Chapter 10 (Fire) Flashcards
What are the two factors that can change the state of matter?
Heat and pressure
What is the density of water?
Water = 1
What are the four method of fire suppression?
Remove the reducing agent
Exclude the oxidizing agent
Reduce the temperature
Interrupt the chemical chain reaction
What is the Auto-ignition Temperature?
The temperature at which a material will ignite spontaneously, independent of an external ignition source.
This concept is crucial for understanding material safety and handling.
Define Flash Point.
The lowest temperature at which fuel will give off enough vapours to ignite when exposed to an external ignition source.
Flash point is important for determining the safe storage and handling of flammable materials.
What is the Fire Point?
The temperature at which a liquid fuel will produce vapours sufficient to support combustion once ignited. The fire point is usually a few degrees above the flash point.
Understanding fire point helps in assessing the combustion characteristics of fuels.
What does Ignition Temperature refer to?
The minimum temperature to which the material must be heated to initiate self-sustained combustion independent of an outside heating source.
This concept is essential for fire prevention and safety measures.
Three types of heat energy exposed to in mine rescue?
Chemical
Electrical
Mechanical Heat
Three types of ways heat can travel?
Conduction
Convection (air)
Radiation (heat waves)
What are the five categories of fire classification?
Class A, Class B, Class C, Class D, Class K
These classes are based on the type of materials combusting and the means of extinguishment.
What materials are involved in Class ‘A’ fires?
Ordinary combustible materials such as paper, wood, and cloth
Class A fires require cooling, blanketing, or wetting agents for extinguishment.
What extinguishing agents are used for Class ‘A’ fires?
Water or multi-purpose dry chemical
These agents help to cool and smother the fire.
What types of materials are involved in Class ‘B’ fires?
Flammable liquids such as gasoline, kerosene, and greases
Class B fires require agents that can interrupt chemical reactions and exclude oxygen.
What are the extinguishing agents for Class ‘B’ fires?
Carbon dioxide, dry chemical, and foam
These agents help to inhibit the release of combustible vapours.
What characterizes Class ‘C’ fires?
Fires involving energized electrical equipment
Class C fires often use carbon dioxide as an extinguishing agent.
What is a typical extinguishing agent for Class ‘C’ fires?
Carbon dioxide
High value areas may use ‘clean agents’ that leave no residue.
What must be done if electricity can be de-energized in a Class ‘C’ fire?
The underlying fuel is often Class A or B
De-energizing the electricity can simplify the firefighting approach.
What materials are involved in Class ‘D’ fires?
Combustible metals such as magnesium, potassium, lithium, titanium, and aluminum
Class D fires require special dry powder extinguishing agents.
What extinguishing agents are required for Class ‘D’ fires?
Special dry powder extinguishing agents designed for specific hazardous metals
If such agents are unavailable, dry sand can be used, but water must not be used.
What are the characteristics of Class ‘K’ fires?
Fires involving commercial kitchen appliances with vegetable oils, animal oils, or fats at high temperatures
Class K fires require specific extinguishing agents due to the nature of the fuels.
What extinguishing agent is used for Class ‘K’ fires?
A wet potassium acetate, low pH-based extinguishing agent
This agent is specifically designed for high-temperature kitchen fires.
What are the four phases of a fire?
Incipient
Growth
Fully Developed
Decay
What is rollover in the context of fire dynamics?
Rollover occurs when unburned combustible gases accumulate at the ceiling and ignite upon mixing with oxygen.
What happens during the rollover phenomenon?
A fire front develops, expanding rapidly and rolling across the ceiling.
Fill in the blank: Rollover occurs when unburned combustible gases _______.
[accumulate at the ceiling]
True or False: Rollover involves the combustion of gases that have already burned.
False
What ignites during rollover to create a fire front?
Unburned combustible gases mixed with oxygen.
What is the visual effect of a fire front during rollover?
Licks of flame igniting in upper layers of smoke.
If an extinguisher says 4A 70B C
5US gallons
70 soft
Class C Fire
