Dry powder extinguishers

Dry powder extinguishers should not generally be used indoors unless mitigated by a fire risk assessment. They have the potential to cause harm from inhalation of powder in a confined space without ventilation could impede safe evacuation from a building.

Electrics can be particularly sensitive to the powder used in some extinguishers. In any environment where moisture is present, the powder can develop into an acidic solution. The dry powder released can contain ingredients with the potential to cause considerable damage to buildings and contents. This is due to its corrosive and abrasive qualities.

All affected surfaces will need cleaning to restore them and prevent further damage from the powder.

Clean-up operations will involve vacuuming the powder, followed by appropriate restoration work using professional cleaning services (conservators will need to be used in respect of listed buildings and churches).

Pipework and electronic circuitry can be particularly susceptible. High-level surfaces should also be attended to carefully, to prevent future deposition of powder onto the area below, and damage to any stonework at high level.

Be mindful of the dangers posed by the potentially corrosive contents of some dry powder extinguishers and the risks involved when they’re discharged.

Both water and carbon dioxide portable fire extinguishers are suitable for most fire scenarios within a building. Where buildings have existing dry powder extinguishers, steps should be taken to ensure they are not located in inappropriate places. Examples include near paintings and expensive furnishings.

We recommend replacing existing dry powder extinguishers with a suitable alternative when they reach the end of their service life. This is usually highlighted during fire risk assessments.

Adopting such an approach and avoiding the use of dry powder extinguishers can significantly reduce the consequences of any accidental or malicious use of extinguishers.