Basic Concepts of Fire Protection and Fire Engineering

The most fundamental concept in fire protection engineering is fire itself, as the purpose of fire protection is to prevent and control fires.

Fire Definition

A fire is uncontrolled combustion in time or space that causes damage. In other words, any uncontrolled burning that results in harm to life or property is considered a fire.

By Fuel Type
by Loss Severity
by Location

Fire Classification by Fuel Type

Based on combustible materials and burning characteristics, fires are classified into six categories: A, B, C, D, E, and F.

Class A

Fires involving solid combustibles, typically organic materials that form embers, such as wood, coal, paper, cotton, wool, and textiles.

Class B

Fires involving flammable liquids or liquefiable solids, such as kerosene, diesel, crude oil, methanol, ethanol, asphalt, and paraffin.

Class C

Fires involving flammable gases, such as natural gas, methane, propane, butane, and hydrogen.

Class D

Fires involving combustible metals, such as potassium, sodium, magnesium, and magnesium alloys.

Class E

Fires involving energized electrical equipment.

Class F

Fires involving cooking oils and fats in cooking appliances.

Fire Classification by Loss Severity

Fires are classified by severity of losses as follows:

Catastrophic Fire: ≥30 fatalities, or ≥100 serious injuries, or direct losses ≥ RMB 100 million.
Major Fire: 10–29 fatalities, or 50–99 serious injuries, or direct losses RMB 50–100 million.
Serious Fire: 3–9 fatalities, or 10–49 serious injuries, or direct losses RMB 10–50 million.
General Fire: < 3 fatalities, or < 10 serious injuries, or direct losses < RMB 10 million.

Fire Classification by Location

By location, fires are classified into above-ground building fires, underground building fires, marine fires, forest fires, and grassland fires.

Above-Ground Building Fire

Underground Building Fire

Marine Fire

Forest Fire

Grassland Fire