What is the primary duty of a Fire Inspector?
To ensure life safety of both the citizens and firefighters of a community
What are the duties of a Fire Inspector
exam building plans, inspect buildings, apply fire and life safety codes and standards adopted by jurisdiction
what is fire?
Fire is a heat producing chemical reaction between a fuel and an oxidizing agent
what is a physical change
a physical change occurs when a material or substance remains chemically the same but changes in size or apperance
Example: Water freezing (liquid to solid)
A chemical change
a chemical change occurs when a substance changes from one type of matter to another
What is a reaction that absorbs energy as they occur
Endothermic
What is a reaction that gives off energy as it occurs/
Exothermic
What type of reaction is fire?
fire is an exothermic reaction called combustion that gives off heat and light.
What is oxidation?
A chemical reaction involving oxygen and another material. examples of oxidation is rust that is slow or the combustion of methane that is fast.
What are the two modes of combustion
flaming and nonflamming or smoldering
Example of nonflamming combustion is charcoals
The material being oxidized or burned in the combustion process
fuel
Two types of fuels
organic and non organic
What are Inorganic fuels?
hydrogen and magnesiuem
what are organic fuels?
They contain carbon
What are the three physical states of matter?
solid, liquid, or gas
For flaming combustion to occur what state must fuel be in?
gaseous
What is Pyrolisis?
Fuel gases and vapor created by a solid fuel
What is the difference between pyrolisis of wood and plastic
Wood releases water as it heats up. Plastic has no water to release.
What is surface to mass ratio?
The shapes and size of solid fuels significantny affect whether they are difficult or easy to light.
What are the characteristic of liquid fuel
They have mass and volume and retain the shap of their container.
What is specific gravity?
Is the ratio of the mass(weight) of an equal volume water at the same temp. Water is = 1
Gasoline is less than 1 (floats on water), epichlorohydrian is more than 1 (heavier than water)
What is vaporization
Transformation of a liquid to a gas
What is vapor pressure?
Pressure produced or exerted by vapors that a liquid releases
flash point
Temperature at which a liquid releases sufficent vapors to ignite but bot sustain combustion.
Flammable/Combustible liquids flash points.
Flammable liquids have a flash point less than 100....Combustile liquids have a flash point greater than 100.
What is solubility
Extent in which a substance mixes with water.
Hydrocarbons (gasoline, diesel) are lighter and do not mix.
Polar solvents (methanol, ethanol) which are alcohols mix readily
What are the problems with water soluble liquids
water based extinguishing agentd (foam) mix with burning liquid making them ineffective
What is Vapor Density
Its the density of a gas in relations to air. Air =1
How much oxygen in air
21%
At normal ambient temperature (70F)how low can the oxygen concentration go and still burn
14%
What happens when oxygen is in higher concentration?
the fire burns more intense
What is Flammable (explosive) range/
The proper fuel to air ratio so combustion can occurr.
What are the two states of energy?
poetential and kinetic
What is poetential energy
it is the energy possessed in an object that may be released in the future
What is kinetic energy?
Energy possesd by a moving object
what are the two forms of ignition
Piloted and auto-ignition
What is ploted ignition
Mixture of fuel finds a external heat source
What is autoignition
The temperature in which the surface of a substance must be heated for ignition and self sustained combustion to occur.
What are the six sources of heat energy?
Chemical, Mechanical, Electrical, Light, Nuclear, and sound
What is chemical heat energy?
Energy that is released when 2 or more chemicls combine with each other
What is self or spontaneous heating?
When a material increases in temperature without the addition of external heat
What is electrical heat energy?
Heat generated as electric current passes through a conductor such as copper wires
what is resistance heating/
Heating produced when electric flows through a conductor
What is overcurrent or over loadinging
Unintended resistance heating. When the current flowing exceeds design limits
What is arching?
High temperature lumminus arch discharging thru a gap such as a charred insulator
What is Mechanical heat energy
Energy generated by friction or compression
The movement of two surfaces against each other
Friction
When gas is compressed it causes
Heat of compression
What is conduction?
The transfer of heat between one object to another.
What is convection
The transfer of heat energy from a fluid (Liquid or gas) to a solid surface
What is radiation?
Transmission of energy as an electromagnetic wave without an intervening medium.
What is the process when molecues break apart and form free radicals that combine with oxygen to form new substances
Self sustained chemical chained reaction
Products of combustion in simple terms
Heat, smoke, and light
What are three more common products of combustion that present hazards to firefighters and occupants?
carbon monoxide, hydrogen cyanide, carbon dioxide
What is CO?
the byproduct of the incomplete combustion of organic materials
What is Hydrogen Cyanide?
Produced in the combustion of materials containing nitrogen and is a significant byproduct of the combustion of polyurethane
What iscarbon dioxide?
Product of complete combustion of organic materials is not toxic in the same manner as CO or HCN but acts as a simple asphyxiant
What is a Class A fire
involves ordinary solid, combustible materials such as wood, cloth, paper, rubber and many plastics
What is a Class B fire?
Involves flammable and combustible liquids such as gasoline, oil, lacquer, paint, mineralspirits
What is a Clas C fire?
Involves energized electrical equipment
What is a Class D fire
Involves combustible metals such as aluminum or magnesiuem
What is a Class K fire
Involves oils and grease normally found in commerical kitchens and food prep facalities
When sufficent oxygen is available, fire development is controlled by the charactristics and configuration of the fuel is called
Fuel controlled
When fire development is limited by air supply the fire is said to be
Ventellation controlled
Fire development in compartments are described by four stages
incepient, growth, fully developed, decay
What starts the incipient stage
ignition. The fire is small and confined to the materials first ignited
What is the growth stage
After the incipent stage a plume of hot gasaes\ rise and combine with cooler air at ceiling called ceiling jet. This transfers the overall temperture in room or compartment
What is Thermal layering?
Gases seperating in a room according to temperature. Hotest gases on the top and coolest gases at bottom
What is mushrooming
When hot gases reach the ceiling and spread horizontally through out compartment
What is it called when hot gases are escaping and cool air is moving into a compartment?
Neutral plane
What is it called when fire moves through the growth stage and pockets of fire move through the hot gas layers
Ghosting
What is ghosting classified as
Fire-gas ignition
What is it called when unburned hot gases accumulate at the top of a compartment and ignite with flames proporgating across the ceiling
rollover
What is the rapid tranition between growth and fully develpoped fire stages in which everything in the compartment reache its ignition temperture at once
Flashover
What are the events that take place before flashover?
Temperature rapidly increases, additional fuels become involved, and the fuel in the compartment is releasing gases caused by pyroloisis
The fire stage in which everything in the compartment is burning. ITS GIVING OFF THE MAXIMUM AMOUNT OF HEAT
Fully developed fire statge
The fire statge as the fuel in the compartment is consumed and the oxygen concentration falls to where combustion can not be supported
Decay statge
What is it called when gases build up due to limited ventellation and maintain an extemely high temperature that when air is introduced can ignite an explosion?
Backdraft
What are the most fundamental fuel characteristics influencing fire development
mass and surface area
What are the factors that influence avaliability and location of additional fuels
Building configuration, content of building, construction of building, construction/interior finish materials,
Is it true that a fire in a large compartment will develop more slowly than one in a small compartment
yes
What are the thermal properties of a compartment?
Insulation, heat reflectivity, retention, conductivity
Does masonary absorb or conduct heat?
Absorbs
Does steel absorb or conduct heat
conducts
What are two famous nightclub fires?
Coconut Grove 1942, 492 people killed. Flammable decorations spread fire.
Station nightclub 61 years later 100 people killed. Pyrotecnics ignited poloyurethene foam sound insulation
In fire control theory firefighters influence fire behavior by doing one or more of the following action
reducing temps, eliminating fuel, seperating fire from available fuel, changing the oxygen concentration, interupting self-sustained chemical chain reaction