A scheme has been developed to rank 70 industrial organic chemicals in order of their priority for further study as potential contaminants of food. Numerical scales were developed for the following seven key criteria concerning environmental issues, food and toxicity: -Production volume -Pattern of usage -Possible fate in the environment -Likelihood of chemical entering the food chain -Mechanism of entry into the food chain -Persistence and accumulation in the food chain -Toxicity. Each chemical was assigned a score for the above criteria, which were combined to give an overall ranking for the chemicals.This scheme has been endorsed by the MAFF Steering Group on Chemical Aspects of Food Surveillance. It will be used in the assessment of relative priorities for further non-statutory surveillance for these contaminants in the UK food supply.