An outline is given of basic concepts of toxicology and it is tried to put hazard evaluation into perspective for a better understanding of the potential health hazards of chemicals in the laboratory/ workshop. A basic knowledge of chemistry is given as well as general precautions concerning chemicals. Regular health monitoring is advised and a few tests are made useful in diagnosing diseases and other hazards present in the working environment. The last section refers to sixty of the hazardous chemicals currently used in paper conservation activities listed as chemical safety data sheets.