IUPAC Name: 2-Methyl-5-nitroaniline
Synonyms of 5-Nitro-o-toluidine (CAS NO.99-55-8): 1-Amino-2-methyl-5-nitrobenzene ; 2-Amino-4-nitrotoluene ; 2-Methyl-5-nitro-benzeneamine ; 2-Methyl-5-nitroaniline ; 2-Methyl-5-nitrobenzenamine ; 5-Nitro-2-methylaniline ; Amarthol Fast Scarlet G Base ; Benzenamine, 2-methyl-5-nitro-
CAS NO: 99-55-8
Molecular Formula: C₇H₈N₂O₂
Molecular Weight: 152.15
Molecular Structure:
EINECS: 202-765-8
H bond acceptors: 4
H bond donors: 2
Freely Rotating Bonds: 2
Polar Surface Area: 49.06 Å²
Index of Refraction: 1.615
Molar Refractivity: 41.85 cm³
Molar Volume: 119.8 cm³
Surface Tension: 54.9 dyne/cm
Density: 1.269 g/cm³
Flash Point: 153 °C
Enthalpy of Vaporization: 57.19 kJ/mol
Boiling Point: 329.4 °C at 760 mmHg
Vapour Pressure: 0.000178 mmHg at 25°C
Melting Point: 104-107°C
Water Solubility: <0.1 g/100 mL at 19 ºC
Appearance: Bright yellow powder.
Stability: Stable. Incompatible with strong oxidizing agents, acid chlorides, acid anhydrides, acids, chloroformates.
Product Categories of 5-Nitro-o-toluidine (CAS NO.99-55-8): Dyes and Pigments;Anilines, Aromatic Amines and Nitro Compounds

 5-Nitro-o-toluidine (CAS NO.99-55-8) is used in organic synthesis.

IARC Cancer Review: Group 3 IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 48 ,1990,p. 169.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Limited Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 48 ,1990,p. 169.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) . NCI Carcinogenesis Bioassay (feed); Clear Evidence: mouse NCITR*    National Cancer Institute Carcinogenesis Technical Report Series. (Bethesda, MD 20014) No. NCI-CG-TR-107 ,1978. . Reported in EPA TSCA Inventory.

Hazard Codes: T,Xi
Risk Statements: 23/24/25-40-52/53
R23/24/25: Toxic by inhalation, in contact with skin and if swallowed. 
R40: Limited evidence of a carcinogenic effect. 
R52/53: Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment.
Safety Statements: 36/37-45-61
S36/37: Wear suitable protective clothing and gloves. 
S45: In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S61: A void release to the environment. Refer to special instructions / safety data sheets.
RIDADR: UN 2660 6.1/PG 3
WGK Germany: 3
RTECS: XU8225000
Hazard Note: Irritant
HazardClass: 6.1
PackingGroup: III
Confirmed carcinogen with experimental carcinogenic data. Moderately toxic by ingestion. Mutation data reported. Decomposes exothermically when heated to 150°C. When heated to decomposition it emits toxic fumes of NO_x. See also NITRO COMPOUNDS of AROMATIC HYDROCARBONS.

DFG MAK: Animal Carcinogen, Suspected Human Carcinogen

General Information: As in any fire, wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear.
Extinguishing Media: In case of fire, use water, dry chemical, chemical foam, or alcohol-resistant foam. 
Handling: Do not breathe dust, vapor, mist, or gas. Do not get in eyes, on skin, or on clothing. Use only in a chemical fume hood.
Storage: Store in a cool, dry place. Store in a tightly closed container.