This note presents the results of a review of chlorine incidents reported to HSE over the period 1992-1998. It also provides details of the main sources of guidance on the storage, handling and use of chlorine. Chlorine and chlorine-based derivatives are reactive materials which are used in the chemical manufacture of a wide range of products such as paper, textiles, dyes, medicines, solvents, paints and plastics. Their oxidizing, bleaching and disinfectant properties are utilised in water treatment plants, swimming pools, food processing and in cleaning agents.