Using science to respond to public exposures from chemical hazards during emergencies in England.

This paper describes how toxicological considerations are an essential component of acute chemical incident response, and how the UK Health Security Agency (UKHSA), as Category 1 responders under the Civil Contingencies Act (2004), provide that expert, authoritative, and timely advice to protect people from exposure to harmful substances. Background information about the general response to emergencies is provided, which gives context to how scientific advice has a positive impact. The importance of chemical identification and speciation, local, and systemic effects, and exposure characteristics are described. The public health risk assessment is considered in conjunction with mixtures, mass casualties, recovery, and psychological impacts. A brief summary of the type of incidents that the UKHSA are notified about is also provided.