Hazard Overview
Health Hazards: It is irritating to the skin and mucous membranes and has an anesthetic effect on the central nervous system.
Acute Poisoning: Inhalation of a high concentration of this product in a short period can cause obvious irritation symptoms of the eyes and upper respiratory tract, conjunctival and pharyngeal congestion, dizziness, headache, nausea, vomiting, chest tightness, limb weakness, staggering gait, and confusion. Severe cases may experience agitation, convulsions, and coma.
Chronic Poisoning: Long-term exposure can lead to neurasthenic syndrome, liver enlargement, and menstrual abnormalities in female workers. It can also cause dry skin, cracking, and dermatitis.
Environmental Hazards: It poses a serious hazard to the environment and can contaminate the air, water environment, and water sources.
Flammability and Explosion Hazard: This product is flammable and irritating.
Toxicity: It is classified as low-toxicity.
Acute Toxicity: LD50 5000mg/kg (oral in rats); LC50 12124mg/kg (dermal in rabbits); human inhalation of 71.4 g/m³ is lethal in a short time; human inhalation of 3 g/m³ for 1–8 hours causes acute poisoning; human inhalation of 0.2–0.3 g/m³ for 8 hours leads to poisoning symptoms.
Irritation:
Human eye exposure: 300ppm causes irritation.
Rabbit dermal exposure: 500mg causes moderate irritation.
Subacute and Chronic Toxicity: Rats and guinea pigs exposed to inhalation of 390 mg/m³ for 8 hours/day over 90–127 days showed changes in the hematopoietic system and parenchymal organs.
Mutagenicity: Micronucleus test: oral administration of 200 mg/kg in mice. Cytogenetic analysis: rats exposed to inhalation of 5400 μg/m³ for 16 weeks (intermittent).
Reproductive Toxicity: Rats exposed to the lowest toxic concentration (TCL0) of 1.5 g/m³ for 24 hours (days 1–18 of pregnancy) showed embryotoxicity and muscle development abnormalities. Mice exposed to the lowest toxic concentration (TCL0) of 500 mg/m³ for 24 hours (days 6–13 of pregnancy) showed embryotoxicity.
Metabolism and Degradation: Toluene absorbed in the body is 80% oxidized to benzyl alcohol in the presence of NADP, then to benzaldehyde in the presence of NAD, and further oxidized to benzoic acid. It then combines with glycine in the presence of coenzyme A and adenosine triphosphate to form hippuric acid. Therefore, 16%–20% of the toluene absorbed by the human body is exhaled unchanged through the respiratory tract, while 80% is excreted by the kidneys in the form of hippuric acid. After exposure to toluene, hippuric acid in urine increases rapidly within 2 hours, then rises more slowly and returns to normal levels 16–24 hours after exposure ends. A small portion of benzoic acid combines with glucuronic acid to form non-toxic substances. Less than 1% of toluene is metabolized to o-cresol. In the environment, toluene oxidizes to benzoic acid or decomposes directly into carbon dioxide and water under strong oxidizing conditions or in the presence of catalysts when exposed to air.
Residue and Accumulation: About 80% of toluene is excreted in the urine of humans and rabbits as hippuric acid, while most of the remainder is exhaled. These authors also reported that 0.4%–1.1% of toluene is excreted as o-cresol. Another study showed that the main metabolite, hippuric acid, is rapidly excreted in urine. Under typical occupational exposure conditions, hippuric acid is almost entirely eliminated within 24 hours after exposure ends. However, due to repeated 8-hour daily exposure followed by 16-hour non-exposure intervals, some accumulation of hippuric acid may occur during the workweek, but concentrations return to pre-exposure levels after the weekend. The amount of hippuric acid in normal urine varies significantly (0.3–2.5 g) depending on dietary intake and individual differences. Therefore, toluene absorption cannot be fully inferred from urinary hippuric acid levels, but it has some accuracy in group surveys for detecting toluene absorption. Rats pretreated with phenobarbital showed an increased rate of toluene disappearance from the blood and shortened sleep time after toluene injection, indicating that induction of liver microsomal enzymes may stimulate toluene metabolism.
Migration and Transformation: Toluene is mainly produced from crude oil through petrochemical processes. It is used as a solvent for oils, resins, natural and synthetic rubber, coal tar, asphalt, and cellulose acetate. It is also used as a solvent in cellulose paints and varnishes, as well as in photolithography and ink solvents. Toluene is also an important raw material in organic synthesis, particularly for benzoyl chloride, phenyl compounds, saccharin, trinitrotoluene, and many dyes. It is also a component of aviation and automotive gasoline. Toluene is volatile and relatively unreactive in the environment. Due to air movement, it is widely distributed in the environment and continuously recycles between air and water through rain and evaporation from water surfaces. It may eventually degrade through biological and microbial oxidation. A summary of average toluene concentrations in urban air worldwide shows typical levels of 112.5–150 μg/m³, primarily from gasoline-related emissions (vehicle exhaust, gasoline processing) and solvent losses and emissions from industrial activities.
First Aid Measures
Skin Contact: Remove contaminated clothing and rinse skin thoroughly with soap and water.
Eye Contact: Lift eyelids and rinse with flowing water or saline solution. Seek medical attention.
Inhalation: Move quickly to fresh air. Maintain an open airway. Administer oxygen if breathing is difficult. Perform artificial respiration if breathing stops. Seek medical attention.
Ingestion: Drink plenty of warm water to induce vomiting. Seek medical attention.
Firefighting Measures
Hazardous Characteristics: Flammable; vapor mixed with air can form explosive mixtures. Exposure to open flames or high heat may cause combustion or explosion. It reacts strongly with oxidants. High flow rates can generate and accumulate static electricity. Vapor is heavier than air and can spread over long distances to lower areas, where it may ignite and flash back.
Hazardous Combustion Products: Carbon monoxide, carbon dioxide.
Firefighting Methods: Cool containers with water spray. Move containers from the fire area to an open area if possible. If containers in the fire zone have changed color or produce sound from pressure relief devices, evacuate immediately.
Fire Extinguishing Agents: Foam, dry powder, carbon dioxide, sand. Water is ineffective for extinguishing.
Leak Emergency Response
Emergency Response: Evacuate personnel from the leak area to a safe zone, isolate, and strictly control access. Eliminate ignition sources. Emergency responders should wear self-contained positive-pressure breathing apparatus and protective clothing. Minimize the leak source. Prevent entry into sewers, drainage ditches, or other confined spaces.
Small Leak: Absorb with activated carbon or other inert materials. Alternatively, wash with an emulsion made from a non-flammable dispersant, dilute the wash liquid, and discharge into the wastewater system.
Large Leak: Construct dikes or pits to contain the spill. Cover with foam to reduce vapor hazards. Use explosion-proof pumps to transfer to tankers or specialized collection containers for recovery or disposal at waste treatment facilities.
Post time: Feb-24-2026