Full Fire Fighting & Fire Protection Course - (Part 4)

                     In this part of the Full fire fighting and Fire protection series, we are going to learn about the Classification of Occupancies as per fire hazards.

Fire hazards can be caused by many different things and have numerous ways of prevention. These are some of the most common types of fire hazards and should be kept in mind while lighting up a joint.

a) Flammable Materials

Flames spread faster than they travel if there is combustible material nearby. Cigarette lighters, matches, and lighter fluid are examples of flammables, and they should always be stored well out of reach of children. Keep these items away from where people may smoke cigarettes or marijuana joints. If any of these materials are spilled, immediately call 911 or get medical help. Do not try to put them out yourself.

b) Electrical Hazards

Electrical current runs along certain paths inside objects and people. When using an electrical object, keep your hands off until the item is completely done charging. Make sure cables are properly connected, and never use extension cords. Never give someone else power tools, especially those with exposed live wires. Always unplug unused appliances before going to bed. And finally, never touch an electric socket!

c) Hot Objects

Keep hot objects away from anything that could burn or spark. Be careful around hot pipes, radiators, furnaces, stoves, and irons. Also, don't place anything near open flames or heating elements.

d) Fumes

Fumes from burning are bad news. Try to avoid smoking at gas stations, restaurants, nail salons, dry cleaners, paint stores, and car washes. If you really need to take a puff, make sure to do so outside or in a separate room.

e) Smoke Explosions

Smoke explosions are dangerous because they create a pocket of oxygen that burns everything. Don't smoke in enclosed places, such as cars, offices, and houses.

f) Spills

Spilled fuel and oil pose a serious threat, even if they're only small amounts. Lighter fluids, gasoline, and diesel fuel are among the most hazardous substances. Keep bottles and jars closed to prevent leaks. If your bottle breaks, stop drinking right away.

Classification of Occupancies

"The International Fire Code (2014) defines two types of hazards: ordinary occupancy hazards and structural hazards. Ordinary Occupancy Hazards are those hazards likely to cause death or serious injury if not controlled. These hazards may occur during normal occupancy conditions unless they are controlled." 

Structural Hazard: Any condition, activity, use, storage or maintenance factor that increases the risk of fire; explosion; collapse; fall, slip, slide or toppling of any object; failure of electrical equipment or wiring; deflagration or detonation of any explosive substance; release of flammable gases or vapors; or chemical reaction resulting in the formation of hazardous substances, including smoke. Structural hazards shall be identified, labeled, guarded and safeguarded to minimize fire, explosions or other accidents involving fires."

 Class 1 - Light Hazard Ordinary - Hazardous occupancies where open flames could produce a flashover into combustible material (e.g., paper). Open flame would ignite woodwork, curtains, bedding, draperies, carpeting and rugs. Also classified as class 1 if exposed heating elements pose a risk of ignition.

Light Hazard Ordinary Occupancy (LHOO)

LHOO means the degree of danger created by the hazard to people while they are ordinarily occupied in sleeping, eating, drinking, using lavatory, dressing, grooming, washing, bathing, working, playing, watching television, or otherwise engaged in activities likely to involve them. Normally, LHOO hazards originate in the building's structure or maintenance, not in furnishings and equipment. A LHOO classification does not mean that all rooms are unsafe; rather that each room may have a different level of risk.

2. Class 2 - Ordinary Hazard - Hazardous occupancies that have some flammable materials present, but only upon exposure to ignition sources (e.g., candles), or direct application of high temperatures (e.g., griddles).

NFPA standards classify fires based on how much damage or injury could result. Class 1 fires have minor injuries and only cause moderate property damage. Class 2 fires are those that have some potential damage and may injure people. Class 3 fires are considered hazardous due to their ability to spread and/or create major structural damage. There are three classifications of class 2 fires: Ordinary Hazard (OH), High-Risk Ordinary (HR-OH) and Extremely High-Risk Ordinay (EH).

Class 2 OHNFPA:

A fire starts normally and causes damage or injury only after it exceeds its ignition temperature. Fires of this classification generally burn slowly and produce little smoke or flame. Most class 2 fires occur indoors where combustible materials are frequently present. Fire hazards associated with class 2 fires include:

• Flames that exceed 8 feet (2.44 m) above the floor level.

• Smoke visible outside the building.

• Flashing lights, flames and sparks.

The equipment or material being worked on may be damaged by melting, burning or exploding.

Firefighters should always check for combustibles around flammable liquids such as gasoline and oil. In addition, firefighters should be aware of the location of electrical wiring and appliances near water and gas pipes.

Class 2 HRNFPA:

This fire occurs at normal working conditions or ambient temperatures. However, the structure’s use increases the risk of explosion and fire spreading. These fires are commonly caused by work related activities such as welding, cutting, soldering, grinding, etc. Fire hazards associated with these fires include:

• Large amounts of fire and smoke produced.

• Explosions.

• Heavy metals released into the air.

• Vibration and noise created by machinery.

 Class 3 - Firelight Hazard - Hazardous occupacies that are not considered hazardous based on use of electric lights or similar lighting devices.

Class 2 ordinary hazard means the fire presents a threat to the structure and/or people located at the site of origin. Ordinary hazards include open flames, sparks, hot surfaces, high temperatures, and exposed electrical wiring, etc. These should be treated as if they were any other combustibles (flammable liquids, solids, gases); therefore, they require special attention. Fire extinguishers may not properly extinguish these fires, and water alone may only temporarily delay or control them. Water cannot be relied upon to put out this type of fire.

 Class 1 ordinary hazard means the fire poses a threat to the structure or property of surrounding buildings or structures. Class 1 includes fires involving explosives, flammable liquid, gas, or other dangerous materials; fires where hazardous chemicals exist or are being prepared; and fires that produce smoke or toxic fumes. If you have questions about whether or not a situation qualifies as a class 1 fire, contact the local fire department. Class 1 fires pose an imminent danger to the public and require prompt action.

 Class 2 extraordinary hazard means the fire presents an extreme threat to life or property. Extraordinary hazards include chemical releases and explosions, structural collapse, fires involving combustible dust or vapors, fires involving ammunition, bombs, or other weapons, fires involving natural gas, electric power failure, and forest fires. Fires classified as extraordinary hazards require quick intervention, especially if they involve hazardous chemicals or explosive materials.

Class 4 extraordinary hazard means the fire threatens the safety of persons or property outside the building or facility, including structures near the building or facility. Class 4 includes fires involving flammable dust or vapors or gases, fires involving noncombustible dust or vapors or gas, and fires involving combustible liquid or solid. Class 4 fires pose an imminent danger and require immediate action to prevent loss of property and lives.

 Class 5 extraordinary hazard means the fire poses an extreme threat to human life and requires rapid intervention to prevent death or injury. A Class 5 fire involves a fire that could cause serious damage to human life or the environment, such as a factory fire or explosion, a blaze in a tall structure, or a burning building.

 Class 6 extraordinary hazard means the fire represents an extreme threat to the physical premises of the establishment. Common examples include fires in warehouses, factories, and restaurants. Fires involving combustible dust or gas require rapid intervention to minimize personal injuries and environmental damage.

Here are some general questions related to fire hazard occupancies...

How does the NFPA classify a fire?

There are two main classifications of fires based on how hazardous they are. Class 1 fires are the ones considered normal and expected in any home. These fires are generally small in size and do not present a significant threat to anyone’s life, including the people who live in those homes. Fires that have been classified as Class 1 may still cause damage however. Class 2 fires are fires that pose a greater risk to the occupants of the property than Class 1 fires. Class 2 fires are further divided into Ordinary Hazards and Special Hazards based on their severity. Ordinary hazards include cooking fires, candlelight, and matches, among others. Special hazards include electrical fires, smoking materials, gas-powered appliances, arson, and explosions.

What are the differences between Ordinary and Special Hazardous Fires?

Ordinary Hazard Fires: Cooking fires, candlelight, matches, etc.

Special Hazardous Fires: Electrical fires, smoking materials, natural gas appliances, arson, explosives, and other similar events

In order for a fire to be classified as an Ordinary Hazard it must meet three criteria. First, if the fire causes no injuries or damage to property. Second, if the fire does not threaten the physical well being of the occupants. Third, if the fire does cause some minor damage, then only damages that cannot be repaired immediately should be counted as damaged. If a fire meets these criteria then it is classified as an Ordinary Fire. If a fire fails to meet these criteria then it is considered a Special Hazard Fire.

Why is a house fire considered a special hazard?

A house fire is considered an extraordinary circumstance because it poses serious threats to the occupant's life. A house fire that has started in a kitchen in the middle of the night could easily lead to death. An open flame in a bedroom can spread quickly, leading to smoke inhalation and possible asphyxiation. Even a small amount of water damage can compromise the integrity of a structure. Because of this, the NFPA considers house fires to be special hazards.

What happens after a house fire?

After a house fire occurs, local fire departments respond and assess the situation. Based on the extent of the damage, the type of fire, and where the fire occurred, firefighters make decisions regarding what steps need to be taken to ensure the safety of the residents. Depending on the results of the evaluation, different actions might be necessary.

Access all the previous parts of this full fire fighting series by clicking the links provided below:

Part 1 --- Click Here!!!

Part 2 --- Click Here!!!

Part 3 --- Click Here!!!