Are Your Fire Extinguishers Ready For The Cold Weather?

When people think about winter risks, they think of frozen pipes, heating issues, and icy walkways. Fire extinguishers rarely make the list, but every winter, cold weather catches businesses out. An extinguisher can be in date, serviced, and correctly mounted, and still fail when it's needed most, simply because it hasn't been protected from the cold.

Why cold weather affects fire extinguishers

Most extinguishers are designed to work at temperatures above 5°C, as set out in manufacturer guidance. Below that, the contents can freeze, thicken, or lose pressure, meaning the extinguisher may not discharge properly when used.

Servicing doesn't fully protect against this. A service confirms an extinguisher is working on the day it's checked, but it doesn't shield the equipment from weeks of cold that follow.

Where the risk is highest

Extinguishers stored outdoors or in unheated spaces are most exposed. That includes:

• Construction sites

• Warehouses, garages, and storage units

• Commercial premises with open doors, overnight heating shutdowns, or poor insulation

These are often the same spaces that hold electrical equipment, machinery, and packaging, so a fire that starts here can escalate fast if the nearest extinguisher doesn't work.

Not all extinguishers handle cold the same way

Water spray, water mist, foam, and some wet chemical extinguishers aren't suitable for use below 5°C. If they freeze or thicken, they may fail to discharge.

Dry powder extinguishers cope far better, often rated down to -20°C or lower. But even these aren't immune. Frost can still affect handles, valves, and pressure gauges, meaning an extinguisher can look fine on the outside while being seized or frozen internally. Pins can jam, and handles can fail to move, exactly when someone's relying on them.

Why winter is a good time to check your fire safety measures

Reviewing how your premises handle fire risk shouldn't be a once-a-year tick-box exercise, but winter is when it matters most. Buildings that work well in summer can become cold, damp, and poorly ventilated once the temperature drops. Heating gets switched off overnight, doors and windows get left open, and some areas can sit unheated for long stretches. A seasonal check helps make sure your fire safety measures still hold up under those conditions.

Winter extinguisher support across Hampshire and surrounding areas

Commfire works with businesses across Hampshire, Wiltshire, and Berkshire to make sure fire extinguishers are fit for the conditions they're kept in, not just the day they're serviced. If you're not sure how your equipment is coping with the cold, it's worth checking before winter puts it to the test.