Terrorism/Hazardous Materials Awareness for First Responders in Ontario: Glossary


2004 ERG	2004 Emergency Response Guidebook: A guidebook for first responders during the initial phase of a dangerous goods/hazardous materials incident. The guidebook is developed by U.S. Department of Transportation in conjunction with Transport Canada and SETIQ (Mexico) and is published every four years in English, French and Spanish.
Abatement	The actions taken to reduce the amount, degree of the hazard, or intensity of the release or threatened release of a hazard.
Absolute Pressure	Gauge pressure plus atmospheric pressure, abbreviated kpa (absolute) psia (true pressure)].
Absorbent Material	A material designed to pick up and hold liquid hazardous material to prevent contamination spread.
Absorption	Taking in toxic material by contact with any exposed body surface. The process of “picking up” a liquid hazardous material to prevent enlargement of the contaminated area.
Acceptable Risk	A risk, judged to be outweighed by corresponding benefits, or one that is of such a degree that it is considered to pose diminished potential for adverse effects.
Access Control Point	The point of entry and exit, which regulates access to and from control zones.
Acid	One of a large class of chemical substances whose water solutions have one or more of the following properties: sour taste, ability to make litmus dye turn red and to cause other indicator dyes to change to characteristic colours, ability to react with and dissolve certain metals to form salts, and ability to react with bases or alkalis to form salts. All acids contain hydrogen. In water, ionization or splitting of the molecule occurs, so that some or most of this hydrogen forms H3O+ ions (hydronium ions), usually written more simply as H+(hydrogen ion).
Acute	Intense. Reaching a crisis rapidly
Acute Effect	A rapid effect to a human or animal body, caused by exposure to a chemical or physical agent, with symptoms developing rapidly. Also see ‘chronic.’
Acute Toxicity	The rapid effects resulting from a single dose or exposure to a substance. Acute effects are defined by the American National Standard Institute (ANSI) Standards for Precautionary Labeling of Hazardous Industrial Chemicals (Z129.1- 1982).
Aerosol	A dispersion of particles of microscopic size in a gaseous medium. Particles may be solid (dust, fume, smoke) or liquid (mist, fog).
Air Bill	A shipping paper prepared from a bill of lading that accompanies each piece of an air shipment.
Air Inversion	A meteorological condition in the earth’s atmosphere in which the temperature of the air some distance above the earth’s surface is higher than the air temperature of the surface. Normally, air temperatures decrease progressively as altitude increases. Such a condition traps air and released gases and vapours near the earth’s surface, thus impeding their dispersion.
Air Modeling	Mathematical models used to predict movement and concentrations of airborne chemicals in the atmosphere
Air Monitoring	The observation, recording, and/or detection of pollutants in ambient air
Air-Reactive Materials	Substances that will ignite at normal temperatures when exposed to air.
Airborne Pollutants	Pollutants that are carried in air
Allocated Resources	Resources dispatched to an incident that have not yet checked in with the incident command system
Alpha Radiation	Alpha particles are the heaviest and most highly charged of the nuclear particles. They cannot travel more than a few inches and will not penetrate outer skin layers. They are hazardous if ingested internally through food or drink.
Ambient Temperature	The temperature of the surrounding environment under consideration.
ANSI	American National Standards Institute; a privately funded, voluntary membership organization that identifies industrial and public needs for national consensus standards and coordinates development of such standards. Many ANSI standards relate to safe design/ performance of equipment such as safety shoes, eyeglasses, etc. and safe practices or procedures, such as noise measurement, testing of fire extinguishers and flame arrestors, etc.
Asphyxiant	A vapour or gas that can cause unconsciousness or death by suffocation (lack of oxygen). Asphyxiants are harmful to the body when they become so concentrated that they reduce the oxygen content in the air (normally about 21%) to dangerous levels or prevent the body from utilizing the oxygen breathed. Asphyxiants are one of the principal potential hazards of working in a confined space.
Asphyxiating Materials	Substances that can cause death through displacement of the oxygen in the air or in the blood stream.
Assigned Protection Factor	See ‘Protection Factor’
Assigned Resources	Resources checked in and assigned work tasks on an accident.
Assisting Agency	An agency directly contributing suppression, rescue, support, or service resources to another agency.
Available Resources	Resources assigned to an incident, available for assignment
Beta Radiation	Beta particles re small and travel faster than alpha particles. They can travel several millimeters through tissue but will not penetrate to vital organs. Exposure from outside the body is normally a slight hazard. Long periods of exposure may burn the skin.
Biological Agent	A biological agent can be a bacteria, virus, rickettsia or toxin. They spread rapidly and cause disease or death. Exposure can be by inhalation (use of aerosols), ingestion (food or water contamination), absorption through the skin or injection by a puncture through the skin surface.
BLEVE	Boiling Liquid Expanding Vapour Explosion. A container failure with a release of energy, often rapidly and violently, accompanied by a release of gas to the atmosphere, followed by ignition (fireball) and propulsion of the container or container pieces.
Boiling Point	The temperature at which a liquid changes to a vapour state, at a given pressure; usually expressed in degrees Celsius (Fahrenheit) at sea level pressure (760 mm Hg, or one atmosphere). For mixtures, the initial boiling point or the boiling range may be given. Flammable materials with low boiling points generally present extreme fire hazards.
Boilover	The violent expulsion of oil and froth from a tank due to the rapid expansion of water into steam when the heat wave in the oil reaches the water layer, usually suspended toward the bottom of a tank of heavy or unrefined oil.
Breakthrough	The penetration of challenge material(s) through a gas or a vapour air-purifying element or fabric. The quantity or extent of breakthrough during service life is often referred to as the percentage of the input concentration.
Bulk Container	A cargo container such as that attached to a tank truck or tank car, used for transporting materials in bulk quantities.
Bulk Plant	That portion of a property where flammable or combustible liquids are received by tank vessel, pipeline, tank cars, or tank vehicle, and are stored or blended in bulk for the purpose of distributing such liquids by tank vessel.
Bung	A cap or screw used to cover the small opening in the top of a drum or barrel.
‘C’ or Ceiling	The maximum allowable human exposure limit (not to be exceeded) for an airborne substance. Also see “PEL”and “TLV.”
CANUTEC	Canadian Transport Emergency Centre operated by the Transport Dangerous Goods Directorate of Transport Canada.
Carboy	A bottle or rectangular container for liquids of 22.5 ∫ to 67.5 ∫ (5 to 15 gallons) capacity that is made of glass, plastic, or metal and is often cushioned in a protective container.
Carcinogen	A substance or agent capable of causing or producing cancer in mammals. (See also ‘Potential Occupational Carcinogen’)
Carcinogenisis	The growth process of cancer as a result of exposure to a particular substance or agent.
Cargo Manifest	A shipping paper that contains all of the contents being carried by the transporting vehicle or vessel.
CBRNE	An acronym for chemical, biological, radiological, nuclear and explosive.
cc	Cubic centimeter; a volume measurement in the metric system, equal in capacity to one milliliter (ml). One quart is about 946 cc.
Chemical	Regulated and nonregulated hazardous materials (solids, liquids, and gases, whether natural or man-made, including petroleum products) with the potential for creating harm to people, the environment and property when released.
Chemical Agent	Can include substances that impede nerve transmission (SARIN), blister agents, block transport of oxygen in the blood (hydrogen cyanide), cause choking (chlorine), or respiratory distress (tear gas or MACE), when in contact with skin or mucous membrane.
Chemical Family	A group of single elements or compounds with a common name. Example: acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) are of the ketone family
CHEMTREC	Chemical Transportation Emergency Center; a national center established by the Chemical Manufacturers Association (CMA) in Washington, DC, in 1970, to relay pertinent emergency information concerning specific chemicals on request.
Chronic Effect	An adverse effect on a human or animal body, with symptoms that develop slowly over a long period of time and exposure to a chemical or physical agent. Also see “acute.”
Chronic Toxicity	Adverse effects resulting from repeated doses of or exposures to a substance over a relatively prolonged period of time. Ordinarily used to denote effects in experimental animals.
Class A Explosive	A material or device that presents a maximum hazard and functions by detonation. (DOT definition)
Class A Poison	A poisonous gas or liquid of such nature that a very small amount of the gas, or vapour of the liquid, is dangerous to life.
Class B Explosive	A material or device that presents a flammable hazard and functions by deflagration. (DOT definition)
Class B Poison	Liquids or solids (other than Class A Poisons or Irritating Materials), which are known to be so toxic to humans as to afford a hazard to health during transportation.
Class C Explosive	A material or device that contains restricted quantities of either Class A or Class B explosives or both, but presents a minimum hazard. (DOT definition)
Clear Text	The use of plain English in radio communication transmissions. No ten codes, or agency specific codes, are used when using clear text.
CO	Carbon Monoxide, a colourless, odourless, flammable and very toxic gas produced by the incomplete combustion of carbon; also a by-product of many chemical processes.
CO2	Carbon Dioxide, a heavy, colourless gas produced by complete combustion and decomposition of organic substances, and is a by-product of many chemical processes. CO2 will not burn and is relatively non-toxic (although high concentrations, especially in confined spaces, can create hazardous oxygen deficient environments). Is an asphixiant.
Cold Zone	This area contains the command post and such other support functions as are deemed necessary to control the incident. This is also referred to as the clean zone or support zone.
Combustible Liquid	A term used by NFPA, and others to classify certain liquids that will burn, on the basis of flash points. In the Hazard Communication Rules, a combustible liquid has a flash point at or above 37.8º C, (100º F) but below 93.3º C (200º F).
Combustion Explosion	Sudden fracture of a container or structure accompanied by a shock wave (sound). Combustion of a flammable mixture within a container or structure producing a gas pressure greater than the container or structure can withstand.
Comm Unit (Communications Unit)	A vehicle (trailer or mobile van) used to provide the major part of an incident communications centre.
Command	The act of directing, ordering, and/or controlling resources by virtue of explicit legal, agency, or delegated authority
Command Staff	The Command Staff consists of the Information Officer, Safety Officer, and Liaison Officer. They all report directly to the Incident Commander.
(CP) Command Post	That location at which the primary command functions are executed and usually co-located with the incident base.
Company	Any piece of equipment having a full complement of personnel.
Competence	Possessing knowledge, skills and judgment needed to perform indicated objectives satisfactorily.
Compressed Gas	Any material which, when enclosed in a container, has an absolute pressure exceeding 275.8 kpa (40 psi) at 21º C (70º F) or exceeding 965.3 kpa (140 psi) at 55º C (130º F).
Compressed gas in Solution	A non-liquefied gas that is dissolved in a solvent but in a solution at high pressures (e.g., acetylene).
Concentration	The relative amount of a substance when combined or mixed with other substances. (e.g., 2 parts per million (ppm) hydrogen sulfide in air; or a 50 percent caustic solution.)
Confinement	Those procedures taken to keep a material in a defined or local area.
Confined Space	An area large enough and so configured that a member can bodily enter and perform assigned work but which has limited or restricted means for entry and exit and is not designed for continuous human occupancy.
Consignee	The person who is to receive a shipment.
Consist	A rail shipping paper similar to a cargo manifest. It may contain a list of the cars in the train, in order or a list of those cars carrying hazmats and their location on the train.
Container	Any bag, barrel, bottle, box can, cylinder, drum, reaction vessel, storage tank, or the like that contains a hazardous material.
Containment	Those “procedures taken to keep a material in a specified area such as a dyke surrounding a tank or a temporary boom surrounding a spill etc.”
Contaminant	A hazardous material that physically remains on or in people, animals, the environment, or equipment, thereby creating a continuing risk of direct injury or a risk of exposure.
Contamination	The process of transferring a hazardous material from it’s source to people, animals, the environment or equipment which may act as a carrier.
Secondary Contamination	The process by which a contaminant is carried out of the hot zone and contaminates people, animals, the environment or equipment.
Control	The procedures, techniques and methods used in the mitigation of a hazardous materials incident, including containment, extinguishment and confinement.
Control Agent	Any material that is used to contain or extinguish a hazardous material or its vapours.
Control Zones	The designation of areas at a hazardous materials incident based upon safety and the degree of hazard.
Cooperating Agency	An agency supplying assistance other than direct suppression, rescue, support or service functions to the incident control effort (e.g., Red Cross, law enforcement agency, telephone company, etc.)
Coordination	The process of systematically analyzing a situation, developing relevant information, and informing appropriate command authority (for its decision) of viable alternatives for selection of the most effective combination of available resources to meet specific objectives. The coordination process (which can either be intra- or inter-agency) does not in and of itself involve command dispatch actions. However, personnel responsible for coordination may perform command or dispatch functions within limits as established by specific agency delegations, procedures, legal authority, etc.,
Corrective Actions	Actions taken by the Incident Commander to correct the problem at hand during a hazmat/terrorist emergency.
Corrosive	A corrosive material is a liquid or solid that causes visible destruction or irreversible alterations in human skin tissue at the site of contact; or a liquid or solid significantly deteriorates the container and/or packaging, resulting in breach of containment.
Cryogenic Liquid	Gases that must be cooled to a very low temperature to bring about a change from gas to liquid. Stored at temperatures from -101º C (-150º F) to absolute zero -272.7º C. (-459º F)
Cutaneous Toxicity	See “Dermal Toxicity
Dangerous Cargo Manifest	A cargo manifest used on ships that contains a list of all the hazardous materials on board, including their locations.
Decomposition	Breakdown of a material or substance (by heat, chemical reaction, electrolysis, decay, or other processes) into parts, elements or simpler compounds.
Decontamination(contamination reduction)	The physical and/or chemical process of reducing and preventing the spread of contamination from persons and equipment used at a hazmat incident.
Decontamination Area	The area, usually located within the warm zone, Area where decontamination takes place.
Deflagration	Propagation of burning that takes place at a speed below the speed of sound.
Degradation	A chemical action involving the molecular breakdown of a protective clothing material due to contact with a chemical. The term “degradation”may also refer to the molecular breakdown of the spilled or released material to render it less hazardous.
Demonstrate	To show, by actual use. This may be supplemented by simulation, explanation, illustration or a combination of these.
Dermal Toxicity	Adverse effects resulting from skin exposure to a substance.
Dermal	Used on, or applied to, the skin.
Detonation	An extremely rapid reaction that generates a shock wave which passes along the body of an explosive, at speeds greater than sound, producing a violently disruptive effect.
Dikes	Temporary walls constructed to halt the flow of a liquid substance. Also, earthen or concrete walls surrounding oil tanks, designed to catch overflow from the tanks and relieve the danger of flowing flammable liquids spreading to other exposures.
Dirty Bomb	An ordinary explosive device containing some radioactive material. Becomes a “radiological dispersal device”. Can use medical isotopes and be as small as one stick of dynamite. Contamination can be widespread and last for decades.
Dispatch	The implementation of a command decision to move a resource or resources from one place to another.
Dispatch Centre	A facility from which resources are directly assigned to an incident.
Disposable Respirators	A respirator that is discarded after the end of its recommended period of use, after excessive resistance or physical damage, or when odour-breakthrough or other warning indicators render the respirator unsuitable for further use.
Division	That organization level having responsibility for operations within a defined geographic area or with functional responsibility. The division level is organizationally between the strike team and the branch. (Also see Group)
Dome	The circular cover on the top of a tank car that contains valves and relief valves.
Dust	Any finely divided solid material. Usually smaller than 420 microns in size.
Dust and Mist Respirators	Respirators approved for the use against dusts or mists that may cause pneumoconiosis and fibrosis.
Emergency Plan (EP)	A document that assigns responsibility to organizations and individuals for carrying out specific actions at projected times and places in an emergency that exceeds the capability or routine responsibility or any one agency.
Emergency Response Guidebook (ERG)	A reference book, written in plain language, to guide emergency responders in their initial actions at the incident scene.
Emergency Respirator Use Situation	A situation that requires the use of respirators due to the unplanned generation of a hazardous atmosphere (often of unknown composition) caused by an accident, mechanical failure, or other means and that requires evacuation of personnel or immediate entry for rescue or corrective action.
Emergency Shut-Off	A means of operating a valve that stops the flow of substance.
Endangered Area	The actual or potential area of exposure from a hazardous material.
Engine Company	Any ground vehicle providing specified levels of pumping, water, hose capacity, and personnel.
Epidemiology	The science that deals with the study of disease in a general population. Determination of the incidence (rate of occurrence) and distribution of a particular disease (as by age, sex, race, or occupation) may provide information about the causes of the disease.
Equilibrium	(1) Chemical equilibrium is a condition in which a reaction and its opposite or reverse reaction occur at the same rate, resulting in a constant concentration of reactants; for example, ammonia synthesis is at equilibrium when ammonia molecules form and decompose at equal velocities (N2 + 3H2Û 2NH3). (2) Physical equilibrium is exhibited when two or more phases of a system are changing at the same rate so that the net change in the system is zero.
Escape Gas Mask	A gas mask that consists of a half-mask face piece or mouthpiece, a canister, and associated connections and that is designed for use during escape only from hazardous atmospheres.
Escape Only Respirator	Respiratory devices that are designed for the use during escape from hazardous atmospheres.
Etiologic Agent	An agent that produces an effect (e.g.: A living microorganism that may cause human disease.)
Evaporation Rate	The rate at which a particular material will vaporize as compared to the rate of vaporization of a known material. The evaporation rate can be useful in evaluating the health and fire hazards of a material. The known material is usually butyl acetate (n-BuAc), with a vaporization rate designated as1.0. Vaporization rates of other solvents or materials are then classified as: FAST evaporating if greater than 3.0 (examples: Methyl Ethyl Ketone (MEK)=3.8, Acetone=5.6, Hexane=8.3); MEDIUM evaporating if 0.8 to 3.0 (examples: 190 proof Ethyl Alcohol=1.4, VM&P Naptha=1.4, MBK=1.6); SLOW evaporating if less than 0.8 (examples: Xylene=.6, Isobutyl Alcohol=.6, Normal Butyl Alcohol=.4, Water=.3, Mineral Spirits=.1).
Excess Flow Valve	A safety valve designed to shut-off the flow of a liquid when the flow exceeds a pre-set rate.
Explosive	Any chemical compound, mixture or device, the primary purpose of which is to function by explosion.
Explosive Limits	A range of concentrations of a mixture of flammable vapour or gas in air, usually expressed in percent by volume, in which a flash will occur or a flame will travel if the mixture is ignited. (Also known as ‘flammable limits’).
Exposures	People, the environment or property that are or that may be exposed to the harmful effects of a hazardous materials emergency.
Feedback	An element of a system that is the return of a portion of the output to the input. This allows the system to evaluate itself.
Filtering Facepiece	A particulate respirator with a filter as an integral part of the face piece or with the entire face piece composed of the filtering medium. (See “Single-use dust”or dust and mist respirators and disposable respirators).
Fire Point	The lowest temperature of a liquid at which vapours are evolved fast enough to support continuous combustion.
First Responder at the Awareness Level	Those persons who, in the course of their normal duties, could be the first on the scene of an emergency involving hazardous materials and who are expected to recognize the presence of hazardous material, protect themselves, call for trained personnel, and secure the scene.
Fit Factor	A quantitative measure of the fit of a specific respirator face piece to a particular individual.
Flame Impingement	The points where flames contact the surface of a container.
Flammable	A “flammable liquid”is defined by NFPA as a liquid with a flash point below 37.8º C (100º F). Solids which will ignite readily or are liable to cause fires under ordinary conditions of transportation through friction or retained heat from manufacturing or processing, and which burn so vigorously and persistently as to create a serious transportation hazard, are classified as “flammable solids.”Also see “combustible.”
Flammable Gas	In order to be considered a ‘flammable’ gas, a chemical must have an LFL of 13% or below, or a flammable range of 12%.
Flammable Limits	See “explosive limits”.
Flammable Liquid	Any liquid having a flash point below 37.8º C (100º F).
Flammable Material	A substance that is capable of being easily ignited and of burning rapidly.
Flammable Solid	Any material, other than an explosive, that is liable to cause fires through friction, retained heat from manufacturing or processing, or that can be ignited readily and when ignited burns so vigorously and persistently as to create a serious transportation hazard.
Flash Point	The lowest temperature at which a liquid substance gives off flammable vapours sufficient to form an ignitable mixture with air near the surface of the liquid. Combustion is not continuous at the flash point. There are several flash point test methods, and flash points may vary for the same material depending on the method used, so the test method is indicated.
Flashback	Re-ignition of flammable liquid caused by exposure of its vapours to an ignition source.
Floating Roof	A type of roof used on oil tanks to stop evaporation loss and reduce the fire hazard by reducing the vapour space over the liquid.
Food Dispenser	Any vehicle capable of dispensing food to incident personnel.
Formula	The conventional scientific designation for a material (water is H2O, sulfuric acid is H2SO4, sulfur dioxide is SO2, etc.)
Frothover	A steady, slow frothing over of a tank without the sudden action that occurs in a boilover.
Fuel Tender	Any vehicle capable of supplying fuel to ground or airborne equipment.
Fume	A solid condensation particulate, usually of vapourized metal.
Fusible Plugs	A safety relief device in the form of a plug of low melting metal. The plugs close the safety relief device channel under normal conditions, and are intended to yield or melt at a set temperature to permit the escape of gas.
Gamma Rays	A type of electromagnetic radiation transmitted through space in the form of waves. They are the most penetrating type of radiation.
G/kg	Grams per kilogram. An expression of dose used in oral and dermal toxicology testing, to indicate the grams of substance dosed per kilogram of animal body weight. Also see “kg” (kilogram).
Gas	A formless atmosphere, which occupies completely a space or an enclosure. An aeriform fluid that is in a gaseous state at a standard temperature and pressure.
Gauge Pressure	The pressure read on a gauge, indicating a value that is above the atmospheric pressure.
General Exhaust	A system for exhausting air-containing contaminants from a general work area. Also see “local exhaust.”
g	Gram. A metric unit of weight. One ounce UIS (avoirdupois) is about 28.4 grams.
Group	A functional division (e.g., air support, salvage, structure protection, etc.)
Half-Life	The time required for an unstable element or nuclide to lose one-half of its radioactive intensity in the form of alpha, beta and gamma radiation. It is a constant for each radioactive element or nuclide. Half-lives vary from fractions of a second for some artificially produced radioactive elements to millions of years. The half-life of Uranium 235, for example, is 710,000,000 years.
Hatch Plan	A schematic drawing of the location of all cargo on a ship (also referred to as a stowage plan).
Hazard Class	A group of materials that share a common major hazardous property, e.g., radioactivity, flammability.
Hazard	A condition that is capable of posing a risk to health, safety, or the environment. Capable of doing harm.
Hazardous Material	A substance that poses a risk to life, the environment, or property, when released from its container.
Hazardous Materials Response Team	A group of trained response personnel operating under an emergency response plan and appropriate standard operating procedures to control or otherwise minimize or eliminate the hazards to people, property, or the environment from a released hazardous material.
Heat Wave	A layer of hot liquid in a tank produced by the heat of the burning vapour at the top of the tank. As the burning progresses, this layer becomes thicker, extending down into the liquid in the tank.
High Temperature Protective Clothing	Protective clothing designed to protect the wearer for short-term high-temperature exposures. This type of clothing is usually of limited use in dealing with chemical commodities.
Hot Zone	The area immediately surrounding a hazardous materials incident that extends far enough to prevent adverse effects from hazardous materials releases to personnel outside the zone. This zone is also referred to as the exclusion zone or restricted zone.
IDLH	Immediately Dangerous to Life and Health. The maximum level of concentration from which one could escape within thirty minutes without any escape impairing symptoms or health effects.
Ignitable	Capable of being set afire
Ignition Temperature	The minimum temperature to which a substance must be heated in order to initiate self-sustained combustion.
Incendiary Device	Any mechanical, electrical or chemical device used to intentionally initiate combustion and start a fire.
Incident	An occurrence or event - either human- caused or natural phenomenon - that requires action by emergency service personnel to prevent or minimize loss of life or damage to property and/or natural resources.
Incident Action Plan	The incident action plan, which is prepared at the initial meeting of incident command, contains general control objectives reflecting the overall incident strategy and specific action plans for the subsequent operational period. When complete, the incident action plans will have a number of attachments.
Incident Base	That location at which the primary logistics functions are coordinated and administered. (The specific incident name or other designator will be added to “base”at the time of an incident.) The incident command post may be co-located with the base. There is only ever one base per incident.
Incident Management System (IMS)	The combination of facilities, equipment, personnel, procedures and communications, operating within a common organizational structure, with responsibility for the management of assigned resources to effectively accomplish stated objectives pertaining to an incident.
Incident Commander	The person responsible (and accountable) for all decisions relating to the management of an incident. The Incident Commander is in charge of an incident.
Incipient Fires	Fires that are in the beginning stages.
Incompatible	Materials that could cause dangerous reactions from direct contact with one another are described as “incompatible.”
Individual Container	A cargo container such as a box or a drum, used to transport materials in small quantities.
Infrared (IR)	A heat detection system used for fire detection, mapping and hot spot identification.
Ingestion	The intake of a substance through the mouth.
Inhalation	Breathing a substance in the form of a gas, vapour, fume, mist or dust.
Inhibitor	A substance that prevents or slows down a process or reaction.
Initial Attack	Resources initially committed to an incident.
Irritant	A substance, which, by contact in sufficient concentration for a sufficient period of time, will cause an inflammatory response or reaction of the eye, skin or respiratory system. The contact may be a single exposure or multiple exposures.
Irritating	An irritating material is a liquid or solid substance which, upon contact with fire, or when exposed to air, gives off dangerous or intensely irritating fumes (not including poisonous materials.)
kg	Kilogram. A metric unit of weight, equivalent to about 2.2 US pounds.
l	Litre. A metric unit of volume. A US quart is about 9/10 of a litre.
Labels	10 cm (4”) square diamond-shaped markers required on individual shipping containers smaller than 18 m³ (640 cu. ft.).
LC	Lethal Concentration. A concentration of a substance that will kill an animal upon inhalation.
LC50	Lethal Concentration 50%. The concentration of a material in air, which, on the basis of laboratory tests, is expected to kill 50% of a group of test animals when administered as a single exposure (usually one to four hours). The LC50 is expressed as parts of material per million parts of air (ppm), by volume for gases and vapours, or as micrograms of material per litre of air (mg/l), or milligrams of material per cubic meter of air (mg/m) for dusts, mists, gases and vapours.
LD	Lethal Dose. A concentration of a substance that will kill an animal by ingestion or skin contact.
LD50	Lethal Dose 50%. A single dose of a material, which, on the basis of laboratory tests, is expected to kill 50% of a group of test animals. The LD50 is expressed as milligrams or grams, or material per kilogram of animal body weight (mg/kg or g/kg).
LEL	Lower Explosive Limit. (also known as “LFL”or “Lower Flammable Limit”) of a gas or vapour. The lowest concentration (lowest percentage of the substance in air) that will produce a flash of fire when an ignition source (heat, arc or flame) is present. At concentrations lower than the LEL, the mixture is too “lean”to burn.
	Also see “UEL.”)
LFL	Lower Flammable Limit. (see LEL).
Light Ends	Petroleum products that have relatively low flashpoints and high vapour pressure. Common light ends are methane, ethane, propane and butane.
Liquefied Gas	A gas that is under pressure and is partially liquid at a temperature of 21º C (70º F).
Liquefied Petroleum Gas	Petroleum gases which can be liquefied under moderate pressures. Common LPGs are butane and propane.
Local Exhaust	A system for capturing and exhausting contaminants from the air at the point where the contaminants are produced (e.g. during welding, grinding, sanding). (Also see “General Exhaust”).
Low Pressure Tank	A storage tank which has been designed to operate at pressures above 3.4 kpa (0.5 psig but not more than 103.4 kpa (15 psig).
Lower Explosive Limit	See “LEL”.
Lower Flammable Limit	See “LFL”.
m3	Cubic Metre. A metric measure of volume equivalent to about 35.3 cubic feet or 1.3 cubic yards.
Material Safety Data Sheets (MSDS)	Documentation provided by manufacturers and compounders of chemicals with minimum information about chemical composition, physical and chemical properties, health and safety hazards, emergency response, and waste disposal.
Mechanical Exhaust	A powered device - such as a motor-driven fan or air stream Venturi tube-for exhausting contaminants from a workplace, vessel or enclosure.
Melting Point	The temperature at which a solid substance changes to a liquid state. For mixtures, the melting “range”may be given.
mg	Milligram. A metric unit of weight. 1000 milligrams = 1 gram (g).
mg/m3	Milligrams per cubic meter. Unit for measuring concentrations of gases,
	vapours or particles in air.
mg/kg	Milligrams per kilogram. May reflect a concentration of dose.
MOE	Ministry of the Environment.
MOL	Ministry of Labour.
Miscibility	A liquid’s ability to mix with water and form a homogeneous mixture.
Mist	A liquid condensation particle.
ml	Milliliter. A metric unit of volume equal to one cubic centimeter or about 1/16 of a cubic inch. 1000 ml = one litre.
mm Hg	Millimeters of Mercury. A unit of measurement for low pressures or partial vacuums.
Mobilization Centre	An off-incident location at which emergency service personnel and equipment are temporarily located pending assignment, release or reassignment.
Monitoring Equipment	Instruments and devices used to identify and quantify contaminants.
Mutagen	A substance or agent capable of altering the genetic material in a living cell.
Mutagenisis	Alteration of the inherited material
N2	Nitrogen. A colourless, odourless and tasteless gas that will not burn and will not support combustion. The earth’s atmosphere is about 78 percent nitrogen. At higher concentrations Nitrogen can displace Oxygen and become a lethal asphyxiant.
NFPA	National Fire Protection Association. An international, voluntary organization dedicated to promoting and improving fire protection and fire-prevention, and to establish safeguards against loss of life and property by fire. Best known on the industrial scene for the National Fire Codes - 16 volumes of codes, standards, recommended practices and manuals developed and periodically updated by NFPA technical committees.
Nerve Agent	A form of chemical agent that disrupts nerve transmissions. Similar to pesticides but with a higher degree of toxicity. Are usually in liquid form that is sprayed as an aerosol. Symptoms include sweating, tearing eyes, muscle twitching, tremors, difficulty breathing.
Non-Flammable Gas	A gas that does not burn, such as Nitrogen, or Carbon dioxide.
Non-Liquefied Gas	A gas that is entirely gaseous at a temperature of 21º C (70º F).
NOS	“Not Otherwise Stated”or “Not Otherwise Specified
NOx	Oxides of nitrogen. Undesirable air pollutants, NOx emissions are regulated by EPA under the Clean Air Act.
OHSA	Occupational Health and Safety Act refer to provincial legislation regarding workplace health and safety. The Workplace Hazardous Materials Information System (WHMIS) is a regulation under this act.
Olfactory	Relating to the sense of smell. The olfactory organ in the nasal cavity is the sensing element that detects odours and transmits information to the brain through the olfactory nerves.
Operational Period	The period of time scheduled for execution of a given set of operational actions as specified in the Incident Action Plan.
Oral	Used in or taken into the body through the mouth.
Oral Toxicity	Adverse effects resulting from taking a substance into the body by ingestion.
Organic Peroxide	An organic derivative of the inorganic compound hydrogen peroxide
Orinasal Respirator	A respirator that covers the nose and mouth and generally consists of a quarter- or half-face piece.
ORM	Other Regulated Materials. Materials that do not meet the definitions of hazardous materials, but possesses enough hazardous characteristics that they require regulation.
Orthophoto Maps	Aerial photographs corrected to the scale such that geographic measurements may be taken directly from prints. They may contain graphically emphasized geographic features and may be provided with overlays of such features as water systems, important facility locations, etc.
Out-Of-Service	Resources assigned to an incident, unavailable for various reasons.
Resources Oxidation	In a literal sense, oxidation is a reaction in which a substance combines with oxygen, provided by an oxidizer or oxidizing agent. (See definitions below). In a broader sense, based on modern atomic theory, science today defines oxidation as a reaction - brought about by an oxidizing agent - in which atoms, molecules or ions lose electrons. In this broader sense, an oxidation reaction may occur even when oxygen is not present.
Oxidizing Ability	The ability to yield oxygen readily to stimulate combustion.
Package Markings	The descriptive name, instructions, cautions, weight or specification marks required to be placed on the outside containers of hazardous materials.
Packaging	Any container that holds a material (hazardous or non-hazardous). Packaging includes non-bulk and bulk packaging.
Bulk Packaging	Any packaging, including transport vehicles, having a liquid capacity or more than 450 L (119 gal), a solids capacity of more than 400kg (880 lb), or a compressed gas water capacity of more than 454kg (998 lb)
Penetration	The movement of a material through a suit’s closures, such as zippers, buttonholes, seams, flaps or other design features of chemical protective clothing, and through punctures, cuts and tears.
Percent Volatile	Percent Volatile by volume: the percentage of a liquid or solid (by volume) that will evaporate at an ambient temperature of 21º C (70º F) (unless some other temperature is stated). Examples: butane, gasoline and paint thinner (mineral spirits) are 100 percent volatile; their evaporation rates vary, but over a period of time, each will evaporate completely.
Permeation	Is the flow of material through a porous material and can be at the molecular level.
Personal Protective Equipment	The equipment provided to shield or isolate a person from the chemical, physical, nuclear, biological and thermal hazards that may be encountered at a hazardous materials incident. Adequate personal protective equipment should protect the respiratory system, skin, eyes, face, hands, feet, head, body and hearing. Personal protective equipment includes both personal protective clothing and respiratory protection.
PH	Indication of the acidity or alkalinity of a substance. A pH from 1 to 7 is acidic and from 7 to 14, alkaline. A pH of 7 is neutral. Technically, pH is the logarithm of the reciprocal of the concentration of hydrogen ions in solution.
Piggyback Transport	A type of shipping in which bulk containers from one mode such as highway transportation are placed on flat cars or container-ships for transportation by another mode such as rail or marine.
Placards	Diamond shaped markers, a minimum of 25 cm x 25 cm (10-3/4 x 10-3/4”) required on hazmat transporting vehicles - trucks, tank cars, freight containers 18 m³(640 cu. ft.) or larger, etc.
Poison, Class A	A gas or liquid so toxic that an extremely small amount of the gas or the vapour formed by the liquid is dangerous to life
Poison, Class B	Less toxic liquids and solids that are hazardous when absorbed or ingested.
Poison, Class C	Liquids or solids that evolve toxic or strongly irritating fumes when heated or when exposed to air (excluding Class A poisons).
Poisons, Class D	Radioactive materials
Polar Solvents	Any flammable liquid that is miscible with water.
Polymerization	A chemical reaction in which one or more small compounds combine to form larger compounds. A hazardous polymerization is such a reaction which takes place at a rate which releases large amounts of energy (usually heat). If hazardous polymerization can occur with a given material, the MSDS usually will list conditions, which could start the reaction, and since the material usually contains a polymerization inhibitor, the expected time period before the inhibitor is used up.
ppb	Parts per billion. Unit for measurement of the concentration of a gas or vapour in air.
ppm	Parts per million. Unit for the measurement the concentration of gases, vapours and solids.
Pressure Vessel	A storage tank or vessel that has been designed to operate at pressures above 103.4 kpa (15psig).
Preventive Actions	Actions taken by the incident commander at an emergency to prevent the problem from increasing.
Protection Factors	Assigned protection factor (APF). The minimum anticipated protection provided by a properly functioning respirator or class of respirators to a given percentage of properly fitted and trained users. Simulated workplace protection factor (SWPF) A surrogate measure of the workplace protection provided by a respirator. Workplace protection factor (WPF) A measure of the protection provided in the workplace by a properly functioning respirator when correctly worn and used.
Protective Clothing	Equipment designed to protect the wearer from heat and/or hazardous materials. Protective clothing is divided into three types: structural fire fighting protective clothing, chemical protective clothing, and high-temperature protective clothing.
psi	Pounds per square inch (1 psi = 6.895 kpa). For MSDS purposes, a unit for measuring the pressure a material exerts on the walls of a confining vessel or enclosure. For technical accuracy, pressure must be expressed as psig (pounds per square inch gauge) or psia(pounds per square inch absolute). However a differentiated pressure is shown as psi.
Pyrophoric Liquid	Any liquid capable of igniting spontaneously when exposed to dry or moist air.
Radio Cache	A cache may consist of a number of portable radios, a base station, and in some cases, a repeater, stored in a predetermined location for dispatch to incidents.
Radiation Sickness	Acute radiation sickness occurs when an individual is exposed to a large amount of radiation within a short period of time. Symptoms include skin irritation, nausea, vomiting, high fever, hair loss and dermal burns.
Radioactive Material(RAM)	Any material that spontaneously emits ionizing radiation
Radiological Dispersal Device (RDD)	A conventional explosive device incorporating nuclear materials in order to spread radioactive material throughout the bombsite.
Reaction	A chemical transformation or change. The interaction of two or more substances to form new substances.
Reactivity	A description of the tendency of a substance to undergo chemical reaction (usually with the release of energy). Undesirable effects such as pressure buildup, temperature increase, and formation of noxious toxic or corrosive products may occur because of the reactivity of a substance by heating, burning, direct contact with other materials or other conditions of use or storage.
Recommended Exposure Limit	See “REL”.
Reducing Agent	In a reduction reaction (which always occurs simultaneously with an oxidation reaction) the reducing agent is the chemical or substance which combines with oxygen, or which loses electrons in the reaction. Also see “oxidation.”
Refinery	A place where crude materials are purified.
REL	Recommended exposure limit. An 8- or 10-hour, time weighted average (TWA) or ceiling (C) exposure concentration recommended by NIOSH which is based on an evaluation of health affects data.
Resources	All of the immediate or supportive assistance available to help control an incident, including personnel equipment, control agents, agencies and printed emergency guides.
Respiratory Protection	Equipment designed to protect the wearer from the inhalation of contaminants. Respiratory protection is divided into three types: positive pressure self-contained breathing s (SCBA); positive pressure supplied-air respirators; and air purifying respirators.
Respiratory System	The body’s breathing system, including the lungs, trachea, mouth and nose and the associated nervous and circulatory supply systems.
Response	That portion of an incident management in which personnel are involved in controlling a hazardous materials incident.
Rupture Disk	A safety relief device in the form of a metal disk that closes the relief channel under normal conditions. The disk bursts at a set pressure to permit the escape of gas.
SAC	Spills Action Centre - a spill reporting centre operated by the MOE.
Safety Relief Valve	A device found on pressure cargo tanks containing an operating part that is held in place by spring force. Valves open and close at set pressures.
Section	That organization level having functional responsibility for primary segments of incident operations such as operations, planning, logistics, finance. The section-level is organizationally between branch-and incident-commander.
Sensitizer	Substance, which on first exposure causes little or no reaction in humans but which, on repeated exposure, may cause a marked response not necessarily limited to the contact site. Skin sensitization is the most common form of sensitization in the industrial setting, although respiratory sensitization to a few chemicals is also known to occur.
Service Life	The length of time for an air-purifying element to reach a specific effluent concentration. Service life is determined by the type of substance being removed, the concentration of the substance, the ambient temperature, the specific element being tested (cartridge or canister), the flow rate resistance and the selected breakthrough value. The service life for a self-contained breathing apparatus (SCBA) is the period of time, as determined by the NIOSH certification tests, in which adequate breathing gas is supplied.
Sheer Section	A safety feature incorporated into cargo tank piping and fittings designed to fail or break completely to prevent damage to shut-off valves or the tank itself.
Shipping Documents	A shipping order, bill of lading, manifest, or other shipping paper or document issued by the carrier.
Single-Use Dust	Respirators approved for use against dusts or mists that may cause pneumoconiosis and fibrosis.
Slopover	An expulsion of oil and froth from the surface of a tank, produced when water or foam is applied to a burning liquid surface.
Solubility	A measure of the amount of a substance that will dissolve in another substance.
Solubility In Water	A term expressing the percentage of a material, by weight, which will dissolve in water at ambient temperature. Solubility information can be useful in determining spill cleanup methods and fire extinguishing methods for a material. Terms used to express solubility are: negligible (less than 0.1 percent), slight (0.1 to 1.0 percent), moderate (1 to 10 percent), appreciable (more than 10 percent), and soluble in all proportions.
Span-Of-Control	The supervisory ratio of three to seven individuals with five being established as a general rule of thumb.
Specific Gravity	The ratio of the density of a substance to the density of a reference substance; it is an abstract number that is unrelated to any units. For solids and liquids, specific gravity is numerically equal to density, but for gases it is not, because of the difference between the density of the reference substances, which are usually water (1g/cc) for solids and liquids and air (0.00129 g/cc, or 1.29 g/L at 0º C and 760 mm Hg) for gases.
Spontaneous Combustion	The process of increase in temperature of a material to a point of ignition without drawing heat from its surroundings.
Stability	An expression of the ability of a material to remain unchanged. For MSDS purposes material is stable if it remains in the same condition under expected and reasonable conditions of storage or use.
Stabilization	The stage of an incident when the immediate problem or emergency has been controlled, contained or extinguished
Stage of Incident	One of five definite and identifiable phases through which an emergency passes from onset (interruption of normal conditions) to stabilization
Staging Area	That location where incident personnel and equipment are assigned. It is expected that personnel and equipment at the staging area must be available within three-minutes to enter the incident-area.
Standard Transportation	A listing of code numbers for categories of
Commodity Code (STCC number)	articles being shipped, in general use by carriers.
STEL	Short-Term Exposure Limit
Stress	A state of tension put on a shipping container by internal chemical action, external mechanical damage or external flames or heat.
Structural Firefighters Protective Clothing	Clothing that will prevent gases, vapours, liquids and solids from coming in contact with the skin. This equipment includes helmet, SCBA, coat, and pants, rubber boots, gloves, bands around the legs, arms, waist and face mask, and covering for neck, ears, and all parts of the head not covered by the helmet or the SCBA or the face mask.
Subsurface Injection	Discharge of foam or water into a storage tank from an outlet at the tank.
Teratogenisis	Alteration in the formation of cells, tissues, and organs, resulting from physiologic and biochemical changes in a fetus during growth.
TLV-C	The ceiling exposure limit - the concentration that should not be exceeded even instantaneously.
Toxic Materials	Substances, which can be poisonous, if inhaled, swallowed or absorbed into the body through cuts or breaks in the skin.
Toxicity	The sum of adverse effects resulting from exposure to a material, generally by ingestion, absorption through the skin or inhalation.
Trade Name	The trademark name or commercial name for a material.
TWA	Time Weighted Average. With reference to exposure, TWA is the airborne concentration of a material to which a person is exposed, averaged over the total exposure time (generally the total work day of 8 to 12 hours).
UEL	Upper Explosive Limit. (Also known as UFL or Upper Flammable Limit). The highest concentration of a vapour or gas that will produce a flash of fire when an ignition source (heat, arc or flame) is present.
UFL	See UEL.
Unified Command	A method for all agencies or individuals who have jurisdictional responsibility, and in some cases who have functional responsibility at an incident, to contribute to determining overall objectives for the incident and the selection of strategy to achieve those objectives.
UN/NA Identification Number	The four-digit number assigned to a hazardous material, which is used to identify and cross-reference products in the transportation mode.
Unit	That organizational element with functional responsibility for a specific incident planning, logistic or finance activity.
Unstable	Tending toward decomposition or other unwanted chemical change during normal handling and/or storage.
Unstable Materials	Substances capable of rapidly undergoing chemical changes or decomposition.
Vapour	Gas given off, with or without the aid of heat, by substances that under normal circumstances are either solid or liquid.
Vapour Density	The weight of a vapour or gas compared to the weight of an equal volume of air, or an expression of the density of the vapour or gas. Materials lighter than air have a vapour density of less than 1.0 (e.g., acetylene, methane, hydrogen). Materials heavier than air have a vapour density of more than 1.0 (e.g., carbon dioxide, propane, hydrogen sulfide, ethane, butane, chlorine, sulfur dioxide).
Vapour Pressure	The pressure exerted by the vaporization of a liquid in a closed container. When vapour pressure tests are performed on products, the test temperature is usually 20º C (68º F) to 37º C (100º F) and the vapour pressure is expressed as pounds per square inch (psig or psia). Vapour pressures reported on MSDSs are calculated in millimeters of mercury (mm Hg) at 20º C (68º F) unless otherwise stated The vapour pressure of a substance at -37.8º C (100º F) will always be higher than the vapour pressure of a substance at 20º C (68º F) Vapour pressures reported on MSDSs in mm Hg are usually very low pressures. 760 mm Hg is equivalent to 14.7 psia The lower the boiling point of a substance the higher its vapour pressure.
Vapour Space	Space left empty inside a tank containing liquefied gas to allow for expansion of the gas due to normal changes in temperature.
Vapourization	The process of changing from liquid to vapour.
Ventilation	See general exhaust, local exhaust and mechanical ventilation.
Viscosity	The flow resistance of a liquid. This characteristic changes with the temperature of the liquid. Low-viscosity liquids have little adhesive qualities and hence flow freely.
Warm Zone	Area where personnel and equipment decontamination and hot zone support takes place. It includes control points for the access corridor and thus assists in reducing the spread of contamination. This is also referred to as the decontamination, contamination reduction or limited access-zone/corridor.
Water Solubility	The ability of a liquid or solid to mix with or dissolve in water
Water-Reactive	Substances, generally flammable solids, that will react in varying degrees when mixed with water or when they come in contact with humid air.
Waybill	The shipping paper prepared by the railroad from a bill of lading. Waybills generally accompany a shipment and are carried by the conductor in the caboose of a train.
Weak Seam	Weak Seam In oil tanks, a special roof-to-shell seam attachment that is designed to give under overpressure and release vapour from the vapour space.
WHMIS	WHMIS Workplace Hazardous Materials Information System (WHMIS) regulation under the Occupational Health and Safety Act (OHSA), which made the use of MSDS a requirement.