Devon And Somerset Fire And Rescue Service Logo
Commercial Services
incident response unit
Incident Response Unit

Devon & Somerset Fire & Rescue Service crew three Incident Response Units (IRU's). They are stationed at Chelston Business Park, Nr Wellington in Somerset and Okehampton and Bovey Tracey Fire Stations in Devon.

It is a National resource supplied by the ODPM, to respond to an incident involving mass decontamination. Mass decontamination is defined as incidents where more than one person can be decontaminated simultaneously using the same equipment.

Each IRU is maintained by a host station with assistance from support stations which all receive training on the equipment at regular periods throughout the year.

Vehicle Specification
A MAN appliance
Vehicle length - 11.2 m
Height - 3.3m
Width - 2.54m
Weight - 21 tonnes

The vehicle is fitted with a differential lock for use in crossing soft or muddy ground.
Rear wheel drive
Mobile phone

Mass Decontamination Equipment

All equipment is stored in cages on the vehicle, six stillages on each side, arranged in three stacks of two.

Forklift Truck:

A forklift truck is carried on the rear of the IRU and is used to remove the equipment cages. Trained fork lift truck operators are required to carry out this procedure.

Disrobe and re-robe packs:

Casualties are required to place all clothing and belongings into a bag and are given a disrobe pack to wear until they are ready to be decontaminated, by walking through a shower system. Once casualties have showered they will be given a re-robe pack to dress in.

This consists of a towel, filter mask, paper underwear, paper suit, jacket and trousers, socks and shoes and personal hygiene items.

Gas Tight Suits:

A one-piece integral suit including gloves and permanently bonded boots with steel toecap covers the wearer and Breathing Apparatus set.

Used for protection against hazardous substances: chemicals, biological hazards and asbestos.

The suit is made of a high performance multilayer polymer fabric with a semi ridge polyester laminated visor and has a limited life of five years.

Each IRU has 48 suits.

Powered Respirator Protection Suits

A one-piece coverall suit, of similar construction to the gas tight suit, utilising an air filtration unit to induce air from atmosphere into the suit. This negates the need for compressed air breathing apparatus and therefore extends the wearing duration of the suit.

The suit is only designed for wearers within the warm zone. Their duties will include handing out dis-robe packs, assisting casualties in the warm zone and marshalling casualties through the shower.

Each wearer is also supplied with a Gas Monitor, Radio and internal Camel-Back for re-hydration.

Tent structures:

There are three different tent structures, which are used for different roles: dis-robe structure, decontamination structure and re-robe structure

Trained fire crews erect the structures and they guide casualties through the decontamination process. Once decontaminated casualties are handed over to the Ambulance crews for assessing and further treatment if required.

Hot water showers:

There are two lines of five showers separated by curtains which allows up to ten people to be decontaminated at a time. The water for the shower is delivered at a temperature of 35 degrees centigrade. The shower consists of a two minute wash followed by a one minute rinse.

The system is able to decontaminate up to 200 ambulant casualties or 100 non-ambulant casualties (on stretchers) per hour.

For non-ambulant casualties the stretcher is placed on a conveyor system to go through the decontamination process.

Water boiler:

Is powered by a 110-volt generator fuelled by diesel to provide warm water at 35 degrees for the shower system.

Hot air blower:

Provides fume free hot air to the tent structure for a comfortable temperature to be maintained.

Diesel generator:

Used to power the water boiler and hot air blower and submersible pump.

Submersible pump:

For use only in the mass decontamination structure. The pump is placed in the shower section to discharge 6000 litres of contaminated water per hour into the dam. Powered by a 110-volt generator.

Firefighter Decontamination Shower:

A rapidly erected decontamination shower with a heavy-duty air inflated frame with integral sump. Has designated entry and exit points, with an additional sump at the exit point.

Six shower positions, which can be fitted with spray heads or washing brushes, which is supplied by feed pipes. The shower system is provided with an induction facility that allows automatic induction of up to two decontamination solutions.

A small 110V pump is provided to transfer the decontamination waste to a storage receptacle at a rate of 130 litres a minute.


Two 6000 litre capacity dams to contain contaminated water. The dams have inflatable collars to rise with the water level. Removable covers to contain the water are kept afloat by bladders attached to their undersides.

Telescopic lighting unit:

Provides an adjustable lighting source up to a height of 6 metres.

Mobile Data Transmission:

Provides a satellite navigation system, with GPS mapping and Chemdata chemical retrieval information.

The chemical retrieval information system allows crews access to a vast database of information on how to deal with a known chemical, including:

  • Substance identification number or UN number
  • How the substance reacts
  • What form it may appear in
  • Emergency Action Code
  • Additional Personal Protection required
  • Tremcard numbers
  • Extinguishment/decontamination measures
  • Environmental risks/hazards
  • Precautions
  • First Aid
  • Tel numbers and addresses for specialist advice

The GPS mapping system:

Allows the crews to zoom in on a specific location identified by name or six figure grid reference. It can also show the vehicle location and direction it is travelling in relation to the incident location.

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