Fire Prevention and Fire Safety

Not All Fires Are the Same

Fires are categorized based on the burning material. Using the wrong extinguisher without knowing the category could not only fail to put out the fire but also make it larger or cause electric shock. That is why extinguishers have mandatory fire category labels such as "A·B·C" on their bodies.

5 Fire Categories

Why Fire Suppression Methods Differ by Grade

• A-grade fires respond best to water. Water lowers the temperature enough to extinguish the fire source.
• Never spray water on B-grade fires. Oil floats on water, causing the fire to spread in all directions. Use foam or powder to cover and block oxygen.
• Spraying water on C-grade fires causes electric shock. Use non-conductive CO₂ or powder, and turn off the circuit breaker if possible.
• Water on D-grade fires causes explosions. Metal powder reacts with water to produce hydrogen. Use specialized metal fire extinguishing agents (D-grade powder) or dry sand.
• K-grade fires involve edible oil at temperatures above the flash point, so even if temporarily extinguished, they reignite. Use a specialized K-grade extinguisher to create a barrier on the oil surface.

Most Common Extinguishers on Site

ABC dry chemical extinguisher is the standard. It can be used for A, B, and C grades, so it is placed throughout the factory. However, remember that it cannot be used for D or K grades.

Machining areas where chips accumulate and cafeterias with deep fryers must have separate extinguishers.

Check These Items During Your First Week at Work

• Location of the nearest extinguisher in your work area (usually within 20m)
• Fire category label on that extinguisher (A, B, or C)
• Fire category that could occur in your process (e.g., B-grade if using cutting oil, C-grade if near a distribution panel)
• Whether the extinguisher pressure gauge needle is within the green range (report immediately if red)