Internationally, the Approved Codes of Practice (ACOPs) supporting the Control of Substances Hazardous to Health Regulations (COSHH), the Control of Asbestos at Work Regulations (CAW) and the Control of Lead at Work Regulations (CLAW) require that wearers of tight fitting respirators are fit tested. Fit testing is a means of checking that a respirator facepiece matches a person’s facial features and seals adequately to their face.