Fire Loss Control - Basic Elements Mgt. & Maint. IgnitionSources Building Construction OCCUPANCY Jail Fireworks Factory Day Care Code Enforcement Fuel Sources ResponseOn & Offsite CombustionProducts Detection & Suppression

NFPA 921 Fire Definition A rapid oxidation process with the evolution of light & heat in varying intensities.

Oxidation as a Chemical Reaction Breaks down the fuel & oxidizer, allowing the atoms to recombine in the form of compounds different from those from which was started: Reactants - fuel & oxidizers Products - new components

Fire Definition A rapid oxidation process that generates heat. Self-sustaining Exothermic Smoke producing

Fire Definition Rapid, self-sustaining oxidizing process that evolves heat, light & smoke in varying quantities

Fire vs. Combustion Fire Unplanned Uncontrolled Combustion Level of control Fuel & oxidizers are regulated High efficiency

Fire Triangle

Fuel (stored energy) Wood, paper Hydrocarbons (methane, butane, propane) Petroleum products

Oxygen & Oxidizers Unlocks the stored energy Oxygen Chlorine Nitrates Chlorates Concentrated nitric acid

Sources of Heat Energy Chemical Electrical Mechanical Nuclear Decaying organic material (oily rags - spontaneous combustion)

Fire Tetrahedron

Chemical Chain Reaction

Combustion Chain Reactions

Heat Transfer Conduction Radiation Convection

Convection / Conduction

Radiation

Fire Extinguishment Theory Heat removal (water / cooling) Fuel removal (sometimes partial) Oxygen removal Stop chemical chain reaction

Definitions Upper Flammable Limit - The largest concentration of gas or vapor in air which can catch fire or explode when exposed to a source of ignition. Lower Flammable Limit - The smallest concentration of gas or vapor in air which can catch fire or explode when exposed to a source of ignition.

LEL / UEL HYDROGEN ACETONE BENZENE ETHYLENE AMMONIA METHANE 0 10 20 30 40 50 60 70 80 90 100 HYDROGEN 4.1 74.2 ACETONE 2.5 13.0 BENZENE 1.3 7.9 ETHYLENE 2.7 36.0 AMMONIA 16.0 25.0 METHANE 5.3 15.0

LEL UEL LEAN REGION RICH REGION TOO MUCH AIR EXPLOSIVE TOO MUCH GAS

Liquid Fuels Key Definitions Evaporation Vapor Pressure - The pressure exerted by a volatile liquid at a specified temperature. Flash Point - The lowest temperature at which a liquid gives off enough vapor to form an ignitable mixture with air and produce a flame when a source of ignition is present.

Liquid Fuels Ignition Temperature -The minimum temperature to which a fuel in air must be heated in order to start self sustained combustion independent of the heating source. Auto-ignition Temperature - The lowest temperature that a flammable gas-air or vapor-air mixture will ignite from its own heat source or contact with a hot surface, without spark or flame.

Classes of Flammable Liquids Class IA - flashpoint below 73oF & boiling points below 100oF Class IB - flashpoint below 75oF & boiling point at or above 100oF Class IC - flashpoint at or above 73oF & below 100oF

Combustible Liquids Class II - flashpoint at or above 100oF & below 140oF Class IIIA - flashpoint at or above 140oF & below 200oF Class IIIB - flashpoint at or above 200oF

Solid Fuels Key Definitions Pyrolysis - the chemical decomposition of a substance through the action of heat Piloted ignition temperature - heat level required to form a gas that will ignite when exposed to a spark Auto-ignition temperature - The lowest temperature that a flammable gas-air or vapor-air mixture will ignite from its own heat source or contact with a hot surface, without spark or flame.

Classes of Fire A - Ordinary combustibles B - Flammable liquids C - Energized electrical equipment D - Combustible metals K - Cooking appliances involving combustible cooking media (vegetable or animal oils & fats)