ABATEMENT: The actions taken to reduce the amount, degree of the hazard or intensity of the release or threatened release of a hazardous material.

ABSOLUTE PRESSURE: Gage pressure plus atmospheric pressure.

ABSOLUTE ZERO: The lowest point on the Kelvin scale, at which there is total absence of heat.

ABSORPTION MATERIAL: Used to soak up liquid hazardous materials. Example: Commercial bagged clay, kitty litter, Zorbal.

ABSORPTION: The taking in of toxic materials by contact with the skin.

ACARICIDE: A pesticide used to control spiders, ticks, and mites.

ACCIDENT: An unexpected event generally resulting in injury, loss of property or disruption of services.

ACGIH: The American Conference of Governmental Industrial Hygienists is a professional society devoted to the administrative and technical aspects of occupational and environmental health. The mission of the ACGIH is to be an indispensable resource for industrial hygienists and related professionals worldwide in a way that promotes excellence in environmental and occupational health; provides technical information of the highest quality; benefits the occupational health and well being of people worldwide; and serves the membership and continually improves the organization, including its financial and human resources.

ACID: A hydrogen-containing corrosive material that reacts with water to produce hydrogen ions; a proton donor.

ACID OR AMMONIA SUITS: Special protective clothing that prevents toxic or corrosive substances or vapors from coming in contact with the body.

ACTION LEVEL: A quatitative limit of chemical, biological, or radiological agent at which actions are taken to prevent or reduce exposure or contact.

ACTIVE INGREDIENT: The chemical that has pesticide action. Active ingredients are listed in order on a pesticide label as percentage by weight or as pounds per gallon of concentrate. See INERT INGREDIENTS.

ACUTE TOXICITY: Any harmful effect produced by a single short-term exposure that may result in severe biological harm or death.

ACQUIFER: A saturated water bearing formation of permeable rock sand or gravel.

ACUTE EXPOSURE: A dose that is delivered to the body in a single event or in a short period of time.

ACUTE POISONING: Poisoning by a single exposure to a toxic chemical.

AEROSOLS: Micron-size liquid droplets or solid particles dispersed in air by pressurized gases. When liquid droplets reach micron dimensions, their behavior becomes similar to solid particles of the same size.

AFFF: Aqueous Film Forming Foam. An extinguishing agent designed to flow on a burning liquid.

AGRICULTURAL CHEMICALS: Chemicals such as pesticides, herbicides, fungicides, insecticides and fertilizers used in agricultural applications to control pests and disease or control/promote growth. The toxicity of agricultural chemicals is classified from I to IV, with class I being the most toxic. There are specific OSHA regulations governing worker safety in the presence of agricultural chemicals.

AIHA: American Industrial Hygiene Association, an organization of professionals trained in the recognition and control of health hazards and the prevention of illness related thereto. It promotes the study and control of environmental factors affecting the health of industrial workers and provides information and communication services pertaining to industrial hygiene.

AIR BILL: A shipping paper prepared from a bill of landing that accompanies each piece of an air shipment.

AIR-BORNE CONTAMINANTS: Solid, liquid or gaseous materials that are mixed in the air and spread with air movements. Chemical vapors will readily mix with moving air. In still air, heavier gases — such as chlorine and gasoline fumes — will settle, whereas lighter gases — such as natural gas or hydrogen — will rise. Aerosols consisting of micron-size solid particles and liquid droplets can also be suspended in moving air but will settle at low air velocities or larger sizes. Asbestos, lead paint dusts, some agricultural chemicals, silica, radioactive particles, viruses, fungal spores, pollen and bacteria are examples of other air-borne contaminants of concern.

AIR DISTRIBUTION SYSTEM: The means by which cooling and/or breathing air is delivered to and distributed in a protective suit.

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 vapors near the earth's surface, thus impeding their dispersion.

AIR-REACTIVE MATERIALS: Substances that will ignite at normal temperatures when exposed to air.

AIR SPRING: A flexible air-inflated chamber in which the air pressure is controlled and varied to support the load and absorb road shocks; formerly called air bag.

ALCOHOL FOAM: Blankets fires in the same manner as conventional foam, but it is intended for use with liquids which are soluble in water, such as alcohol and acetone. It must be applied more carefully than regular foam because the mechanical strength of the bubbles is less.

ALKALI: A hydroxide-containing (-OH) corrosive material that is soluble in water, neutralizes acids and is irritating or destructive to tissue.

ALPHA RAYS: Made up of very large particles which are the same as the nucleus of the helium atom.

AMBIENT AIR QUALITY: Quality of the surrounding atmosphere or circulating air.

AMBIENT TEMPERATURE: The temperature of the surrounding area. Room temperature is an example of ambient temperature.

ANALYTICAL TECHNIQUE: A procedure whereby the concentration of a chemical in a collection medium is quantitatively determined.

ANHYDROUS: Free from water, dry.

ANISOTROPIC: Non-symmetrical performance. In protective clothing, fabric physical properties such as tearing strength or stretch often differ when measured across the sheet vs. the long axis of the fabric.

ANSI: The American National Standards Institute serves as a clearing house for nationally coordinated voluntary safety, engineering and industrial standards developed by industrial firms, trade associations, technical societies, consumer organizations and government agencies.

ANSI/ISEA 101-1996: An upgrade of ANSI 101-1985, this is the standard developed to address protective clothing sizing issues in limited-use protective clothing.

ASBESTOS: A known carcinogen, asbestos is a group of small, jagged sub-micron mineral fibers. Common types of asbestos include chrysotile, crocidolite and anthophyllite. Inhaling substantial quantities of asbestos may cause asbestosis (a disease that blocks the lungs with thick, fibrous tissue); bronchogenic cancer (cancer of the bronchial tubes); or mesothelioma (a rare and fatal cancer of the lining of the chest or abdomen).

ASEPTIC: Sterile, free from viable microbiological contamination.

ASPHYXIATING MATERIALS: Substances that can cause death through displacing the oxygen in the air.

ASSAY: Analysis of a mixture to determine the presence or concentration of a particular component.

ASSAY FLUID: A sterile liquid used to wash the test specimen surface to determine microbiological penetration.

ASSESSMENT: The process of determining the nature and degree of hazard of a hazardous material or hazardous materials incident.

ASTM: The American Society for Testing and Materials establishes voluntary consensus standards for materials, products, systems and services. The society sponsors research projects and develops standard test methods, specifications and recommended practices now in use.

ASTM Committee F23 on Protective Apparel: A broad cross-section of users, manufacturers and consultants, this committee developed most of the industry standard test methods for chemical, thermal and fire protection clothing materials.

ASTM D747: "Standard Test Method for Apparent Bending Modulus of Plastics by Means of a Cantilever Beam." This test relates stiffness to the effort needed to bend a strip of material.

ASTM D751: "Standard Test Method for Coated Fabrics (Grab Tensile Test)." Used in conjunction with ASTM D3786, this test measures the breaking strength of a material. Also used with ASTM D1682 to determine breaking strength and elongation of a fabric sample. Breaking strength is the effort required to break the sample, and elongation is how much the sample has stretched when it breaks.

ASTM D1682: "Standard Test Method for Breaking Load and Elongation of Textile Fabrics (Strip Tensile Test)". Along with ASTM D751, this test is used to determine breaking strength and elongation of a fabric sample. The difference between ASTM D751 and ASTM D1682 is the size of the clamps relative to the size of the test sample. SEE ASTM D751.

ASTM D2136: "Standard Test Method for Coated Fabrics — Low Temperature Bend Test." This simple pass/fail test determines if a material will crack when bent at low temperature.

ASTM D2582: "Standard Test Method for Puncture Propagation Tear Resistance of Plastic Film and Thin Sheeting." This test determines the effort needed to puncture and then tear a material.

ASTM D3786: "Standard Test Method for Hydraulic Bursting Strength of Knitted Goods and Nonwoven Fabrics — Diaphragm Bursting Strength Tester Method." Along with ASTM D751, this test measures the pressure required to burst a material.

ASTM D4533: "Standard Test Method for Trapezoidal Tearing Strength of Geotextiles." This test determines the effort required to continue a tear across a fiber.

ASTM F739: "Standard Test Method for Resistance of Protective Clothing Materials to Permeation by Liquids or Gases Under Conditions of Continuous Contact." This is the standard test used in North America for measuring the permeation of chemical protective apparel material. Specifically, it is used to determine whether or not a challenge chemical permeates through a nonporous barrier.

ASTM F903: "Standard Test Method for Resistance of Protective Clothing Materials to Penetration by Liquids." This pass/fail test determines if a material is porous to potentially hazardous liquids at a given pressure.

ASTM F1001: "Standard Guide for Selection of Chemicals to Evaluate Protective Clothing Standards," is a standard battery of 21 chemical liquids and vapors chosen to compare the permeation performance of chemical barrier fabrics.

ASTM F1052: "Standard Practice for Pressure Testing of Gas-Tight Totally Encapsulating Chemical-Protective Suits." A technique used to determine whether vapor-protective suits maintain 4 in. positive air pressure with up to a 20% drop in pressure after four minutes.

ASTM F1154: Developed by the ASTM Committee F23 on Protective Apparel, this series of exercises evaluates garment fit and function for chemical ensembles only.

ATMOSPHERIC PRESSURE: The pressure caused by the weight of the air elevated above the earth's surface. At sea level it equals 14.7 pounds per square inch (psi).

ATOM: The smallest particle of an element that can exist.

ATTO: Metric prefix for 10-18, 0.000 000 000 000 000 001, abbreviated a.

AUTOIGNITION TEMPERATURE: Same as ignition temperature.

AXLE WEIGHT: Amount of weight transmitted to the ground by one axle or the combined weight of the two axles in a tandem assembly.


BACTERIAL PENETRATION: The infiltration of bacteria through protective clothing materials.

BACTERICIDE: A pesticide used to contol bacteria.

BACTERIOPHAGE: A type of virus that infects bacteria.

BAFFLE: An intermediate partical bulkhead that reduces the surge effect in a partially loaded tank.

BARRIER: In protective clothing, barrier is the ability to isolate the body from a chemical, physical, biological, radioactive or thermal hazard, among others.

BARRIER CLOTHING: Protective clothing that provides a barrier against hazards, such as dry particulates, chemical liquids, vapors and solids, biological agents, radiation, fire or heat.

BARRIER DURABILITY: How well a garment retains its barrier after being worn or after being conditioned in a way that simulates the effects of actual wearing, such as abrasion, stretching or flexing.

BARRIER PERFORMANCE: The degree to which a fabric or garment provides barrier against a hazard. Permeation barrier performance is measured by breakthrough times and permeation rates. Liquid penetration performance is measured by the pressure required to force a liquid through the fabric. Particle barrier performance is measured by the fraction of particles that impact and penetrate a barrier material.

BASE (CHEMICAL): A hydroxide-containing (-OH) corrosive material that, when in a water solution, is bitter, more or less irritating or caustic to the skin.

BETA RAYS: Smaller than alpha rays, beta radiation is made up of electrons.

BIOHAZARDS: Infectious agents presenting a risk or potential risk to living organisms, either directly through infection or indirectly through disruption of the environment.

BIOLOGICAL AGENTS: Biological materials that are capable of causing acute or long-term damage to living organisms.

BIOLOGICAL MONITORING: The chemical analysis of chemicals or metabolites, or both, from a worker's blood, urine, fingernails, sweat, breath, etc.

BIPYRIDYLS: A group of synthetic organic pesticides that include the herbicide paraquat.

BLEVE (BOILING LIQUID-EXPANDING VAPOR EXPLOSION): A major container failure, into two or more pieces, at a moment in time when the contained liquid is at a temperature well above its boiling point at normal atmospheric pressure.

BLISTERING AGENTS (VESICANTS): These toxic warfare chemical agents, which include mustard (agent HD) and lewisite (agent L), destroy skin and eyes on contact, and if ingested or inhaled, destroy internal tissues as well. Mustard is insidious because of the delayed onset of symptoms, whereas lewisite's effects are immediate. Mustard is a systemic poison, causing damage to the internal organs and structures of the body, and a carcinogen.

BLOOD-BORNE PATHOGEN: A pathogenic microorganism that is present in human blood and can cause disease in humans. OSHA 29CFR1910.1030 is the regulation covering the protection of workers from blood-borne pathogens.

BLOW DOWN VALVE: A manually operated valve whose function is to quickly reduce tank pressure to atmosphere.

BMCS: Bureau of Motor Carrier Safety, under the Federal Highway Administration og DOT. Responsible for establishing regulations for in-service motor vehicles and their operators (drivers).

BODY FLUID: Any liquid produced, secreted or excreted by the human body.

BODY FLUID SIMULANT: A liquid that is used to act as a model for human body liquids.

BODY MEASUREMENT: In anthropometry, a standardized distance between two specified points on the human anatomy.

BOILING LIQUID EXPANDING VAPOR EXPLOSION (BLEVE): A container failure with a release of energy, often rapidly and violently, that is accompanied by a release of gas to the atmosphere and propulsion of the container or container pieces due to an overpressure rupture.

BOILING POINT: The temperature at which the vapor pressure of a liquid equals the atmospheric pressure. The boiling point is an indicator of the vapor pressure of a substance. A liquid with a low boiling point (less than 100 degree F (37.7 degree C) has a higher vapor pressure. This will, in turn, indicate a tendency to BLEVE.

BOOTIE: An extension of a protective apparel that covers the foot. Unless specifically constructed with a durable sole, booties should be worn on the inside of durable shoes or boots.

BOUND SEAM: A seam construction in which a seam material is sandwiched by an extra strip of fabric during sewing.

BOYLE'S LAW: When the temperature and mass of a gas are kept constant, the product of the pressure and volume is equal to a constant.

BRAKE HOSES: A flexible conductor for the transmission of fluid pressure in the brake system.

BREAKING STRENGTH: The effort required to break a garment sample.

BREAKTHROUGH TIME: The elapsed time between initial contact of the hazardous chemical with the outside surface of a barrier, such as protective clothing material, and the time at which the chemical can be detected on the inside surface of the material.

BREATHABILITY: The ability of air to flow through a material. Air flow is a more effective principal cooling mechanism with clothing fabrics. Moisture vapor transport rate (MVTR), a measure of the static water vapor diffusion rate, is sometimes mistakenly represented as a measure of breathability.

BRITISH THERMAL UNIT (BTU): The amount of heat necessary to raise one pound of water, one degree fahrenheit in temperature from 63 degrees F to 64 degrees F.

BUDDY SYSTEM: A means of organizing employee work groups whereby each participant is matched with another so that prompt assistance can be rendered in the case of any emergency.

BULK CONTAINER: A cargo container, such as that attached to a tank truck or tank car, used for transporting materials in bulk quantity.

BULKHEAD: A structure used to protect against damage caused by shifting cargo and/or to separate loads.

BUNG: A cap or screw used to cover the small opening in the top of a metal drum or barrel.

BUTYL: A synthetic rubber used in chemical protective suits


CARBAMATE: A synthetic organic pesticide containing carbon,hydrogen, nitrogen, and sulfur.

CARBON DIOXIDE: A gas stored in cylinders and applied through a fixed or semifixed system, of from a portable extinguisher. It is useful for inerting a closed area or for putting out small local fires.

CARCINOGEN: An agent that produces or is suspected of producing cancer.

CARE AND MAINTENANCE: Effective cleaning to remove soil and maximize use life of garments while maintaining (not removing) protective properties.

CARGO MANIFEST: A shipping paper that containes all of the contents being carried by the transporting vehicle or vessel.

CAS NUMBER: Chemical Abstracts Service (CAS) numbers are uniquely assigned to molecules and mixtures by the American Chemical Society (ACS). CAS numbers are often used by local and state hazardous materials compliance legislation for tracking chemicals in the workplace and in the community. These numbers provide a unique identification for chemicals as well as a means for cross-checking chemical names.

CDC: Centers for Disease Control. This Department of Health and Human Services agency includes the National Center for Chronic Disease Prevention and Health Promotion; National Center for Environmental Health; National Center for Health Statistics; National Center for HIV, STD and TB Prevention; National Center for Infectious Diseases; National Center for Injury Prevention and Control; National Institute for Occupational Safety and Health; Epidemiology Program Office; International Health Program Office; Public Health Practice Program Office; and the National Immunization Program.

CEN: French acronym for European Committee for Standardization.

CENTI: Metric prefix for 10 2, 0.01, abbrviated c.

CERTIFICATION LABEL: A label permanently affixed to the forward left side of the trailer stating that the vehicle conforms with applicable Federal Motor Vehicle Safety Sandards in effect on the date of original manufacture.

CHALLENGE AGENT: The chemical liquid, vapor, solid, mixture, solution or microbe against which a protective suit is tested.

CHARLES'S LAW: If the volume of a gas is kept constant and the temperature is increased, the pressure increases in direct proportion to the increase in absolute temperature.

CHEMICAL BARRIER: For chemical liquids or vapors, chemical barrier is based on the ability of the fabric to resist chemical permeation, as measured by ASTM F739. Liquid penetration measurements, such as ASTM F903, are not recommended for protective apparel decisions involving skin-absorbed toxins or carcinogenic chemicals. Liquid penetration tests have limited application for nonhazardous liquids. Although there is no single standard test to evaluate barrier against solid chemicals, a number of tests have been adopted that measure the fraction of solid chemical particles that impact - but do not penetrate - a material.

CHEMICAL PROPERTIES: Properties of a material that relate to toxicity, flammability, or chemical reactivity.

CHEMICAL PROTECTIVE CLOTHING: Any material or combination of materials used in an item of clothing for the purpose of isolating parts of the body from direct contact with a potentially hazardous chemical.

CHEMICAL RESISTANCE: An ambiguous term that can refer to either how well a material maintains its integrity when exposed to chemicals or how well a material protects against chemical exposure.

CHEMICAL WARFARE AGENTS: Warfare chemicals, which are very toxic through skin contact and inhalation, are divided into blistering agents (vesicants); blood agents; lung-damaging agents (choking agents); nerve agents; and riot control agents (harassing or incapacitating agents).

CHEMTREC: The Chemical Transportation Emergency Center, operated by the Chemical Manufacturers Association (CMA), can provide information and technical assistance to emergency responders. The center can be reached at (800) 424-9300.

CHLORINE KITS: Standardized kits commercially manufactured by contract with the Chlorine Institute to provide equipment to control or stop leaks in chlorine cylinders, tanks and transportation tank cars.

CHRONIC EXPOSURE: Low doses repeatedly received by the body over a long period of time.

CHRONIC POISONING: Poisoning that is a result of repeated exposure to a sublethal doses over a period of time.

CIH: A certified industrial hygienist is an individual who has met the training and proficiency requirements in the field of industrial hygiene. This certification is granted by the American Board of Industrial Hygiene.

CLASS A COMBUSTBLES: Ordinary combustibles, which leave a residue after burning.

CLASS B COMBUSTIBLES: Flammable liquids and gases.

CLASS C COMBUSTIBLES: Class A or B fires that occur in or near electrical equipment.

CLASS D COMBUSTIBLES: Combustible metals that are easily oxidized.

CLASS A EXPLOSIVE: A material or device that presents a maximum hazard through detonation.

CLASS B EXPLOSIVE: A material or device that presents a flammable hazard and functions by deflagration.

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.

CLASS A POISON: A poisonous gas or liquid of such nature that a very small amount of the gas, or vapor of the liquid, is dangerous to life.

CLASS B POISON: A substance that is known to be so toxic to human life that it affords a severe health hazard during transportation.

CLEANOUT FITTING: Fitting installed in the top of a tank to facilitate washing of the tank interior.

CLEAN AREA WORK ENVIRONMENT: A work area in which the number and size of air-borne contaminants is minimized and controlled. Certain production processes, such as the production of computer chips, are very sensitive to the presence of small particles. The "clean working environments" must not only be protected from common sources of particles - dust, pollen and soot, for example - but also from particles shed by workers, including hair, dead cells, bronchial aerosols and soap and cosmetic residues. Particle barrier clothing is often used to protect these environments. Some working areas in which microbes are handled may also be designated as clean work areas.

CLEANROOM: An entire room in which the number and size of ambient particles is minimized and controlled. Cleanrooms are classified by the average number of particles present greater than 0.5 microns. For example, Class 10 cleanrooms have no more than 10 particles greater than 0.5 microns per cubic foot of air; Class 100 cleanrooms have no more than 100 particles greater than 0.5 microns per cubic foot of air; Class 1,000 cleanrooms have no more than 1,000 particles greater than 0.5 microns per cubic foot of air; and so on. Class 10 corresponds to Grade 1.5 of Federal Standard 209E, Class 100 corresponds to Grade 2.5, Class 1000 corresponds to Grade 3.5, etc. Enacted in 1992, Federal Standard 209E establishes both metric and English standard classes of air cleanliness for airborne particulate levels in cleanrooms and clean zones. This standard prescribes methods for class verification and monitoring of air cleanliness and addresses other factors as they affect control of airborne particulate contamination. There are five class limits with specific particulate sizing per volume units.

CLO: Unit used to express the resistance to dry heat transfer provided by clothing; one clo is equal to 0.155 K m2/W.

CODE OF FEDERAL REGULATIONS (CFR): The formal name given to those books or documents that contain the specific regulations provided for by law.

COFC: Container -on-Flatcar

COLD ZONE: The area outside of the warm zone. Equipment and personnel are not expected to become contaminated in this area. This is the area where resources are assembled to support the hazardous materials operation.

COLLECTION MEDIUM: A liquid or gas that does not affect the measured permeation and in which the test chemical is freely soluble or adsorbed to a saturation concentration greater than 0.5 weight or volume %.

CONTAMIMENT/CONTAMINATION: An unwanted and non-beneficial substance

COMBINATION: The change that occurs when two chemicals are combined and the result is a different chemical.

COMBUSTIBLE LIQUID: Any liquid that has a flash point at or above 100 degree F (37.7 degree C) and below 200 degree F (93.3 degree C).

COMBUSTIBLE METAL: Metal that will burn.

COMBUSTION: A rapid oxidation or chemical combination,usually accompanied by heat or light.

COMMAND POST: Central control point for the incident. Information flows to and from the command post. Special resource people are based at the command post.

COMMON NAME OF PESTICIDE: Well-known made-up name accepted by the Environmental Protection Agency to identify the active ingredients in a pesticide. It is listed under the active ingredients statement on the label.

COMBUSTIBLE LIQUIDS: Liquids with a flashpoint above 100oF.

COMBUSTION: A chemical process of oxidation that occurs at a rate fast enough to produce heat and usually light either as glow or flames.

COMBUSTION PRODUCT: By-products produced or generated during the burning or oxidation of a fuel.

COMPATIBILITY: The matching of protective chemical clothing to the hazardous material involved to provide the best protection for the worker.

COMPOSITE: An item made of several types of materials that contribute special properties to its overall performance. The common car tire is an excellent example of a composite that combines the flexibility of the rubber matrix with the strength of the carcass and belt cord. In the case of chemical protective clothing, the material is often a composite of a high-strength tear-resistant fabric and a chemical protective elastomer or plastic film.

COMPOUND: A pure substance composed of two or more elements.

COMPRESSED GAS: Any material or mixture having in the container absolute pressure exceeding 40 psi at 70 degree F (21 degree C), or having an absolute pressure exceeding 104 psi at 130 degree F (54 degree C).

COMPRESSED GAS IN SOLUTION: A nonliquefied gas that is dissolved in a solvent, but at high pressures.

CONDENSATION: Going from the gaseous to the liquid state.

CONDITIONING: In physical testing, conditioning is one or more actions - such as laundering, flexing, abrading or exposure to light, heat or radiation - used to consistently reproduce the effects of actual usage.

CONDUCTION: Heat transfer through the movement of atoms within a substance.

CONNECTION BOX: Contains fittings for trailer emergency and service brake connections and electical connector to which the lines from the towing vehicle may be connected. Formerly called junction box, light box, bird box.

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 hazardous materials and their location on the train.

CONTAINER: An article of transport equipment that is:

1. Of a permanent character snd strong enough for repeated use.

2. Specifically designed to facilitate the carriage of goods by one or more modes of transport without intermediate reloading.

3. Fitted with devices permitting its ready handling, particularly its transfer from one mode to another.

The term CONTAINER does not include vehicles. Also referred as: freight container, cargo container, intermodal container.

CONTAINER CHASSIS: A trailer chassis having simply a frame with locking devices for securing and transporting a container as a wheeled vehicle.

CONTAINER SHIP: A ship specially equipped to transport large freight containers in horizontal, or, more commonly, in vertical container cells. The containers are loaded and unloaded usually automatically by special cranes.

CONTAINER SPECIFICATION NUMBER: A number found on a shipping container preceded by the initials DOT, which indicate that the container has been built according to federal specifications.

CONTAMINANT: A pesticide or other toxic material found as a residue in or on s substance where it is not wanted.

CONTROL AGENTS: Any material that is used to contain or extinguish a hazardous material or its vapor.

CONVECTION: Heat transfer from one place to another by actual motion of the hot material.

CORRECTIVE ACTIONS: Actions taken by the incident commander to correct the problem at hand in a hazardous materials emergency.

CORROSION PRODUCT: A chemical species formed by the action of a corrosive chemical on another material. Rust, a common corrosion product, is formed by the corrosive action of oxygen on iron.

CORROSIVE: The ability to cause destruction of living tissue or many solid materials surfaces by chemical action.

CRACKING PRESSURE: For exhaust valves in totally encapsulating chemical protective suits, this is the pressure at which the valve allows air to begin to escape (limiting the internal suit pressure).

CROSSOVER LINE: Installed in a tank piping system to allow unloading from either side of the tank.

CRYOGENICS: Substances having temperatures below-150 degrees F (-101.1 degrees C).

CRYOGENIC LIQUID: Generally, a cryogenic liquid is any liquid with a temperature less than -200oC. Liquid oxygen and liquid nitrogen are the most common cryogenic liquids encountered. Some common gases - such as ammonia, natural gas, chlorine and hydrogen chloride - are often shipped as cold liquids but are actually cryogenic liquids. Certain components of chemical protective clothing ensembles, especially elastomeric gloves, can become stiff and brittle when exposed to these liquefied gases.

CRYOGENS: Gases that must be cooled to a very low temperature in order to bring about a change from a gas to a liquid.

CSP: Certified Safety Professional, a certification granted by the Board of Certified Safety Professionals.

CUBIC CAPACITY: Useful internal load-carrying space usually expressed in cubic feet, cubic yards, or cubic meters Also referred to as available cube, or simply cube.

CUMULATIVE PERMEATION: The total mass of chemical that permeates during a specified time from when the material is first contacted.

CURIE: The amount of radioactive material that will give 37 billion disintegrations per second.


DANGEROUS CARGO MANIFESTS: A cargo manifest used on ships that contains a list of all the hazardous materials on board, including their location.

DECA: Metric prefix for 10 1, 10.0, abbreviated DA.

DECI: Metric prefix for 10-1, 0.1, abbreviated D.

DECONTAMINATION: Physical or chemical means to remove, deactivate or destroy hazardous materials in the surface and in the matrix of protective clothing. In the case of hazardous material emergencies, a preliminary decontamination is done near the scene to allow the wearer to safely remove a chemical protective garment. However, before the exposed garment can be worn again, it must be thoroughly decontaminated to remove any chemical that may have been absorbed into the protective barrier.

DECOMPOSITION: Breaking down of a substance to a less complex form. This can be accomplished by the introduction of heat, through the addition of neutralized chemicals, oe through biodegradation.

DEFLAGRATION: The intense burning rate of some explosives; black powder being one example, fireworks.

DEFOLIANT: A herbicide used to remove unwanted plant growth without killing the whole plant.

DEGRADATION: An unfavorable change in a protective clothing material. This includes a change in color, embrittlement, cracking or hole formation. Just because a material does not degrade in the presence of a chemical does not necessarily mean it provides protection. (See chemical resistance.)

DEGREE OF HAZARD: A relative measure of how much harm a substance can do.

DESICCANT: A substance, such as silica gel, that removes moisture (water vapor) from the air to maintain a dry atmosphere in containers of food or chemical packaging.

DETECTION LIMIT: A number, expressed in units of concentration (or amount), that describes the lowest concentration level (or amount) that an analyst can determine to be different from an analytical blank (background level).

DETONATION: A wave that passes along the body of an explosive, instantaneously converting the explosive into gas, e.g., dynamite.

DILUENT: Any liquid or solid material used to carry or dilute an active ingredient.

DIP TUBE: Installed for pressure unloading of product out the top of the tank.

DIRECT-READING INSTRUMENTS: A portable device that measures and displays, in a short time period, the concentration of a contaminant in the environment.

DISINFECTANT: A pesticide that controls germs.

DISTILLATION: Going from the liquid to gaseous to liquid state.

DOME: The circular fixture on the top of a tank cat that contains valves and relief devices.

DON: To put on an article of clothing.

DOSE: The amount of substance ingested, absorbed and/or inhaled per exposure period.

DOSIMETER: Designed for measuring accumulated exposure doses of gamma radiation to emergency response personnel.

DOT: Department of Transportation; the administrative body of the executive branch of the federal government responsible for transportation policy, regulations, and enforcement. See also FHWA & NHTSA & BMCS.

DOUBLES: Trailer combination consisting of a truck trailer, semitrailer, and a full trailer coupled together. Formerly called double trailer or double bottom.

DRY CHEMICAL: A special fire-extinguishing chemical, sodium or potassium bicarbonate or monosodium phosphate power, usually available from semi-fixed or portable extinguisher.

DRY PARTICULATES: Micron-sized dry chemicals or materials.

DUMMY COUPLER: A fitting used to seal the opening in an air brake hose connection (gladheads) when the connection is not in use; a dust cap.


EC: European Community

EDEMA: The swelling of body tissues resulting from fluid retention.

ELASTOMER: The class of synthetic polymers that have the stretch and recovery properties of rubber.

ELEMENT: The simplest form of a substance and the basic building block of chemistry.

ELONGATION: Stretching under load.

EMERGENCY: A sudden and unexpected event calling for immediate remedial action.

EMERGENCY SHUTOFF LEVER: An automatic or manually operated safety valve control that stops the flow of a liquid.

EMERGENCY VALVE: A self-closing tank outlet valve.

EMERGENCY VALVE OPERATOR: A device used to open and close emergency valves.

EMERGENCY VALVE REMOTE OPERATOR: A secondary closing means, remote from tank discharge openings, for operation in event of fire or other accident.

EMS: Emergency Medical Services functions as required to provide emergency medical care for ill or injured persons by trained providers.

EMULSIFIABLE CONCENTRATE: Material mixed with a solvent (usually petroleum) which forms an emulsion when mixed with water for application.

EMULSION: A mixture in which one liquid is suspended as tiny drops in another liquid, such as oil in water.

END USER: For the purpose of this glossary, this term is used to identify specifically the party requiring protective clothing.

ENDOTHERMIC REACTION: Heat is absorbed during the reaction.

ENVIRONMENTAL ASSESSMENT: The measurement or prediction of the transport, dispersion, and final location of a released hazardous substance.

ENVIRONMENTAL EMERGENCIES: Incidents involving the release (or potential release) of hazardous materials into the environment which may require immediate corrective action.

ENVIRONMENTAL HAZARD: A condition capable of posing an unreasonable risk to air, water, or soil quality, and to plants and wildlife.

ENVIRONMENTAL SAMPLE: Samples that are considered to contain no contaminants or low concentrations of contaminants.

EOD: Explosive Ordnance Disposal refers to military or civilian bomb squads.

EPA: The purpose of the Environmental Protection Agency is to protect and enhance our environment today and for future generations to the fullest extent possible under the laws enacted by Congress. The Agency's mission is to control and abate pollution in the areas of water, air, solid waste, pesticides, noise and radiation. The EPA's mandate is to mount an integrated, coordinated attack on environmental pollution in cooperation with state and local governments.

EPA Level A: See Level A.
EPA Level B: See Level B.
EPA Level C: See Level C.
EPA Level D: See Level D.

EPA REGISTRATION NUMBER: The number that appears on the pesticide label to identify the individual pesticide product. May appear as "EPA Reg. NO."

EPISODE: Incident

ETIOLOGIC AGENT: A living micro-organism that may cause human disease, e.g., germs.

EURONORM (EN) OR EUROPEAN STANDARD: A European Community (EC) standard that carries with it the obligation to be implemented at a national level and having priority over any conflicting national standard in EC member nations. Prior to final ratification, Euronorms are generally known as PrEns (Preliminary European Norms).

EVAPORATION: The conversion of a material from liquid state to vapor state below the material's boiling point.

EXCESS FLOW VALVE: A safety valve designed to shut off the flow of a liquid when the flow rate exceeds a set rate.

EXOTHERMIC REACTION: Reaction that produces heat.

EXPLOSIVE: A material capable of burning or bursting suddenly and violently. See CLASS A, B, C EXPLOSIVES

EXPLOSIVE LIMITS: Same as flammable limits.

EXPOSURES: People, property, or the environment that are or that may be exposed to the harmful effects of a hazardous materials emergency.

EXTREMELY FLAMMABLE: A liquid pesticide that has a flash point of 20 degrees F (-6.67 degrees C) or lower, determined by closed cup or Seta flash test.


FABRIC CONSTRUCTION: The type of weave in a woven material, including the number of warp yarns (extending lengthwise in a loom) and weft yarns (extending widthwise in a loom) per square centimeter of fabric. These are described as ends and picks per 10 cm.

FEMTO: Metric prefix for 10-15, 0.000 000 000 000 001,abbreviated F.

FEP: Fluorinated ethylene polymer, a type of highly chemical-resistant barrier polymers sold by DuPont as Teflon®.

FHWA: Federal Highway Administration; the DOT division concerned with highway construction and usage. Other similar divisions of DOT relate to air, rail, and water transportation.

FIBERGLASS: A man-made fiber used primarily in the production of insulating materials and for reinforcing plastics and composites. The primary hazard is that thin fibers can be inhaled and deposited in the lung, where they can accumulate and may cause fibrotic changes. An additional hazard is eye and skin irritation.

FICK'S LAWS OF DIFFUSION: Mathematical descriptions of the movement of one type of molecule through another.

FIFTH WHEEL: A device used to connect a truck tractor or converter dolly to a semitrailer in order to permit articulation between the units. It generally is composed of a lower part consisting of a trunnion, plate, and latching mechanism mounted on the truck tractor (or dolly) and a kingoin assembly mounted on the semitrailer.

FIFTH WHEEL PICKUP RAMP: A steel plate designed to lift the front end of a semitrailer to facilitate engagement to the kingpin into the fifth wheel.

FILL OPENING: An opening in top of a tank used for filling the tank. Usually incorporated in a manhole cover.

FINISH: A chemical or mechanical modification, or both, of the fabric for a specific performance result.

FINISHING TECHNIQUE: As applies to laundry and dry cleaning procedures, the mechanical means by which the garment is put in its final state (for example, pressing, drying, wrinkle removal, etc.).

FIRST RESPONDER: The first trained personnel to arrive on the scene of a hazardous material incident. Usually officials from local emergency services, firefighters, and police.

FISSION: The physical process in which atoms split into lighter elements. Generally, this process is accompanied by the production of heat and radiation.

FIT: The quality, state or manner in which the length and closeness of clothing, when worn, relates to the human body.

FLAME IMPINGEMENT: The points where flames contact the surface of a container.

FLAME RESISTANCE: Resistance to being ignited by fire.

FLAME RETARDANT: The degree to which an ignited material will extinguish itself.

FLAMMABILITY: The degree to which a material will catch fire and support combustion. Flammability also refers to the rate at which a material will be consumed by fire.

FLAMMABLE: Any material that is capable of being easily ignited and of burning with extreme rapidity.

FLAMMABLE COMPRESSED GAS: Any flammable material or mixture in a container having a pressure exceeding psi at 100 degrees F (37.78 degrees C).

FLAMMABLE GAS: Any compressed gas that will burn.

FLAMMABLE LIMITS: The range of gas or vapor concentrations (percent by volume in air) that will burn or explode if an ignition source is present. Limiting concentrations are commonly called the LOWER EXPLOSIVE LIMIT (LEL) and the UPPER EXPLOSIVE LEVEL (UEL). Below the LEL the mixture is too lean to burn, and above the UEL it is too rich to burn.

FLAMMABLE LIQUID: Any liquid that has a flash point below 100 degrees F (37.7 degree C).

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 FIRE: A rapid burning of flammable gases characterized by high temperature, short duration and a considerable shock wave.

FLASHING: Liquid-tight rail on top of a tank that contains water and spillage and directs it to suitable drains. May be combined with DOT overturn protection.

FLASHING DRAIN: Metal or plastic tube that drains water and spillage from flashing to the ground.

FLASHPOINT: The minimum temperature of a liquid at which it gives off vapors sufficiently fast to form an ignitable mixture with air and will flash when subjected to an external ignition source (but will not continue to burn).

FOOD PROCESSING: Activities in which food is handled, such as food packaging, cooking and serving.

FREEZING POINT: The temperature on degrees C of degrees F at which a liquid solidifies.

FULL PROTECTIVE CLOTHING: Clothing that will prevent gases, vapors, liquids and sloids from coming in contact with the skin. Full protective clothing includes the helmet self-contained breathing apparatus, coat and pants customarily worn by fire fighters (turnout or bunker coat and pants), rubber boots, gloves, bands around legs, wrist and waist. As well as covering for the neck, ears and other parts of the head not protected by the helmet, breathing apparatus, or face mask.

FUNGICIDE: A pesticide that controls or inhibits fungus growth.

FUSIBLE PLUGS: A safety release 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 form of electromagnetic radiation similar to x-rays.

GAS-TIGHT SUIT: A misnomer for vapor-protective suits, "gas-tight suits" - as defined by OSHA in HAZWOPER - are acceptable for use (that is, maintain 4-in. positive air pressure) with up to a 20% drop in pressure after four minutes in a standard inflation test (see ASTM F1052).

GENERAL DUTY CLAUSE: Specifically, this refers to section 5(a)(1) of the Occupational Safety and Health Act (29 U.S.C. et seq.) that requires each employer to "furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or likely to cause death or serious physical harm to his employees."

GUAGE PRESSURE: The pressure read on a guage, which does not take atmospheric pressure into account. The abbreviation for this pressure reading is psig.

GIGA: Metric prefix for 10 9, 1 000 000 000.0, abbreviated G.

GLADHANDS: Fittings for connection of air brake lines between vehicles. Are also called hose couplings, hand shakes, or polarized couplers.

GLOW: Visible, flameless combustion of the solid phase of a material.

GRAM: The weight of one cubic centimeter of water at 4 degrees C.

GRAM-CALORIE: One gram-calorie is the amount of heat necessary to raise one gram of water one degree centigrade from 14.5 degrees C to 15.5 degrees C.

GRANULES: Dry, coarse particles of some porous material (clay, corncobs, walnut shells) into which a pesticide is absorbed.

GROUNDING: A method that prevents static electricity from discharging sparks and producing subsequent ignition points.

GROUNDWATER: Water in a saturated zone or formation beneath the surface of land or water.

GROSS WEIGHT: The weight of a trailer together with the weight of its entire contents.

GUIDE TO THRESHOLD LIMIT VALUES (TLVTM) FOR CHEMICAL SUBSTANCES AND PHYSICAL AGENTS AND BIOLOGICAL EXPOSURE INDICES (BEITM): A pocket-sized reference guide on exposure limits to common industrial hazards, such as chemicals, noise, heat, cold, radiation and biological agents. This guide is published yearly by the ACGIH and represents experts' consensus on exposure limits.


HALF-LIFE: The length of time it takes for one-half of a given amount of radioactive substance to change into the next element.

HALOGENS: A chemical family that includes fluorine, chlorine, bromine and iodine.

HATCH PLAN: A schematic drawing of the location of all cargo on a ship.

HAZARD: A circumstance or condition that can do harm. Hazards are catorized into four groups: biological, chemical, radiation and physical.

HAZARDOUS: Capable of posing an unreasonable risk to health and safety (Dept. of Transportation). Capable of doing harm.

HAZARD CLASS: A group of materials, as designated by the Department of Transportation, that share a common major hazardous property, i.e., flammable liquids, explosives gases, oxidizers, radioactive materials, corrosives, flammable solids, poisonous and infectious substances, and dangerous substances.

HAZARD ASSESSMENT: The determination of the lack of safety or degree of risk based on all integral parts of an exposure situation, including the characteristics of the chemical(s) to which one is exposed and the conditions that determine degree of exposure.

HAZARD EVALUATION: The impact or risk the hazardous substance poses to public health and the environment.

HAZARDOUS CHEMICAL: Either a chemical that can cause chronic or acute harm upon exposure or a chemical listed in a specific EPA, OSHA, FDA, USDA or DOT regulation.

HAZARDOUS CHEMICAL EMERGENCY: Any emergency involving a hazardous chemical.

HAZARDOUS MATERIAL: A substance or material in a quantity or form that may pose an unreasonable risk to health and safety, or property, when transported in commerce.

HAZARDOUS MATERIAL EMERGENCY: An uncontrolled or unexpected release of a hazardous material.

HAZARDOUS SAMPLE: Samples that are considered to contain high concentrations of contaminants.


1) A material and its mixtures or solutions that is identified by the letter "E" in column (1) of the Hazardous Materials Table, 49 CFR 172.101, when offered for transportation in one package or in one transport vehicle if not packaged, and when the quantity of the material therein equals or exceeds the reportable quantity.

2) Any substance designated pursuant to Section 311(b)(2)

(A) of the Federal Water Pollution Contorl Act,
(B) any element, compound, mixture, solution, or substance designated pursuant to Section 102 of this Act,

(C) any hazardous waste having the characteristics identified under or listed pursuant to Section 3001 of the Solid Waste Disposal Act (but not including any waste the regulation of which under the Solid Waste Disposal Act has been suspended by Act of Congress),
(D) any toxic pollutant listed under Section 307(a) of the Federal Water Pollution Control Act,
(E) any hazardous air pollutant listed under Section 112 of the Clean Air Act, and
(F) any imminently hazardous chemical substance or mixture with respect to which the Administrator has taken action pursuant to Section 7 of the Toxic Substances Control Act. The term does not include petroleum, including crude oil or any fraction thereof which is not otherwise specifically listed or designated as a hazardous substance under subparagraphs (A) through (F) of this paragraph, and the term does not include natural gas, natural gas liquids, liquified natural gas or synthetic gas usable for fuel (of mixtures of natural gas and such synthetic gas).

HAZARDOUS WASTE: Any material that is subject to the hazardous waste manifest requirements of the Environmental Protection Agency specified in 40 CFR, Part 262 or would be subject to these requirements in the absence of an interim authorization to a State under 40 CFR Part 123, Subpart F.

HAZWOPER: Hazardous Waste Operations and Emergency Response [29CFR 1910.120]. The OSHA regulation regarding the protection of worker health and safety in situations exposing them to hazardous materials. This includes cleanup operations; remediation after cleanup; hazardous waste disposal; treatment or storage; or response to a hazardous material emergency. The regulation also includes a section on training, documentation and personal protective equipment and clothing.

HEAD: The front and rear closure of a tank shell.

HEATING TUBE: A tube installed inside a tank used to heat the contents. Also may be called "fire tube."

HEAT OF FUSION: The quantity of heat that must be supplied to a material at its melting point to convert it completely to a liquid at the same temperature.

HEAT OF VAPORIZATION: The quantity of heat that must be supplied to a liquid at its boiling point to convert it completely to a gas at the same temperature.

HEAT STRESS: The strain placed on the body as it attempts to cope with excess internal heat.

HEAVY METALS: High-density metallic elements that may demonstrate health hazards as a result of exposure and may contribute to contamination of the environment, including chromium (Cr); beryllium (Be); lead (Pb); mercury (Hg); zinc (Zn); copper (Cu); cadmium (Cd); and others.

HECTO: A metric prefix for 10 2. 100.0, abbreviated h.

HEMISPHERICAL HEAD: A head that is half a sphere in shape. Used on MC-331 high -pressure tanks.

HERBICIDE: Pesticide that controls plant life.

HIGH-EXPANSION FOAM: Detergent-base foam that expands in ratio of 1,000 to 1. It is low water-content foam.

HITCH A connecting device at the rear of a vehicle used to pull a trailer with provision for easy coupling.

HOPPER: Sloping panels at bottom of tank that direct dry bulk solids to the outlet piping.

HOSE TUBE A housing used on tank and bulk commodity trailers for the storage of cargo-handling hoses. Also called hose troughs.

HOT ZONE: An 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 area is also referred to as the "exclusion zone," the "red zone" and the "restricted zone" in other documents.

HOUSEHOLD HAZARDOUS WASTE (HHW): Hazardous materials, such as paints, pesticides, motor oil and batteries, that require careful storage and proper disposal.

HYGROSCOPIC: A substance, such as silica gel, that has the property of absorbing moisture from the air.

HYPERGOLIC: Two chemical substances that spontaneously ignite upon mixing.


ICC: Interstate Commerce Commission. An independent federal government agency in the Executive Branch (not affiliated with DOT) charged with administering acts of Congress affecting rates and routes for transport of interstate commerce.

IDLH: Immediately Dangerous to Life or Health, an atmospheric concentration of any toxic, corrosive or asphyxiant that poses an immediate threat to life or would cause irreversible or delayed adverse health effects or would interfere with an individual's ability to escape from a dangerous atmosphere. (29 CFR 1910.120)

IGNITION TEMPERATURE: The minumum temperature in degrees F or degrees C required to ignite gas or vapor without a spark or flame being present. Values provided in reference texts are only approximate because they change in geometry, gas, or vapor concentrations and in the presence of catalysts. The temperature at which a fuel or substance ignites and the flame is selfpropagating.

IMMEDIATE REMOVAL: Actions undertaken to prevent or migrate immediate and significant risk of harm to human life or health or to the environment. As set forth in the National Contingency Plan, these actions shall be terminated after $1 million has been obligated or six months have elapsed from the date of initial response.

IMPERMEABLE: Cannot be penetrated by liquid or vapor.

INCIDENT: The release or potential release of a hazardous substance into the environment.

INCIDENT CHARACTERIZATION: The process of identifying the substance(s) involved in an incident, determining exposure pathways and projecting the effect it will have on people, property, wildlife and plants, and the disruption of services.

INCIDENT COMMANDER: The person who has the responsibility for total operations at a hazardous materials emergency.

INCIDENT EVALUATION: The process of assessing the impact released or potentially released substances pose to public health and the environment.

INCIPIENT FIRES: Fires in the beginning stages.

INDIVIDUAL CONTAINER: A cargo container, such as a box or drum, used to transport materials in small quantities.

INDUSTRIAL HYGIENIST: A person who, by experience or academic training, is qualified to anticipate, recognize, evaluate and control hazards in the workplace. Some industrial hygienists are nationally certified (see CIH).

INERT INGREDIENTS: Material in a pesticide formulation that generally has no pesticidal activity, but could be flammable or combustible.

INFECTIOUS WASTE: Waste-containing pathogens; may consist of tissues, organs, body parts, blood and body fluids.

INORGANIC COMPOUNDS: Chemical compounds that do not contain the element carbon, with the exception of carbon oxides and carbon sulfides.

INFORMATION: Knowledge acquired concerning the conditions or circumstances particular to an incident.

INGESTION: The taking in of toxic materials through the mouth.

INHALATION: The taking in of toxic materials by breathing through the nose and mouth.

INHIBITOR: A chemical added to another substance to prevent or slow down an unwanted or sudden occurrence of chemical change.

INORGANIC CHEMISTRY: The branch of chemisrty dealing with compounds that do not contain carbon.

INSECTICIDE: A chemical product used to kill and control insects.

INSPECTION: Same as investigation

INTELLIGENCE: Information obtained from existing records or documentation, placards, labels, signs, special configuration of containers, visual observations, technical records, eye witnesses, and others.

IRRITANT: A material with an anesthetic, irritating, noxious, toxic or other similar property that can cause extreme annoyance or discomfort.

IRRITATING MATERIALS: Liquids or solid substances which, upon contact with fire or when exposed to air, give off dangerous or intensely irritating fumes.

ISEA: Industrial Safety Equipment Association

ISO: International Organization for Standardization

ISO 9000 & 14000: Two well-known global systems for managing quality and environmental performance.

ISO 14001-EMS: Part of ISO 14000, this standard outlines the basic Environmental Management System.

ISOLATION PERIMETERS: An area around a pesticide incident within which only necessary personnel with full protective gear are allowed.


JACKET: A metal cover that protects the tank insulation.

JACKNIFE: Condition of truck tractor-semitrailer combination when their relative positions to each other form an angle of 90 degrees or less about the trailer kingpin.


KILO: Metric prefix for 10 3, 1000, abbreviated k.

KINGPIN: Attaching pin on a semitrailer that mates with and pivots within the lower coupler of a truck tractor or converter dolly while coupling the two units together.

KINGPIN ASSEMBLY: See Upper Coupler Assembley.


LABELS: Four-inch-square diamond markers required on individual shipping containers that are smaller than 640 cu ft.

LACRIMATOR:A material that strongly irritates the eyes, nose and mucous membranes and causes tearing.

LD 50: The dose of a pesticide active ingredient taken by mouth or absorbed by the skin which is expected to cause death in 50 percent of the test animals. The lethal dose is measured in milligrams per kilogram of body weight.

LEAD DUST: A malleable type of hazardous dry particulate derived from the heavy soft metallic element. Lead is a suspected carcinogen and can cause brain disorders if consumed.

LEL: Lower Explosive Limit, the lowest concentration of the material in air that can be detonated by spark, shock or fire, etc.

L: Type of protective clothing worn when the highest level of skin, respiratory and eye protection against chemicals is required. Generally, this consists of a totally encapsulating, vapor-protective ensemble worn with a self-contained breathing apparatus (SCBA) when the ambient environment presents both a respiratory and skin contact IDLH hazard and impairs a worker's ability to escape. Originally developed by the EPA, this definition subsequently has been adopted by OSHA in HAZWOPER (29CFR1910.120).

LEVEL B:Type of protective clothing worn when the highest level of respiratory protection is required, but a lesser level of skin protection is needed. Generally, this consists of a chemical liquid splash protective suit worn with an SCBA when the ambient environment presents an IDLH inhalation hazard, but does not present a skin contact hazard nor does it impair a worker's ability to escape. Originally developed by the EPA, this definition subsequently has been adopted by OSHA in HAZWOPER (29CFR1910.120).

LEVEL C:Type of protective clothing worn when the concentrations and types of air-borne substances are known and the criteria for using air-purifying respirators are met (29CFR1910.120). Generally, this consists of a full-face or half-face respirator and hooded chemical protective clothing.

LEVEL D: A work uniform offering minimal protection and worn for nuisance contamination only.

LIMITED QUANTITY: With the exception of Poison B materials, the maximum amount of a hazardous material for which there is a specific labeling or packaging exception.

LIMITED-USE DISPOSABLE GARMENTS: Protective garments intended for one or several uses. The number of reuses depends on the situation. The following questions can provide the wearer with a starting point when deciding whether to reuse any type of limited use or reusable PPE. Is the PPE contaminated with hazardous materials? Does the PPE still provide adequate protection? (That is, has abrasion, flexing or stretching affected the performance of the product?) Is the material torn, worn or otherwise no longer able to protect after wearing?

LIQUID TIGHTThe absence of detectable liquid penetration inside the chemical protective suit when sprayed with the liquid at a specified pressure, direction and duration

LIQUEFIED GAS: A gas that is partially liquid at a temperature of 70 degree F(21 degrees C).

LITER: The volume of one kilogram of water at 4 degrees C.

LOWER EXPLOSIVE LIMITS: See flammable limits for definition.


MANHOLE: Openings usually equipped with removable, lockable covers and large enough to admit a person into a tank trailer or dry bulk trailer.

MANIFOLD: Used to join a number of discharge pipelines to a common outlet.

MEGA metric prefix for 10 6, 1 000 000.0, abbreviated M.

MELTING POINT: The temperature in degrees F or degrees C at which a solid becomes a liquid.

METER: A measure of length based on the spectrographic color line of the element krypton.

MICRO: Metric prefix for 10 6, 0.000 001, abbreviated ?

MICROORGANISM: A living organism not discretely visible to the unaided eye.

MICROPOROUS FILM: A sheet structure with micron-sized and sub-micron-sized pores.

MILLI: Metric prefix for 10-3, 0.001, abbreviated m.

MINIMUM DETECTABLE MASS PERMEATED: The smallest mass of test chemical that is detectable with the complete permeation test system. This value is not necessarily the sensitivity of the analytical instrument.

MINIMUM DETECTABLE PERMEATION RATE: The lowest rate of permeation that is measurable with the complete permeation test system. This value is not necessarily the sensitivity of the analytical instrument.

MISCIBLE: Two or more liquids that can be mixed and will remain mixed under normal conditions.

MITIGATION: Actions taken to prevent or reduce the severity of harm.

MIXTURE: A combination of chemicals that contains two or more substances that do not lose their individual identities.

MONITORING: The process of measuring certain environmental parameters on a real-time basis for spatial and time variations. For example, air monitoring may be conducted with direct-reading instruments to indicate relative changes in air contaminant concentrations at various times.

MORPHOLOGY: The form and structure of a particular organism.

MUTAGEN: A substance capable of causing genetic damage.

MVTR: Moisture vapor transport rate, a measurement of the rate at which water vapor diffuses through a fabric without the benefit of air flow. MVTR is often mistakenly used to describe the comfort and breathability of clothing materials. Research at DuPont has shown that comfort and breathability are also highly dependent on air flow through the fabric.

MSDS: Material Safety Data Sheet, a document containing information about the specific identity of hazardous chemicals, including health effects, first aid, chemical and physical properties and emergency phone numbers.


NARCOSIS: Stupor or unconsciousness produced by chemical substances.

NATIONAL CONTINGENCY PLAN: Policies and procedures that the Federal Government follows in implementing responses to hazardous substances.

NECROSIS: Death in a particular part of a living tissue.

NEMATICIDE: A pesticide used to control nematodes.

NEPHROTOXIC: A substance that negatively affects the kidneys.Nmeatodes are microscopic roundworms.

NERVE AGENTS: Compared with industrial chemicals, these very toxic, lethal chemical warfare agents, which include tabun (agent GA); sarin (agent GB), soman (agent GD) and agent VX, are liquid at room temperature but evaporate fast enough to create toxic vapor clouds in confined areas. The most volatile agent, sarin, evaporates about as quickly as water. These agents are cholinesterase inhibitors that interfere with nerve impulse transmission; hence the term "nerve gases." These chemicals can be absorbed through the skin or inhaled.

NEUROTOXIC: A substance that negatively affects the nervous system.

NEUTRALIZATION: The process by which acid or alkaline properties of a solution are altered by addition of certain reagents to bring the hydrogen and hydroxide concentrations to equal value (pH 7 is neutral).

NEWTON: The force required to impart an acceleration of one meter per second to a mass of one kilogram.

NFPA: National Fire Protection Association, an international voluntary membership organization that promotes improved fire protection and prevention; establishes safeguards against loss of life and property by fire; and writes and publishes Fire Safety Standards.

NFPA: Chemical Protective Standards: Developed by the NFPA's Committee on Fire Service Protective Clothing and Equipment, these three standards (NFPA 1991, 1992 and 1993) provide performance requirements for chemical protective clothing garment materials, gloves, footwear and visors.

NFPA 1991: Standard on Vapor-Protective Suits for Hazardous Chemical Emergencies. This standard is the most demanding of the three NFPA standards on chemical protective clothing.

NFPA 1992: Standard on Liquid Splash-Protective Suits for Hazardous Chemical Emergencies.

NFPA 1993: Standard on Support Function Protective Clothing for Hazardous Chemical Emergencies.NFPA 704 National Fire Protection Association Pamphlet 704, which describes a system for marking hazardous materials as to their health hazard, flammability, and reactivity.

NHTSA: National Highway Traffic Safety Administration of DOT responsible for establishing motoer vehicle safety standards and regulations for new vehicles. Formerly called National Highway Safety Bureau (NHSB).

NIOSH: National Institute for Occupational Safety and Health. NIOSH is one of the Centers for Disease Control (see CDC).

NITROPHENOLS: Synthetic organic pesticides containing carbon, hydrogen, nitrogen, and oxygen that are used as wood preservatives, fungucides, or disinfectants. Affect liver and central nervous system in the human body.

NONFLAMMABLE GAS: A compressed gas not classified as flammable.

NONLIQUIFIED GAS: One that is entirely gaseous at a temperature of 70 degrees F (21.11 degrees C).

NONWOVEN: Technical textile term used to refer to any fabric that is not woven or knitted, such as unidirectional fabrics and felts.

NORMALIZED BREAKTHROUGH DETECTION TIME: In an open-loop test, the time at which the permeation rate reaches 0.1 ug/cm2/min. In a closed-loop test, the time at which the mass of chemical permeated reaches 0.25 ug/cm2.

N.O.S.: Not otherwise specified.

NRTL: Nationally Recognized Testing Laboratories. The NRTL is certified by OSHA for testing safety equipment and environmental samples. NANO Metric prefix for 10 9, 0.000 000 001, abbreviated n.


OCCLUSION: The physical process of covering a chemical that has been applied to or spilled on the skin, thereby disallowing its evaporation and generally increasing its absorption through the skin.

ODOR THRESHOLD: The lowest concentration in the atmosphere that can be detected by the human sense of smell. Often, this is a poor indicator of toxicity risk.

OFF-SITE: Presence outside of the worksite.

OIL: Any of numerous mineral, vegetable and synthetic substances and vegetable and animal fats that are generally slippery, combustible, viscous, liquid or liquefiable at room temperature.

OIL HAZARDOUS MATERIALS-TECHNICIAN ASSISTANCE DATA SYSTEM (OHM-TADS): Organization within the Environmental Protection Agency (EPA) that provides information on some hazardous substances to emergency teams responding to spills.

OLFACTORY: Pertaining to the sense of smell.

ON-SITE: Presence within the boundaries of the worksite.

ORAL TOXICITY: Adverse effects resulting from taking a substance into the body through the mouth.

ORGANIC CHEMISTRY: The branch of chemistry that deals with compounds containing carbon.

ORGANIC COMPOUNDS: Compounds principally made of carbon in combination with hydrogen, nitrogen and oxygen. Generally, organic compounds are found in living organisms.

ORGANIC PEROXIDE: Strong oxidizers, often chemically unstable, containing the -O-O- structure. They react readily with solvents or fuels, resulting in an explosion or fire.

Sythetic organic pesticides that contain chlorine, carbon, and hydrogen. These pesticides affect the central nervous system. Examples; DDT and Endrin.

ORGANOPHOSPHATES: Synthetic organic pesticides that contain carbon, hydrogen and phosphorous. Toxic to humans because they prevent proper transmission of the nerve impulses. Examples; Parathion and Malation.

ORMS: (Other regulated materials) Materials that do not meet the definition of hazardous materials, but possess enough hazardous characteristics that they require some regulation.

OSHA: Occupational Safety and Health Administration. OSHA is an agency within the Department of Labor responsible for regulations of safety in the workplace.

OSHA PPE STANDARD: This standard is contained in 29 CFR 1910, Subpart I, and includes General Requirements (.132); Eye and Face Protection (.133); Respiratory Protection (.134); Head Protection (.135); Occupational Foot Protection (.136); Electrical Protective Devices (.137); Hand Protection (.138); and Non-Mandatory Compliance Guidelines for Hazard Assessment and PPE Selection (Appendix B). Other OSHA Occupational Safety and Health Regulations have specific paragraphs dealing with PPE, including HAZWOPER (.120); Blood-Borne Pathogens (.130); Electrical Safety (.335); Welding, Cutting and Brazing (.252); and Electrical Power Generation (.269).

OSHA 29 CFR 1910.120: Hazardous Waste Operations and Emergency Response. These civilian standards for protection against chemical warfare agents are more stringent than military standards.

OSHA 29 CFR 1910.132: This standard covers general requirements for personal protective equipment (PPE) for eyes, face, head and extremities, protective clothing, respiratory devices, and protective shields and barriers.

OSHA 29 CFR 1910.133: Addresses specific requirements for eye and face protection.

OSHA 29 CFR 1910.135: Addresses specific requirements for head protection.

OSHA 29 CFR 1910.136: Addresses specific requirements for foot protection.

OSHA 29 CFR 1910.138: Addresses specific requirements for hand protection.

OSHA TECHNICAL MANUAL: This manual serves as a guidance document for OSHA Compliance Safety and Health Officers in current occupational safety and health technical procedures and information. It also provides safety professionals with technical information and guidance to promote hazard recognition and the establishment of sound safety and health programs.

OUTAGE: The space left in a vessel filled with a flammable liquid.

OUTLET VALVE: The valve farthest downstream in tank piping system, to which the discharge hose is attached.

OUTRIGGER: Structural load-carrying membbers attached to and extending outward from the main longitudinal frame memebers of a trailer.

OVERTURN PROTECTION: For fittings on top of a tank in case of rollover. May be combined with flashing rail or flashing box.

OXIDIZER: A chemical, other than a blasting agent or explosive, that initiates or promotes combustion in other materials, thereby causing fire either of itself or through the release of oxygen or other gases.

OXIDIZING MATERIAL: A substance that yields oxygen readily stimulate the combustion of organic matter and inorganic matter.


PACKAGE MARKINGS: The descriptive name, instructions, cautions, weight, or specification marks required to be placed on outside of containers of hazardous materials.

PAINT SPRAYING: Used in many industries, including automotive, aircraft, boating and appliances, paint spraying may pose inhalation and skin contact hazards from solvents, pigments and additives.

PAPRs: Powered Air Purifying Respirators are breathing masks with specific chemical cartridges designed to either filter particulates or absorb contaminants before they enter the worker's breathing zone. PAPRs use portable motors to force air through the filtering/purifying cartridges. They are intended for use only in atmospheres where the chemical hazards and concentrations are known.

PASCAL: The pressure obtained when a force of one newton acts on an area of one square meter.

PATHOGENS: Any disease-producing organisms, including viruses.

PATHWAYS OF DISPERSION: The mode (water,groundwater, soil, and air) by which a chemical moves through the environment.

PEL: OSHA's Permissible Exposure Limit, which is similar to maximum allowable concentration (MAC).

PENETRATION: The flow of a liquid through closures, porous materials, seams and pinholes or other imperfections in a protective clothing material on a nonmolecular level.

PERMEATION: The process by which a chemical moves through a protective clothing material on a molecular level. Permeation involves the following:

  • Sorption of molecules of the chemical into the contacted (outside) surface of a material.
  • Diffusion of sorbed molecules in the material, and
  • Desorption of the molecules from the opposite (inside) surface of the material into the collecting medium.

PERSISTENT CHEMICALS: A substance which resists biodegradation and/or chemical oxidation when released into the environment and tends to accumulate on land, in air, in water, or in organic matter.

PESTICIDES: Chemical or mixture of chemicals used to destroy prevent, or control any living organism considered to be a pest.

pH: A numerical designation of the negative logarithm of hydrogen ion concentration. A pH of 7.0 is neutrality; higher values indicate alkalinity and lower values indicate acidity.

PHYSICAL-CHEMICAL PARAMETERS: Values for physical or chemical properties of a permeant or polymer, or both, such as solubility parameters, molecular weight, vapor pressure, etc.

PHYSICAL PROPERTIES: Properties of a material that relate to the physical states common to all substances, i.e. a solid, a liquid, or a gas.

PICKUP PLATE: A sloped plate and structure of a trailer, located forward of the kingpin and designed to facilitate engagement of fifth wheel to kingpin.

PICO: Metric prefix for 10-12, 0.000 000 000 001, abbreviated p.

PIGGYBACK TRANSPORT: 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.

PINTLE: See Hitch

PIPELINE: A way to transport a product.

PLACARDS: 10-3/4 in. (273.0 mm)-square diamond markers required on the transporting vehicle such as a truck or tank car, or a freight container 640 cu ft (18.1m3) or larger.

PLANNED REMOVAL: The removal of released hazardous substances from the environment within a non-immediate, long term, time period. Under CERCLA, actions intended to minimize increases in exposure such that time and cost committments are limited to 6 months and/or one million dollars.

PLASTIC: A material that contains, as an essential ingredient, one or more organic polymeric substances of large molecular weight, is solid in its finished state, and, at some stage in its manufacture of processing into finished articles, can be shaped by flow.

POLARIZED COUPLERS: Fittings for connecting of air brake lines between vehicles. The service and emergency couplings are unilateral and will not mate with each other.

POLLUTANT: A substance or mixture which after release into the environment and upon exposure to any organism will or may reasonably be anticipated to cause adverse effects in such organisms or their offspring.

POLLUTANT TRANSPORT: An array of mechanisms by which a substance may migrate outside the immediate location of the release or discharge of the substance. For example, pollution of groundwater by the migration of hazardous wastes from a landfill.

POLYESTER: Man-made fiber with a high level of strength, stability and abrasion resistance.

POLYMER: A substance consisting of molecules characterized by repetition (neglecting ends, branches, junctions, and other minor irregularities) of one or more chemically bonded types of monomeric units.

POLYMERIZATION: A chemical reaction, usually carried out with a catalyst, heat or light - and often under high pressure - that generates high temperature and may be violent when uncontrolled.

POST-CONSUMER RECYCLED (PCR) CONTENT: In the case of Tyvek® spunbonded olefin fabrics, the amount of polyethylene recovered from used plastic containers that, after cleaning, is used to make certain Tyvek® products.

PPE: Personal protective equipment, including gloves, helmets, glasses, hard-toed shoes, garments, face shields and ear plugs.


PRECIPITATE: Result when s solution of one chemical is combined with a solution of another chemical and an insoluble material is produced.

PRESSURE: A force applied over a given area.

PROTECTIVE CLOTHING: A garment used for the purpose of isolating parts of the body from potential contact with a hazard.

PROTECTIVE CLOTHING MATERIAL: Any material or combination of materials used in an item of clothing for the purpose of isolating parts of the body from a potential hazard.

PROTECTIVE ENSEMBLE: The combination of head, hand, face, foot and body protective equipment - including respiratory protection and accessories such as cooling and communications devices - used together to protect against specific hazards.

PSIA: See Absolute Pressure for definition.

PSTN: Pesticide Safety Team Network. Regional teams of the National Agricultural Chemical Association designed to assist with pesticide incidents.

PULMONARY: Pertaining to the lungs.

PUMPOFF LINE: A pipeline that usually runs from the tank discharge openings to the front of the trailer. Most pumps are mounted on the tractor.

PURGE TIME: In an intermittent contact test, the time immediately following the termination of the contact time when the test chemical is removed from the challenge side chamber and air or nitrogen is blown over the outside surface of the protective clothing material.

PYROPHORIC LIQUID: Any liquid that ignites spontaneously in dry or moist air at or below 130 degree F (54 degree C)


QSSP: A qualified safety sales professional is certified by the Safety Equipment Distributors Association (SEDA).

QUALIFIED INDIVIDUAL: A person who through education, experience, or professional accreditation is competent to make judgements concerning a particular subject matter. A Certified Industrial Hygenist may be a qualified individual for preparing a site safety plan.


RADIATION: Heat transfer by electromagnetic waves.

RADIOACTIVE: Capable of spontaneously emitting ionizing radiation.

RADIOACTIVE MATERIAL: Any material, or combination of materials, that spontaneously emits ionizing radiation and has a specific activity greater than 0.002 microcuries per gram.

RADIOISOTOPES: Artificially radioactive elements

REACTIVE MATERIALS: Substances capable of or tending to react chemically with other substances.

REACTIVITY: The degree of ability of one substance to undergo a chemical combination with another substance.

REDUCING AGENT: A fuel that becomes chemically changed in the oxidizing process.

REFRIGERATION UNIT: Cargo space cooling equipment.

REGULATED MATERIAL: A substance or material that is subject to regulations set forth by the Environmental Protection Agency, the Department of Transportation, or any other federal agency.

REED VAPOR PRESSURE: Equilibrium pressure exerted by vapor over the liquid at 100 degrees F (37.78 degrees C) as expressed in pounds per square inch absolute, as defined in 46 CFR 30.10-59.

RELAY EMERGENCY VALVE: A combination valve in an air brake system, which controls brake application and which also provides for automatic emergency brake application should the trailer become disconnected from the towing vehicle.

REMEDIAL ACTIONS: As in the National Contingency Plan, responses to releases on the National Priority List that are consistent with permanent remedy to prevent or mitigate the migration of a release of hazardous substances into the environment.

REMEDIATION: In environmental situations, this term refers to the removal, disposal, deactivation, neutralization, entombment or decontamination of hazardous materials from a contaminated parcel of land.

REPORTABLE QUANTITY: As set forth in the Clean Water Act, the minimum amount (pounds or kilograms) of a substance that may be discharged in a 24 hour period that require notification of the appropriate government agency.

RESIDUE: A material remaining in a package after its contents have been emptied and before the package is refilled or cleaned and purged of vapor to remove any potential hazard.

RESOURCES: All of the immediate or supportive assistance available to help control an incident; including personnel, equipment, control agents, agencies and printed emergency guides.

RESPONSE ACTIVITIES: Activities taken to recognize, evaluate and control an incident.

RESPONSE OPERATIONS: Same as Response Activities.

RISK: The probability that an unwanted event (harm) will occur.

RISK ASSESSMENT: The use of factual base to define the health effects of exposure of individuals or populations to hazardous materials and situations.

RISK MANAGEMENT: The process of weighing policy alternatives and selecting the most appropriate regulatory action integrating the results of risk assessment with engineering data and with social and economic concerns to reach a decision.

ROTARY GUAGE: A gauge for determining the liquid level in a pressurized tank.

ROUTES OF EXPOSURE: The manner in which a chemical contaminant enters the body. E.G. oral, inhalation, and cutaneous, and routes of entry.

RUNNING LIGHTS: Marker, clearance, and identification lights required by regulations.

RUPTURE DISK: A safety 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.


SAFETY: Freedom from man - equipment - material - environmental interactions that result in injury or illness.

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.

SANDSHOE: A flat steel plate that serves as ground contact on the supports of a trailer and used instead of wheels particularly where the ground surface is expected to be soft.

SAMPLING: The collection of representative portion of the universe. Example: the collection of a water sample from a contaminated stream.

SBPP: See spunbonded polypropylene.

SECOND RESPONDERS: Those personnel required to assist or relieve first responders at a hazardous materials incident due to their specialized knowledge, equipment, or experience. These can include State environmental protection or health officials, commercial response and clean-up companies, and appropriate industry representatives.

SELF-ACCELERATING DECOMPOSITION TEMPERATURE: The temperature above which the decomposition of an unstable material proceeds itself, independently of the external temperature.

SEMITRAILER: a truck trailer equipped with one or more axles and constructed so that the front end and a substantial part of its own weight and that of its load rests upon a truck tractor.

SENSITIZER: A substance that, on first exposure, causes little or no reaction in humans or test animals. On repeated exposure, however, the same substance may cause a marked response not necessarily limited to the contact site.

SEVERE: A relative term used to describe the degree to which hazardous materials releases can cause adverse effects to human health and the environment.

SHEER SECTIONS: A safety feature, such as a valve or joint, built onto a cargo tank, which is designed to fail or break completely to prevent a failure or break of the tank itself.

SHELTERING IN PLACE/IN PLACE PROTECTION: To direct people to quickly go inside a building and remain inside until the danger passes.

SHIPPING PAPERS: A shipping order, bill of lading, manifest, or other shipping document issued by the carrier.

SITE: Location.

SITE SAFETY PLAN: Written site-specific safety criteria that establishes requirements for protecting the health and safety of responders during all activities conducted at an incident.

SIZE: One of a series of graduated measurements in manufactured articles of clothing conventionally identified by numbers, letters or words.


SLIDING FIFTH WHEEL: A fifth wheel assembly capable of being moved forward or backward on the truck tractor to vary load distribution on the tractor and to adjust the overall length of combination.

SLOPE SHEET: Panels located at each end of payload compartment that direct product by gravity to hoppers.

SMS: See spunbonded-meltblown-spunbonded fabrics.

SOIL CONTAMINATION: Contamination of the ground area where a pesticide spill or fire occurs, or where contaminated runoff water flows.

SOLUBILITY: The ability or tendency of one substance to blend uniformly with or dissolve into another.

SOLUTION: Mixture of one or more substances in another in which all ingredients are completely dissolved.

SOLVENT: A liquid that will dissolve a substance to form a solution. Some examples of solvents are water, petroleum distillate, xylene, or methanol.

SPECIFIC GRAVITY: The weight of a substance as compared to the weight of an equal volume of water.

SPLASH-PROTECTIVE SUIT: A one- or multi-piece garment that is constructed of protective clothing materials, designed and configured to protect the wearer's torso, head, arms and legs against liquid splashes of hazardous chemicals.

SPONTANEOUSLY COMBUSTIBLE: The process in increase in temperature of a material to a point of ignition, without drawing heat from its surroundings.

SPUNBONDED-MELTBLOWN-SPUNBONDED (SMS) FABRICS: SMS fabrics are generic nonwovens generally made of polypropylene. Primarily used in diapers, SMS fabrics consist of a thin layer of small meltblown fibers sandwiched between layers of spunbonded fibers.

SPUNBONDED OLEFIN: Spunbonded olefin is manufactured via a proprietary process in which fine polyolefin fibers are randomly distributed on a moving belt and thermally bonded to produce a sheet structure.

SPUNBONDED POLYPROPYLENE (SBPP): SBPP fabrics are a generic class of nonwoven material with minimal barrier properties used in low-cost, disposable commodity applications such as diapers.

STANDARD TRANSPORTATION COMMODITY CODE (or STCC Code Number): A listing of code numbers for categories of articles being shipped, in general use by carriers.

STERILE: Free from viable microorganisms.

STRESS: A state of tension put on or in a shipping container by internal chemical action, external mechanical damage or external flames or heat.

STAGE OF THE INCIDENT: One of the five definite and identifiable phases through which an emergency passes from onset (interruption of normal conditions) or stabilization.

STANDARDIZED MANAGEMENT SYSTEMS: Global systems such as ISO 9000 and ISO 14000 for managing quality and environmental performance.

STEADY-STATE PERMEATION RATE: A constant rate of permeation that occurs after breakthrough when all forces affecting permeation have reached equilibrium.

STEL: The Short-Term Exposure Limit refers to an exposure that may be tolerated for a brief time.

STRENGTH-TO-WEIGHT RATIO: A measure of a material's value based on the ratio of tensile strength to basis weight.

SUBLIMATION: Going from the solid to gaseous to solid state.

SUMP: The low point of a tank at which the emergency valve or outlet valve is attached.

SUPPORT ZONE: See Cold Zone.

SURROGATE: A less-hazardous, less-expensive substitute material that acts similarly to a hazardous material of interest. In protective clothing testing, nonhazardous surrogates are sometimes used in place of hazardous materials, such as extremely toxic chemicals or hazardous microbes.

SURROGATE MICROBE: A nonpathogenic microorganism used in testing as a substitute for a highly pathogenic microorganism. For example, in ASTM F1671, a nonpathogenic virus is used to evaluate the barrier of garment fabrics against hepatitis and AIDS viruses.

SWEATING HOT PLATE: A laboratory simulation used to evaluate how clothing impacts the body's cooling mechanism via sweating.

SWITCH LIST: A list of the cars in the train used by railroad crews in a yard when they are making up a train.

SYNERGISTIC EFFECT: The combined effect of two chemicals that is greater than the sum of the effect of each agent alone.

SYNTHETIC: Man made; not made from a natural process.

SYNTHETIC BLOOD: A mixture of red dye/surfactant, thickening agent and distilled water having a surface tension and viscosity, and a red color representative of blood and other body fluids, making it more usable for visible detection.

SYSTEMIC: Pertaining to the internal organs and structures of the body.


TACTICS: Successful methods or procedures used to deploy various tactical units (resources) to achieve objectives.

TANDEM: Two-axle suspension.

TECHNICAL ASSISTANCE: Personnel, agencies, or printed materials that provide technical information on the handling of hazardous materials.

TECHNICAL PESTICIDE: Highly concentrated pesticide, which is to be combined with other materials to formulate pesticide products.

TEMPERATURE: The condition of an object that determines whether heat will flow to or form another object.

TENSILE STRENGTH: The force required to rupture a material by pulling on it.

TERA: Metric prefix for 10 12, 1 000 000 000 000.0, abbreviated T.

TERATOGEN: A substance or agent that can result in malformations of a fetus.

TEST CHEMICAL: The liquid or gas that is used to challenge the protective clothing material specimen.

TESTING PROGRAMS: Programs involving test procedures to determine chemical/protective clothing material interactions or compatibilities. Testing programs include, but are not limited to, testing protective clothing materials for resistance to degradation, penetration and permeation.

THIRD RESPONDERS: Those personnel required to help the first or second responders handle special situations or conduct the clean-up, removal, and associated activities. These can include federal environmental protection and health officials, other federal agencies commercial response and cleanup companies, and appropriate industry representatives.

THRESHOLD LIMIT VALUE: The concentration of a toxic substance that can be tolerated with no ill effects.

TIME INTERVAL: The time between weighings of the permeation cup.

TIR: Transport International Routier, translated: International Transport by Road. This is the name of a customs convention (or agreement) that exists among many countries, principally European. It permits vehicles or containers, properly approved and certified to be sealed under Customs direction in one country and be transported across borders of member countries without reinspection until arrival of its final destination where the seal is then removed under Customs supervision

TITER: The quantity of a substance required to react with, or to correspond to, a given amount of another substance.

TLV: For an airborne toxic material, the Threshold Limit Value is used as a guide in the control of health hazards and represents the concentration to which nearly all workers may be exposed eight hours per day over extended periods of time without adverse effects.

TLV-TWA: Threshold Limit Value-Time Weighted Average is an exposure level under which most people can work consistently for eight hours a day, day after day, with no harmful effects.

TOFC: Trailer-on-Flatcar; also referred to as a piggyback.

TOTALLY-ENCAPSULATING CHEMICAL PROTECTIVE SUIT (TECP): A full body garment that is constructed of protective clothing materials; covers the wearer's torso, head, arms and legs; covers the wearer's hands and feet with either permanently or tightly attached gloves and boots; and completely encloses the wearer by itself or in combination with the wearer's respiratory equipment, gloves and boots.

TOW BAR: A beam structure used to maintain rigidly the distance between a towed vehicle and the towing vehicle

TOXICITY: The ability of a substance to produce injury once it reaches a susceptible site in or on the body.

TOXIC MATERIALS: Substances that can be poisonous if inhaled, swallowed, or absorbed into the body through cuts or breaks in the skin.

TRAPEZOIDAL TEAR: A test that measures the force required to propagate a tear across a fabric.

TRIBOELECTRIC EFFECT: The creation of static electrical charges when two dissimilar materials, such as amber rod and silk cloth, are rubbed together.

TRITIATED WATER VAPOR: Tritium oxide (heavy, heavy water) vapor.

"TUMBLING ENVELOPE" TEST METHOD: This fabric test evaluates the mechanical interaction of the fabric and test particles.


UEL: The Upper Explosive Limit is the highest concentration of the material in air that can be detonated.

UNSTABLE MATERIALS: Substances capable of rapidly undergoing chemical changes or decomposition.


VAPOR: An air dispersion of molecules of a substance that is normally a liquid or solid at standard temperature and pressure.

VESICANTS: Agents that induce blistering (see Blistering Agents).

VIRAL PENETRATION: The penetration of a material by a virus.

VIRAL RESISTANT: Referring to materials that impede viral penetration under specified laboratory test conditions and detection methods.

VIRUS: A minute infectious agent, which lacks independent metabolism and is only able to replicate within a living host cell.

VISIBILITY: When evaluating garment colors for safety applications, visibility refers to the color of a garment fabric in brightly lit and dimly lit situations, as well as the difference in color between the fabric and the background. Visibility also refers to the ability to see through a face plate in an encapsulated suit.


WARM ZONE: The 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," "yellow zone," "support zone" or "limited access zone" in other documents.

WATER-REACTIVE MATERIALS: Substances, generally flammable solids, that will react in varying degrees when mixed with water or when they come in contact with humid air.

WATER SOLUBILITY: The ability of a liquid or solid to mix with or dissolve in water.

WAYBILL: The shipping paper prepared by the railroad from a bill of landing. Waybills generally accompany a shipment and are carried by the conductor in the caboose of the train.

WET BULB GLOBE TEMPERATURE (WBGT): This is the OSHA-recommended method for assessing heat-stress potential.

WORK PLAN: Written directives that specifically describe all work activities that are to take place at a work site.





All information © Mike Callan, 2001, unless otherwise indicated