pertechnetate in 10 mL of water. Non-peristaltic low-amplitude and long-duration waves were the most common findings detected in patients with strictures longer than 20% of esophageal length (N = 11). Compared with the control group, these patients presented lower mean amplitude and longer mean duration of waves (24.4 +/- 11.2 vs 97.9 +/- 23.7 mmHg, P < 0.05, and 6.7 +/- 2.4 vs 1.6 +/- 0.1 s, P < 0.05, respectively). Six patients presented low-amplitude waves just below the constricted site. Ten children presented delayed esophageal transit. There was an association between dysphagia and abnormalities on manometry (P = 0.02) and between symptoms and scintigraphy data (P = 0.01). Dysphagia in caustic strictures is due to esophageal motility abnormalities, which are closely related to the scarred segment.
Da-Costa-Pinto EA et al; Braz J Med Biol Res. 37 (11): 1623-30 (2004)
/HUMAN EXPOSURE STUDIES/ ... The irritant effects and barrier disruption properties of ... sodium hydroxide (NaOH), particularly in combination with an anionic detergent, sodium lauryl sulphate (SLS) /were quantified/. In a tandem repeated irritation test, the irritants were applied for 30 min twice daily for 4 days to the skin of the mid-back of 19 healthy volunteers of both sexes. ... Used bioengineering techniques for measurement of transepidermal water loss (TEWL) and skin colour reflectance, as well as visual scoring. ... NaOH induced a strong reaction when applied occlusively and nonocclusively as well as in combination with SLS, with an early onset of the inflammatory signs, leading to discontinuation of the application on the third day in most of the test fields. Notably, the irritant effect of NaOH was not as marked when applied sequentially with SLS.
Fluhr JW et al; Br J Dermatol. 151 (5): 1039-48 (2004)
/HUMAN EXPOSURE STUDIES/ A human skin irritation test with 0.5 % NaOH was performed using exposure periods of 15, 30 and 60 min. The treatment sites were assessed 24, 48 and 72 hr after patch removal. The results showed that after a maximum exposure of 60 min, 61 % of the volunteers (20 of 33) showed a positive skin irritation reaction.
Organization for Economic Cooperation and Development; Screening Information Data Set for Sodium Hydroxide, (1310-73-2) p.14 (March 2002). Available from, as of October 4, 2011: https://www.inchem.org/pages/sids.html
/HUMAN EXPOSURE STUDIES/ A NaOH concentration of 0.5 % was tested within an interlaboratory evaluation of a human patch test for the identification of skin irritation hazard /after 1 hr exposure/. A 25 mm Plain Hill Top Chamber containing a Webril pad was used and the treatment sites were assessed for irritation using a four-point scale at 24, 48 and 72 hr after initiation of exposure. NaOH 0.5 % was irritating for 55 % of the volunteers.
Organization for Economic Cooperation and Development; Screening Information Data Set for Sodium Hydroxide, (1310-73-2) p.14 (March 2002). Available from, as of October 4, 2011: https://www.inchem.org/pages/sids.html
For more Human Toxicity Excerpts (Complete) data for SODIUM HYDROXIDE (28 total), please visit the HSDB record page.

14.1.12 Non-Human Toxicity Excerpts

/LABORATORY ANIMALS: Acute Exposure/ ... Enucleated bovine and porcine (n = 59 each) eyes were used for exposure to sodium, ammonium, and calcium hydroxide, respectively, /in three different concentrations 11 M, 6 M, or 0.25 M and were splashed onto the eye using a syringe. Approximately 5 mL each alkali solution was splashed onto the fully exposed cornea, ensuring that the entire cornea was covered. Each assigned to a predesignated time interval (30 sec, 60 sec, 12 min, 30 min, 8 hr, and 24 hr) for exposure and were immediately washed in water./ Eyes were subjected to fluorescein staining, 5-bromo-2'-deoxy-uridine (BrdU) labeling. Excised cornea was subjected to protein extraction, spectrophotometric determination of protein amount, dynamic light scattering and SDS-PAGE profiling, mass spectrometric protein identification, and iTRAQ-labeled quantification. Select identified proteins were subjected to Western blot and immunohistochemical analyses. Alkali exposure resulted in lower protein extractability from corneal tissue. Elevated aggregate formation was found with strong alkali exposure (sodium hydroxide>ammonium, calcium hydroxide), even with a short duration of exposure compared with controls. The protein yield after exposure varied as a function of post exposure time. Protein profiles changed because of alkali exposure. Concentration and strength of the alkali affected the profile change significantly. Mass spectrometry identified 15 proteins from different bands with relative quantification. Plexin D1 was identified for the first time in the cornea at a protein level that was further confirmed by Western blot and immunohistochemical analyses. Exposure to alkaline chemicals results in predictable and reproducible changes in corneal protein profile. Stronger alkali, longer durations, or both, of exposure resulted in lower yields and significant protein profile changes compared with controls.
Parikh T et al; Invest Ophthalmol Vis Sci. 52 (3): 1819-31 (2011)
/LABORATORY ANIMALS: Acute Exposure/ Keratin material in the skin underwent rapid decomposition in sodium hydroxide above pH 9.2. Aliquots of washed human hair and fingernails were mixed with various amounts of sodium solution and the extent of keratin breakdown was measured by estimating the cystine produced. The cystine portion of the keratin complex of human hair or nails was readily cleaved by sodium hydroxide in the S-S bond. After 20 hr of contact with 0.1N or 0.25N sodium hydroxide, 61.4% and 97.6%, respectively, of the nail keratin were decomposed. Thus, a high degree of destruction of tissue even by a dilute sodium hydroxide solution can occur from prolonged contact.
NIOSH; Criteria Document: Sodium Hydroxide p.30 (1975) DHEW Pub. NIOSH 76-105
/LABORATORY ANIMALS: Acute Exposure/ The objective of this study was/ to investigate immediate changes in water-soluble metabolites of ocular tissue in alkali-burned eyes by using high-resolution 1H-NMR spectroscopy. Adult New Zealand rabbit eyes were burned with 1 M NaOH for 1 min. Normal eyes were used as control. Samples from aqueous humor and perchloric acid extracts of the cornea and lens were analyzed on a NMR spectrometer operating at 500 MHz for protons. Metabolites were quantified by comparing peak area with an added internal standard, TSP (3'-trimethylsilylpropinate-2,2,3,3-d4). Alkali burn of corneal surface causes immediate changes in concentration of many water-soluble metabolites in the anterior segment. Even as far away as the lens a significant increase in lactate was found. Cornea showed a significant increase in glucose and a significant decrease in hypo-taurine concentration. Most changes were observed in aqueous humor, with significant increases in succinate, creatine, scyllo- and myo-inositol and a significant decrease in citrate concentration. Furthermore, a small decrease in ascorbate concentration in aqueous humor was observed.
Risa O et al; Graefes Arch Clin Exp Ophthalmol. 240 (1): 49-55 (2002)
/LABORATORY ANIMALS: Acute Exposure/ ... To study morphological and functional alterations of the esophagus in rabbits submitted to esophageal infusion of caustic soda (NaOH). The 88 rabbits studied were divided into 4 groups: G1 (n=22) were submitted to esophageal infusion with distilled water. G2, G3, and G4 were submitted to esophageal infusion of 2%, 4% and 6% NaOH respectively. Morphological alterations were studied in 12 animals from each group and manometric alterations in the remaining 10. An analysis was made of lower esophageal sphincter (LES) pressure, number and amplitude of contractions in the distal third of the esophagus. These studies were performed before (moment M1) and at 30 min, 6 hr, and 24 hr after (moments M2, M3, and M4, respectively) esophageal infusion. Morphological evaluation: G1 - no alterations; G2 - edema, hyperemia, and ecdysis; G3 - enlarged calibre of esophagus, ulcers, ecdysis of mucosa; G4 - lesions similar to G3, but more intense, areas of extensive hemorrhage at M3 and M4. Functional evaluation: LES was higher at M2; the number of distal third lower esophageal contractions in G3, and G4 was lower; and the contraction amplitude was lower in G4. ... Esophageal infusion with NaOH caused lesions in the esophageal wall, with gravity proportional to solution concentration. Infusion caused LES spasm at M2, and reduced both contraction number and amplitude in the distal third of the esophagus.
Henry MA et al; Acta Cir Bras. 23 (1): 16-21 (2008)
For more Non-Human Toxicity Excerpts (Complete) data for SODIUM HYDROXIDE (27 total), please visit the HSDB record page.

14.1.13 Non-Human Toxicity Values

LD50 Rabbit dermal 1,350 mg/kg
National Research Council; Prudent Practices in the Laboratory. Handling and Management of Chemical Hazards. the National Academies Press, Washington, D.C. 2011, p. CD
LD50 Rat oral 140-340 mg/kg
National Research Council; Prudent Practices in the Laboratory. Handling and Management of Chemical Hazards. the National Academies Press, Washington, D.C. 2011, p. CD
LD50 Mouse ip 40 mg/kg
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 3254

14.2 Ecological Information

14.2.1 Ecotoxicity Values

EC50; Species: Ceriodaphnia dubia (Water Flea) age <24 hr neonate; Conditions: freshwater, static, 23 °C; Concentration: 40380 ug/L for 48 hr (95% confidence interval: 34590-47130 ug/L); Effect: intoxication, immobilization /100% purity/
Warne MSJ, Schifko AD; Ecotoxicol Environ Saf 44 (2): 196-206 (1999) as cited in the ECOTOX database. Available from, as of November 15, 2011: https://cfpub.epa.gov/ecotox/
LC50; Species: Carassius auratus (Goldfish); Conditions: freshwater, static; Concentration: 160000 ug/L for 24 hr
Jensen RA; A Simplified Bioassay Using Finfish for Estimating Potential Spill Damage, In: Proc Control of Hazardous Material Spills: 104-108 (1978) as cited in the ECOTOX database. Available from, as of November 15, 2011: https://cfpub.epa.gov/ecotox/
LC100; Species: Cyprinus carpio; Concentration: 180 ppm for 24 hr at 25 °C /Conditions of bioassay not specified in source examined/
Nishiuchi Y; Suisan Zoshoku 23: 132 (1975)
LC50; Species: Poecilia reticulata (Guppy) age 3-4 week young organisms; Conditions: saltwater, renewal, 24 °C, pH >9.8-<10.0, salinity 2.8%, dissolved oxygen > or =70% saturated; Concentration: 209000 ug/L for 24 hr (95% confidence interval: 153000-286000 ug/L) /98.6% purity/
Adema DMM; Aquatic Toxicity of Compounds that may be Carried by Ships (Marpol 1973 Annex II). A Progress Report for 1985, Tech Rep No R85/217: 40 (1985) as cited in the ECOTOX database. Available from, as of November 15, 2011
For more Ecotoxicity Values (Complete) data for SODIUM HYDROXIDE (6 total), please visit the HSDB record page.

14.2.2 Ecotoxicity Excerpts

/AQUATIC SPECIES/ Concentration 20-100 mg/L in water kills some species of aquatic wildlife due to increase in pH.
Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) p.1 (1981)
/AQUATIC SPECIES/ Chronic exposure of guppies to sodium hydroxide (> or =25 mg/L) decreased their survival rate and weight gain, and caused either late or premature sexual maturity resulting in decreased fertility.
Rustamova SA; Gidrobiol ZH 13 (3): 96-9 (1977)

14.2.3 ICSC Environmental Data

This substance may be hazardous to the environment. Special attention should be given to aquatic organisms.

14.2.4 Environmental Fate

AQUATIC FATE: In the case of a solid, anhydrous sodium hydroxide spill on soil, ground water pollution will occur if precipitation occurs prior to clean up. Precipitation will dissolve some of the solid (with much heat given off) and create an aqueous solution of sodium hydroxide, which then would be able to infiltrate the soil. However, prediction of the concentration and properties of the solution produced would be difficult.
Environment Canada; Tech Info for Problem Spills: Sodium Hydroxide (Draft) p.24 (1981)

14.2.5 Environmental Biodegradation

BOD: none
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

14.2.6 Environmental Water Concentrations

GROUNDWATER: Sodium hydroxide was identified as a chemical of concern in wells associated with the Pavilion Area Groundwater Plume in Pavilion Wyoming in Fremont County. Land use in the area is agricultural with some properties used for natural gas production. Sampling was conducted from March 2 through 6, 2009 and May 14, and 15, 2009(1).
(1) US EPA; Expanded Site Investigation - Field Sampling Plan, Pavillion Area Groundwater Investigation. Pavilion, Fremont County, Wyoming. USEPA Contract No. EP-W-05-050. TDD No., 0901-01. January 6, 2010. START 3. Superfund Technical Assessment and Response Team 3-Region 8.Available from, as of Oct 11, 2011: https://www.epa.gov/region8/superfund/wy/pavillion/Pavillion_GWInvestigationFSP.pdf

14.2.7 Effluent Concentrations

Estimated emissions of sodium hydroxide as one of the typical pollutants released from the synthetic organic chemical manufacturing industry (production/processing) may range from (unit process, product): alkylation, ethylbenzene, 1.9 to 21.5; condensation, polyethylene terephthalate, 0.065 to 23.1; dehydrogenation, isoprene, 0.5 to 19; dehydrohalogenation, vinylidene chloride, 45.5 to 605.5; polymerization, polyethylene terephthalate, 0.1 to 23.1 (all in g/kg produced)(1). The compound was spilled at an estimated 3,500 gallons into the Newark Bay on October 1991 from the Gist Brocades facility(2). Sodium hydroxide was involved in 2.6% of 6,928 chemical accidents in the US over a 5 year period up to 1985 at a reportable quantity of 2200 kg(3).
(1) Carpenter CE et al; Toxic Subst J 10: 323-71 (1990)
(2) Gunster DG et al; Ecotoxicol Environ Saf 25: 202-13 (1993)
(3) Meharg AA; Rev Environ Contam Toxicol 138: 21-48 (1994)

14.2.8 Probable Routes of Human Exposure

According to the 2006 TSCA Inventory Update Reporting data, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use of sodium hydroxide is 1000 or greater; the data may be greatly underestimated(1).
(1) US EPA; Inventory Update Reporting (IUR). Non-confidential 2006 IUR Records by Chemical, including Manufacturing, Processing and Use Information. Washington, DC: U.S. Environmental Protection Agency. Available from, as of Sept 9, 2011: https://cfpub.epa.gov/iursearch/index.cfm
NIOSH (NOES Survey 1981-1983) has statistically estimated that 2,819,743 workers (995,960 of these were female) were potentially exposed to sodium hydroxide in the US(1). NIOSH (NOES Survey 1981-1983) has statistically estimated that 370,582 workers (137,156 of these were female) were potentially exposed to liquid sodium hydroxide in the US(1). The NOES Survey does not include farm workers. Occupational exposure to sodium hydroxide may occur through dermal contact with this compound at workplaces where sodium hydroxide is produced or used(SRC).
(1) NIOSH; NOES. National Occupational Exposure Survey conducted from 1981-1983. Estimated numbers of employees potentially exposed to specific agents by 2-digit standard industrial classification (SIC). Available from, as of Oct 11, 2011: https://www.cdc.gov/noes/
Inhalation of dust or mist, ingestion, and skin or eye contact.
Sittig M; Handbook of Toxic and Hazardous Chemicals p.606 (1981)

15 Associated Disorders and Diseases

16 Literature

16.1 Consolidated References

16.2 NLM Curated PubMed Citations

16.3 Springer Nature References

16.4 Thieme References

16.5 Wiley References

16.6 Chemical Co-Occurrences in Literature

16.7 Chemical-Gene Co-Occurrences in Literature

16.8 Chemical-Disease Co-Occurrences in Literature

17 Patents

17.1 Depositor-Supplied Patent Identifiers

17.2 WIPO PATENTSCOPE

17.3 Chemical Co-Occurrences in Patents

17.4 Chemical-Disease Co-Occurrences in Patents

17.5 Chemical-Gene Co-Occurrences in Patents

18 Interactions and Pathways

18.1 Protein Bound 3D Structures

18.2 Chemical-Target Interactions

19 Biological Test Results

19.1 BioAssay Results

20 Classification

20.1 MeSH Tree

20.2 NCI Thesaurus Tree

20.3 ChEBI Ontology

20.4 KEGG: Drug

20.5 KEGG: JP15

20.6 EPA Safer Choice

20.7 ChemIDplus

20.8 CAMEO Chemicals

20.9 UN GHS Classification

20.10 EPA CPDat Classification

20.11 NORMAN Suspect List Exchange Classification

20.12 EPA DSSTox Classification

20.13 Consumer Product Information Database Classification

20.14 EPA TSCA and CDR Classification

20.15 EPA Substance Registry Services Tree

20.16 MolGenie Organic Chemistry Ontology

21 Information Sources

  1. Agency for Toxic Substances and Disease Registry (ATSDR)
    LICENSE
    The information provided using CDC Web site is only intended to be general summary information to the public. It is not intended to take the place of either the written law or regulations.
    https://www.cdc.gov/Other/disclaimer.html
  2. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
    LICENSE
    Copyright (c) 2022 Haz-Map(R). All rights reserved. Unless otherwise indicated, all materials from Haz-Map are copyrighted by Haz-Map(R). No part of these materials, either text or image may be used for any purpose other than for personal use. Therefore, reproduction, modification, storage in a retrieval system or retransmission, in any form or by any means, electronic, mechanical or otherwise, for reasons other than personal use, is strictly prohibited without prior written permission.
    https://haz-map.com/About
  3. CAMEO Chemicals
    LICENSE
    CAMEO Chemicals and all other CAMEO products are available at no charge to those organizations and individuals (recipients) responsible for the safe handling of chemicals. However, some of the chemical data itself is subject to the copyright restrictions of the companies or organizations that provided the data.
    https://cameochemicals.noaa.gov/help/reference/terms_and_conditions.htm?d_f=false
    CAMEO Chemical Reactivity Classification
    https://cameochemicals.noaa.gov/browse/react
  4. ChEBI
  5. DrugBank
    LICENSE
    Creative Common's Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/legalcode)
    https://www.drugbank.ca/legal/terms_of_use
  6. Australian Industrial Chemicals Introduction Scheme (AICIS)
  7. CAS Common Chemistry
    LICENSE
    The data from CAS Common Chemistry is provided under a CC-BY-NC 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc/4.0/
  8. ChemIDplus
    ChemIDplus Chemical Information Classification
    https://pubchem.ncbi.nlm.nih.gov/source/ChemIDplus
  9. DTP/NCI
    LICENSE
    Unless otherwise indicated, all text within NCI products is free of copyright and may be reused without our permission. Credit the National Cancer Institute as the source.
    https://www.cancer.gov/policies/copyright-reuse
  10. EPA Chemical Data Reporting (CDR)
    LICENSE
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    https://www.epa.gov/web-policies-and-procedures/epa-disclaimers#copyright
  11. EPA Chemicals under the TSCA
    EPA TSCA Classification
    https://www.epa.gov/tsca-inventory
  12. EPA DSSTox
    CompTox Chemicals Dashboard Chemical Lists
    https://comptox.epa.gov/dashboard/chemical-lists/
  13. European Chemicals Agency (ECHA)
    LICENSE
    Use of the information, documents and data from the ECHA website is subject to the terms and conditions of this Legal Notice, and subject to other binding limitations provided for under applicable law, the information, documents and data made available on the ECHA website may be reproduced, distributed and/or used, totally or in part, for non-commercial purposes provided that ECHA is acknowledged as the source: "Source: European Chemicals Agency, http://echa.europa.eu/". Such acknowledgement must be included in each copy of the material. ECHA permits and encourages organisations and individuals to create links to the ECHA website under the following cumulative conditions: Links can only be made to webpages that provide a link to the Legal Notice page.
    https://echa.europa.eu/web/guest/legal-notice
  14. FDA Global Substance Registration System (GSRS)
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  15. Hazardous Substances Data Bank (HSDB)
  16. ILO-WHO International Chemical Safety Cards (ICSCs)
  17. International Fragrance Association (IFRA)
    LICENSE
    (c) The International Fragrance Association, 2007-2021. All rights reserved.
    https://ifrafragrance.org/links/copyright
  18. New Zealand Environmental Protection Authority (EPA)
    LICENSE
    This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International licence.
    https://www.epa.govt.nz/about-this-site/general-copyright-statement/
  19. NJDOH RTK Hazardous Substance List
  20. Occupational Safety and Health Administration (OSHA)
    LICENSE
    Materials created by the federal government are generally part of the public domain and may be used, reproduced and distributed without permission. Therefore, content on this website which is in the public domain may be used without the prior permission of the U.S. Department of Labor (DOL). Warning: Some content - including both images and text - may be the copyrighted property of others and used by the DOL under a license.
    https://www.dol.gov/general/aboutdol/copyright
  21. Risk Assessment Information System (RAIS)
    LICENSE
    This work has been sponsored by the U.S. Department of Energy (DOE), Office of Environmental Management, Oak Ridge Operations (ORO) Office through a joint collaboration between United Cleanup Oak Ridge LLC (UCOR), Oak Ridge National Laboratory (ORNL), and The University of Tennessee, Ecology and Evolutionary Biology, The Institute for Environmental Modeling (TIEM). All rights reserved.
    https://rais.ornl.gov/
  22. EU Food Improvement Agents
  23. California Safe Cosmetics Program (CSCP) Product Database
  24. EU Pesticides Database
  25. Consumer Product Information Database (CPID)
    LICENSE
    Copyright (c) 2024 DeLima Associates. All rights reserved. Unless otherwise indicated, all materials from CPID are copyrighted by DeLima Associates. No part of these materials, either text or image may be used for any purpose other than for personal use. Therefore, reproduction, modification, storage in a retrieval system or retransmission, in any form or by any means, electronic, mechanical or otherwise, for reasons other than personal use, is strictly prohibited without prior written permission.
    https://www.whatsinproducts.com/contents/view/1/6
    Consumer Products Category Classification
    https://www.whatsinproducts.com/
  26. Cosmetic Ingredient Review (CIR)
  27. NORMAN Suspect List Exchange
    LICENSE
    Data: CC-BY 4.0; Code (hosted by ECI, LCSB): Artistic-2.0
    https://creativecommons.org/licenses/by/4.0/
    Sodium Hydroxide
    NORMAN Suspect List Exchange Classification
    https://www.norman-network.com/nds/SLE/
  28. Emergency Response Guidebook (ERG)
  29. The National Institute for Occupational Safety and Health (NIOSH)
    LICENSE
    The information provided using CDC Web site is only intended to be general summary information to the public. It is not intended to take the place of either the written law or regulations.
    https://www.cdc.gov/Other/disclaimer.html
  30. ChEMBL
    LICENSE
    Access to the web interface of ChEMBL is made under the EBI's Terms of Use (http://www.ebi.ac.uk/Information/termsofuse.html). The ChEMBL data is made available on a Creative Commons Attribution-Share Alike 3.0 Unported License (http://creativecommons.org/licenses/by-sa/3.0/).
    http://www.ebi.ac.uk/Information/termsofuse.html
  31. Comparative Toxicogenomics Database (CTD)
    LICENSE
    It is to be used only for research and educational purposes. Any reproduction or use for commercial purpose is prohibited without the prior express written permission of NC State University.
    http://ctdbase.org/about/legal.jsp
  32. EPA Chemical and Products Database (CPDat)
  33. Crystallography Open Database (COD)
    LICENSE
    All data in the COD and the database itself are dedicated to the public domain and licensed under the CC0 License. Users of the data should acknowledge the original authors of the structural data.
    https://creativecommons.org/publicdomain/zero/1.0/
  34. DailyMed
  35. EPA Safer Choice
    EPA Safer Chemical Ingredients Classification
    https://www.epa.gov/saferchoice
  36. Joint FAO/WHO Expert Committee on Food Additives (JECFA)
    LICENSE
    Permission from WHO is not required for the use of WHO materials issued under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Intergovernmental Organization (CC BY-NC-SA 3.0 IGO) licence.
    https://www.who.int/about/policies/publishing/copyright
  37. Hazardous Chemical Information System (HCIS), Safe Work Australia
  38. NITE-CMC
    Sodium hydroxide - FY2009 (Revised classification)
    https://www.chem-info.nite.go.jp/chem/english/ghs/09-mhlw-2010e.html
    Sodium hydroxide - FY2006 (New/original classication)
    https://www.chem-info.nite.go.jp/chem/english/ghs/06-imcg-0592e.html
  39. Regulation (EC) No 1272/2008 of the European Parliament and of the Council
    LICENSE
    The copyright for the editorial content of this source, the summaries of EU legislation and the consolidated texts, which is owned by the EU, is licensed under the Creative Commons Attribution 4.0 International licence.
    https://eur-lex.europa.eu/content/legal-notice/legal-notice.html
  40. FDA Substances Added to Food
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  41. Human Metabolome Database (HMDB)
    LICENSE
    HMDB is offered to the public as a freely available resource. Use and re-distribution of the data, in whole or in part, for commercial purposes requires explicit permission of the authors and explicit acknowledgment of the source material (HMDB) and the original publication (see the HMDB citing page). We ask that users who download significant portions of the database cite the HMDB paper in any resulting publications.
    http://www.hmdb.ca/citing
  42. Japan Chemical Substance Dictionary (Nikkaji)
  43. KEGG
    LICENSE
    Academic users may freely use the KEGG website. Non-academic use of KEGG generally requires a commercial license
    https://www.kegg.jp/kegg/legal.html
    Therapeutic category of drugs in Japan
    http://www.genome.jp/kegg-bin/get_htext?br08301.keg
    Drugs listed in the Japanese Pharmacopoeia
    http://www.genome.jp/kegg-bin/get_htext?br08311.keg
  44. National Drug Code (NDC) Directory
    LICENSE
    Unless otherwise noted, the contents of the FDA website (www.fda.gov), both text and graphics, are not copyrighted. They are in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from FDA. Credit to the U.S. Food and Drug Administration as the source is appreciated but not required.
    https://www.fda.gov/about-fda/about-website/website-policies#linking
  45. NCI Thesaurus (NCIt)
    LICENSE
    Unless otherwise indicated, all text within NCI products is free of copyright and may be reused without our permission. Credit the National Cancer Institute as the source.
    https://www.cancer.gov/policies/copyright-reuse
  46. NIOSH Manual of Analytical Methods
    LICENSE
    The information provided using CDC Web site is only intended to be general summary information to the public. It is not intended to take the place of either the written law or regulations.
    https://www.cdc.gov/Other/disclaimer.html
  47. NLM RxNorm Terminology
    LICENSE
    The RxNorm Terminology is created by the National Library of Medicine (NLM) and is in the public domain and may be republished, reprinted and otherwise used freely by anyone without the need to obtain permission from NLM. Credit to the U.S. National Library of Medicine as the source is appreciated but not required. The full RxNorm dataset requires a free license.
    https://www.nlm.nih.gov/research/umls/rxnorm/docs/termsofservice.html
  48. Pistoia Alliance Chemical Safety Library
    METHANOL + 5-METHYLISOXAZOLE + SODIUM HYDROXIDE
    https://safescience.cas.org/
  49. SpectraBase
  50. Springer Nature
  51. SpringerMaterials
  52. Thieme Chemistry
    LICENSE
    The Thieme Chemistry contribution within PubChem is provided under a CC-BY-NC-ND 4.0 license, unless otherwise stated.
    https://creativecommons.org/licenses/by-nc-nd/4.0/
  53. Wikidata
  54. Wikipedia
  55. Wiley
  56. Medical Subject Headings (MeSH)
    LICENSE
    Works produced by the U.S. government are not subject to copyright protection in the United States. Any such works found on National Library of Medicine (NLM) Web sites may be freely used or reproduced without permission in the U.S.
    https://www.nlm.nih.gov/copyright.html
  57. PubChem
  58. GHS Classification (UNECE)
  59. EPA Substance Registry Services
  60. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  61. PATENTSCOPE (WIPO)
CONTENTS