Key definitions
Chemical incident
An uncontrolled release of a chemical from its containment that either threatens to, or does, expose people to a chemical hazard (IPCS 1999, Public Health and Chemical Incidents: Guidance for National and Regional Policy Makers in the Public/Environmental Health Roles). Such an incident could occur accidentally, for example a chemical spill or deliberately, for example the use of sarin on a public transport system. In both cases the release of the chemical or chemicals is usually obvious.
Acute Public Health Chemical Incident
A public health chemical incident where the exposure dose is rising or is likely to rise rapidly and where rapid public health measures may limit the exposure.
Chemical Emergency
A chemical incident that has passed the control capability of one emergency service.