Different types of fire extinguishers are used for different kinds of fires, and all of them are highly dependent on what kind of material is being burned. A class C fire extinguisher is required to put out electrical fires, also referred to as charged electrical fires.
If this type of fire breaks out, the electrical supply must be located and turned off because it will act as a persistent source of ignition for the fire. These fires can escalate quickly and turn into another type of fire depending on the surrounding materials, whether standard combustibles like wood and paper, to the more drastic situations involving flammable liquids or gases.
Here’s a guide to help you choose the best type and class fire extinguisher, including colors, fire classes, and uses. Each type of fire is unique, so many extinguishers can be used, depending on the fire class.
Many types of fire extinguisher can work, so it cannot be easy to choose the right one. Portable extinguishers can be very effective and save lives. A survey by four significant trade associations representing the UK fire industry found that portable extinguishers are more effective than ever.
In 2003, 80% of fires were successfully extinguished. By 2021, 93% had been extinguished.
First, determine what materials are in the area that needs to be protected from fire. They can be broken down into six fire classes that use different substances.
- Class A fires caused by combustible carbon-based solids like paper, wood, or textiles
- Class B fires are caused by flammable liquids, e.g., petrol, diesel, or oil (but no cooking oil).
- Flammable gases, such as propane, butane, or methane, cause Class C fires
- Class D fire is caused by burning metals (e.g., aluminum, lithium, or magnesium).
- Electric equipment that causes fires (indicated with an electric spark symbol and not the letter “E”)
- Class F flames brought on by fats and oils while cooking
The UK’s BS EN3 Standard requires that portable extinguishers be colored red. A small band of color indicates the type and brand of fire extinguisher. Red for water, white for water mist, cream for foam, and blue for dry powder. Yellow-coded extinguishers can be used for wet chemicals, clean agents, and CO2 extinguishers.
Fire extinguisher – are five main types
- Water, water mist, or water spray fire extinguishers
- Foam fire extinguishers
- Standard or specialised dry powder fire extinguishers
- Carbon Dioxide (‘CO2’) fire extinguishers
- Wet Chemical fire extinguishers
Types and uses of fire extinguishers
Fig: Types and uses of fire extinguishers
- Water fire extinguishers with red labels
Only Class A fires can use water extinguishers. Red-coded extinguishers are only used for Class A fires. Water extinguishers spray water from a spray nozzle to cover a larger area. These extinguishers are the most popular and cost-effective.
They range from about PS25 for 3- and 6-litre models to around PS35 for 9-liter regular models and PS50 for freeze-protected extinguishers. Some extinguishers have an additive that makes the water more efficient and reduces the size and weight.
These are slightly more expensive. Water extinguishers, which only contain water, are the easiest to use and least dangerous. By soaking the fire and any materials in water, they cool it. This helps to extinguish the flames and absorbs heat from any objects that are burning.
They can be found in offices, shops, retail premises, schools, and warehouses. They can usually put out a complete fire. They cannot be used to burn fat, oil, metals (Class F), liquids (Class A), or light electrical appliances fires.
- Water mist extinguishers
This is the newest type of extinguisher. These powerful devices are smaller than the previous models and emit a fine mist of microscopic, demineralized water particles. These extinguishers are safe and efficient to use on Class A, B, and C fires.
It is not necessary to have more than one type in most homes. A water mist fire extinguisher for electrical fires exceeding 1,000 Volts is one of the best choices. They cool the fire and reduce the oxygen supply.
They are designed to replace traditional wet chemical extinguishers that were used for the suppression of deep fat fryer fires. They are recyclable, and they do not contain chemicals. They cannot be used for Class D fires (metals).
Water mist extinguishers can be more expensive than water extinguishers. They cost from about PS50 per litre up to PS100 for six litres.
Fig: Fire extinguisher to use on electrical
- Water spray fire extinguishers.
Water spray extinguishers come in three- and six-litre sizes. They are ideal for fires that involve solid organic materials like wood, cloth, paper, or plastics. It is not recommended to use them on oil, fats, or electrical appliances.
The jet is used to point at the flames and then move them steadily and continuously across the fire until it goes out. An example of a CO2 and water-based extinguisher in an office.
You can ditch the jet nozzle in favor of a spray nozzle which produces fine spray due to the higher pressure. This extracts heat faster by hitting a larger surface area. Surfactants may be used To help water penetrate deeper into the burning material.
- Foam extinguishers (cream label)
Foam extinguishers can be used to extinguish fires in liquids and solids (Class A and B) but not in cooking fats or oils (Class F). If the foam has been tested, it can be used to extinguish electrical fires up to 1 metre from them.
They leave behind a residue that must be cleaned up and are generally more expensive than water extinguishers at about PS25 for a litre and PS55 to 9 litres.
- Dry powder extinguishers (Blue Label)
Powder extinguishers can be used to fight burning liquids, solids, and gases (Class A and B fires). Specialized powder extinguishers can deal with type D fires involving combustible metals like lithium, magnesium, and aluminum.
The powder forms a crust that smothers the flames and prevents them from spreading. The powder is not able to soak into materials and doesn’t have a practical cooling effect, which could lead to fire rekindling.
The inhaled powder can be dangerous, so it should only be used in areas that are well-ventilated. They also shouldn’t be used in offices or domestic settings. The powder can cause damage to machinery and soft furnishings. They are not suitable for use on chip pan fires (Class A).
They are usually inexpensive and strong and come in sizes of 1, 2, 4, 6, and 9 kg. A 1kg model costs as low as PS15, while a 9kg model will run you around PS35.
- Dry powder fire extinguisher
Fig: Dry powder fire extinguisher
What types of fire extinguishers should you use?
- Fire extinguisher Class A – Water, water mist and foam, dry powder, or wet chemical
- Fire extinguisher Class B – Water mist, dry foam powder, CO2, some other wet chemical
- Fire extinguisher Class C – Water mist, dry powder
- Specialist dry powder Class D fire extinguisher
- Fire extinguisher to use on electrical – CO2
- Fire extinguisher Class F – Water mist, wet chemical
- CO2 extinguishers (black label)
They do not leave any residue because they only contain pressurized carbon dioxide gas. CO2 extinguishers can be used for fires involving liquids (Class A) and electrical fires such as large computers and other electronic equipment.
The CO2 fire extinguisher to use on electrical works by sucking the fire, and it does not damage electrical equipment or cause a short circuit. The CO2 extinguishers can get very cold when they are discharged. Those that do not have frost-free, double-lined swivels horns could cause fingers to freeze to the end of deployment.
They can become smothered in tight spaces. The strong jet of the extinguisher may also carry the burning fat from deep-fat fryers. They are not able to provide post-fire security because fires can quickly rekindle once the CO2 has been released into the atmosphere.
CO2 extinguishers are pretty expensive. A 2kg model is around PS33, while a 5kg model for servers and factories costs about PS65.
- Wet chemical extinguishers (yellow labels)
They are the only extinguishers that are suitable for Class F oil fires (fats, cooking oils), and they are used primarily in deep-fat fryers. Some can be used on Class A fires, while others can be used for Class B. They are made up of an alkali salt solution in water.
When operated, they create a fine mist that cools the flames and prevents splashing. They are more expensive than others and cost about PS35 for 2-litres, PS70 for 3-litres, and PS110 for 6-litres.
Fire extinguisher to use on electrical devices
A survey found that almost four out of ten construction workers used the wrong type of fire extinguisher to use on electrical fires in 2017. Due to an increased reliance on batteries and electrical products, electrical fires are becoming more common.
According to a survey by the fire industry, electricity was the leading cause of fire in 2021 (roughly 19%). It’s, therefore, essential to choose the right extinguishant.
Use a CO2 fire extinguisher to use on electrical fires. They work by discharging oxygen into the atmosphere, helping to stop the fire from spreading. This is why they are frequently found in data/computer server rooms, offices, kitchens, and construction sites.
The dry powder extinguishers have a blue label and are safe to use for electrical fires with equipment below 1000v. However, CO2 extinguishers should still be used.
Respondents should not use wet chemical extinguishers, whether water-based, foam, or when an electrical fire occurs.
How and when to use a fire extinguisher
Fig: Tips to how and when to use a fire extinguisher
A fire extinguisher should only be used by someone who is trained in the use of them. The following text does NOT count as training. A fire extinguisher should be used only after the fire alarm has been activated and you have determined a safe evacuation route.
If you are unsure whether to use an extinguisher or if it is the best option, evacuate the building immediately. The following technique is a refresher for anyone who has ever received training or if someone does not have the training to use it. It will increase the chance that everyone survives without injury.
Here are ten rules that you should remember when using a fire extinguisher.
- Fires usually start small. If the fire is slight, you may need to use an extinguisher, such as a trashcan. You only have seconds to do this. A fire that burns for l minutes will triple its size.
- Only use an extinguisher when all your family members have been alerted and the fire department called. You should also ensure that you are free from smoke and that there is no escape route between you and the fire.
- An independent laboratory should test a fire extinguisher before you buy it. It would help if you also looked for one that is labeled A–B–C, as it can be used on any fire that might occur in your home. It is vital to ensure that the fire extinguisher used will be effective in putting out the flames.
- You must be able to use an extinguisher safely. Some models can be challenging to hold and operate.
- You should be able to operate an extinguisher quickly. During an emergency, you won’t have time to read the instructions.
- Your extinguisher should be kept in a convenient place. You should ensure that it isn’t blocked by anything that could prevent you from quickly grabbing it in an emergency.
- Keep in mind the PASS.
- Pull, Aim and Squeeze to Sweep
- If you feel your escape route is being compromised while using an extinguisher at any point, leave the house immediately and call the fire department.
- Do not hesitate to use an extinguisher to put out a fire. Stay out!
- Please get in touch with the department if you are interested in scheduling a training class or workshop for your company.
Conclusion:
Each type of fire extinguisher has its pros and cons. It would help if you determined which extinguisher suits your needs best. Do you work in an environment susceptible to flammable chemicals or other potentially hazardous substances?
If so, class D fire extinguishers might be the best option. Perhaps your business has an electrical component. In that case, a class D fire extinguisher to use on electrical is the best choice. No matter what, we hope this article helped you to understand the differences between fire extinguishers.
