TERM

DEFINITION

ABSORPTION

Entry of toxic material into the body by contact with the skin.

ACUTE EXPOSURE

Exposure of short duration, usually to relatively high concentrations or amounts of material.

ACUTE HEALTH EFFECT

An adverse effect on the body, with symptoms developing rapidly.

ASPHYXIATING MATERIALS

Substances that can cause death by diluting or taking the place of oxygen in the air.

ATMOSPHERIC GASES

Air, nitrogen, oxygen, argon, krypton, neon, and xenon.

B.L.E.V.E.

Boiling Liquid Expanding Vapor Explosion.

Uncontrolled fire and explosion of vapor as it escapes from a ruptured container of liquefied flammable gas.

BULK PACKAGING

A packaging in which hazardous materials are loaded with no intermediate form of containment and which has:

1. A maximum capacity greater than 119 gallons as a receptacle for a liquid;
2. A maximum net mass greater than 882 pounds and a maximum capacity greater than 119 gallons as a receptacle for a solid; or
3. A water capacity greater than 1000 pounds as a receptacle for a gas.

CHEMTREC

The Chemical Transportation Emergency Center operated by the Chemical Manufacturers Association to provide information on materials involve din transportation accidents. For emergency information when the shipping paper is not available or the emergency response number is not listed, call 1-800-424-9300.

CHRONIC EXPOSURE

Continuous or intermittent exposure over a long time period, usually to relatively low material amounts or concentrations.

CHRONIC HEALTH EFFECT

An adverse effect on the body with symptoms that develop slowly over a long time period and persist or that recur frequently.

COFC

Container-on-flat-car.

COMPRESSED GAS

Any material which is a gas at normal temperature and pressure, and which is contained under pressure as a dissolved gas or liquefied by compression or refrigeration.

CONSIST

Also called wheel report. Shipping documents that lists cars as they are place din the train, indicates cars carrying hazardous materials and their location in the train and may have emergency response information attached. Union pacific lists cars from rear of the train forward.

CRYOGENIC LIQUID

A refrigerated liquefied gas with a boiling point colder than -130*F.

ELEVATED TEMPERATURE MATERIAL

A material which, when transported in a bulk packaging:

1. Is a liquid and at a temperature at or above 212*F;
2. Is a liquid with a flash point at or above 100*F that is intentionally heated and transported above its flash point; or
3. Is a solid and at a temperature at or above 464*F.

ENGINEERING CONTROLS

Systems too reduce potential hazards by isolating the worker from the hazard or by removing the hazard from the workplace. Methods include substitution, ventilation, isolation, and enclosure.

EXPOSURE

People, the environment or property that may be exposed to the harmful effects of hazardous materials in an emergency.

FLASH POINT

The lowest temperature at which a liquid substance gives off enough flammable vapors to form an ignitable mixture with air near the surface of the liquid.

FUMIGATED LADING

A transported material, such as grain, which has been treated with a toxic agent in vapor form to destroy rodents, insects and germs.

HAZARD CLASS

A category of hazards assigned to a hazardous material by the U.S. Department of Transportation. A material may meet the definition of more than one hazard class but is assigned to only one hazard class.

HAZARD ZONE

One of four levels of hazard (Hazard Zones A through D) assigned to gases by the U.S. Department of Transportation and one of two levels of hazards (Hazard Zones A and B) assigned to liquids that are poisonous by inhalation.

HAZARDOUS MATERIAL

A substance or material determined by the Secretary of Transportation to be capable of posing an unreasonable risk to health, safety, and property when transported in commerce.

HAZARDOUS WASTE

A material designated by the U.S. Environmental Protection Agency and subject to the Hazardous Waste Manifest Requirements.

HAZMAT EMPLOYEE

A person who is employed by a hazmat employer and who on the job directly affects hazardous materials transportation safety.

INGESTION

Entry of toxic materials into the body through the mouth.

INHALATION

Entry of toxic materials into the body by breathing through the nose or mouth.

INHIBITED

A hazardous material in transportation with an added compound (inhibitor) that slows or stops an undesired chemical reaction, such as polymerization, corrosion, or oxidation.

INTERMODAL CONTAINER

Freight container designed and constructed to permit it to be used interchangeably in two or more modes of transportation.

INTERMODAL PORTABLE TANK

OR IM Portable Tank means a specific class of portable tanks designed primarily for international intermodal use.

LIQUEFIED PETROLEUM GAS

Gases which can be liquefied under moderate pressures. Common LPGs are butane and propane.

MARKING

A descriptive name, identification number, instructions, cautions, weight, specification, or UN marks required on outer packagings of hazardous materials.

NATIONAL RESPONSE CENTER

Operated by the U.S. Coast Guard, the NRC receives reports required when dangerous goods and hazardous substances are spilled. The NRC notifies the appropriate Federal On-Scene Coordinator and concerned Federal Agencies.

NON-BULK PACKAGING

A packaging which has:

1. A maximum capacity of 119 gallons or less as a receptacle for a liquid:
2. A maximum net mass of 882 pounds or less and a maximum capacity of 119 gallons or less as a receptacle for a solid; or
3. A water capacity of 1000 pounds or less as a receptacle for a gas.

N.O.S.

Not Otherwise Specified.

OXIDIZER

A material that may, generally by providing oxygen, cause or increase the burning of other materials more than air does.

PACKAGING

A receptacle and any other components or materials necessary for the receptacle to perform its containment function.

PACKING GROUP

A grouping according to the degree of danger presented by hazardous materials. Packing Group I indicates great danger; Packing Group II, medium danger; Packing Group III, minor danger.

PERSONAL PROTECTIVE EQUIPMENT

Devices or clothing worm to help insulate a worker from direct exposure to hazardous materials. Examples includes gloves and respirators.

PLACARDED CAR POLYMERIZATION

A rail car which is placarded according to the Hazardous Materials Regulations. A chemical reaction, which may be violent, when some materials are heated or mixed with other materials. The reaction may produce heat and build up pressure causing explosion of the container.

RAIL CAR

A car designed to carry freight or non-passenger personnel by rail, and includes a box car, flat car, gondola car, hopper car, tank car, and occupied caboose.

REPORTABLE QUANTITY

The designated amount released into the environment for hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act, requiring a report to the National Response Center.

RESIDUE

The hazardous material remaining in a packaging, including a tank car, after its contents have been unloaded to the maximum extent practicable and before the packaging is either refilled or cleaned of hazardous material and purged to remove any hazardous vapors.

SHIPPING PAPERS

A shipping order, bill of lading, manifest, or other shipping document containing information required by the Hazardous Materials Regulations.

SPECIFIC GRAVITY

The weight of a substance compared with the weight of an equal volume of water (for solids and liquids) or an equal volume of air (for gases).

STCC

Standard Transportation Commodity Code or "stick" number assigned by the Association of American Railroads to commodities carried by rail. Numbers beginning with 49 indicate a hazardous material, numbers beginning with 48 indicate a hazardous waste.

TOFC

Trailer-on-flat-car.

TOXICITY

The ability of a substance to cause injury to biologic tissue.

TOXIC MATERIALS

Substances than can be harmful if inhaled, swallowed or absorbed into the body through the skin.

TRACK LIST

A report of any cars on a track (track list) or cars being switched into a yard (switch list). Identifies cars loaded with hazardous materials and may include emergency response information.

TRANSPORT VEHICLE

A cargo-carrying vehicle such as a truck, tank car or rail car used for transportation of cargo by any mode. Each cargo-carrying body (trailer, rail car, etc.) is a separate transport vehicle.

UN

United Nations.

UNSTABLE MATERIALS

Substances capable of rapidly undergoing chemical changes or decomposition.

VAPOR

Gas given off, with or without the aid of heat, by substances that under ordinary conditions are either solid or liquid.

VAPOR DENSITY

Measurement of the relative density of a vapor compared with air. A vapor density of less than 1 indicates a vapor that is lighter than air. A vapor density that is more than 1 indicates a vapor that is heavier than air.

VAPORIZATION

The process of change from liquid to vapor.

VAPOR PRESSURE

The pressure from a liquid vaporizing in a closed container. This pressure will vary with different liquids and will vary depending upon temperature.

VAPOR SPACE

Space left empty inside a trunk containing liquefied gas to allow for expansion of the gas due to normal changes in temperature.

WAYBILL

Shipping document that lists the contents and instructions for handling a single rail car, trailer, or container.