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Methyl orange

PubChem CID
23673835
Structure
Methyl orange_small.png
Methyl orange_3D_Structure.png
Molecular Formula
Synonyms
  • METHYL ORANGE
  • 547-58-0
  • Orange III
  • MethylOrange
  • Acid Orange 52
Molecular Weight
327.34 g/mol
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Dates
  • Create:
    2008-02-05
  • Modify:
    2025-01-04
Description
4-dimethylaminoazobenzene-4-sulfonic acid, sodium salt is an orange powder. (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.

1 Structures

1.1 2D Structure

Chemical Structure Depiction
Methyl orange.png

1.2 3D Conformer

3D Conformer of Parent

2 Names and Identifiers

2.1 Computed Descriptors

2.1.1 IUPAC Name

sodium;4-[[4-(dimethylamino)phenyl]diazenyl]benzenesulfonate
Computed by Lexichem TK 2.7.0 (PubChem release 2021.10.14)

2.1.2 InChI

InChI=1S/C14H15N3O3S.Na/c1-17(2)13-7-3-11(4-8-13)15-16-12-5-9-14(10-6-12)21(18,19)20;/h3-10H,1-2H3,(H,18,19,20);/q;+1/p-1
Computed by InChI 1.0.6 (PubChem release 2021.10.14)

2.1.3 InChIKey

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

2.1.4 SMILES

CN(C)C1=CC=C(C=C1)N=NC2=CC=C(C=C2)S(=O)(=O)[O-].[Na+]
Computed by OEChem 2.3.0 (PubChem release 2024.12.12)

2.2 Molecular Formula

C14H14N3NaO3S
Computed by PubChem 2.2 (PubChem release 2021.10.14)

2.3 Other Identifiers

2.3.1 CAS

547-58-0

2.3.3 Deprecated CAS

1342-24-1, 1773488-61-1, 66777-17-1
1342-24-1, 1773488-61-1, 2734910-57-5, 66777-17-1

2.3.4 European Community (EC) Number

2.3.5 UNII

2.3.6 UN Number

2.3.7 DSSTox Substance ID

2.3.8 Nikkaji Number

2.3.9 Wikidata

2.3.10 Wikipedia

2.4 Synonyms

2.4.1 MeSH Entry Terms

  • C.I. 13025
  • C.I. Acid Orange 52
  • C.I. Acid Orange-52
  • C.I.-13025
  • Gold Orange
  • helianthine
  • methyl orange
  • methyl orange, 35S-labeled
  • methyl orange, sodium salt
  • p(((p-dimethylamino)phenyl)azo)benzenesulfonic acid sodium salt
  • Tropaeolin D

2.4.2 Depositor-Supplied Synonyms

3 Chemical and Physical Properties

3.1 Computed Properties

Property Name
Molecular Weight
Property Value
327.34 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
6
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Rotatable Bond Count
Property Value
4
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Exact Mass
Property Value
327.06535677 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Monoisotopic Mass
Property Value
327.06535677 Da
Reference
Computed by PubChem 2.2 (PubChem release 2021.10.14)
Property Name
Topological Polar Surface Area
Property Value
93.5 Ų
Reference
Computed by Cactvs 3.4.8.18 (PubChem release 2021.10.14)
Property Name
Heavy Atom Count
Property Value
22
Reference
Computed by PubChem
Property Name
Formal Charge
Property Value
0
Reference
Computed by PubChem
Property Name
Complexity
Property Value
448
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

4-dimethylaminoazobenzene-4-sulfonic acid, sodium salt is an orange powder. (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
Orange powder, insoluble in water; [CAMEO]

3.2.2 Color / Form

ORANGE-YELLOW POWDER OR CRYSTALLINE SCALES
Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 1041

3.2.3 Melting Point

>300 °C
Green FJ; The Sigma-Aldrich Handbook of Stains, Dyes and Indicators. Milwaukee, Wisconsin: Aldrich Chemical Company, Inc. p. 461 (1990)

3.2.4 Solubility

less than 1 mg/mL at 64 °F (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
SOL IN 500 PARTS WATER; MORE SOL IN HOT WATER
Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 1041
PRACTICALLY INSOL IN ALC
Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 1041
INSOL IN ETHER; SLIGHTLY SOL IN PYRIMIDINE
Lide, D.R. (ed.). CRC Handbook of Chemistry and Physics. 76th ed. Boca Raton, FL: CRC Press Inc., 1995-1996., p. 3-62
20 mg/ml in 2-methoxyethanol; 0.3 mg/ml in ethanol
Green FJ; The Sigma-Aldrich Handbook of Stains, Dyes and Indicators. Milwaukee, Wisconsin: Aldrich Chemical Company, Inc. p. 461 (1990)
In water= 200 mg/l at 25 °C
Dehn WM; J Am Chem Soc 39: 1399-404 (1917)

3.2.5 Dissociation Constants

3.2.6 Other Experimental Properties

PH: 3.1 RED, 4.4 YELLOW.
Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 1041

3.3 Chemical Classes

Dyes -> Azo Dyes

4 Spectral Information

4.1 UV Spectra

MAX ABSORPTION (ALC): 265 NM (LOG E= 4.2); 305 NM (LOG E= 3.9); 420 NM (LOG E= 4.6)
Weast, R.C. (ed.). Handbook of Chemistry and Physics. 60th ed. Boca Raton, Florida: CRC Press Inc., 1979., p. C-378
Absorption peak at 507 nm in water + 0.5 ml 1N hydrochloric acid.
Green FJ; The Sigma-Aldrich Handbook of Stains, Dyes and Indicators. Milwaukee, Wisconsin: Aldrich Chemical Company, Inc. p. 553 (1990)

4.2 IR Spectra

IR Spectra
IR: 15647 (Sadtler Research Laboratories IR Grating Collection)

6 Chemical Vendors

7 Drug and Medication Information

7.1 Drug Labels

Active ingredient and drug

8 Pharmacology and Biochemistry

8.1 MeSH Pharmacological Classification

Indicators and Reagents
Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant and Hackh's Chemical Dictionary, 5th ed, p301, p499) (See all compounds classified as Indicators and Reagents.)

8.2 Absorption, Distribution and Excretion

KINETIC ANALYSIS OF BILIARY EXCRETION OF IV DOSE OF [(3)H]METHYL ORANGE & PRODUCTS OF DEMETHYLATION (MONO- & DI-) SHOWED THAT SUCCESSIVE REMOVAL OF METHYL GROUP RESULTED IN MUCH FASTER BILIARY EXCRETION OF CMPD.
The Chemical Society. Foreign Compound Metabolism in Mammals. Volume 2: A Review of the Literature Published Between 1970 and 1971. London: The Chemical Society, 1972., p. 160
BILIARY EXCRETION OF IV ADMIN METHYL ORANGE & METABOLITES, 4'-SULFO-4-METHYLAMINOAZOBENZENE & 4'-SULFO-4-AMINOAZOBENZENE, BY RATS WAS USED TO ILLUSTRATE A ONE-COMPARTMENT PHARMACOKINETIC MODEL IN WHICH A DRUG UNDERWENT 2 SUCCESSIVE METABOLIC REACTIONS.
O'REILLY WJ ET AL; BRIT J PHARMACOL 43 (1): 167 (1971)

8.3 Metabolism / Metabolites

YIELDS 4'-METHYLAMINOAZOBENZENE-4-SULFONIC ACID IN RAT, IN MOUSE. /FROM TABLE/
Goodwin, B.L. Handbook of Intermediary Metabolism of Aromatic Compounds. New York: Wiley, 1976., p. M-35
METHYL ORANGE IS CONVERTED TO N,N-DIMETHYL-P-PHENYLENEDIAMINE BY INTESTINAL ANAEROBIC BACTERIA. SULFANILIC ACID IS ANOTHER METABOLITE.
CHUNG K ET AL; MUTAT RES 58 (2-3): 375 (1978)

8.4 Transformations

9 Use and Manufacturing

9.1 Uses

Sources/Uses
Used as a pH indicator for the pH range of 3.1-4.4; [Ullmann]
Reagent for the detection of bromine.
Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984., p. V4 239 (1978)
As a pH indicator. Employed for titrating most mineral acids, strong bases, estimating alkalinity of waters; useless for organic acids. In dyeing and printing of textiles.
Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 1041

9.1.1 Household Products

Household & Commercial/Institutional Products

Information on 1 consumer products that contain Methyl Orange in the following categories is provided:

• Auto Products

9.2 Methods of Manufacturing

Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 1041

9.3 Formulations / Preparations

As pH indicator in 0.1% aq soln
Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 1041

9.4 U.S. Production

(1977) PROBABLY GREATER THAN 2.27X10+6 GRAMS
SRI
(1978) PROBABLY GREATER THAN 2.27X10+6 GRAMS
SRI

9.5 General Manufacturing Information

EPA TSCA Commercial Activity Status
Benzenesulfonic acid, 4-[2-[4-(dimethylamino)phenyl]diazenyl]-, sodium salt (1:1): ACTIVE
Methyl orange is very seldom used in textile applications because it is fugitive and sensitive to acids; however, on occasion, it has been used to dye wool and silk from an acid bath.
Green FJ; The Sigma-Aldrich Handbook of Stains, Dyes and Indicators. Milwaukee, Wisconsin: Aldrich Chemical Company, Inc. p. 461 (1990)

10 Safety and Hazards

10.1 Hazards Identification

10.1.1 GHS Classification

Note
Pictograms displayed are for 99.5% (212 of 213) of reports that indicate hazard statements. This chemical does not meet GHS hazard criteria for 0.5% (1 of 213) of reports.
Pictogram(s)
Acute Toxic
Signal
Danger
GHS Hazard Statements
H301 (99.5%): Toxic if swallowed [Danger Acute toxicity, oral]
Precautionary Statement Codes

P264, P270, P301+P316, P321, P330, 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 213 reports by companies from 4 notifications to the ECHA C&L Inventory.

Reported as not meeting GHS hazard criteria per 1 of 213 reports by companies. For more detailed information, please visit ECHA C&L website.

There are 3 notifications provided by 212 of 213 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.

10.1.2 Hazard Classes and Categories

Acute Tox. 3 (99.5%)

10.1.3 Health Hazards

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

Highly toxic, may be fatal if inhaled, ingested or absorbed through skin. 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. (ERG, 2024)

10.1.4 Fire Hazards

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

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways. (ERG, 2024)

10.1.5 Hazards Summary

Azo, diazo, azido compounds can detonate, especially organic azides that have been sensitized by adding metal salts or strong acids. [CAMEO]

10.2 First Aid Measures

10.2.1 First Aid

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.

10.3 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)

10.4 Accidental Release Measures

10.4.1 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)

10.4.2 Disposal Methods

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

10.5 Handling and Storage

10.5.1 Nonfire Spill Response

SMALL SPILLS AND LEAKAGE: If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then dampen the solid spill material with toluene, then transfer the dampened material to a suitable container. Use absorbent paper dampened with toluene to pick up any remaining material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent-wash all contaminated surfaces with toluene followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

STORAGE PRECAUTIONS: You should store this material in a refrigerator. (NTP, 1992)

National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.

10.6 Exposure Control and Personal Protection

10.6.1 Personal Protective Equipment (PPE)

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)
National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.

10.7 Stability and Reactivity

10.7.1 Air and Water Reactions

Azo dyes can be explosive when suspended in air at specific concentrations. Insoluble in water.

10.7.2 Reactive Group

Azo, Diazo, Azido, Hydrazine, and Azide Compounds

Sulfonates, Phosphonates, and Thiophosphonates, Organic

Salts, Acidic

10.7.3 Reactivity Profile

4-DIMETHYLAMINOAZOBENZENE-4-SULFONIC ACID, SODIUM SALT is an azo compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides.

10.8 Transport Information

10.8.1 DOT Label

Poison

10.9 Regulatory Information

The Australian Inventory of Industrial Chemicals
Chemical: Benzenesulfonic acid, 4-[[4-(dimethylamino)phenyl]azo]-, sodium salt
New Zealand EPA Inventory of Chemical Status
C.I. Acid Orange 52: Does not have an individual approval but may be used under an appropriate group standard

10.10 Other Safety Information

10.10.1 Special Reports

... The mutagenicity of a number of azo dyes is reviewed in this paper.[Chung KT; Mutat Res 114 (3): 269-81 (1983)]

11 Toxicity

11.1 Toxicological Information

11.1.1 Acute Effects

11.1.2 Non-Human Toxicity Excerpts

METHYL ORANGE & ITS METAB, N,N-DIMETHYL-P-PHENYLENEDIAMINE WERE MUTAGENIC TO SALMONELLA TYPHIMURIUM WHEN TESTED IN PRESENCE OF LIVER HOMOGENATE. SULFANILIC ACID ANOTHER METABOLITE WAS NOT MUTAGENIC.
CHUNG K ET AL; MUTAT RES 58(2-3) 375 (1978)
When various dyes and indicators were fed to partially hepatectomized male rats as supplements in basal diet for 10 days after surgery, liver regeneration was stimulated by 1-phenylazo-2-naphthol and by 1-(p-phenylazophenylazo)-2-naphthol, as such or with methyl substituents on the phenyl rings, and also by methyl orange. The efficacy of the azonaphthiols stemmed from the activity of the metabolic intermediate, 1-amino-2-naphthol, which was tested in rats at a level of 0.20% (as the hydrochloride). The presence of a nitro group pr two methoxy groups of the phenyl ring of 1-phenylazo-2-naphthol or of sulfonic acid groups on either of the azonaphthol series led to cmpd that were ineffective. The stimulants generally elicited liver enlargement when fed to intact rats for the same interval. In contrast to p-dimethylaminoazobenzenesulfonate (methyl orange) ... was stimulatory. Sulfanilic acid, a prominent metabolite of several azo dyes, proved inactive in partially hepatectomized males at a level of 0.20%.
Gershbein LL; Food Chem Toxicol 20 (1): 1-8 (1982)

11.1.3 TSCA Test Submissions

Clastogenic activity was evaluated in 3 cultures of RL1 rat liver cells per dose, exposed for 22 hours to 4-dimethylaminoazobenzene-4-sulphonic acid, sodium salt at concentrations of 0, 12.5, 25.0, or 50.0 ug/ml of culture medium. Concentrations were chosen to be approximately 1/4, 1/2, and 1x the GI50 (concentration at which 50% growth inhibition is achieved). Both positive (methyl-methanesulfonate) and solvent (dimethylsulfoxide) controls were used. No metabolic activation system was used. Cell division was arrested, and at least 380 metaphases from each test concentration were examined. The test substance did not induce a significant frequency of chromatid or chromosome aberrations. The proportions of cells showing chromatid aberrations were 0.7% for the negative control, 0% at both 12.5 and 25.0 ug/ml, and 0.3% at 50.0 ug/ml. The proportions showing chromosomal aberrations were 0.1% for the negative control, 0.3% at 25.0 ug/ml, and 0% at the other concentrations. Although the positive control showed 3.3% of cells with chromatid aberrations, no chromosome aberrations were induced.
Shell Chem. Co.; The Activity of 27 Coded Compounds in the RL1 Chromosome Assay (1989), EPA Document No. 86-890000950, Fiche No. OTS0520388

11.2 Ecological Information

11.2.1 Environmental Fate / Exposure Summary

Methyl orange's production and use as a pH indicator and as a dye for textiles may result in its release to the environment through various waste streams. The ionic state of methyl orange makes this compound essentially non-volatile, therefore methyl orange should exist solely in the particulate phase in the ambient atmosphere. Particulate-phase methyl orange may be physically removed from the air, mainly by wet deposition. An estimated Koc of 240 suggests that methyl orange will have moderate mobility in soil although its ionic nature may result in ion-exchange processes with clay that would retard leaching. The volatilization of the dye from moist soil surfaces to air will not be important as methyl orange is an ionic compound. Based on limited data, this compound is expected to be resistant to aerobic biodegradation in both soil and water; methyl orange was not degraded over 5 days in an aqueous BOD screening test. Under anaerobic conditions, methyl orange should readily biodegrade. It may adsorb to clay sediments and particulate matter in the water due to ion-exchange processes. The loss of the dye from water surfaces by volatilization should not be important due to its ionic nature. The potential for bioconcentration in aquatic organisms is expected to be low based on an estimated BCF value of 30. Occupational exposure may be through inhalation of dusts and dermal contact with this compound at workplaces where methyl orange is produced or used. The general population may be exposed to methyl orange via dermal contact with products containing this compound. (SRC)

11.2.2 Artificial Pollution Sources

Methyl orange's production and use as a pH indicator and as a dye for textiles(1) may result in its release to the environment through various waste streams(SRC).
(1) Budavari S; The Merck Index - Encyclopedia of Chemicals, Drugs, and Biologicals. 12th Ed. Rahway, NJ: Merck and Co., Inc. p. 1537 (1996)

11.2.3 Environmental Fate

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 240(SRC), determined from a measured water solubility(2) and a recommended regression-derived equation(3), indicates that methyl orange will have moderate mobility in soil(SRC). Due to the ionic nature of methyl orange, the retention of the dye by ion-exchange processes(4,SRC), particularly on clay surfaces, and adsorption at mineral surfaces such as geothite(5,SRC), may slow down or prevent leaching(SRC). As methyl orange is an ionic compound, volatilization of this compound will not be important from moist soil surfaces(4,SRC). Based on limited data, methyl orange is expected to be resistant to aerobic biodegradation in soil(SRC). In an aqueous BOD screening test, this compound was not degraded over a 5 day period(6). This compound may be susceptible to biodegradation under anaerobic conditions(SRC); intestinal microflora were able to metabolize methyl orange, forming N,N-dimethyl-phenylene diamine(7).
(1) Swann RL et al; Res Rev 85: 23 (1983)
(2) Dehn WM; J Am Chem Soc 39: 1399-404 (1917)
(3) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington DC: Amer Chem Soc pp. 4-9 (1990)
(4) Baughman GL, Perenich TA; Amer Dyestuff Reporter p. 19-22. February (1988)
(5) Evans, LJ; Environ Sci Technol 23: 1046-56 (1989)
(6) Heukelekian H, Rand MC; J Water Pollut Contr Assoc 27: 1040-53 (1955)
(7) Chung KT et al; Crit Rev Microbiol 18: 175-90 (1992)
AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 240(SRC), determined from a measured water solubility(2) and a recommended regression-derived equation(1), indicates that methyl orange should not adsorb to suspended solids and sediment in water(SRC). However, due to the ionic nature of methyl orange, the retention of the dye by ion-exchange processes(3,SRC), particularly on clay surfaces, and adsorption at mineral surfaces such as geothite(4,SRC), may lead to increased adsorption on some sediment and particulate surfaces(SRC). As methyl orange is an ionic compound, volatilization from water surfaces is not expected(3,SRC). According to a classification scheme(5), an estimated BCF value of 30(1,SRC), from a measured water solubility(2), suggests that bioconcentration in aquatic organisms is low(SRC). Based on limited data, methyl orange is expected to be resistant to aerobic biodegradation in water(SRC). In an aqueous BOD screening test, this compound was not degraded over a 5 day period(6). This compound may be susceptible to biodegradation under anaerobic conditions; intestinal microflora were able to metabolize methyl orange, forming N,N-dimethyl-phenylene diamine(7).
(1) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington DC: Amer Chem Soc pp. 4-9, 5-4, 5-10, 15-1 to 15-29 (1990)
(2) Dehn WM; J Am Chem Soc 39: 1399-404 (1917)
(3) Baughman GL, Perenich TA; Amer Dyestuff Reporter p. 19-22. February (1988)
(4) Evans, LJ; Environ Sci Technol 23: 1046-56 (1989)
(5) Franke C et al; Chemosphere 29: 1501-14 (1994)
(6) Heukelekian H, Rand MC; J Water Pollut Contr Assoc 27: 1040-53 (1955)
(7) Chung KT et al; Crit Rev Microbiol 18: 175-90 (1992)
ATMOSPHERIC FATE: The ionic state of methyl orange makes this compound essentially non-volatile(1,SRC); therefore, this compound should exist in the particulate phase in the ambient atmosphere. Particulate-phase methyl orange may be physically removed from the air, mainly by wet deposition(SRC).
(1) Baughman GL, Perenich TA; Amer Dyestuff Reporter p. 19-22. February (1988)

11.2.4 Environmental Biodegradation

Methyl orange was not biodegraded in a standard 5 day BOD test using a sewage inoculum(1). Intestinal microflora were able to metabolize methyl orange under anaerobic conditions, forming N,N-dimethyl-phenylene diamine(2).
(1) Heukelekian H, Rand MC; J Water Pollut Contr Assoc 27: 1040-53 (1955)
(2) Chung KT et al; Crit Rev Microbiol 18: 175-90 (1992)

11.2.5 Environmental Bioconcentration

An estimated BCF value of 30 was calculated for methyl orange(SRC), using a measured water solubility(1) and a recommended regression-derived equation(2). According to a classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms is low(SRC).
(1) Dehn WM; J Am Chem Soc 39: 1399-404 (1917)
(2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington DC: Amer Chem Soc pp. 5-4, 5-10 (1990)
(3) Franke C et al; Chemosphere 29: 1501-14 (1994)

11.2.6 Soil Adsorption / Mobility

The Koc of methyl orange is estimated as approximately 240(SRC), using a measured water solubility of 200 mg/l(1) and a regression-derived equation(2,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that methyl orange has moderate mobility in soil(SRC). Due to the ionic nature of the dye, the retention of methyl orange by ion-exchange processes(4,SRC), particularly on clay surfaces and adsorption at mineral surfaces such as geothite(5,SRC), may slow down or prevent leaching(SRC).
(1) Dehn WM; J Am Chem Soc 39: 1399-404 (1917)
(2) Lyman WJ et al; Handbook of Chemical Property Estimation Methods. Washington DC: Amer Chem Soc pp. 4-9 (1990)
(3) Swann RL et al; Res Rev 85: 23 (1983)
(4) Baughman GL, Perenich TA; Amer Dyestuff Reporter p. 19-22. February (1988)
(5) Evans, LJ; Environ Sci Technol 23: 1046-56 (1989)

11.2.7 Volatilization from Water / Soil

Since methyl orange is an ionic compound, volatilization from water and moist soil surfaces will not be important(1,SRC).
(1) Baughman GL, Perenich TA; Amer Dyestuff Reporter p. 19-22. February (1988)

11.2.8 Probable Routes of Human Exposure

NIOSH (NOES Survey 1981-1983) has statistically estimated that 23,943 workers (3,278 of these are female) are potentially exposed to methyl orange in the US(1). Occupational exposure may be through inhalation of dusts and dermal contact with this compound at workplaces where methyl orange is produced or used(SRC). The general population may be exposed to methyl orange via dermal contact with products containing this compound(SRC).
(1) NIOSH; National Occupational Exposure Survey (NOES) (1983)

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 DSSTox Classification

15.7 Consumer Product Information Database Classification

15.8 EPA TSCA and CDR Classification

15.9 EPA Substance Registry Services Tree

15.10 MolGenie Organic Chemistry Ontology

16 Information Sources

  1. Australian Industrial Chemicals Introduction Scheme (AICIS)
    Benzenesulfonic acid, 4-[[4-(dimethylamino)phenyl]azo]-, sodium salt
    https://services.industrialchemicals.gov.au/search-inventory/
  2. 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
    4-DIMETHYLAMINOAZOBENZENE-4-SULFONIC ACID, SODIUM SALT
    https://cameochemicals.noaa.gov/chemical/20226
    CAMEO Chemical Reactivity Classification
    https://cameochemicals.noaa.gov/browse/react
  3. ChemIDplus
    ChemIDplus Chemical Information Classification
    https://pubchem.ncbi.nlm.nih.gov/source/ChemIDplus
  4. EPA Chemicals under the TSCA
    Benzenesulfonic acid, 4-[2-[4-(dimethylamino)phenyl]diazenyl]-, sodium salt (1:1)
    https://www.epa.gov/chemicals-under-tsca
    EPA TSCA Classification
    https://www.epa.gov/tsca-inventory
  5. EPA DSSTox
    CompTox Chemicals Dashboard Chemical Lists
    https://comptox.epa.gov/dashboard/chemical-lists/
  6. 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
    Sodium 4-(4-dimethylaminophenylazo)benzenesulphonate
    https://echa.europa.eu/substance-information/-/substanceinfo/100.008.115
    Sodium 4-(4-dimethylaminophenylazo)benzenesulphonate (EC: 208-925-3)
    https://echa.europa.eu/information-on-chemicals/cl-inventory-database/-/discli/details/5788
  7. 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
  8. Hazardous Substances Data Bank (HSDB)
  9. 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/
  10. 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
  11. 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/
  12. DailyMed
  13. IUPAC Digitized pKa Dataset
  14. Japan Chemical Substance Dictionary (Nikkaji)
  15. 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/
    Methyl orange
    NORMAN Suspect List Exchange Classification
    https://www.norman-network.com/nds/SLE/
  16. Springer Nature
  17. 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/
  18. Wikidata
  19. Wikipedia
  20. Wiley
  21. PubChem
  22. 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
  23. GHS Classification (UNECE)
  24. EPA Substance Registry Services
  25. MolGenie
    MolGenie Organic Chemistry Ontology
    https://github.com/MolGenie/ontology/
  26. PATENTSCOPE (WIPO)
CONTENTS