Occupational exposure limit values (OELs) are adopted under two legal frameworks (CAD and CMRD) that form an integral part of the EU’s mechanism for protecting the health of workers. In addition, there is a specific directive on asbestos that includes an OEL for this substance. The frameworks set out minimum standards for worker protection.

As for any European directive, Member States must transpose the requirements of the directives into a national legislative framework, as well as the OELs, within the timeline set in the respective directive. 

Chemical Agents Directive (CAD)

The Chemical Agents Directive (Directive 98/24/EC) sets out the minimum requirements for protecting workers from risks to their safety and health - arising or likely to arise - from the effects of chemical agents in the workplace or the use of chemical agents at work. It lays down indicative and binding OELs, as well as biological limit values.

A chemical agent is defined as any chemical substance, on its own or in a mixture that occurs in its natural state or is produced, used or released (including release as waste) by any work activity. This applies whether the substance is produced intentionally or is to be placed on the market. The CAD therefore also covers the evaluation of emissions and process wastes.

Carcinogens, Mutagens or Reprotoxic substances Directive (CMRD)

The Carcinogens, Mutagens or Reprotoxic substances Directive (Directive 2004/37/EC, CMRD from 9 March 2022) sets out the minimum requirements for protecting workers against risks to their health and safety - arising or likely to arise - from exposure to carcinogens, mutagens or reprotoxic substances at work. It lays down preventive and protective measures, as well as exposure limits.

CMRD applies to a substance or mixture that meets the criteria for classification as a Category 1A or 1B carcinogen, Category 1A or 1B germ cell mutagen or Category 1A or 1B reproductive toxicant set out in Annex I to the CLP Regulation. In addition, it applies to carcinogenic substances, mixtures or processes referred to in Annex I to the CMRD, as well as substances or mixtures released by a process in that annex.

The fourth amendment of the Carcinogens or Mutagens Directive (CMD) Directive (EU) 2004/37/EC added reprotoxic substances to the scope of the directive.