Equipment for Putting Out Fires: Fire Extinguishers Detailed
Understanding Fire Extinguishers: A Guide to Classification and Usage
Fire extinguishers are essential safety equipment in any workplace, home, and vehicle. They are designed to combat different types of fires, and understanding their classification can help you respond effectively in an emergency.
The Universal Classification System (UCS) categorizes fire extinguishers into five designations: A, B, C, D, and K. Each class represents a specific type of fire:
- Class A: Fires involving normal combustibles such as paper, wood, plastics, and cloth. These fires are best fought with water-based extinguishers, foam extinguishers, and multipurpose dry chemical extinguishers. These extinguishers cool and suppress the fire by reducing heat and smothering the flames.
- Class B: Fires involving flammable liquids like gasoline, grease, and solvents. For these fires, carbon dioxide (CO₂) extinguishers and dry chemical extinguishers are effective as they displace oxygen or interrupt chemical reactions to smother the flames.
- Class C: Fires involving electrical equipment such as short circuits and electrical motors. Non-conductive agents like CO₂ and dry chemical extinguishers are used for Class C fires to avoid electrical shock hazards.
Some extinguishers carry a combined rating such as ABC, indicating they are safe and effective on Class A, B, and C fires.
- Class D: Fires involving combustible metals, such as magnesium, titanium, and sodium. These fires are fought with Class D fire extinguishers, which use dry sand, graphite, or other dry chemical agents to smother the flames.
- Class K: Fires involving cooking oils, fats, and grease. These fires are fought with Class K fire extinguishers, symbolized by a black square.
It's crucial to ensure that fire extinguishers are located throughout the workplace, including at every exit and wherever potential fire hazards are great. They should also be located on each vehicle or piece of equipment in the event a fire occurs in a location remote from nearby buildings.
Monthly visual inspection of fire extinguishers is recommended. The inspection procedure includes checking if extinguishers are in their recommended location, the hose and nozzle are unobstructed, and the gauge on a fire extinguisher shows enough pressure to discharge the contents. If the gauge does not show enough pressure, the extinguisher should be replaced or recharged. Damaged fire extinguishers should be replaced as well.
Fire safety standards require annual inspection of all extinguishers by trained personnel. Inspection records must be available upon request.
References:
- National Fire Protection Association (2012)
- OSHA (2014)
- Kent McGuire, CFAES Safety and Health Coordinator, Food, Agricultural and Biological Engineering
In an emergency, remember the PASS acronym when fighting a fire: Pull the pin, Aim the fire extinguisher nozzle, Squeeze the handle to discharge the fire extinguisher contents, and Sweep the spray back and forth at the base of the fire, not at the flames.
Stay safe and prepared!
Incorporating health and wellness into the workplace can be achieved by promoting workplace-wellness programs that include regular workplace inspections and maintenance of safety equipment like fire extinguishers. Proper maintenance includes regular monthly visual inspections and annual professional inspections to ensure each fire extinguisher is functioning correctly (complying with safety standards set by organizations like NFPA, OSHA, and experts such as Kent McGuire). Moreover, practicing science-backed fire safety measures such as using the PASS acronym during emergencies can contribute to a safer and healthier workplace environment.
