This code is published in response to a resolution concerning the working environment adopted by the International Labour Conference at its 59th Session (June 1974). With the Code of Practice on the Protection of Workers against Noise and Vibration in the Working Environment, it supplements the Working Environment (Air Pollution, Noise and Vibration) Convention (No.148) and Recommendation (No.156), adopted by the Conference at its 63rd Session (June 1977). It was approved by an ILO/WHO Meeting of Experts on Limits of Exposure (Geneva, Nov. 1977). Contents: role of bodies and persons concerned with the prevention of contamination of the working environment (competent authority, employers' and workers' organisations, occupational health officers, manufacturers and vendors, scientific research, co-operation between all concerned); principles of the prevention of contamination of the working environment; exposure limits (establishment and application of TLVs, measurement and control of harmful airborne substances); medical surveillance and examinations (biological monitoring, biological limits). Glossary. Subject index.