Toluene, also known as methylbenzene, is used as a solvent in paints, varnishes, inks, adhesives and resins. It also serves as a synthesis intermediate in the chemical industry and is a component of certain fuels.
At room temperature, it is a colourless, volatile liquid with an aromatic odour. It has low water solubility and is miscible with many organic solvents.
1Main properties
These values apply to toluene. The characteristics of commercial mixtures depend on their composition.
2What are the hazards?
Toluene is highly flammable. Its vapours can form explosive mixtures with air in the presence of an ignition source.
It causes skin irritation and may cause drowsiness or dizziness. Repeated or prolonged exposure may cause serious organ damage.
It is also classified as a Category 2 reproductive toxicant, with the hazard statement “Suspected of damaging the unborn child”.
Swallowing presents a pulmonary aspiration hazard: the substance can be fatal if it enters the respiratory tract.
3What occupational exposure limits apply?
The INRS factsheet dated July 2021 reports the following binding regulatory occupational exposure limits established in France in 2012:
| Reference period | ppm | mg/m³ |
|---|---|---|
| 8-hour average | 20 | 76.8 |
| Short-term, 15 minutes | 100 | 384 |
The skin notation indicates that skin absorption may contribute to overall exposure. The noise notation highlights the risk of hearing damage during combined exposure.
These limits do not, on their own, constitute gas detector alarm settings.
4How can risks be prevented?
Prevention relies on enclosed processes wherever possible, capturing vapours at source and providing suitable ventilation. Atmospheric exposure must be assessed regularly.
Keep away from heat sources, flames and sparks. Prevent electrostatic discharges through suitable earthing and equipotential bonding. Equipment must be suitable for the explosive atmosphere hazard.
Gloves, protective clothing, eye protection and any respiratory protective equipment must be selected according to the risk assessment and their compatibility with toluene.
Store in compatible, closed and labelled containers in a cool, ventilated area with suitable secondary containment, away from strong oxidising agents.
If swallowed, do not induce vomiting and seek immediate medical assistance.
Sources: INRS, Toxicological Factsheet No. 74, “Toluene”, July 2021 edition, in French; INRS occupational exposure limits database, “Toluene”, in French.