On 3 August 2026, the European Chemicals Agency (ECHA) published a scientific assessment report on the occupational exposure limit (OEL) for toluene (CAS 108-88-3), recommending a substantial reduction of the current 8-hour time-weighted average (TWA) from 50 ppm (192 mg/m³) to 20 ppm (77 mg/m³), alongside the introduction of a 15-minute short-term exposure limit (STEL) set at 100 ppm (383 mg/m³).
Background
Toluene (EC No. 203-625-9) is a highly volatile aromatic hydrocarbon, classified under the CLP Regulation as Reproductive Toxicity Category 2 (H361d), Specific Target Organ Toxicity – single exposure (H336) and repeated exposure (H373), and Skin Irritant (H315). It is metabolized primarily via hepatic oxidation to hippuric acid, which is excreted in urine; occupational biological monitoring typically uses urinary toluene or blood toluene as exposure indicators.
As a high-production-volume chemical with annual EU production in the millions-to-tens-of-millions-of-tonnes range, toluene is widely used in coatings, inks, adhesives, gasoline additives, and chemical intermediates. The proposed limit reduction will directly impact occupational hygiene monitoring and engineering control strategies in solvent-intensive industries such as gravure printing, rubber processing, and surface coating.
Summary of Key Recommendations
|
Limit Type |
Current EU Indicative Limit |
ECHA New Proposal |
|
8-hour TWA |
50 ppm (192 mg/m³) |
20 ppm (77 mg/m³) |
|
15-minute STEL |
— |
100 ppm (383 mg/m³) |
|
Biological Limit Value (BLV) |
No harmonised EU limit |
Urinary toluene: 30 µg/L |
|
Occupational Hygiene Notation |
Skin notation |
Skin notation + Noise notation |
The report has now entered a two-month public consultation period, with comments accepted until 3 October 2026. ECHA's Committee for Risk Assessment (RAC) will formulate its final scientific opinion based on the feedback received.
