Fire crews were put through their paces at a mock chemical emergency staged at a chemicals manufacturer in Peterborough.
Firefighters from Cambridgeshire Fire and Rescue tested their emergency response to a chemical incident at the Safapac factory in Orton Southgate.
The mock scenario involved a chemical leak with two people reported missing.
Crews from Stanground, Sawtry and Dogsthorpe were involved in the emergency training, which was held on Tuesday.
Rob Allport, Watch Commander for Cambridgeshire Fire and Rescue Service, said the aim of the exercise was to expose the emergency services to the hazards and risks associated with such an incident.
These include good communication with specialist advisors, management of the incident scene, casualty location and handling, evacuation, decontamination and ensuring environmental protection.
He said: "We are indebted to Safapac for helping us with this emergency scenario.
"Both the emergency services and Safapac benefited hugely from the exercise as a means of testing their responses and procedures.
"This type of thing is invaluable to us.
"A full exercise de-brief will be held to review all the procedures adopted to ensure that everything that should have been done was done correctly and to focus on areas where improvements could be achieved."
John Blaydes, Safapac's technical director, said: "Like all local businesses we appreciate the hard work and commitment of our emergency services and given that we are dealing with potentially hazardous materials there is huge value for both us and the fire service with a practice exercise like this.
"There is inevitably a major focus on health, safety and the environment at Safapac and we continue to work closely with all agencies to constantly ensure we get it right."