COSHH stands for the Control of Substances Hazardous to Health Regulations 2002.
Using chemicals or other hazardous substances at work can put people’s health at risk, causing diseases including asthma, dermatitis or cancer. The COSHH regulations require employers to control substances that can harm workers' health.
HSE (Health & Safety Executive) have detailed information on this topic including specific sector related e.g. catering. See Link.