The Health and Safety at Work (Hazardous Substances) Regulations 2017 (the Regulations), require that a person have a Controlled Substance Licence (CSL) to possess certain explosives, vertebrate toxic agents and fumigants.

The requirements for CSLs are set out in Part 7 of the Regulations. The provisions for authorisations are covered by Part 5 Subpart 2 of the Health and Safety at Work Act 2015 (HSWA).

Controlled substances are particularly hazardous and pose a risk of serious injury, ill-health or death if they are not handled appropriately. The purpose of the CSL authorisation regime is to protect health and safety of workers and the public by limiting possession of controlled substances to people who have a legitimate work need for them and who can manage the risks associated with them.