Glossary of Terms For Emergency Response to Chemical Spills

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USFA Hazardous Materials Guide for First Responders
Glossary Terms and Abbreviations

A chemical which neutralizes alkalis forming salts. Acids have low pH's.
Having a rapid onset and progression.
Particles dispersed in a gas (usually air). Examples are fog (liquid particles) and smoke (solid particles).
A chemical which neutralizes acids forming salts. Alkalis have high pH's. Alkalis are corrosive.
Containing no water.
An abbreviation for asymmetrical - referring to a particular arrangement of elements within a chemical molecule.
Injury or death caused by the replacement of oxygen in the environment by another gas or vapor.
Awareness Level Trained
First responders at the awareness level are those persons who, in the course of their normal duties may be the first on the scene of an emergency involving hazardous materials. First responders at the awareness level are expected to recognize hazardous materials presence, protect themselves, call for trained personnel, and secure the area. (NFPA 472)
Basic Life Support (CPR)
First aid measures done to assist a victim's breathing and heart action such as cardiopulmonary resuscitation.
An acronym for Boiling Liquid Expanding Vapor Explosion. Materials which BLEVE may cause storage containers and parts of containers to rocket great distances, in many directions. Any liquid may cause a BLEVE.
To change from a liquid state to a gaseous state.
Acronym for Computer Aided Management of Emergency Operations developed by the National Oceanic and Atmospheric Administration.
CAS Identification Number
A number assigned to each unique chemical entity by the Chemical Abstract Service of the American Chemical Society.
A substance which, when present in a very small amount, increases the rate at which two or more chemicals react together.
Chemical Protective Clothing
Items such as clothing, hood, boots and gloves (fully-encapsulating suit) made from chemical-resistant materials that are designed and configured to protect the wearer from hazardous materials.
The CHEMical TRansportation Emergency Center, a public service of the Chemical Manufacturers Association. Located in Washington D.C. Available 24 hours a day. (1-800-424-9300)
An acronym for the Chemical Hazard Response Information System. Written and maintained by the United States Coast Guard.
Occurring over a long time - many days or longer.
refers to a particular arrangement of elements with a chemical molecule.
The process of burning.
Compressed Gas
A gas which exerts a pressure of at least 41 psi in the container in which it is stored.
The amount of one substance mixed or dissolved in a specified amount of a second substance.
Confined Space
A space that has limited openings for entry and exit and has poor natural ventilation.
Actions taken to keep a material in a defined or local area after it is released.
Anything that holds material, including storage tanks, pipelines and packaging (drums, carboys, etc).
Containing potentially harmful material.
A release of hazardous material from its source to people, animals, the environment or equipment.
Any material which causes visible damage or irreversible alteration of human tissue (skin, eyes, etc.) at the site of contact or causes metals or plastics to corrode at a rapid rate.
Acronym for CardioPulmonary Resuscitation an emergency procedure used to maintain and restore breathing and blood circulation.
A material at a very low temperature.
Breaking apart into smaller different chemicals.
The removal of a hazardous material from a victim or equipment.
Decontamination Area
Area located on the upwind edge of the Hot Zone used to decontaminate personnel and equipment. All personnel coming out of the Hot Zone must pass through the Decontamination Area for decontamination.
Changing shape.
A flooding quantity of water.
The rapid decomposition of an explosive material leading to a rapidly moving wave of high temperature and high pressure. May be started by impact, friction or heat.
Barrier constructed to hold back a spill or leak.
To scatter in different directions.
An acronym for United States Department of Transportation.
The rapid expansion of a material or container with the release of energy, heat or pressure.
Any substance designed to produce an explosion (i.e. an extremely rapid release of gas and heat) or capable of producing an explosion by reacting with itself.
An acronym for Facility Emergency Coordinator.
An acronym for United States Federal Emergency Management Agency.
Fire Fighting Gear
Turnout gear including footwear, trousers, a coat, gloves, a helmet, and respiratory protection. (NFPA 472)
First Responder
The individual who arrives first at the scene of a Hazmat incident with the responsibility to act.

In this volume, defined as the equivalent of NFPA Flammability Hazard Class 1.
Very Flammable
In this volume, defined as the equivalent of NFPA Flammability Hazard Class 2.
Highly Flammable
In this volume, defined as the equivalent of NFPA Flammability Hazard Class 3.
Extremely Flammable
In this volume, defined as the equivalent of NFPA Flammability Hazard Class 4.
The lowest temperature at which the vapor of a substance will catch on fire. It will not continue to burn without the addition of more heat. The flashpoint is lower than the ignition temperature.
Liquid particles dispersed in air.
To change from a liquid state to a solid state.
Injury caused to skin or other tissue by very cold materials. The medical consequences are similar to those caused by burns.
A general term for vapors, gases, or smoke.
A state of matter in which the material can expand and contract in response to pressure or temperature.
A potential risk or danger.
Hazardous Material
Any substance capable of causing harm to people, animals, property or the environment.
Hazmat Incident
Actual or potential unplanned release of a hazardous material.
Name given to the 29CFR 1910.120 regulation entitled Hazardous Waste OPeration and Emergency Response.
An acronym for Heating, Ventilating, and Air Conditioning systems.
Hot Zone
The area immediately around the incident site. Appropriate protective clothing and equipment must be worn by all personnel in the Hot Zone. Awareness Level and Operational Level trained personnel are not permitted in the Hot Zone.
An acronym for Incident Command System.
Ignition Temperature
The minimum temperature to which a material must be raised before it will burn. The ignition temperature is higher than the flashpoint.
Incident Commander (IC)
The individual responsible for the management and coordination of all incident operations.
Breathing a chemical into the lung.
Containing a small amount of another substance included to prevent the first material from reacting with itself or other things in its environment.
Not able to be dissolved.
A material with the same chemical composition (i.e. kind and number of elements) as another material but with a different arrangement of those elements. For example, n-butyl alcohol and t-butyl alcohol are isomers of one another.
An acronym for Local Emergency Planning Committee.
An abbreviation for "meta". Referring to a particular arrangement of groups attached to a benzene molecule.
An abnormal form of hemoglobin which will not carry oxygen in the blood.
A self supporting fire fighting nozzle which can function unattended and delivers a large volume of fire suppressant material.
An acronym for Material Safety Data Sheet. Information provided by the manufacturer of a material about its physical and chemical properties as well as the hazards associated with its use.
An abbreviation for "normal". It refers to the arrangement of carbon atoms in a chemical molecule.
A symbol used in some chemical names indicating that the next section of the name refers to a chemical group attached to a nitrogen atom.
NA Identification Number
An acronym for North America. A four-digit number assigned to some chemicals found in transport in North America.
An acronym for National Fire Protection Association, Inc.
An acronym for United States National Institute of Occupational Safety and Health.
Not capable of being burned under normal conditions.
An abbreviation for "ortho". Referring to a particular arrangement of elements within a chemical molecule.
Operations Level Trained
First responders at the operational level are those persons who respond to releases or potential releases of hazardous materials as part of the initial response to the incident for the purpose of protecting nearby persons, the environment, or property from the effects of the release. They shall be trained to respond in a defensive fashion to control the release from a safe distance and keep it from spreading. (ANSI/NFPA 472)
An acronym for United States Occupational Safety and Health Administration.
A chemical which when mixed with combustible or flammable material will start a fire or make an existing fire worse.
An abbreviation for "para". Referring to a particular arrangement of elements within a chemical molecule.
Chemicals which contain two oxygen atoms bound together. Often explosive.
A sign or symbol designed to be hung on a wall, container or vehicle containing warning information to convey the level of hazard.
Sharp or irritating.
That portion of incident management in which personnel are involved in controlling a hazardous materials incident. (ANSI/NFPA 471)
A measure of the chances that damage to life, property, or the environment will occur if a hazard occurs. Risk includes consideration of the severity of the damage.
Excess water produced during fire fighting or from rain.
Superfund Amendments and Reauthorization Act of 1986. Title III of SARA, the Emergency Planning and Community Right-to-Know Act of 1986, includes detailed provisions for community planning.
An acronym for Self Contained Breathing Apparatus. SCBA includes a seal tested mask, positive pressure regulator and a pressurized air supply.
An abbreviation for "secondary". Referring to a particular arrangement of elements within a chemical molecule.
Shelter in Place
Protect people without evacuating by keeping them inside a building with windows and doors closed and external ventilation systems shut off until a hazardous situation has resolved.
The degree to which one material may be completely mixed with or dissolved in another material.
Containing a small amount of another substance included to keep the first material from changing form.
STCC Identification Numbers
An acronym for Standard Transportation Commodity Code. A seven digit identification number commonly used for materials shipped by rail. Numbers beginning with 49- are hazardous materials.
To change from a solid state to a gaseous state without becoming a liquid.
An abbreviation for "symmetrical". Referring to a particular arrangement of elements within a chemical molecule.
An abbreviation for "tertiary". Referring to a particular arrangement of elements within a chemical molecule.
An abbreviation for "tertiary". Referring to a particular arrangement of elements within a chemical molecule.
Containing a sulfur atom.
Capable of causing human injury. A poison.
Referring to a particular arrangement of elements within a chemical molecule.
UN Identification Number
An international four digit number assigned to all hazardous materials regulated by the United Nations.
Easily changes from a liquid to a vapor.
A symbol meaning "greater than".
A symbol meaning "less than".

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This page was updated on 30-Mar-2016