Every year exposure to hazardous substances at work effects the health of many thousands of people. Common examples include lung disease (e.g. dusty conditions), skin irritation, dermatitis or skin cancer (e.g. frequent contact with oils, contact with corrosive liquids), occupational asthma (e.g. sensitisation to isocyanates in paints or adhesives), toxic fumes, occupational cancer etc. The high costs of ill-health arise from loss of earnings, loss of productivity, prosecution and civil action amongst others.