On 17 January 2020 HSE published a revised version of EH40/2005 ‘Workplace exposure limits’.

This has been updated in order to implement amendments to the Carcinogens and Mutagens Directive (2004/37/EC) which introduces or revises 13 binding occupational exposure limit values for a number of carcinogenic substances.

Occupational exposure limits are implemented in the UK via the Control of Substances Hazardous to Health (COSHH) Regulations as Workplace Exposure Limits (WELs) via Table 1 of EH40/2005 ‘Workplace exposure limits’ for use with COSHH.

COSHH requires exposure to carcinogenic substances to be reduced to ‘as low as is reasonably practicable’.

IMPORTANT NOTE: The WELs listed in Table 1 of EH40/2005 ‘Workplace Exposure Limits’ supersede any limits contained in other HSE guidance or publications.

For practical advice and guidance on the Control of Substances Hazardous to Health (COSHH), visit the HSE website You can find information on what the law requires, and advice on completing COSHH assessments.


Contains public sector information licensed under the Open Government Licence v3.0.