The aim of this paper is two-fold. A review of mass casualty chemical incidents occurring naturally or as a result of industrial activities or deliberate release provided an opportunity to consider the problems experienced in medical and public health response. In addition, a literature review of procedures to assist in the management of chemical incidents by medical and public health professionals was conducted, targeted at summarising what tools exist to minimise the impact on public health from such events. We found that most of the large chemical incidents worldwide were unprecedented and unexpected, and as a consequence emergency services, hospitals and public health had access to very little relevant information in the first few hours. Several lessons were highlighted that would aid future response. The review of procedures showed that there are currently no written procedures that are both sufficiently generic and sufficiently detailed to effectively support the public health management of the emergency response to chemical incidents. There is therefore a need to fill this obvious gap and to develop a procedural guide for the emergency management of chemical incidents by public health professionals. This work is now under way.