© 2026 Nanjing Finechem Holdings Co., Ltd,
All Right Reserved
Chemical Name: o-Toluidine
Synonyms: 2-Aminotoluene, orthotoluidine
Chemical Formula: C7H9N
Appearance: Pale yellow to brownish oily liquid
Odor: Aromatic, reminiscent of aniline
CAS Number: 95-53-4
Main Uses: Dye production, chemical intermediate in the synthesis of rubber chemicals, pesticides, pharmaceuticals
Health Hazards: Recognized as a probable human carcinogen, linked to bladder cancer
Routes of Exposure: Absorbed through skin, inhaled as vapor or dust, ingested
Main Symptoms: Skin and eye irritation, headaches, dizziness, methemoglobinemia (blood disorder causing reduced oxygen transport)
Chronic Effects: Repeated contact increases cancer risk, can damage blood cells and liver
Classification: Acute toxicity, suspected carcinogen according to IARC, OSHA, and NTP
Main Component: o-Toluidine (typically over 98 percent by weight in industrial settings)
Impurities: Trace amounts of aniline or isomers (like p-toluidine) from synthesis routes
Formulation: Often supplied undiluted but can be found in blends for research or production
Inhalation: Everyone in a lab who breathes in fumes should step into fresh air right away; seek medical attention if breathing feels difficult or if coughing persists.
Skin Contact: Wash off any splashes from skin quickly under running water for fifteen minutes; contaminated clothes must be removed; repeated contact makes risk worse.
Eye Contact: Rinse eyes with low-pressure water for at least twenty minutes; eyelids kept open; get checked by a medical professional.
Ingestion: Rinse mouth thoroughly, seek immediate medical evaluation — never induce vomiting; potential for serious toxicity is high.
Suitable Extinguishing Media: Alcohol-resistant foam, dry chemical, or carbon dioxide; avoid water jets as they may spread contamination.
Fire Hazards: Combustible at higher temperatures; releases toxic vapors including nitrogen oxides and carbon oxides when burned.
Protective Equipment: Firefighters need full self-contained breathing apparatus and protective gear; smoke can linger and endanger lungs.
Special Notes: Nearby chemicals may react; keeping drums away from heat sources and storing in proper conditions lowers ignition risk.
Personal Precautions: Chemical-resistant gloves, goggles, and respirator needed for cleanup; splashes on exposed skin spell trouble, and those handling it equate to carrying invisible risk.
Environmental Precautions: Prevent spilled liquid from reaching drains, soil, or bodies of water as it can harm aquatic life and seep into groundwater.
Cleanup Techniques: Use absorbent materials such as sand or vermiculite; place in clearly labeled drums for disposal; never sweep dust or powder carelessly, as fine particles will spread and linger.
Safe Handling: Good ventilation is more than a suggestion — fumes build up even in what seem like large spaces; working on open benches multiplies the risk, so fume hoods and closed systems matter.
Storage Conditions: Store containers in a cool, dry, and well-ventilated area; keep away from sunlight and sources of ignition; avoid contact with strong oxidizers or acids.
Container Tips: Label storage drums clearly and check seals regularly, as leaks draw in moisture and expose workers to invisible cause for health problems.
Exposure Limits: OSHA and ACGIH list permissible exposure limits (PEL) and threshold limit values (TLV); for o-toluidine, the recommendation keeps it as low as possible, often at 2 ppm.
Engineering Controls: Local exhaust ventilation, sealed systems, and emergency wash stations are not just best practice but practical protections.
Personal Protective Equipment: Nitrile or butyl rubber gloves, chemical safety goggles, splash-resistant lab coats; in high-exposure areas, full respirators and face shields step in.
Boiling Point: Around 200°C, which means hot environments drive up vapor risk
Melting Point: Less than 0°C; stays liquid in most rooms
Vapor Pressure: Low at room temperature, but enough to worry about with repeated contact
Solubility: Slightly mixes with water, more with alcohols and ethers
Density: Heavier than water, so spills pool at the bottom in tanks or spills
Color and Odor: Telltale yellow to brown, with sharp, chemical scent
Chemical Stability: Holds steady under normal storage; problems start with heat, light, or long storage
Reactivity Risks: Strong oxidizers — like bleach or nitric acid — rapidly break it down, sometimes with fire or toxic byproducts
Hazardous Decomposition: Nitrogen oxides, aniline, and carbon monoxide are real concerns on degradation; these gases escape unnoticed in accidents
Acute Toxicity: Can enter the bloodstream through skin or lungs; blood disorders appear with even moderate, repeated exposure
Chronic Exposure: Linked to serious conditions including bladder cancer, as shown in decades of workplace studies; cough, headache, blue-tinged skin (cyanosis), and fatigue signal trouble
Sensitization: Some workers end up with allergic reactions in the skin or airways
Mutagenicity: Genetic changes in cells reported; both animal and human studies point to DNA damage at sustained doses
Aquatic Toxicity: Toxic to fish and aquatic invertebrates even at low concentrations; contamination can mean dead fish or algae bloom disruption.
Persistence: Lingers in soil and water for long periods, breaking down only slowly; uptake by plants is possible
Bioaccumulation: Builds up in organisms, such as fish, making cleanup all the more urgent after spills
Waste Disposal: Treated as hazardous waste; incineration in approved facilities is the best route
Container Handling: Plastic or metal drums that held o-toluidine must be triple-rinsed and labeled before final disposal; never dump leftovers down a drain or toilet
Regulations: Waste codes for hazardous chemicals apply; careful record-keeping is key during audits
Shipping Classification: Regulated as a hazardous chemical for land, sea, and air transport
Labeling: Markings for toxicity, environmental impact, and flammability are mandatory during shipping
Packaging: Leak-proof drums, sealed bags, and secondary containment required to prevent accidental exposure
Special Precautions: Notify receiving facilities before shipment arrives; loaded separately from food or other consumer goods to prevent cross-contamination
US Regulation: Listed under the Clean Air Act for hazardous air pollutants; OSHA and EPA classify o-toluidine as carcinogenic
EU Regulation: Classified under REACH; strong restrictions on workplace exposure and environmental release
Industry Requirements: Exposure tracking, routine health surveillance for workers, medical checkups, and strict record management are non-negotiable in plants and research labs
Labelling Standards: Clear hazard pictograms, risk phrases, and handling instructions set by GHS (Globally Harmonized System)
