Definitions Flashcards
Oxydizing Agent
A Substance that yields oxygen during a chemical reaction
Smoke
A suspension of heated gases and visible small particles of liquids and solids such as steam, carbon, tars and dust in the air resulting from the incomplete combustion of a fuel
Stratification
When heated smoke and gases rise until their temp. and pressure equal ambient air
Bight
A section of rope doubled on itself
Loop
The rope crosses itself to form a circle
Round turn
The rope is wrapped 2 or more times on itself to form a circle
Bend
A tie that is used to join two pieces of rope or webbing together
Hitch
A configuration of a rope that needs an object within to retain its integrity
Knot
A rope intertwined on itself to form a predetermined configuration.
Adiabatic compression
The generation of heat when a gas is compressed
Fission
Splitting atoms to release energy
Fusion
Combining atoms to release energy
Diffusion
A situation in which both fuel and oxidizer, that were previously separate, are now mixing as a direct result of the effects of a premixed flame
Laminar
Likened to the actions of a single smooth flame produced by the ignition of a match
Turbulent
The result of a number of laminar flames interacting with each other thereby creating more disruptive and uncontrolled convected air currents and producing a more unstable and unpredictable movement
Ventilation
Ventilation, as applied in firefighting, is the planned and systematic release and removal of heated air, smoke and toxic gases from a confined area and the controlled replacement of these products of combustion with a supply cooler, fresh air.
Discipline
Refers to the organizations rules, regulations or policies that define the limits or boundaries for the expected performance required to satisfy the goals and objectives of the organization.
SOP’S
The laws of the department and these directives must be adhered to
- They use words like “must” and “will”
- They may result in possible legal implications for a member
SOG’S
Guidelines developed for the safe and efficient mitigation of a myriad of events
- They use words like “may” and “shall”
- May be deviated from and are flexible provided you can justify your actions
Saponification
A reaction that emulsifies the oil to form a type of soap that floats on the surface of the oil and prevents re-ignition of the oil vapors
Reducing agent (fuel)
A substance that is being oxidized in the combustion process
Auto ignition Temp.
Auto Ignition Temperature – the lowest temperature at which a combustible material will ignite without an external source of ignition
Pyrolysis
Pyrolysis defined is the chemical decomposition of a solid material by heating
Vaporization
Vaporization defined is a physical process that changes a liquid into a gaseous state.
endothermic reactions
Chemical reactions that absorb thermal energy or heat are endothermic reactions.
exothermic reactions
Chemical reactions that release thermal energy or heat are exothermic reactions.
Self-Heating
a form of oxidation, is a chemical reaction that increases the temperature of a material without the addition of external heat
Spontaneous Ignition
Initiation of combustion of a material by an internal chemical or biological reaction that has produced sufficient heat to ignite the material
Conduction
Is the transfer of heat through or between solids that are in direct
contact.
Convection
Is the transfer of thermal energy by the circulation or movement of a
fluid (liquid or gas)
Radiation
Is the transmission of energy as an electromagnetic wave, such as
light waves, radio waves, or X-rays, without an intervening medium.
Specific gravity
Specific gravity is the ratio of the mass of a given volume of a liquid compared with the mass of an equal volume of water at the same temperature.
vapor pressure.
The pressure that vapors escaping from a liquid exert is known as vapor pressure.
Flash point
Flashpoint is the minimum temperature at which a liquid fives off sufficient vapors to ignite, but not sustain combustion.
Fire point
Fire point is the temperature at which sufficient vapors are being generated to sustain the combustion reaction.
Solubility
Solubility describes the extent to which a substance (in this case a liquid) will mix with water.
miscible
Materials that are miscible in water will mix any proportion
polar solvents
polar solvents such as alcohols (i.e. methanol, ethanol) will mix readily with water.
Lower Explosive Limit (LEL)
LEL can be defined as the lowest concentration of a combustible or flammable gas in air that will support combustion.
Upper Explosive Limit (UEL)
UEL is the highest concentration of a combustible or flammable gas in air that will support combustion.
Hazardous Material
Any material or substance which even in normal use poses a risk to health, safety, property or the environment
Thermal layering
Thermal layering is the tendency of gases to form into layers according to temperature.
STEL: Short Term Exposure Limit
The average amount of gas (in PPM) a worker can be exposed to in a 15 minute period with no long term health effects. This may occur 4 times a shift with one hour between 15 minute exposures.
TWA: Time Weighted Average
The average amount of gas (in PPM) a worker can be exposed to over a certain time period. This time is defined as 8 hours to represent a normal work day.
IDLH: Immediately Dangerous to Life and Health
The maximum concentration of gas (in PPM) from which a worker could escape within 30 minutes without experiencing any escape-impairing or irreversible health effects
Unstable substances
Unstable substances are capable of changing spontaneously; they decompose violently with little or no outside stimulus.
Reactive substances, as the name indicates, react with other substances. Reactive substances can be hypergolic, pyrophoric, or water reactive.
♦ Hypergolics ignite when they come into contact with each other
♦ Pyrophoric substances react on contact with air.
♦ Water reactive substances react when they come into contact with water or humid air.
physical change
A physical change occurs when a substance remains chemically unchanged but changes in size, shape, or appearance.
chemical change
A chemical change occurs when a substance changes from one type of matter into another, such as two or more substances combining to form compounds.
Energy
Energy is the capacity to perform work.
Potential energy
Potential energy represents the amount of kinetic energy that an object can release at some point in the future.
Kinetic energy
Kinetic energy is the energy possessed by a moving object.
Fire
Fire is an exothermic chemical reaction called combustion that releases energy in the form of heat and sometimes visible light.
Combustion
Combustion is a chemical reaction in which a substance reacts rapidly with oxygen and gives off heat while fire is a possible result of combustion.
Flashover
Flashover is a very rapid transition from local burning of the contents within a compartment to widespread burning of all exposed fuels with that compartment.
Smoke explosion
It is the ignition of a premixed pocket of fire gases and oxygen that may occur when an ignition source is introduced.
Forcible entry
The act of gaining access to a structure through means other than open windows or doors, using applied techniques and available tool which aid in reducing unnecessary damage to the occupancy or compromising structural integrity.
Salvage
Consists of those methods and operating procedures allied to firefighting which aid in reducing forcible entry, fire, water and smoke damage during and after fires.
Boiling point
The temp. at which the vapour pressure of a liquid equals the total pressure of the surface
Vapour density
The density of a gas in relation to air
Specific gravity
The ratio of a mass of a given volume of liquid compared with the mass of an equal volume of water
Density
How tightly the molecules of a substance are packed together
Overhaul
Consists of the search for and extinguishment of hidden or remaining fires, placing the building its contents and the fire area in a safe condition, possibly determining the origin/cause of the fire and recognizing and preserving any evidence of arson.
Water hammer
A surge of pressure caused by he sudden closing or opening of a valve which may cause damage to a pipe or valve.
Incident commander
The person with the overall responsibility and authority for the management of a sec. alarm or multiple alarm incident.
Fire commander
The person with the overall responsibility to manage dispatched resources at an emergency event.
