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Control measure
Controlled burn

Control measure knowledge

UK law does not require fire and rescue services to extinguish fires. There are times when an incident commander may consider stopping or limiting firefighting, for example, when it is not possible to contain polluted fire water. A controlled burn may reduce environmental damage by avoiding or restricting the use of extinguishing media or allowing better combustion of pollutants. However, it may also worsen them. See Section 3.7, Environmental Protection Handbook.

Examples of when a controlled burn could be considered as a tactical option are shown below.

Controlled burn considered

Controlled burn likely to be inappropriate

Life or health is not at risk or a controlled burn will reduce risk to people

Life or health is at immediate risk or a controlled burn will increase risk to people

There is little chance of extinguishing the fire

There is a high chance of extinguishing the fire with minimal health or environmental impacts

Fighting the fire with other techniques could cause a significant risk to firefighters

The fire is likely to spread widely or to high hazard areas

Property is beyond salvage

Important or valuable buildings are involved

Fire conditions, weather conditions and/or the local landscape are appropriate for minimising air quality impacts

Fire conditions, weather conditions and/or the local landscape are inappropriate

Fire water run-off could damage an area of high environmental sensitivity or value

Drainage from the site leads to an area of low environmental sensitivity or fire water is not polluting

Fire water run-off could affect drinking water sources or affect sewage treatment works

Fire water can be contained on site or off-site


Incident commanders will decide whether to allow a controlled burn. They should take specialist advice, wherever possible, from tactical advisers, environment agency staff, owners/occupiers and public health bodies. The decision should be communicated as appropriate, including to the public via the media, if necessary.

A controlled burn strategy may be considered at any time during an incident. At incidents where it is expected that the fire will burn for some time it may be appropriate to use both controlled burn and extinguishing tactics. For example, using a controlled burn in the initial stages of an intense fire may result in lower concentrations and better dispersion of pollutants because of the high combustion temperatures as well as reduced run-off.

The technique of introducing an accelerated control burn which may include the use of fire service positive pressure ventilation fans (PPV) can help to increase temperature and therefore decrease the combustion time.

However, with both controlled burn and an accelerated controlled burn, as the fire dies back and begins to smoulder, the pollutant levels in the smoke plume may increase, resulting in less dispersion of pollutants and lowering of smoke plume and contents in the atmosphere. At this point an extinguish strategy could be used. Such a strategy would also give more time for fire water containment measures to be put in place.

Certain buildings and their contents have a high value because of their architectural, historical or monetary significance. In these cases, the benefits of a controlled burn must be considered against the building's value. Advice should be taken from the owner or occupier and the appropriate conservation body and decisions made on a case-by-case basis. Other containment measures may be used when a building is of high value and/or poses a high environmental risk.

Note: a controlled burn does not relate to the controlled burn of moorland, heathland etc., or agricultural or other wastes.

For further information see Section 3.7, Environmental Protection Handbook.

Strategic actions

Fire and rescue services should:
  • Develop a controlled burn policy and procedures
  • Identify pre-determined sites where a controlled burn strategy may be appropriate

Tactical actions

Incident commanders should:
  • Carry out an environmental risk assessment
  • Liaise with site owner or occupiers
  • Consider other options to reduce environmental impacts
  • Request appropriate resources, i.e. DIM/HMA additional environmental protection equipment
  • Inform, or request the attendance of the relevant environment agency and any other appropriate agencies such as:

    • Nature conservation bodies
    • Public health organisations
    • Local authority
    • Highway agencies
    • Local media
  • Communicate the tactic 'Use of a controlled burn' to all personnel on the fire ground, the fire control room, the site operator (if present) the environment agency and local environmental health departments.
  • When an identified nature conservation site is at risk, implement an appropriate protection plan
  • Reduce the use of firefighting water, recycling or fire water run-off to foul sewer as alternative tactic to limit fire water run-off