Wednesday 18th June 2025
Water fire extinguishers are essential tools for fighting Class A fires involving solid combustible materials such as wood, paper, textiles and coal. These red extinguishers provide an effective way to control fires by cooling the burning materials and preventing them from reigniting.
At Safelincs, we supply water extinguishers kitemarked to BS EN3 that come fully charged and with wall brackets for proper installation. Our water extinguishers are designed to meet the highest safety standards, ensuring you have reliable fire protection when needed.
How Water Fire Extinguishers Work
Water fire extinguishers work on a simple but effective principle. When you activate a water fire extinguisher, it releases a steady jet of water that:
- Cools the burning material by absorbing heat from the fire
- Penetrates deep into porous materials like wood and fabric
- Lowers the temperature below the ignition point
- Creates a cooling effect that prevents reignition
The cooling action is the main way water extinguishers fight fires. When water comes into contact with flames and hot materials, it absorbs heat and turns to steam. This process draws heat away from the fire, eventually reducing the temperature to a point where combustion can no longer continue.
Water Fire Extinguisher Colour and Identification
Water fire extinguishers feature an all-red body with a red identification panel. To help with quick identification, they have a thick border around the ID field with the words ‘water extinguisher’ clearly marked.
For proper identification and to avoid confusion about usage restrictions, we suggest installing water fire extinguisher signs above your units. These signs help to clarify that the extinguisher contains water and highlight important limitations, such as not using them on fires involving live electrical equipment unless specifically tested for this purpose.
What Fires Can Water Extinguishers Be Used On?
Water fire extinguishers are specifically designed for Class A fires involving solid combustible materials:
- Wood and wooden structures
- Paper and cardboard
- Textiles and fabrics
- Coal and other solid fuels
Their effectiveness comes from water’s ability to soak into these materials, cooling them thoroughly and preventing hot spots from reigniting.
Water Fire Extinguisher Limitations
It is crucial to understand that standard water fire extinguishers should not be used on:
- Class B fires (flammable liquids)
- Class C fires (flammable gases)
- Class D fires (combustible metals)
- Class F fires (cooking oils and fats)
Using a standard water extinguisher on these types of fires can be ineffective and potentially dangerous. On cooking oil fires, water can cause violent flare-ups as it sinks below the oil surface and rapidly turns to steam, ejecting burning oil.
Only use water extinguishers on live electrical equipment if they display the ‘safe for use on electrical equipment’ symbol, indicating they have passed testing on live electrical equipment up to 1000v according to BS EN 3-7 standards.
How Water Mist Fire Extinguishers Work
Water mist fire extinguishers represent advanced firefighting technology that works differently from traditional water models. These innovative units:
- Use a supersonic nozzle to create microscopic water droplets
- Form a fine mist that surrounds the fire
- Reduce oxygen supply to the flames
- Create a cooling barrier over burning materials
- Prevent reignition through efficient heat absorption
The extremely small water particles in the mist have a much larger combined surface area than a solid jet of water. This allows them to absorb heat more efficiently and turn to steam faster, suffocating the fire by displacing oxygen.
Because the water droplets are so small, they do not conduct electricity in the same way as a solid stream of water. The deionised water used in these extinguishers further reduces conductivity, making them safe for use on electrical fires up to 1000 volts.
Benefits of Water Mist Fire Extinguishers
Water mist fire extinguishers offer several advantages over traditional water and other types of extinguishers:
- Suitable for multiple fire classes (A, B, C and fires involving live electrical equipment)
- Contain only deionised water with no harmful chemicals
- Leave virtually no residue when discharged
- Environmentally friendly with no chemical discharge
- Safe to use around children and vulnerable people
- Effective on clothing fires without harming the person
- Low-pressure discharge that minimises damage to surroundings
These versatile units are becoming increasingly popular as alternatives to AFFF foam extinguishers, which will soon face international restrictions due to environmental concerns.
Where to Use Water Mist Extinguishers
Water mist fire extinguishers are suitable for a wide range of locations:
- Homes and house shares (HMOs)
- Schools and nurseries
- Offices and reception areas
- Churches and places of worship
- Retail environments
- Caravans and campervans
- Boat cabins
- Domestic kitchens (for small cooking oil fires)
- Heritage buildings
Their versatility makes them an excellent choice for environments where different types of fire risks exist and where users might not have extensive fire safety training. The simple operation and wide application range mean there is less confusion about which extinguisher to use in an emergency.
For cooking oil fires, water mist extinguishers are suitable for small domestic incidents, such as shallow frying pans and small deep fat fryers (2-3 litres). The mist creates a cooling blanket above the oil, reducing oxygen and preventing reignition. However, for larger commercial deep fat fryers with greater surface area and oil volume, we recommend wet chemical extinguishers with a 25F or higher rating.
Water fire extinguishers provide effective protection against Class A fires through their cooling properties. The newer water mist technology expands this protection to include multiple fire classes while offering environmental benefits and reduced collateral damage.
For guidance on selecting the right fire extinguisher for your needs, our fire extinguisher guide provides further information on different types and their capabilities. At Safelincs, we are committed to providing quality fire safety products with excellent customer service to ensure your protection needs are met.
All information correct at time of posting.
