This paper describes a method of assessment of toxic risks from warehouse fires. Such assessments will allow operators of enclosed stores containing toxic materials to judge the level of risk to nearby populations in the event of fire. This analysis is important both in developing mitigation strategies and in demonstrating that risks have been reduced as low as is reasonably possible. The production of risk assessments covering toxic fire fume can be required as a duty under Health & Safety at Work and COMAH regulations but there has been little available in the literature to guide the work.

This paper draws on the (often painful) experiences of operators, consultants and regulators over a period of more than 25 years to develop methods that are appropriately reliable but straightforward enough to be applied without excessive effort/expense. The method described aims for simplicity and transparency, even if the price for this is that the method uses assumptions that have to be made that introduce a level of conservatism.