Quite a few people seem unsure about powder fire extinguishers following some changes to advice a few years ago about their use. That change stemmed from an amendment to the standard BS 5306-8 aimed at addressing some concerns associated with them. Knowing which fire extinguisher to use for what type of fire is something that can cause confusion.
Dry powder fire extinguishers put fires out primarily by quickly interrupting the chemical reaction taking place and cutting off the oxygen supply. While there are different types of powder fire extinguishers available, the type most commonly used can extinguish Class A, B and C fires. Their high extinguishing capacity for their weight combined with their versatility made them popular for use in many settings. But over the years it became apparent there could be some problems resulting from their use.
Impaired visibility
When powder fire extinguishers are discharged within a building or small confined space, it can lead to a sudden reduction of visibility. That can result in people struggling to see well enough to quickly exit the area and follow escape routes. Clearly, that has the potential to endanger lives.
Inhalation
If inhaled, the fine powder can impair breathing and trigger asthma attacks. That’s a significant concern in itself, let alone given the fact it could impair someone’s ability to escape quickly. Even after the emergency is over, if the powder isn’t cleaned up thoroughly, it could continue to cause problems for some people.
Damage to property and the surrounding area
The powder particles are very fine which makes it easy for them to spread across a large area. They can affect a vast array of materials, corroding metal and damaging electrical equipment and machinery. If used in a kitchen, any food in the vicinity will be contaminated and have to be disposed of. It can get into nooks and crannies and is notoriously difficult to clean up in heritage properties.
Clearly, a fire is capable of doing a great deal of damage and using any kind of fire extinguisher is going to cause a mess. But it makes sense to choose a fire extinguisher that not only puts out the fire, but causes as little damage as possible in doing so.
What can powder fire extinguishers be used for? powder fire extinguishers generally should not be used indoors, or in small spaces, unless specified as the most appropriate choice by a fire risk assessment. In some circumstances, having powder fire extinguishers that haven’t been specified through a fire risk assessment could even end up invalidating your insurance. But they do still have an important role to play in tackling certain types of fires.
Powder fire extinguishers are best suited to businesses using chemical processes or where welding and flame cutting takes place.
