How to Distinguish Between the Different Classes of Fire

KnowledgeCity

17 Aug 201802:32

Summary

TLDRThis video explains how different types of fires require specific extinguishing methods. It covers the dangers of using the wrong fire retardant, which could worsen the situation, especially with liquids or electrical equipment. The video introduces fire classifications: Class A for solid combustibles like paper, Class B for flammable liquids, Class C for electrical fires, and Class D for combustible metals. Each class demands a unique extinguishing approach, such as water, chemical foams, or dry chemicals, depending on the fire’s fuel source. Viewers are urged to be aware of fire types and respond safely.

Takeaways

🧯 To extinguish a fire, it's crucial to use the appropriate retardant based on the materials involved and the location of the fire.
💧 Water is effective for Class A fires involving solid materials like paper and wood, as it cools the materials and deprives them of oxygen.
🚫 Using water on Class B fires, which involve flammable liquids, can spread the fire further.
⚠️ Pouring water on electrical fires can lead to electrocution due to water's conductivity.
🧪 Class B fires are extinguished using chemical foams that create a blanket to cut off the fire's oxygen supply.
🔌 Class C fires involve electrical equipment and are best extinguished by smothering with non-conductive dry chemicals to starve the fire of oxygen.
🛠️ Dry chemical agents like mono ammonium phosphate, potassium bicarbonate, and potassium chloride are used for Class C fires.
🌀 Class D fires are rare and involve combustible metals; they require immediate professional assistance from the fire department.
📚 Understanding the different classes of fires (A, B, C, D) is essential for selecting the correct method and materials for extinguishing them.
☎️ In case of a Class D fire, do not attempt to extinguish it yourself and call the local fire department immediately.

Q & A

What is the primary purpose of using retardants when extinguishing a fire?
-The primary purpose of using retardants like water, baking soda, or sand is to reduce the heat of the fire or deprive it of fuel or oxygen.
Why is it crucial to consider the type of materials burning when extinguishing a fire?
-It is crucial because using the wrong fire retardant can exacerbate the situation. For instance, water can spread a fire involving burning liquids.
What are the potential dangers of using water on fires involving electrical equipment?
-Using water on fires involving electrical equipment can be dangerous because water conducts electricity, leading to the risk of electrocution.
What are Class A fires, and how can they be extinguished?
-Class A fires involve everyday solid combustibles like paper and wood. They can be extinguished with water, which cools the materials and helps deprive them of oxygen.
What types of fires are classified as Class B, and how are they typically extinguished?
-Class B fires involve flammable gases, liquids, and some plastics. They are typically extinguished by applying chemical foams that blanket the area and cut off the fire's oxygen supply.
What are Class C fires, and what method is used to extinguish them?
-Class C fires involve electricity and can occur in equipment like copiers and electrical wiring. They are extinguished by smothering, starving them of oxygen, using non-conductive dry chemicals.
What substances are used to extinguish Class C fires, and why?
-Dry chemicals such as mono ammonium phosphate, potassium bicarbonate, and potassium chloride are used for Class C fires because they are non-conductive and can safely smother the fire.
What distinguishes Class D fires, and what is the recommended action when encountering one?
-Class D fires occur when combustible metals like potassium, sodium, and magnesium catch fire. The recommended action is to call the local fire department immediately and not attempt to extinguish it yourself.
Why is it advised not to attempt to put out a Class D fire without professional help?
-It is advised not to attempt to put out a Class D fire without professional help because these fires involve reactive metals that require specialized knowledge and equipment to handle safely.
How does the method of extinguishing a fire differ based on the class of fire?
-The method of extinguishing a fire differs based on the class of fire because each class requires a specific approach and type of retardant to effectively reduce heat, deprive the fire of fuel or oxygen, or cut off its oxygen supply without causing additional hazards.

Outlines

00:00

🔥 Understanding Fire Extinguishing Basics

This paragraph explains the basic methods of putting out fires by using substances like water, baking soda, or sand. It emphasizes that extinguishing a fire requires either reducing heat or depriving the fire of fuel or oxygen. It also introduces the importance of understanding different fire types and their environments, as the wrong extinguishing agent could worsen the situation.

🚨 The Dangers of Using Water Incorrectly

This section discusses the risks associated with using water inappropriately when extinguishing fires. For example, using water on burning liquids will spread the fire, and using it on electrical fires could cause electrocution due to water's conductivity. This highlights the need to use the correct fire retardant based on the situation.

📋 Classifying Fires into Different Classes

To help with fire safety, fires have been classified into specific categories. Class A involves solid combustibles like paper and wood, which can be extinguished with water. Class B consists of fires fueled by flammable liquids or gases like gasoline, which are best put out using chemical foams that cut off oxygen. This classification helps in applying the right extinguishing method.

⚡ Extinguishing Electrical Fires (Class C)

This paragraph introduces Class C fires, which involve electrical equipment such as light fixtures and wiring. It explains that such fires are best extinguished by starving them of oxygen, a process called smothering. Non-conductive dry chemicals like mono ammonium phosphate or potassium bicarbonate are commonly used to safely handle these types of fires.

🧯 Combustible Metals: Rare but Dangerous Class D Fires

Class D fires are rare and involve combustible metals such as potassium and magnesium. These types of fires are highly unusual and dangerous, requiring specialized fire-fighting techniques. The advice given is not to attempt extinguishing a Class D fire but to call the local fire department for help.

Mindmap

Keywords

💡Fire retardant

A fire retardant is a substance used to slow down or stop the spread of fire. In the video, different retardants such as water, baking soda, or sand are mentioned, which can reduce heat or deprive a fire of oxygen or fuel. The choice of fire retardant is crucial as using the wrong one, like water on a grease fire, can worsen the situation.

💡Class A fires

Class A fires involve everyday solid combustibles such as paper, wood, and cardboard. These materials can typically be extinguished using water, which cools the fire and reduces oxygen. The video explains that this is the most common type of fire, and water is a safe retardant in these situations.

💡Class B fires

Class B fires involve flammable liquids or gases, such as gasoline, propane, or some plastics. These types of fires cannot be safely extinguished with water, as water spreads the burning liquid, worsening the fire. Instead, chemical foams are used to cut off the oxygen supply. The video highlights the importance of using the correct retardant for each fire type.

💡Class C fires

Class C fires involve electrical equipment such as wiring, fuse boxes, and light fixtures. Water is dangerous in these fires because it conducts electricity and can lead to electrocution. Instead, dry chemicals like potassium bicarbonate or mono ammonium phosphate are used, which are non-conductive and can smother the fire.

💡Class D fires

Class D fires are caused by combustible metals like sodium, potassium, or magnesium. These fires are rare, but highly dangerous. The video advises not to attempt extinguishing these fires yourself, but to call the fire department, as specialized equipment is required. Class D fires are unique in their behavior and need specialized treatment.

💡Oxygen deprivation

Oxygen deprivation is a key method of extinguishing fires. The video explains that fires need oxygen to burn, so many extinguishing techniques involve removing or blocking the oxygen supply. For example, chemical foams and dry chemicals used in Class B and Class C fires work by cutting off oxygen, a technique called smothering.

💡Water

Water is a common fire retardant, especially effective on Class A fires involving solid combustibles like wood and paper. The video explains that water cools the materials and deprives them of oxygen. However, water can be dangerous if used on Class B (flammable liquids) or Class C (electrical) fires, where it may spread the flames or cause electrocution.

💡Smothering

Smothering is a method of extinguishing a fire by cutting off its oxygen supply. The video mentions this in relation to Class C fires, where dry chemicals are used to smother electrical fires safely. The concept also applies to Class B fires, where foams are used to cover burning liquids, preventing further oxygen from fueling the fire.

💡Flammable liquids

Flammable liquids, such as gasoline and propane, are mentioned in the video in the context of Class B fires. These substances ignite easily and spread quickly, making them particularly dangerous. The video emphasizes that using water on these fires is not safe, as it can spread the flames. Instead, chemical foams are used to block oxygen and extinguish the fire.

💡Combustible metals

Combustible metals like magnesium, sodium, and potassium are involved in rare Class D fires. The video notes that these metals burn at high temperatures and require specialized fire extinguishing agents. People are advised not to attempt to put out these fires themselves due to the unusual behavior of these metals when burning.

Highlights

To extinguish fires, different types of retardants like water, baking soda, or sand are used to reduce heat or deprive fires of fuel or oxygen.

Fire retardant selection is crucial as using the wrong one can exacerbate the situation.

Water effectively extinguishes fires involving materials like cardboard but can spread fires involving burning liquids.

Using water on electrical fires can lead to electrocution due to water's conductivity.

Fires are categorized into classes to determine appropriate extinguishing methods.

Class A fires involve solid combustibles like paper and wood, which can be extinguished with water.

Class B fires involve flammable gases, liquids, and some plastics, and are extinguished with chemical foams.

Class C fires involve electrical equipment and require smothering with non-conductive dry chemicals.

Class D fires are rare and involve combustible metals; they require immediate professional intervention.

Chemical foams for Class B fires blanket the area and cut off the fire's oxygen supply.

Dry chemicals used for Class C fires include mono ammonium phosphate, potassium bicarbonate, and potassium chloride.

Smothering is a safe method to extinguish Class C fires by starving them of oxygen.

Class D fires are unusual and require calling the local fire department for assistance.

Understanding fire classes is essential for selecting the correct extinguishing agent and ensuring safety.

The importance of not attempting to extinguish Class D fires alone is emphasized for personal safety.

Proper fire extinguishing techniques can prevent the spread of fire and protect people and property.

Fire safety involves knowing how to respond to different types of fires with the appropriate materials.