This thesis probes a neglected area lying at the interface between medical and labour history and is concerned with issues of occupational health and safety in the British chemical industry between the First World War and the passage of the Health and Safety at Work Act of 1974. The research is presented thematically and draws on a wide variety of primary and secondary source material to reveal the causes of ill health, the politics of reform and the role of the key players, such as the government, medical profession, employers and trade unions.