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Selenium Oxides

PubChem CID
24007
Structure
Selenium Oxides_small.png
Molecular Formula
Synonyms
  • SELENIUM DIOXIDE
  • Selenium(IV) oxide
  • 7446-08-4
  • Selenium oxide
  • Selenious anhydride
Molecular Weight
110.97 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2005-03-26
  • Modify:
    2025-01-11
Description
Selenium dioxide appears as a white or creamy-white volatile lustrous crystal or crystalline powder with a pungent sour smell. Melting point 340 deg C. Density 3.954 g / cm3. Toxic by ingestion and inhalation.
Selenium dioxide is an oxide of selenium. It is used in organic synthesis, glass colorants, and as a toner in photographic developing. Selenium is a nonmetal element with the atomic number 34 and the chemical symbol Se. Selenium rarely occurs in its elemental state in nature and is usually found in sulfide ores such as pyrite, partially replacing the sulfur in the ore matrix. It may also be found in silver, copper, lead, and nickel minerals. Though selenium salts are toxic in large amounts, trace amounts of the element are necessary for cellular function in most animals, forming the active center of the enzymes glutathione peroxidase, thioredoxin reductase, and three known deiodinase enzymes. (L620, L726)
L620: Wikipedia. Selenium. Last Updated 7 June 2009. http://en.wikipedia.org/wiki/Selenium
L726: Wikipedia. Selenium dioxide. Last Updated 1 June 2009. http://en.wikipedia.org/wiki/Selenium_dioxide
Inorganic compounds formed through the oxidation of selenium.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Selenium Oxides.png

1.2 3D Status

Conformer generation is disallowed since MMFF94s unsupported element

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

selenium dioxide
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

2.1.2 InChI

InChI=1S/O2Se/c1-3-2
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 InChIKey

JPJALAQPGMAKDF-UHFFFAOYSA-N
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.4 SMILES

O=[Se]=O
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

O2Se
Computed by PubChem 2.2 (PubChem release 2021.10.14)
SeO2

2.3 Other Identifiers

2.3.1 CAS

7446-08-4
12640-89-0

2.3.3 Deprecated CAS

12397-00-1

2.3.4 European Community (EC) Number

2.3.5 UNII

2.3.6 UN Number

2.3.7 ChEMBL ID

2.3.8 ICSC Number

2.3.9 Nikkaji Number

2.3.10 NSC Number

2.3.11 Wikidata

2.3.12 Wikipedia

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • Dioxide, Selenium
  • Monoxide, Selenium
  • Oxide, Selenium
  • Oxides, Selenium
  • selenium dioxide
  • Selenium Monoxide
  • selenium oxide
  • Selenium Oxides
  • selenium trioxide
  • Trioxide, Selenium

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
110.97 g/mol
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Donor Count
Property Value
0
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Hydrogen Bond Acceptor Count
Property Value
2
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
111.90635 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
111.90635 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
34.1 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
3
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
18.3
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
1
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

Selenium dioxide appears as a white or creamy-white volatile lustrous crystal or crystalline powder with a pungent sour smell. Melting point 340 deg C. Density 3.954 g / cm3. Toxic by ingestion and inhalation.
White or yellowish-white to slightly reddish, lustrous, crystalline powder or needles. [HSDB]
LUSTROUS WHITE HYGROSCOPIC CRYSTALS OR POWDER. ITS YELLOWISH GREEN VAPOUR HAS A PUNGENT SOUR SMELL.

3.2.2 Color / Form

Lustrous tetragonal needles; yellowish green vapor
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456
White or yellowish-white to slightly reddish, lustrous, crystalline powder or needles.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 1114

3.2.3 Odor

Vapor has a pungent sour smell
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456
Rotten radishes.
Langner BE; Ullmann's Encyclopedia of Industrial Chemistry. 7th ed. (1999-2010). New York, NY: John Wiley & Sons; Selenium and Selenium Compounds. Online Posting Date: June 15, 2000

3.2.4 Taste

Acidic taste; leaves a burning sensation.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456

3.2.5 Boiling Point

599 °F at 760 mmHg (sublimes) (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.

3.2.6 Melting Point

340 °C under pressure
Bingham E; Patty's Toxicology. (1999-2011). New York, NY: John Wiley & Sons, Inc. Phosphorus, Selenium, Tellurium, and Sulfur. On-line posting date: April 16, 2001

3.2.7 Solubility

Soluble in concentrated sulfuric acid
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456
Solubility (parts/100 parts solvent): 10.16 in methanol at 11.8 °C; 6.67 in 93% ethanol at 14 °C; 4.35 in acetone at 15.3 °C; 1.11 in acetic acid at 13.9 °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. 1456
In water, 400 g/L at 20 °C
Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 798
264 g/100 g water at 22 °C
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 4-86
For more Solubility (Complete) data for SELENIUM DIOXIDE (6 total), please visit the HSDB record page.
Solubility in water, g/100ml at 20 °C: 40

3.2.8 Density

3.95 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.
3.954 at 15 °C/15 °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. 1456
Density (at 15 °C): 3.95 g/cm³

3.2.9 Vapor Pressure

12.5 mm Hg at 70 °C; 20.2 mm Hg at 94 °C; 39.0 mm Hg at 181 °C; 760 mm Hg at 315 °C; 848 mm Hg at 320 °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. 1456
Vapor pressure, kPa at 70 °C: 1.65

3.2.10 Stability / Shelf Life

Stable to light and heat.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456

3.2.11 Decomposition

When heated to decomposition ... emits toxic fumes of /selenium/.
Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 3196

3.2.12 Corrosivity

In presence of water will corrode most metals
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
... Soluble in water forming selenic acid, a corrosive material. ...
Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, DC: Association of American Railroads, Bureau of Explosives, 1994., p. 955

3.2.13 Odor Threshold

0.0002 mg/cu m
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
Air: 2.0 ppm
Fazzalari, F.A. (ed.). Compilation of Odor and Taste Threshold Values Data. ASTM Data Series DS 48A (Committee E-18). Philadelphia, PA: American Society for Testing and Materials, 1978., p. 148

3.2.14 Refractive Index

Index of refraction: less than 1.76 at 20 °C/D
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456

3.2.15 Other Experimental Properties

Dipole moment: 2.62 debye
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 9-49
Dissolves in water to form selenious acid
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 2018
Electron affinity: 1.823 eV
Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 10-159
Heat of formation: at 25 °C -238.5 kJ/mol
Hoffman JE, King MG; Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2011). New York, NY: John Wiley & Sons; Selenium and Selenium Compounds. Online Posting Date: February 22, 2011
For more Other Experimental Properties (Complete) data for SELENIUM DIOXIDE (13 total), please visit the HSDB record page.

3.3 Chemical Classes

Other Classes -> Other Inorganic Compounds

4 Spectral Information

4.1 Mass Spectrometry

4.1.1 GC-MS

1 of 3
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NIST Number
158252
Library
Main library
Total Peaks
40
m/z Top Peak
112
m/z 2nd Highest
110
m/z 3rd Highest
96
Thumbnail
Thumbnail
2 of 3
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Instrument Name
311A
Source of Spectrum
Chemical Concepts, A Wiley Division, Weinheim, Germany
Copyright
Copyright © 2002-2024 Wiley-VCH Verlag GmbH & Co. KGaA. All Rights Reserved.
Thumbnail
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4.2 IR Spectra

4.2.1 FTIR Spectra

Technique
4000-1350 CM^-^1=MULLED IN PERFLUORINATED HYDROCARBON; 1350-450 CM^-^1=MULLED IN MINERAL OIL
Source of Sample
Aldrich Chemical Company, Inc., Milwaukee, Wisconsin
Catalog Number
20010
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
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4.3 Raman Spectra

1 of 2
Instrument Name
Bio-Rad FTS 175C with Raman accessory
Technique
FT-Raman
Source of Sample
PCR, Inc., Gainesville, Florida
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
Thumbnail
2 of 2
Instrument Name
Bio-Rad FTS 175C with Raman accessory
Technique
FT-Raman
Source of Sample
PCR, Inc., Gainesville, Florida
Copyright
Copyright © 1980, 1981-2024 John Wiley & Sons, Inc. All Rights Reserved.
Thumbnail
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6 Chemical Vendors

7 Pharmacology and Biochemistry

7.1 Metabolism / Metabolites

... In vitro experiments suggested that trace amounts of hydrogen selenide, which is an intermediate of selenite metabolism, probably induced hemolysis. For evaluation of the therapeutic value of hemoperfusion in selenium poisoning, in vitro hemoperfusion experiments were performed, which revealed only a moderate effect on selenium blood levels.
Koppel C et al; J Toxicol Clin Toxicol 24 (1): 21-35 (1986)
Selenium may be absorbed through inhalation and ingestion, while some selenium compounds may also be absorbed dermally. Once in the body, selenium is distributed mainly to the liver and kidney. Selenium is an essential micronutrient and is a component of glutathione peroxidase, iodothyronine 5'-deiodinases, and thioredoxin reductase. Organic selenium is first metabolized into inorganic selenium. Inorganic selenium is reduced stepwise to the intermediate hydrogen selenide, which is either incorporated into selenoproteins after being transformed to selenophosphate and selenocysteinyl tRNA or excreted into the urine after being transformed into methylated metabolites of selenide. Elemental selenium is also methylated before excretion. Selenium is primarily eliminated in the urine and feces, but certain selenium compounds may also be exhaled. (L619)
L619: ATSDR - Agency for Toxic Substances and Disease Registry (2003). Toxicological profile for selenium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp92.html

8 Use and Manufacturing

8.1 Uses

Sources/Uses
Used to make other selenium compounds; Also used as a reagent and oxidizing agent; [Merck Index #8434]
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. #8434
Industrial Processes with risk of exposure

Photographic Processing [Category: Other]

Glass Manufacturing [Category: Industry]

Activities with risk of exposure
Glassblowing [Category: Hobbies]
In the manufacture of other selenium compounds.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456
Analysis (testing for alkaloids), oxidizing agent, antioxidant in lubricating oils, catalyst.
Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 1114
Added to baths used in etching, formation of decorative colors on galvanized iron and nonferrous metals and alloys, and corrosion-protective coatings in magnesium alloys; synthesis of drug products; used in the manufacture of cortisone and nicotinic acid (niacin).
Hoffman JE, King MG; Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2011). New York, NY: John Wiley & Sons; Selenium and Selenium Compounds. Online Posting Date: February 22, 2011
Selenium dioxide is used in organic synthesis, glass colorants, and as a toner in photographic developing. (L726)
L726: Wikipedia. Selenium dioxide. Last Updated 1 June 2009. http://en.wikipedia.org/wiki/Selenium_dioxide

8.1.1 Use Classification

Hazard Classes and Categories ->

8.2 Methods of Manufacturing

Selenium dioxide, SeO2, is prepared by burning selenium in a current of air or oxygen and, optionally, by passing it over a catalyst or by oxidation with nitric acid to selenous acid followed by evaporation to dryness by heating.
Hoffmann JE, King MG; Selenium and Selenium Compounds. Kirk-Othmer Encyclopedia of Chemical Technology. (1999-2011). John Wiley & Sons, Inc. Online Posting Date: December 17, 2010.
Prepared by burning selenium in oxygen; ... by burning selenium in oxygen and nitrogen dioxide.
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456

8.3 Formulations / Preparations

Grades or Purity: Commercial, 99.5+%
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
-20 mesh, 99.5 and 99.999% purity grades /available/
Kuney, J.H. and J.N. Nullican (eds.) Chemcyclopedia. Washington, DC: American Chemical Society, 1988., p. 204

8.4 Consumption Patterns

It ... is the most widely used selenium compound in industry.
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 2018

8.5 U.S. Production

Production volume for non-confidential chemicals reported under the 2006 Inventory Update Rule. Chemical: Selenium oxide (SeO2). Aggregated National Production Volume: < 500,000 lbs.
US EPA; Non-Confidential 2006 Inventory Update Reporting. National Chemical Information. Selenium Oxide (SeO2) (7446-08-4). Available from, as of March 9, 2011: https://cfpub.epa.gov/iursearch/index.cfm?s=chem&err=t

8.6 U.S. Imports

(1977) 1.65X10+7 GRAMS
SRI
(1979) 7.00X10+6 GRAMS
SRI
(1986) 17248 lb
BUREAU OF THE CENSUS. US IMPORTS FOR CONSUMPTION AND GENERAL IMPORTS 1986 P. 1-517

8.7 General Manufacturing Information

EPA TSCA Commercial Activity Status
Selenium oxide (SeO2): ACTIVE
EPA TSCA Commercial Activity Status
Selenium oxide: ACTIVE
Experimental use: The feasibility of using selenite ion as a systemic deer repellent for the protection of Douglas fir seedlings is evaluated. When applied to the soil, the Se is absorbed by the seedling roots, transported to the foliage, and thereafter volatilized. Animal repellency is demonstrated at concentration as low as 1-2 ppm.
Allan GG et al; For Ecol Manage 7 (3): 163-81 (1984)

9 Safety and Hazards

9.1 Hazards Identification

9.1.1 GHS Classification

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Pictogram(s)
Corrosive
Acute Toxic
Health Hazard
Environmental Hazard
Signal
Danger
GHS Hazard Statements

H301 (100%): Toxic if swallowed [Danger Acute toxicity, oral]

H314 (10.2%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318 (10.2%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H331 (89.8%): Toxic if inhaled [Danger Acute toxicity, inhalation]

H373 (100%): May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

H400 (52.3%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Precautionary Statement Codes

P260, P261, P264, P264+P265, P270, P271, P273, P280, P301+P316, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P319, P321, P330, P363, P391, P403+P233, P405, 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 264 reports by companies from 21 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

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.

9.1.2 Hazard Classes and Categories

Acute Tox. 3 (100%)

Skin Corr. 1B (10.2%)

Eye Dam. 1 (10.2%)

Acute Tox. 3 (89.8%)

STOT RE 2 (100%)

Aquatic Acute 1 (52.3%)

Aquatic Chronic 1 (100%)

Acute toxicity (Oral) - Category 2

Serious eye damage/eye irritation - Category 2A-2B

Specific target organ toxicity - Single exposure - Category 1 (heart, central nervous system, blood system), Category 2 (respiratory system)

Specific target organ toxicity - Repeated exposure - Category 1 (respiratory system, liver), Category 2 (kidney)

Hazardous to the aquatic environment (Acute) - Category 1

Hazardous to the aquatic environment (Long-term) - Category 1

9.1.3 Health Hazards

Absorption of selenium may be demonstrated by presence of the element in the urine and by a garlic-like odor of the breath. Inhalation of dust can cause bronchial spasms, symptoms of asphyxiation, and pneumonitis. Acute symptoms of ingestion include sternal pain, cough, nausea, pallor, coated tongue, gastrointestinal disorders, nervousness, and conjunctivitis. Contact with eyes causes irritation. (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.

9.1.4 Fire Hazards

Special Hazards of Combustion Products: Sublimes and forms toxic vapors when heated in fire. (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.
Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.

9.1.5 Hazards Summary

Reacts with water to produce selenious acid; Can cause severe burns and irritation of the eyes and respiratory tract; A strong vesicant and is absorbed through the skin; [Olson, p. 761] A corrosive substance that can induce pulmonary edema; Has potential to cause skin sensitization and liver injury; [ICSC] See Selenium.
Olson - Olson KR (ed). Poisoning & Drug Overdose, 7th Ed. New York: Lange Medical Books/McGraw-Hill, 2018., p. 761

9.1.6 Skin, Eye, and Respiratory Irritations

The dioxide itself forms selenious acid with water or sweat, and the acid is an irritant.
Clayton, G.D., F.E. Clayton (eds.) Patty's Industrial Hygiene and Toxicology. Volumes 2A, 2B, 2C, 2D, 2E, 2F: Toxicology. 4th ed. New York, NY: John Wiley & Sons Inc., 1993-1994., p. 796
Causes intense local irritation of skin, eyes ... .
O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 2006., p. 1456

9.1.7 EPA Hazardous Waste Number

D010; A waste containing selenium (such as selenium dioxide) may or may not be characterized a hazardous waste following testing by the Toxicity Characteristic Leaching Procedure as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations.[40 CFR 261.24 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 8, 2011: http://www.ecfr.gov]
U204; A toxic waste when a discarded commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or manufacturing chemical intermediate.[40 CFR 261.33 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 8, 2011: http://www.ecfr.gov]

9.2 Safety and Hazard Properties

9.2.1 OSHA Standards

Permissible Exposure Limit: 8 Hr Time Weighted Avg: 0.2 mg/cu m. /Selenium compounds (as Se)/
29 CFR 1910.1000 (USDOL); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 7, 2011: https://www.ecfr.gov

9.2.2 NIOSH Recommendations

Recommended Exposure Limit: 10 Hr Time-Weighted Avg: 0.2 mg/cu m. /Selenium; The REL also apply to other selenium compounds (as Se) except selenium hexafluoride./
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)

9.3 First Aid Measures

Inhalation First Aid
Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention.
Skin First Aid
Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer 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. Refer for medical attention .

9.3.1 First Aid

Consult physician after all exposures to this compound.

INHALATION: remove victim to fresh air; give oxygen if needed.

INGESTION: induce vomiting; follow with gastric lavage and saline cathartics.

EYES: flush immediately and thoroughly with water.

SKIN: flush with water. (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.

9.4 Fire Fighting

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Water spray, fog or regular foam. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal. Avoid aiming straight or solid streams directly onto the product.

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. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

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

9.4.1 Fire Fighting Procedures

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. Keep run-off water out of sewers and water sources. /Selenium compound, solid, nos/
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 792
Personnel protection: Wear appropriate chemical protective clothing. Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Selenium compound, solid, nos/
Association of American Railroads; Bureau of Explosives. Emergency Handling of Hazardous Materials in Surface Transportation. Association of American Railroads, Pueblo, CO. 2005, p. 792

9.5 Accidental Release Measures

9.5.1 Isolation and Evacuation

Excerpt from ERG Guide 151 [Substances - Toxic (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)

9.5.2 Spillage Disposal

Evacuate danger area! Consult an expert! Sweep spilled substance into covered containers. Carefully collect remainder. Then store and dispose of according to local regulations. Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT let this chemical enter the environment.

9.5.3 Cleanup Methods

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.

9.5.4 Disposal Methods

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D010; U204, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
40 CFR 240-280, 300-306, 702-799 (USEPA). Available from, as of March 30, 2011: https://www.ecfr.gov

9.5.5 Preventive Measures

All sources of selenium oxide or fumes should be fitted with exhaust ventilation systems with an air speed of at least 30 m/min. ... smoking, eating and drinking at the workplace should be prohibited, and messrooms and sanitary facilities including showers and locker rooms should be provided ... wherever possible, operations should be mechanized, automated or provided with remote control.
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 2018
Non-impervious clothing which becomes contaminated with selenium, sodium selenite, sodium selenate, selenium dioxide or liquids containing these compounds should be removed promptly and not reworn until the contaminant is removed from the clothing.
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. 4
Skin Exposure: If selenium or its inorganic compounds get on the skin, immediately wash the contaminated skin. If selenium, sodium selenite, sodium selenate, or selenium dioxide soak through the clothing, remove the clothing immediately and wash the skin. If irritation persists after washing, get medical attention.
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. 5
Smoking, eating, & drinking at the workplace should be prohibited, & messrooms & sanitary facilities incl showers & locker rooms should be provided at a point distant from exposure areas. Wherever possible, operations should be mechanized, automated, or provided with remote control. /selenium oxide/
International Labour Office. Encyclopaedia of Occupational Health and Safety. 4th edition, Volumes 1-4 1998. Geneva, Switzerland: International Labour Office, 1998., p. 63.37
For more Preventive Measures (Complete) data for SELENIUM DIOXIDE (13 total), please visit the HSDB record page.

9.6 Handling and Storage

9.6.1 Nonfire Spill Response

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

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. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. For solids, prevent dust cloud and avoid inhalation of dust. (ERG, 2024)

9.6.2 Safe Storage

Separated from food and feedstuffs. Dry.

9.7 Exposure Control and Personal Protection

Maximum Allowable Concentration (MAK)
0.02 [mg/m3], as Se, inhalable fraction[German Research Foundation (DFG)]

9.7.1 Permissible Exposure Limit (PEL)

0.2 [mg/m3], as Se

9.7.2 Immediately Dangerous to Life or Health (IDLH)

1.0 [mg/m3], as Se

9.7.3 Threshold Limit Values (TLV)

0.2 [mg/m3], as Se
8 hr Time Weighted Avg (TWA): 0.2 mg/cu m. /Selenium and compounds, as Se/
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2010, p. 51
Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded. /Selenium and compounds, as Se/
American Conference of Governmental Industrial Hygienists TLVs and BEIs. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, OH 2010, p. 5
0.2 mg/m

9.7.4 Occupational Exposure Limits (OEL)

MAK (Maximale Arbeitsplatz Konzentration)
(as Se, inhalable fraction): 0.02 mg/m

9.7.5 Inhalation Risk

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed.

9.7.6 Effects of Short Term Exposure

The substance is corrosive to the eyes, skin and respiratory tract. Inhalation may cause lung oedema. The substance may cause effects on the eyes. This may result in allergic-type reaction of the eyelids (rose eye). Medical observation is indicated.

9.7.7 Effects of Long Term Exposure

Repeated or prolonged contact may cause skin sensitization. The substance may have effects on the respiratory tract, gastrointestinal tract, central nervous system and liver. This may result in nasal irritation, persistent garlic odour, stomach pain, nervousness and liver impairment.

9.7.8 Radiation Limits and Potential

OCCUPATIONAL VALUES FOR SELENIUM (Class W, oxides, hydroxides, carbides, and elemental Se. Class D, all compounds except those given for W)
RADIONUCLIDE
Selenium-70, Class D
ORAL Ingestion ALI (uCi)
2E+4
INHALATION ALI (uCi)
4E+4
INHALATION DAC (uCi/mL)
2E-5
RADIONUCLIDE
Selenium-70, Class W
ORAL Ingestion ALI (uCi)
1E+4
INHALATION ALI (uCi)
4E+4
INHALATION DAC (uCi/mL)
2E-5
RADIONUCLIDE
Selenium-73, Class D
ORAL Ingestion ALI (uCi)
3E+3
INHALATION ALI (uCi)
1E+4
INHALATION DAC (uCi/mL)
5E-6
RADIONUCLIDE
Selenium-73, Class W
ORAL Ingestion ALI (uCi)
-
INHALATION ALI (uCi)
2E+4
INHALATION DAC (uCi/mL)
7E-6
RADIONUCLIDE
Selenium-73m, Class D
ORAL Ingestion ALI (uCi)
6E+4
INHALATION ALI (uCi)
2E+5
INHALATION DAC (uCi/mL)
6E-5
RADIONUCLIDE
Selenium-73m, Class W
ORAL Ingestion ALI (uCi)
3E+4
INHALATION ALI (uCi)
1E+5
INHALATION DAC (uCi/mL)
6E-5
RADIONUCLIDE
Selenium-75, Class D
ORAL Ingestion ALI (uCi)
5E+2
INHALATION ALI (uCi)
7E+2
INHALATION DAC (uCi/mL)
3E-7
RADIONUCLIDE
Selenium-75, Class W
ORAL Ingestion ALI (uCi)
-
INHALATION ALI (uCi)
6E+2
INHALATION DAC (uCi/mL)
3E-7
RADIONUCLIDE
Selenium-79, Class D
ORAL Ingestion ALI (uCi)
6E+2
INHALATION ALI (uCi)
8E+2
INHALATION DAC (uCi/mL)
3E-7
RADIONUCLIDE
Selenium-79, Class W
ORAL Ingestion ALI (uCi)
-
INHALATION ALI (uCi)
6E+2
INHALATION DAC (uCi/mL)
2E-7
RADIONUCLIDE
Selenium-81, Class D
ORAL Ingestion ALI (uCi)
6E+4 (St. wall)
INHALATION ALI (uCi)
2E+5
INHALATION DAC (uCi/mL)
9E-5
RADIONUCLIDE
Selenium-81, Class W
ORAL Ingestion ALI (uCi)
-
INHALATION ALI (uCi)
2E+5
INHALATION DAC (uCi/mL)
1E-4
RADIONUCLIDE
Selenium-81m, Class D
ORAL Ingestion ALI (uCi)
4E+4
INHALATION ALI (uCi)
7E+4
INHALATION DAC (uCi/mL)
3E-5
RADIONUCLIDE
Selenium-81m, Class W
ORAL Ingestion ALI (uCi)
2E+4
INHALATION ALI (uCi)
7E+4
INHALATION DAC (uCi/mL)
3E-5
RADIONUCLIDE
Selenium-83, Class D
ORAL Ingestion ALI (uCi)
4E+4
INHALATION ALI (uCi)
1E+5
INHALATION DAC (uCi/mL)
5E-5
RADIONUCLIDE
Selenium-83, Class W
ORAL Ingestion ALI (uCi)
3E+4
INHALATION ALI (uCi)
1E+5
INHALATION DAC (uCi/mL)
5E-5
U.S. Nuclear Regulatory Commission; Table 1, Appendix B to Part 20--Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for Occupational Exposure. Available from, as of March 31, 2011: https://www.nrc.gov/reading-rm/doc-collections/cfr/part020/appb/

9.7.9 Personal Protective Equipment (PPE)

This compound is highly toxic if inhaled or ingested. Dust mask; rubber gloves; protective clothing (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.
SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.
All sources of selenium oxide or fumes should be fitted with exhaust ventilation systems with an air speed of at lease 30 m/min. /Selenium compounds/
International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 2018
... Dispensing & weighing /selenium dioxide/ powder can be carried out in efficient fume cupboards wearing gloves, whereas cleaning ... electrostatic precipitators & ducting containing red fume mixt of selenium & selenium dioxide can only be done /with/ ... completely impervious suits supplied by air lines.
Friberg, L., G.R. Nordberg, and V.B. Vouk. Handbook on the Toxicology of Metals. New York: Elsevier North Holland, 1979., p. 572
Wear appropriate personal protective clothing to prevent skin contact. /Selenium/
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)
For more Personal Protective Equipment (PPE) (Complete) data for SELENIUM DIOXIDE (8 total), please visit the HSDB record page.

9.7.10 Preventions

Exposure Prevention
PREVENT DISPERSION OF DUST! STRICT HYGIENE!
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. Wash hands before eating.

9.8 Stability and Reactivity

9.8.1 Air and Water Reactions

In presence of water will corrode most metals (USCG, 1999). Readily soluble in water forming selenious (selenous) acid.
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.

9.8.2 Reactive Group

Oxidizing Agents, Strong

9.8.3 Reactivity Alerts

Strong Oxidizing Agent

9.8.4 Reactivity Profile

Inorganic oxidizing agents, such as SELENIUM DIOXIDE, react with reducing agents to generate heat and products that may be flammable, combustible, or otherwise reactive. SELENIUM DIOXIDE reacts with water, particularly hot water, to give selenious (selenous) acid, a weak acid that is corrosive. Stable to light and heat. Rapidly absorbs dry hydrogen fluoride, hydrogen chloride, hydrogen bromide to form the corresponding selenium oxohalide. A good oxidizing agent. Reacts oxidatively with ammonia to form dinitrogen gas and selenium [Merck]. Oxidizes many organic substances.

9.8.5 Hazardous Reactivities and Incompatibilities

Do not use metal and acid to reduce selenium compounds. This will produce toxic gaseous hydrogen selenide. /Selenium compounds/
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. 278
Acids, strong oxidizers, chromium trioxide, potassium bromate. /Selenium/
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)

9.9 Transport Information

9.9.1 DOT Emergency Guidelines

/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.
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
/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.
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.
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.
U.S. Department of Transportation. 2008 Emergency Response Guidebook. Washington, D.C. 2008
For more DOT Emergency Guidelines (Complete) data for SELENIUM DIOXIDE (8 total), please visit the HSDB record page.

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

IMO 6.1; Selenium oxide
NA 2811; Selenium oxide
UN 3283; Selenium compound, solid, n.o.s

9.9.3 Standard Transportation Number

49 233 40; Selenium oxide

9.9.4 DOT Label

Poison

9.9.5 Packaging and Labelling

Do not transport with food and feedstuffs.

9.9.6 EC Classification

Symbol: T, N; R: 23/25-33-50/53; S: (1/2)-20/21-28-45-60-61; Note: A

9.9.7 UN Classification

UN Hazard Class: 6.1; UN Pack Group: II

9.10 Regulatory Information

The Australian Inventory of Industrial Chemicals
Chemical: Selenium oxide (SeO2)
REACH Registered Substance
New Zealand EPA Inventory of Chemical Status
Selenium oxide: HSNO Approval: HSR003738 Approved with controls

9.10.1 Atmospheric Standards

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Selenium dioxide is included on this list.
Clean Air Act as amended in 1990, Sect. 112 (b) (1) Public Law 101-549 Nov. 15, 1990

9.10.2 Federal Drinking Water Standards

Maximum contaminant levels for inorganic contaminants: 0.05 mg/L /Selenium/
40 CFR 141.62 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 8, 2011: https://www.ecfr.gov

9.10.3 Federal Drinking Water Guidelines

Maximum contaminant level goals for inorganic contaminants: 0.05 mg/L /Selenium/
40 CFR 141.51 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 8, 2011: https://www.ecfr.gov

9.10.4 State Drinking Water Standards

(AZ) ARIZONA 10 ug/L /Selenium/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
(NY) NEW YORK 10 ug/L /Selenium/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present

9.10.5 State Drinking Water Guidelines

(AZ) ARIZONA 45 ug/L /Selenium/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
(CT) CONNECTICUT 10 ug/L /Selenium/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
(ME) MAINE 35 ug/L /Selenium/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present
(MN) MINNESOTA 30 ug/L /Selenium/
USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93) To Present

9.10.6 Clean Water Act Requirements

Selenium dioxide 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 March 8, 2011: https://www.ecfr.gov
Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations. /Selenium and compounds/
40 CFR 401.15 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 7, 2011: https://www.ecfr.gov

9.10.7 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 10 lb or 4.54 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 March 8, 2011: https://www.ecfr.gov

9.10.8 RCRA Requirements

D010; A solid waste containing selenium (such as selenium dioxide) may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste.
40 CFR 261.24 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 8, 2011: https://www.ecfr.gov
U204; As stipulated in 40 CFR 261.33, when selenium dioxide, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).
40 CFR 261.33 (USEPA); U.S. National Archives and Records Administration's Electronic Code of Federal Regulations. Available from, as of March 8, 2011: https://www.ecfr.gov

9.11 Other Safety Information

9.11.1 Toxic Combustion Products

... Forms toxic vapors when heated in fire.
U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.

9.11.2 Special Reports

WHO; Environ Health Criteria: Selenium 58: 1-306 (1987). EHC are designed for scientists and administrators responsible for the establishment of safety standards and regulations and provide basic scientific risk evaluations of a wide range of chemicals and groups of chemicals.[Available from, as of April 1, 2011: http://www.inchem.org/documents/ehc/ehc/ehc58.htm#SectionNumber:7.1]
US Dept of Interior/Fish & Wildlife Service Contaminant Reviews; Selenium Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review Biol Rept No (85)1.5 (1985)

10 Toxicity

10.1 Toxicological Information

10.1.1 Toxicity Summary

Selenium readily substitutes for sulfur in biomolecules and in many biochemical reactions, especially when the concentration of selenium is high and the concentration of sulfur is low. Inactivation of the sulfhydryl enzymes necessary for oxidative reactions in cellular respiration, through effects on mitochondrial and microsomal electron transport, might contribute to acute selenium toxicity. Selenomethionine (a common organic selenium compound) also appears to randomly substitute for methionine in protein synthesis. This substitution may affect the structure and functionability of the protein, for example, by altering disulfide bridges. Inorganic forms of selenium appear to react with tissue thiols by redox catalysis, resulting in formation of reactive oxygen species and causing damage by oxidative stress. (L619)
L619: ATSDR - Agency for Toxic Substances and Disease Registry (2003). Toxicological profile for selenium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp92.html

10.1.2 Carcinogen Classification

Carcinogen Classification
3, not classifiable as to its carcinogenicity to humans. (L135)

10.1.3 Health Effects

Chronic oral exposure to high concentrations of selenium compounds can produce a disease called selenosis. The major signs of selenosis are hair loss, nail brittleness, and neurological abnormalities (such as numbness and other odd sensations in the extremities). Animal studies have shown that selenium may also affect sperm production and the female reproductive cycle. (L619)
L619: ATSDR - Agency for Toxic Substances and Disease Registry (2003). Toxicological profile for selenium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp92.html

10.1.4 Exposure Routes

The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.
Oral (L619) ; inhalation (L619) ; dermal (L619)
L619: ATSDR - Agency for Toxic Substances and Disease Registry (2003). Toxicological profile for selenium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp92.html

10.1.5 Symptoms

Inhalation Exposure
Burning sensation. Cough. Laboured breathing. Sore throat. Shortness of breath. Symptoms may be delayed.
Skin Exposure
Redness. Pain. Skin burns. Blisters.
Eye Exposure
Redness. Pain. Severe deep burns.
Ingestion Exposure
Abdominal pain. Burning sensation. Sore throat. Shock or collapse.
Short-term oral exposure to high concentrations of selenium may cause nausea, vomiting, and diarrhea. Brief exposures to high levels of elemental selenium or selenium dioxide in air can result in respiratory tract irritation, bronchitis, difficulty breathing, and stomach pains. Longer-term exposure to either of these air-borne forms can cause respiratory irritation, bronchial spasms, and coughing. (L619)
L619: ATSDR - Agency for Toxic Substances and Disease Registry (2003). Toxicological profile for selenium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/toxprofiles/tp92.html

10.1.6 Adverse Effects

Neurotoxin - Other CNS neurotoxin

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Reproductive Toxin - A chemical that is toxic to the reproductive system, including defects in the progeny and injury to male or female reproductive function. Reproductive toxicity includes developmental effects. See Guidelines for Reproductive Toxicity Risk Assessment.

Dermatotoxin - Skin burns.

Skin Sensitizer - An agent that can induce an allergic reaction in the skin.

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

10.1.7 Acute Effects

10.1.8 Toxicity Data

LD50: 23 mg/kg (Oral, Mouse) (L727) LD50: 4 mg/kg (Dermal, Rabbit) (L727) LD50: 3.6 mg/kg (Intraperitoneal, Rat) (L727) LD50: 9 mg/kg (Intravenous, Mouse) (L727) LD50: 4 mg/kg (Subcutaneous, Rabbit) (L727)
L727: The Physical and Theoretical Chemistry Laboratory of Oxford University (2005). Material Safety Data Sheet (MSDS) for selenium dioxide. http://msds.chem.ox.ac.uk/SE/selenium_dioxide.html

10.1.9 Minimum Risk Level

Chronic Oral: 0.005 mg/kg/day (L134)
L134: ATSDR - Agency for Toxic Substances and Disease Registry (2001). Minimal Risk Levels (MRLs) for Hazardous Substances. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). http://www.atsdr.cdc.gov/mrls/

10.1.10 Interactions

Acute toxicity tests showed that selenium dioxide (SeO2) was a strong antagonist against mercuric chloride toxicity in goldfish (Carassius auratus). Paradoxically, whole body accumulations of total mercury (Hg) were significantly increased with the admin of selenium (Se).
Heisinger JF et al; Arch Environ Contam Toxicol 8 (3): 279-83 (1979)
The chemopreventive efficacies of selenate, selenite, selenium dioxide, selenomethionine and selenocystine were examined during the promotion phase of carcinogenesis in the 7,12-dimethylbenz(a)anthracene-induced mammary tumor model in rats. Each agent was added to the diet of a final concentration of 3 ppm selenium. In general, there was no significant difference in the potency of these five selenium compounds in inhibiting the development of mammary tumors. The interaction of vitamin E (500 ppm) with either selenite or selenomethionine was further characterized in a second carcinogenesis study. Results of this experiment suggested that vitamin E enhanced the protective effect of selenite but not that of selenomethionine. In an attempt to explore the synergistic mechanism of selenium and vitamin E, the effects of these two agents on mitogen-induced blastogenesis and natural killer cytotoxic activity were also investigated. No consistent changes in these in vitro immune functions were detected resulting from supranutritional feeding of either selenite or vitamin E or both. ...
Ip C, White G; Carcinogenesis 8 (12): 1763-6 (1987)
Studies of lipid peroxidation induced by nickel in experimental animals are reviewed. Male Sprague-Dawley rats injected subcutaneously with nickel chloride show significantly increased lipoperoxidation (as indicated by the presence of thiobarbituric-acid (TAB) chromogens) in the liver, kidney, and lung and dose related increases in hepatotoxicity (as measured by serum aspartate-aminotransferase). ... When pretreated with ... selenium dioxide ..., followed by 500 ug/kg nickel-chloride, the increase of TBA chromogens in rat kidney homogenates is partially suppressed by selenium dioxide. ...
Sunderman FW Jr; Toxicol Environ Chem 15 (1-2): 59-69 (1987)
The effects of selenium on cadmium toxicokinetics and on the ability of cadmium to induce metallothionein, a metal-binding protein that is thought to confer tolerance to cadmium toxicity /is determined/. To assess the acute protective effects of selenium, male Wistar (WFr) rats were given selenium (as SeO2; 10 umol/kg, sc) at -24, and +24 hr relative to cadmium (as CdCl2; 45 umol/kg, sc). Over a 14-day period this dose of cadmium killed 6 out of 10 rats, while 100% of the cadmium-treated rats given concurrent selenium treatments survived. The acute increases in testicular weight that were seen with cadmium, indicative of edematous damage, were also prevented by concurrent selenium treatments.
Wahba ZZ et al; J Toxicol Environ Health 38 (2): 171-182 (1993)

10.1.11 Antidote and Emergency Treatment

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Selenium and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 418
Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for shock and treat if necessary ... . Monitor for pulmonary edema and treat if necessary ... . Treat seizures if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Selenium and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 418
Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... .Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Selenium and Related Compounds/
Currance, P.L. Clements, B., Bronstein, A.C. (Eds).; Emergency Care For Hazardous Materials Exposure. 3Rd edition, Elsevier Mosby, St. Louis, MO 2005, p. 418
Emergency and supportive measures. Maintain an open airway and assist ventilation if necessary. Administer supplemental oxygen. Treat coma, convulsions, bronchospasm, hypotension, and pulmonary edema if they occur. Since hypotension is often multifactorial, evaluate and optimize volume status, peripheral vascular resistance, and myocardial contractility. Observe for at least 6 hours after exposure. ... /Selenium/
Olson, K.R. (Ed.); Poisoning & Drug Overdose. 5th ed. Lange Medical Books/McGraw-Hill. New York, N.Y. 2007., p. 340
Decontamination: Inhalation. Immediately remove the victim from exposure and give supplemental oxygen if available. Skin and eyes. Remove contaminated clothing and wash exposed skin with soap and copious water. Irrigate exposed eyes with copious tepid water or saline. Ingestion. Ingestion of elemental selenium or selenium salts does not usually benefit from GI decontamination. In light of the risk of severe corrosive GI injury, gastric lavage plus activated charcoal may be of value for ingestion s of selenious acid seen within 1 hour. Invitro experiments indicate that vitamin C can reduce selenium salts to elemental selenium, which poorly absorbed. Its use has not been studied in vivo, but oral or nasogastric administration of several grams of ascorbic acid has been recommended. /Selenium/
Olson, K.R. (Ed.); Poisoning & Drug Overdose. 5th ed. Lange Medical Books/McGraw-Hill. New York, N.Y. 2007., p. 341

10.1.12 Medical Surveillance

Those workers who develop garlic odor of breath should be temporarily removed from work with selenium. 10 days is usually sufficient for garlic breath to disappear. Workers who develop an allergy to selenium dioxide have to be removed permanently from work with selenium or any of Its compounds. /Selenium compounds/
Friberg, L., G.R. Nordberg, and V.B. Vouk. Handbook on the Toxicology of Metals. New York: Elsevier North Holland, 1979., p. 572

10.1.13 Human Toxicity Excerpts

/SIGNS AND SYMPTOMS/ Long-term Exposure: Prolonged exposure to selenium, sodium selenite, sodium selenate, or selenium dioxide may cause paleness, coated tongue, stomach disorders, nervousness, metallic taste and a garlic odor of the breath. ... Prolonged skin contact with selenium oxide or selenium oxychloride may cause skin sensitization.
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. 1
/SIGNS AND SYMPTOMS/ Short-term Exposure: Inhalation of large quantities of selenium dioxide ... may cause severe breathing difficulties which may not appear for several hours after exposure. Skin contact with selenium dioxide ... may cause skin burns. Skin exposure to selenium dioxide dust may cause a skin rash. Splashes of selenium dioxide may cause eye irritation. Selenium dioxide dust may cause "rose eye" an allergy of the eyelids in which they may become puffy.
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. 1
/SIGNS AND SYMPTOMS/ ... Selenium dioxide ... caused skin burns and dermatitis. The compound caused excruciating pain when it penetrated under the free edge of the fingernails. It also could cause conjunctivitis and, eventually, an allergic type reaction of the eyes in workers exposed to the dust.
American Conference of Governmental Industrial Hygienists. Documentation of the TLV's and BEI's with Other World Wide Occupational Exposure Values. CD-ROM Cincinnati, OH 45240-4148 2010.
/SIGNS AND SYMPTOMS/ Selenium dioxide is more than a primary irritant, it causes extremely painful burns on the skin which, however, always heal without a scar. Theoretically, the selenium dioxide powder itself does not burn the skin (and if dropped on to the skin should be immediately brushed off dry). However, in practice, in the industrial environment, there is sufficient moisture on the skin from sweating to be taken up by this white solid to form a sticky solution of selenious acid within seconds, or at the most, minutes, of coming into contact with the skin.
WHO; Poison Information Monograph 483 (1987) https://www.inchem.org/documents/pims/chemical/pim483.htm
For more Human Toxicity Excerpts (Complete) data for SELENIUM DIOXIDE (17 total), please visit the HSDB record page.

10.1.14 Non-Human Toxicity Excerpts

/LABORATORY ANIMALS: Acute Exposure/ ... The toxic effects of respiratory exposure to selenium dioxide (SeO2) /were examined/ under conditions similar to those that occur in industry, i.e., heating of selenium ion. In acute studies, white rats were exposed to air concentrations of selenium dioxide of 0.15 - 0.6 mg/L, and all rats died within one-half to 4 hr. Morphological examination of the organs revealed that intraalveolar and perivascular edema occurred in the lungs, and hemorrhages and degenerative changes in the liver, kidney, and heart. In 4 additional studies, all rats survived 4 hr when exposed to doses of 0.09, 0.06-0.07, or 0.03-0.04 mg selenium dioxide/L, but all rats exposed to the highest dose (equal to 5-5.2 mg/kg body weight) died within 24 hr.
WHO; Environmental Health Criteria 58: Selenium (1987). Available from, as of April 1, 2011: https://www.inchem.org/documents/ehc/ehc/ehc58.htm#SectionNumber:7.1
/LABORATORY ANIMALS: Acute Exposure/ Pulmonary function was assessed in non-sensitized male guinea pigs (206-445 g) before and after intratracheal (ITr) treatment with saline or selenium (Se, 0.06 mg/100 g body weight) as selenium dioxide or seleno-L-methionine. Pulmonary functional parameters such as the respiratory rate (f), tidal volume (TV), dynamic lung compliance (Cdynl) and lung resistance (Rl) were determined using the respiratory flow (F) signal and the transpulmonary signal obtained via the intrapleural pressure (P) from the animal. Although, pulmonary dysfunction was observable with exposure to two different Se compounds, the selenium dioxide-induced changes in f and Rl were significant (P < 0.05). Treatment with seleno-L-methionine did not result in alteration of any of the parameters significantly. Results indicated that acute intratracheal selenium dioxide exposure affects respiration precipitated by a significantly decreased f and an increased Rl unlike after seleno-L-methionine. The Cdynl did not change significantly after treatment with either of the two Se compounds. Comparing the immediate effects of the two different Se compounds on respiration, acute intratracheal selenium dioxide exposure was found to be more detrimental to pulmonary function than seleno-L-methionine.
Nonavinakere VK et al; Toxicol Lett 104 (3): 231-7 (1999)
/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ This study was undertaken to investigate the effects of selenium dioxide (SeO2) on rat blood and femoral bone-marrow oxidant mechanisms. Treatment with SeO2, 67 microg Se/kg i.p. daily for 14 days, significantly decreased lipid peroxidation and the concentrations of Fe in serum and bone marrow. The concentrations of Se in serum and bone-marrow cells were significantly increased after SeO2 treatment. The activities of glutathione peroxidase (GPx) in blood and bone-marrow cells were markedly increased. The levels of oxyhemoglobin in blood were significantly increased, while the concentrations of methemoglobin were decreased after SeO2 administration. The fragility of erythrocytes membranes was significantly decreased in SeO2-treated rats compared to controls. Data suggest that treatment with a low dose of SeO2 may provide antioxidant nutrients to blood and bone marrow.
Chen CY, Lin TH; J Toxicol Environ Health A 59 (7): 553-60 (2000)
/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ ... The toxic effects of respiratory exposure to selenium dioxide (SeO2) /were examined/ under conditions similar to those that occur in industry, i.e., heating of selenium ion. ... In a series of long-term studies, rats were exposed to repeated doses of selenium dioxide at 0.01-0.03, 0.006-0.009, or 0.003-0.005 mg/L for 6 hr, every other day, for one month. The lowest dose did not produce any effects on body weight or on the blood picture, and all the rats survived. Histological examination revealed degenerative changes in the liver, renal tubules, dystrophy of heart muscle, and hyperaemia and hypertrophy of the splenic pulp. At the dose of 0.006-0.009 mg/L, all the rats but one died within 27-33 days. For the first 2 weeks, there was no difference in body weight between the exposed and unexposed control rats but, during the last 2 weeks, the exposed rats lost body weight and all but one of the exposed rats died. The histopathological changes consisted of multiple necrosis and degeneration in the liver and myocardial fibres, and involvement of renal tubules. In the third group of rats, which was exposed to 0.01-0.03 mg/L, the animals showed respiratory distress, weight loss, and, in 3 rats, anemia. All the rats died between days 8 and 18 of exposure. In the liver, kidneys, myocardium, and spleen, the changes observed were similar to those seen at lower doses, but more pronounced. Moreover, lung edema similar to that noted in the acute exposure studies was seen.
WHO; Environmental Health Criteria 58: Selenium (1987). Available from, as of April 1, 2011: https://www.inchem.org/documents/ehc/ehc/ehc58.htm#SectionNumber:7.1
For more Non-Human Toxicity Excerpts (Complete) data for SELENIUM DIOXIDE (14 total), please visit the HSDB record page.

10.1.15 Non-Human Toxicity Values

LD50 Mouse (male) oral 16 mg/kg/day
U.S. Dept Health & Human Services/Agency for Toxic Substances & Disease Registry; Toxicological Profile for Selenium p.38 (September 2003) Available from, as of March 16, 2011: https://www.atsdr.cdc.gov/substances/indexAZ.asp#S
LD50 Rat oral 48 mg/kg/day
U.S. Dept Health & Human Services/Agency for Toxic Substances & Disease Registry; Toxicological Profile for Selenium p.38 (September 2003) Available from, as of March 16, 2011: https://www.atsdr.cdc.gov/substances/indexAZ.asp#S
LD50 Rabbit subcutaneous 4 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. 3196

10.2 Ecological Information

10.2.1 Ecotoxicity Values

EC50; Species: Anabaena flosaquae (Blue-Green Algae); Conditions: freshwater, static, 20 °C; Concentration: 4800 ug/L for 3 days (95% confidence interval: 3200-10000 ug/L); Effect: decreased population biomass
Abdel-Hamid MI, Skulberg OM; Lakes Reserv Res Manag 1 (3): 205-11 (1995) as cited in the ECOTOX database.
EC50; Species: Chlorella sp. (Green algae); Conditions: freshwater, static, 20 °C; Concentration: 800 ug/L for 3 days (95% confidence interval: 320-1000 ug/L); Effect: decreased population biomass
Abdel-Hamid MI, Skulberg OM; Lakes Reserv Res Manag 1 (3): 205-11 (1995) as cited in the ECOTOX database.
EC50; Species: Microcystis aeruginosa (Blue-Green algae); Conditions: freshwater, static, 20 °C; Concentration: 7200 ug/L for 3 days (95% confidence interval: 3200-10000 ug/L); Effect: decreased population biomass
Abdel-Hamid MI, Skulberg OM; Lakes Reserv Res Manag 1 (3): 205-11 (1995) as cited in the ECOTOX database.
EC50; Species: Pseudokirchneriella subcapitata (Green algae); Conditions: freshwater, static, 20 °C; Concentration: 1200 ug/L for 3 days (95% confidence interval: 1000-3200 ug/L); Effect: decreased population biomass
Abdel-Hamid MI, Skulberg OM; Lakes Reserv Res Manag 1 (3): 205-11 (1995) as cited in the ECOTOX database.
For more Ecotoxicity Values (Complete) data for SELENIUM DIOXIDE (43 total), please visit the HSDB record page.

10.2.2 Ecotoxicity Excerpts

/PLANTS/ The feasibility of using selenite ion (selenium dioxide (SeO2) or sodium selenite (Na2SeO3)) as a systemic deer repellent for the protection of Douglas fir seedlings is evaluated. When applied to the soil, the selenium (Se) is absorbed by the seedling roots, transported to the foliage, and thereafter volatilized. Acute phytotoxicity is observed only when Se foliar concn exceed 100 ppm, while animal repellency is demonstrated at concn as low as 1-2 ppm. ...
Allan GG et al; For Ecol Manage 7 (3): 163-81 (1984)

10.2.3 ICSC Environmental Data

The substance is harmful to aquatic organisms.

10.2.4 Artificial Pollution Sources

Selenium dioxide is formed by combustion of elemental selenium present in fossil fuels or rubbish.
US Dept of Interior/Fish & Wildlife Service Contaminant Reviews; Selenium Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review Biol Rept No (85)1.5 p.3 (1985)
Up to 90% of the selenium content in ambient air is emitted during the burning of fossil fuels. Selenium dioxide is formed during combustion of elemental selenium present in fossil fuels.
Friberg, L., Nordberg, G.F., Kessler, E. and Vouk, V.B. (eds). Handbook of the Toxicology of Metals. 2nd ed. Vols I, II.: Amsterdam: Elsevier Science Publishers B.V., 1986., p. V2486

10.2.5 Environmental Fate

ATMOSPHERIC FATE: Volatile selenium dioxide is expected to exist in the gaseous state in the atmosphere(1,2). Selenium dioxide released to the air from the combustion of fossil fuels is expected to be reduced to elemental selenium by sulfur dioxide formed during the combustion(2). Selenium dioxide reacting with atmospheric moisture generates selenious acid aerosols(2).
(1) Fishbein L; pp. 1153-90 in Metals and Their Compounds in the Environment, Merian E, ed., Weinheim, Fed. Rep Ger: VCH (1991)
(2) ATSDR; Toxicological Profile for Selenium. Atlanta, GA: Agency for Toxic Substances and Disease Registry, US Public Health Service (2003)

10.2.6 Atmospheric Concentrations

The atmospheric level of selenium in most urban regions ranges from 0.1 to 10 ng/cu m. A greater part of the atmospheric selenium is bound to fly ash and to suspended particles that contain from 1.4 to 11 ug/g and from 1 to 110 ug/g, respectively.
Friberg, L., Nordberg, G.F., Kessler, E. and Vouk, V.B. (eds). Handbook of the Toxicology of Metals. 2nd ed. Vols I, II.: Amsterdam: Elsevier Science Publishers B.V., 1986., p. V2 486

10.2.7 Probable Routes of Human Exposure

... by ingestion and inhalation (dust).
Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, D.C.: Assoc. of American Railroads, Hazardous Materials Systems (BOE), 1987., p. 614
Selenium dioxide can affect the body if it is inhaled, if it comes in contact with the eyes or skin, or if it is swallowed. Selenium dioxide may enter the body through the skin.
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. 1
ACUTE POISONING THROUGH INHALATION MAY OCCUR IN INDUSTRY (SELENIUM DUST & FUMES, SELENIUM DIOXIDE & HYDROGEN SELENIDE). ...
Friberg, L., G.R. Nordberg, and V.B. Vouk. Handbook on the Toxicology of Metals. New York: Elsevier North Holland, 1979., p. 556
Selenium fumes may contain selenium dioxide in concentrations as high as 50% and are often described as the main selenium problem in the work environment.
Friberg, L., Nordberg, G.F., Kessler, E. and Vouk, V.B. (eds). Handbook of the Toxicology of Metals. 2nd ed. Vols I, II.: Amsterdam: Elsevier Science Publishers B.V., 1986., p. V2 489
For more Probable Routes of Human Exposure (Complete) data for SELENIUM DIOXIDE (9 total), please visit the HSDB record page.

11 Associated Disorders and Diseases

Associated Occupational Diseases with Exposure to the Compound
Contact dermatitis, allergic [Category: Skin Disease]

12 Literature

12.1 Consolidated References

12.2 NLM Curated PubMed Citations

12.3 Springer Nature References

12.4 Thieme References

12.5 Wiley References

12.6 Chemical Co-Occurrences in Literature

12.7 Chemical-Gene Co-Occurrences in Literature

12.8 Chemical-Disease Co-Occurrences in Literature

13 Patents

13.1 Depositor-Supplied Patent Identifiers

13.2 WIPO PATENTSCOPE

13.3 Chemical Co-Occurrences in Patents

13.4 Chemical-Disease Co-Occurrences in Patents

13.5 Chemical-Gene Co-Occurrences in Patents

14 Biological Test Results

14.1 BioAssay Results

15 Classification

15.1 MeSH Tree

15.2 ChemIDplus

15.3 CAMEO Chemicals

15.4 UN GHS Classification

15.5 NORMAN Suspect List Exchange Classification

15.6 EPA TSCA and CDR Classification

15.7 EPA Substance Registry Services Tree

15.8 MolGenie Organic Chemistry Ontology

16 Information Sources

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  13. Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
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    http://www.ebi.ac.uk/Information/termsofuse.html
  16. NITE-CMC
    Selenium dioxide - FY2006 (New/original classication)
    https://www.chem-info.nite.go.jp/chem/english/ghs/06-imcg-0282e.html
    Selenium dioxide - FY2014 (Revised classification)
    https://www.chem-info.nite.go.jp/chem/english/ghs/14-mhlw-2055e.html
  17. Japan Chemical Substance Dictionary (Nikkaji)
  18. NIST Mass Spectrometry Data Center
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  19. SpectraBase
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  29. EPA Substance Registry Services
  30. MolGenie
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    https://github.com/MolGenie/ontology/
  31. PATENTSCOPE (WIPO)
CONTENTS