Clandestine drug laboratories are a contravention of Canada's Narcotic Control Act and Food and Drug Act. Additionally, legislation is being drafted to make it illegal to possess certain precursors when producing illicit drugs. The easy availability of precursor chemicals, low production costs, ease of manufacture, and high profits from drug sales have led to more clandestine drug laboratories operating in Canada than ever before. Law enforcement officers are at increased risk for personal injury during raids on clandestine drug laboratories due to the fact that laboratory operators do not follow legislated environmental and occupational safety and health guidelines for manufacturing, storing, and disposing of chemicals and drugs. Health effects of chemicals and drugs are described for solvents, irritants and corrosives, and metals and salts, as well as appropriate first aid procedures. Ways of identifying precursor traffickers are outlined, and the importance of education about precursor diversion is emphasized. Further, the need for adequate law enforcement safety training and personal protective clothing is noted. 1 table and 6 photographs