Chemicals with Workplace Exposure Limits

Many chemicals have Workplace Exposure Limits (WELs), also sometimes referred to as Occupational Exposure Limits (OELs) in the UK.  These can be exposure limits for the concentrations and exposure time for inhalation, or dermal contact.  Biological limit values, e.g. quantity of a substance in the bloodstream, may also be given.

There are two types of WEL, EU WELs, and national WELs.  In theory, the EU WELs are the same in every country of the EU, but different countries in the EU may have different national WELs, and not every substance has an WEL in every EU country.  Sometimes a national WEL is more severe than an EU WEL.

Chemicals which hold WELs are not required to be identified as such on the label, nor are substance components in a mixture which hold WELs required to be identified under “contains”, unless the substance also has a relevant health hazard.  However, substances with EU WELs, or mixtures with component substances which have EU WELS are required to have  a Safety Data Sheet (SDS) available on request by a downstream user (or distributor or warehouser) where a substance with a European OEL is present at any level.  This requirement applies to substances or mixtures containing European WELs, regardless of whether they are classified for CLP or not, unless they are consumer products, in which case an SDS is not required.

In the SDS, Section 8.1 Control Parameters should contain national and EU occupational limit values for the substance or component substances in a mixture which apply to the Member State where the SDS is being provided.

This information can be downloaded from the GESTIS database , which includes EU OELs and national OELs for all EU countries, and also information from non-EU countries.

UK WELs (both EU and National) are contained in the HSE guide EH40/2005, Workplace Exposure Limits (2011 edition with updates), which can be downloaded for free as a pdf from .

Important note – lead metal, lead compounds, and products containing these will be affected by the WEL for lead. However, this is not listed in EH40, but instead sits in the Control of Lead at Work Regulations Approved Code of Practice, 2002, which can be downloaded from free as a pdf from .


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