Develop, update and harmonize Occupational Exposure Limits (OELs)

Governments should develop, update and harmonize evidence-based Occupational Exposure Limits (OELs) for key hazardous chemicals in their regions. OELs are regulatory values which indicate levels of airborne exposure that are considered safe for a chemical substance in a workplace. Unfortunately, OELs do not exist for many chemicals and those that do exist are often outdated. There is also a lack of harmonized data between different countries and safety bodies.

For airborne exposures, there are three types of limits in common use:

• The time-weighted average (TWA) exposure limit - the maximum average concentration of a chemical in air for a normal 8-hour working day and 40-hour week.
• The short-term exposure limit (STEL) - the maximum average concentration to which workers can be exposed for a short period (usually 15 minutes).
• The ceiling value - the concentration that should not be exceeded at any time.

In addition, biological exposure indices (BEIs) represent the concentration of chemicals in the body that would correspond to inhalation exposure at a specific concentration in air.

Suggested actions include:

• Create a priority system for OELs in your region, focusing on those that do not exist or need to be updated
• Ensure that OELs are easily understandable and accessible