Toluene is a clear, colourless liquid with a distinctive sweet odour. It is an aromatic hydrocarbon that occurs naturally in crude oil and the tolu tree and is also produced during the process of making gasoline.
Chemically, toluene is a methylbenzene, the simplest member of the toluene family. It is insoluble in water, and its vapours are heavier than air.
What is Toluene used for?
Toluene has widespread industrial and consumer applications, including:
Fuel: used as an octane booster in aviation and automobile gasoline.
Solvent: in paints, nail polish, adhesives, glues, permanent markers, and leather and printing processes.
Industrial feedstock: for chemical manufacturing.
Recreational inhalant: sometimes misused due to its intoxicating effects.
Toluene is widely used as a solvent in various consumer products—including nail polish, paints, adhesives, glues, permanent markers, and in leather and printing processes.
Routes of Exposure
Air pollution: the most common route, especially from automobile emissions.
Indoor exposure: paints, nail polish, adhesives, and cleaning products are major indoor sources.
Cigarette smoke: also contributes to toluene exposure.
Exposure routes: inhalation, skin contact, ingestion, or eye contact.
Levels of toluene are typically highest indoors, followed by urban environments, and lowest in rural areas.
Health Effects
Toluene exposure can affect multiple systems in the body, particularly the nervous, respiratory, and cardiovascular systems.
Acute Effects
The central nervous system (CNS) is the primary target.
Symptoms may include: narcosis, CNS dysfunction, fatigue, sleepiness, headache, and nausea.
Inhalation: generally has low chemical toxicity but can still cause CNS effects.
Ingestion: may cause swollen liver, CNS depression, lung congestion and haemorrhage, and heart tissue damage.
Cardiac arrhythmias can occur in acute cases.
Chronic Effects
Neurological: long-term exposure can cause CNS depression, ataxia, cerebral atrophy, nystagmus, and behavioural changes.
Respiratory: prolonged exposure can cause sore throat, headaches, respiratory tract irritation, and degeneration of nasal and respiratory tissues.
Developmental: pregnant women exposed to high levels may have children with developmental delays, minor limb abnormalities, attention deficits, and CNS dysfunction.
Renal: children of mothers who abused toluene have shown temporary renal tubular acidosis.
Safety
First Aid Measures
Ingestion: Rinse mouth with water. Do not induce vomiting. Call a doctor or poison centre immediately. If vomiting occurs, place the person in the recovery position.
Skin contact: Wash skin or hair thoroughly under running water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse. Seek medical advice.
Eye contact: Flush eyes with water for at least 15 minutes, ensuring water reaches beneath the eyelids. Seek medical attention immediately.
Inhalation: Move the person to fresh air and monitor breathing. If breathing stops, administer CPR. If breathing is difficult, provide oxygen. Seek urgent medical assistance.
Exposure Controls and Personal Protection
Engineering Controls
Use with local exhaust ventilation or in a laboratory environment whenever possible.
Ensure safety showers and emergency eyewash stations are nearby.
Maintain adequate general ventilation.
Personal Protective Equipment
Safety glasses with side shields
Solvent-resistant protective gloves
Solvent-resistant apron or protective clothing
Regulation
United States
The Occupational Safety and Health Administration (OSHA) has set an 8-hour time-weighted average (TWA) concentration for toluene of 200ppm, with an acceptable ceiling concentration of 300ppm.
Australia
Safe Work Australia: Safe Work Australia has set an 8-hour TWA concentration for toluene of 50ppm, and a short-term exposure limit—usually 15 minutes—of 150ppm.
As scientists who evolve with technology we treat innovation as a way of life, a life we dedicate to improvement and advancement of Safety, Health and Environment.
