Water vs Foam Fire Extinguishers - the key differences explained.

One of the most common questions we get asked is, “What are the benefits of a foam extinguisher compared with a water extinguisher?”

Water extinguishers remain one of the most popular types of fire extinguisher. They are relatively inexpensive, are completely environmentally friendly, and water is a very effective way of fighting a fire.

One of the most common reasons for specifying a foam extinguisher as opposed to a water fire extinguisher is that foam fire extinguishers carry a Class B rating, making them suitable for use on flammable liquid fires. So if your premises carries any flammable liquids (oils, greases, solvents etc) you will need to ensure the fire extinguishers on site are able to deal with these fires. Don’t forget that plastics turn to liquids in a fire too, so where significant amounts of plastic are present it may be worth considering upgrading from water to foam extinguishers. Using a water extinguisher on flammable liquids can actually make the fire worse with potentially disastrous consequences.

Another advantage of a foam fire extinguisher is the speed at which it knocks a fire down. The foam additive acts as a ‘wetting agent’ and increases the surface area of the water droplets when they hit the burning material. This makes a far more effective fire extinguisher.

One of the main reasons for specifying foam extinguishers is actually risk-based. With the advantage of a faster knockdown than water, and their capability at tackling fires involving flammable liquids, foam extinguishers reduce the risk of incorrect selection of fire extinguisher. Don’t forget, when fire strikes it’s too easy to grab the wrong extinguisher, and the effects of getting it wrong can be catastrophic.

So in short, whilst water extinguishers are great at putting fires out, and we sell thousands of them, foam extinguishers are growing in popularity due to their increased capability and the reduction in risk they can offer.