Agent Name


Alternative Name


CAS Number




Major Category

Nitrogen Compounds


Nitro-o-toluidine; AI3-01557; Amarthol Fast Scarlet G Base; Amarthol Fast Scarlet G Salt; 2-Amino-4-nitrotoluene; Azoene Fast Scarlet GC Base; Azoene Fast Scarlet GC Salt; Azofix Scarlet G Salt; Azogene Fast Scarlet G; Benzenamine, 2-methyl-5-nitro-; CI Azoic Diazo Component 12; CI 37105; Dainichi Fast Scarlet G Base; Daito Scarlet Base G; Devol Scarlet B; Devol Scarlet G Salt; Diabase Scarlet G; Diazo Fast Scarlet G; Fast Red SG Base; Fast Scarlet G; Fast Scarlet G Base; Fast Scarlet Base J; Fast Scarlet T Base; Fast Scarlet M4NT Base; Fast Scarlet GC Base; Fast Scarlet G Salt; Fast Scarlet J Salt; Hiltonil Fast Scarlet G Base; Hiltonil Fast Scarlet GC Base; Hiltonil Fast Scarlet G Salt; Kayaku Scarlet G Base; Lake Scarlet G Base; Lithosol Orange R Base; 2-Methyl-5-nitroaniline; 6-Methyl-3-nitroaniline; 2-Methyl-5-nitro-benzenamine; Mitsui Scarlet G Base; Naphthanil Scarlet G Base; Naphtoelan Fast Scarlet G Base; Naphtoelan Fast Scarlet G Salt; 4-Nitro-2-aminotoluene; 3-Nitro-6-methylaniline; PNOT; Scarlet G Base; Scarlet Base Ciba II; Scarlet Base IRGA II; Scarlet Base NSP Sugai Fast Scarlet G Base; Symulon Scarlet G Base; o-Toluidine, 5-nitro-; Nitro-o-toluidine; [HSDB] 4-Nitro-2-aminotoluene; [Guide to Occupational Exposure Values, 2002] UN2660




Yellow crystals; [ACGIH]


Workers are exposed during production or handling of more than 35 commercial dyes (orange or red) of which 5-nitro-o-toluidine is the major component; [ACGIH]


Several Japanese workers were admitted to the hospital with severe liver damage after handling repeatedly (12-20 times) 5-nitro-o-toluidine for 4-5 hours at a time. Workers had scooped the powder by hand while wearing respirators. [Gut 2002 Feb;50(2):266-70] Methemoglobinemia is a potential adverse effect after exposure to this agent. [HSDB]

Reference Link

Liver dysfunction among workers handling 5-nitro-o-toluidine

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data


1 mg/m3, inhalable fraction

Vapor Pressure

0.000975 mm Hg

Explanatory Notes

See "2018 Notice of Intended Changes." [TLVs and BEIs]

Adverse Effects

Hepatotoxin, Primary


Methemoglobinemia, Secondary

IARC Carcinogen

Not Classifiable

ACGIH Carcinogen

Confirmed Animal

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information


Chemical Information

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Biomedical References

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Related Information in HazMap

Occupational diseases associated with exposure to this agent: