Glossary
This glossary contains acronyms and technical terms that are used throughout this Manual. The
definitions are general in nature and are intended to serve as a quick reference tool. More
detailed information can be found in the relevant module(s) of the Manual, the primary reference
described (e.g., OSHA, EPA, ACGIH), or comprehensive reference sources (e.g., Hawley's, The
Condensed Chemical Dictionary, Van Nostrand Reinhold Company, New York, latest edition.)
ABIH
American Board of Industrial Hygiene. A professional organization dedicated to improving the
practice and educational standards of the profession of industrial hygiene. One of their main
responsibilities is certifying and regulating certification maintenance for industrial hygiene.
Absolute
A chemical substance that is not mixed; pure. An example is absolute alcohol: ethyl alcohol
containing not more that one percent by weight of water.
Accident
An unexpected event generally resulting in injury, loss of property, or disruption of service.
ACGIH
American Conference of Governmental Industrial Hygienists. An organization of professionals
in governmental agencies or educational institutions engaged in occupational safety and health
programs. ACGIH develops and publishes recommended occupational exposure limits for
chemical substances and physical agents (see TLV).
Acid
Materials that have a pH of 0-6.9. Acids with pH in the 0-2 range can be corrosive to human
tissue and will cause burns to the eyes and skin. Acids will react with alkali materials (see also
Alkali and Base).
Action level
The exposure level (a material's concentration in air) at which OSHA regulations to protect
employees take effect. This level of contaminant concentration is below the permissible exposure
limit (PEL), but above the level at which OSHA requires additional sampling or other action,
such as medical surveillance. Usually, action levels are one-half the PEL for a given substance.
Acute effect
An adverse effect on a human or animal body, characterized by severe symptoms that develop
rapidly.
Acute toxicity
The adverse effects resulting from a single (or small number) dose or exposure to a substance.
Aerosol
A fine aerial suspension of liquid (mist, fog) or solid (dust, fume, smoke) particles that are small
enough to remain suspended.
Agent
1
Any substance, force, radiation, organism, or influence that affects the body in a beneficial of
injurious manner.
AIHA
American Industrial Hygiene Association. Organization of professionals trained in the
recognition and control of health hazards and the prevention of illness related thereto. Industries
are eligible for associate membership. Promotes the study and control of environmental factors
affecting the health of industrial workers; provides information and communication services
pertaining to industrial hygiene.
ALARA
Acronym for as low as reasonably achievable that is used to describe radiation levels.
Alkali
Any compound having highly basic properties (pH from 7.1-14). Alkalies are usually oxides and
hydroxides of certain metals, and include sodium carbonate, lime, lye, potash, caustic soda, and
bicarbonate of soda. Alkalies are caustic and dissolve human tissue.
Alpha radiation
A type of ionizing radiation consisting of alpha particles, which are two protons and two neutrons
bound together, with an electrical charge of +2. An alpha particle is equivalent to a helium
nucleus.
Ambient
Usual or surrounding conditions.
American National Standards Institute
See ANSI.
API
American Petroleum Institute. A voluntary membership organization of the petroleum industry.
Among its services, API uses the consensus process to assist its member committees in
developing, and publishing recommended practices for drilling and well servicing, storage tank
installation, tank cleaning, piping and fittings, other industry related design, installation and
operating practices; also funds and publishes basic references books and manuals, such as
Industrial Hygiene Monitoring Manual for Petroleum Refineries and Selected Petrochemical
Operations.
Aquifer
A saturated, water-bearing formation of permeable rock, sand, or gravel.
American Society for Testing and Materials
See ASTM.
Anhydride
A compound derived from another compound by removing hydrogen and oxygen.
ANSI
American National Standards Institute. A privately funded organization that identifies industrial
and public national consensus standards and oversees their development. Many of these
2
standards relate to safe design and performance of equipment, and safe work practices and
procedures.
APR
Air Purifying Respirator. A type of respirator that uses physical and/or chemical means to filter
the air breathed in by the user.
Asphyxiant
A chemical that either displaces oxygen in the air (a simple asphyxiant), or prevents bodily
absorption of oxygen (a chemical asphyxiant), to cause suffocation (asphyxiation). Examples
include carbon dioxide, carbon monoxide, and helium.
ASR
Atmosphere Supplying Respirator. A type of respirator which supplies air (or oxygen) to the user.
ASSE
American Society of Safety Engineers. Professional society of safety engineers, safety directors
and others concerned with accident prevention and safety programs. Compiles statistics.
ASTM
American Society for Testing and Materials. An organization that develops consensus standards
for materials characterization and use. ASTM is a resource for sampling and testing methods,
health and safety aspects of materials, safe performance guidelines, and effects of physical,
biological, and chemical agents.
Autoignition temperature
The minimum temperature at which a substance ignites without application of a flame or spark.
Autoreactive
A compound that is reactive under normal conditions without initiation by heat or other
compounds or change in conditions.
Base
Substances that liberate OH anions when dissolved in water and have a pH above 7. Bases react
with acids to form salts and water. They may be corrosive to human tissue (see also Alkali).
BLEVE
Boiling Liquid Expanding Vapor Explosion. A highly dangerous condition that can occur when a
container of liquified gas is exposed to a fire.
Bloodborne pathogen
According to OSHA, pathogenic microorganisms that are present in human blood and in other
potentially infectious materials (OPIM), and can cause disease in humans (e.g., hepatitis B and
human immuno-deficiency virus {HIV}) (see also OPIM).
BOE
Bureau of Explosives. A professional group that researches explosives and provides technical
assistance in the event of incidents.
Boiling point
3
The temperature of a liquid at which its vapor pressure is equal to or very slightly greater than the
atmospheric pressure of the environment. For water at sea level it is 212°F (100°C). Flammable
materials with low boiling points generally present special fire hazards.
Bonding
A fire safety procedure in which two objects (tanks, containers, etc.) are interconnected with
clamps and wires to equalize the electrical potential between the objects. This helps eliminate
static sparks that can ignite flammable materials.
Breakthrough time
The time elapsed between initial contact of a chemical with the outside surface of a protective
clothing material and the time at which the chemical can be detected at the inside surface of the
material.
Bulk container
A cargo container, such as that attached to a tank truck or tank car, used for transporting
substances in large quantities.
Bulking
Mixing together of chemicals in large quantities for transport.
Bung
A cap or screw used to cover the small opening in the top of a metal drum or barrel.
“C” or ceiling limit
The airborne concentration that should not be exceeded during any part of the working exposure.
CAA
Clean Air Act. Public Law PL 91-604, with regulations enacted by the Environmental Protection
Agency found in 40 CFR 50-80. The regulatory vehicle authorizing the Environmental
Protection Agency to control and monitor airborne pollution hazardous to public health or natural
resources.
Canister
A purifying device for an air-purifying respirator that is held in a harness attached to the body or
attached to the chin part of a facepiece, is connected to the facepiece by a breathing tube, and
removes particulates or specific chemical gases or vapors from the ambient air as it is inhaled
through the canister.
Carboy
A bottle or rectangular container for holding liquids, with a capacity of approximately 5 to 15
gallons, made of glass, plastic, or metal, and often cushioned in a protective container.
Carcinogen
A substance or agent capable of causing or producing cancer in mammals. A carcinogen is
defined by the OSHA Hazard Communication Standard as any substance which meets one or
more of the following criteria:
•
•
Regulated by OSHA as a carcinogen
Listed as a carcinogen or potential carcinogen in National Toxicology Program’s Annual
Report on Carcinogens
4
•
Evaluated by the International Agency for Research on Cancer (IARC) and found to be a
carcinogen or potential carcinogen.
Cartridge
A purifying device for an air-purifying respirator that attaches directly to the facepiece and
removes particulates or specific chemical gases or vapors from the ambient air as it is inhaled
through the cartridge.
CAS
Chemical Abstracts Service; a Columbus, Ohio, organization that indexes information published
in Chemical Abstracts by the American Chemical Society and provides index guides by which
information about particular substances may be located in the Abstracts when needed. “C.A.S.
numbers” identify specific chemicals.
Caustic
See Alkali
cc
Cubic centimeter; a volume measurement in the metric system, equal in capacity to one milliliter
(ml). One quart is about 946 cubic centimeters.
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act (also called
Superfund). Public Law PL 96-510, with regulations enacted by the Environmental Protection
Agency (EPA), found in 40 CFR 300. Provides for the identification and cleanup of hazardous
materials that have been released to the land, air, water, and groundwater. CERCLA establishes
superfund, a trust fund to help pay for the cleanup of the hazardous materials sites. The EPA has
the authority to collect the cost of the cleanup from the generators of the waste material.
CFR
Code of Federal Regulations; a compilation of all current regulations and standards published by
the Office of the Federal Register.
CFR 40
Code of Federal Regulations, Title 40; governs treatment storage and disposal of hazardous
waste.
CFR 49
Code of Federal Regulations, Title 49; governs hazardous material (includes waste)
transportation.
CGI
Combustible gas indicator. A meter that detects the presence of flammable gases or vapor.
Results are displayed as percentage of lower explosive limit.
Chemical cartridge respirator
A respirator that uses various chemical substances to purify inhaled air of certain contaminants.
Chemical family
A group of single elements or compounds with a common general name. Example: acetone,
methyl ethyl ketone, and methyl isobutyl ketone are of the “ketone” family.
5
Chemical Hygiene Officer (CHO)
An employee who is designated by the employer, and who is qualified by training or experience,
to provide technical guidance in the development and implementation of the provisions of the
Chemical Hygiene Plan. This definition is not intended to place limitations on the position
description or job classification that the designated individual shall hold within the employer's
organization structure. (per 29 CFR 1910.1450).
Chemical Hygiene Plan (CHP)
A written plan that specifies the procedures the employer has implemented to ensure that
employees are protected from exposures to hazardous chemicals. The plan should address such
elements as work practices controls, protective equipment, engineering controls, training,
standard operating procedures, and medical evaluations.
Chemical protective clothing (CPC)
An item of clothing used to isolate parts of the body from direct contact with a potentially
hazardous chemical.
Chemical reactivity
The ability of a material to chemically change, possibly resulting in hazardous effects such as
heat, explosions, or the production of toxic substances.
CHEMTREC
Chemical Transportation Emergency Center; a national center established by the Chemical
Manufacturers Association (CMA) in Washington, D.C. in 1970, to relay pertinent emergency
information concerning specific chemicals on request. CHEMTREC has a 24-hour toll free
telephone number (800-424-9300), intended primarily for use by those who respond to chemical
transportation emergencies.
CHLOREP
Chlorine Emergency Response Plan. A written procedure to be implemented in the event of an
emergency situation involving chlorine.
CHMM
Certified Hazardous Material Manager
CHO
See Chemical Hygiene Officer
CHP
See Chemical Hygiene Plan
CHP
Certified Health Physicist. A properly qualified professional devoted to the protection of man and
his environment from radiation hazards and certified by the American Board of Health Physics.
CHRIS
Chemical Hazards Response Information System. CHRIS consists of four manuals, a regional
contingency plan, a computer system, and an organizational entity at Coast Guard Headquarters,
all designed to aid Coast Guard responders.
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Chronic health effect
An adverse effect on a human or animal body, with symptoms that develop slowly over a
relatively prolonged period of time.
Chronic toxicity
Adverse effects resulting from repeated doses of or exposures to a substance over a relatively
prolonged period of time.
CIH
Certified Industrial Hygienist. An industrial hygiene or health and safety professional possessing
a minimum of 5 years of relevant experience and certified by the ABIH after passing an
examination.
Clean Air Act
See CAA
Clean Water Act
See CWA
Closed-Circuit SCBA
A type of self-contained breathing apparatus that recycles exhaled air by removing CO2 and
replenishing O2. Also called a rebreather SCBA.
CMA
Chemical Manufacturer's Association. An industry trade group providing technical support to its
members.
CNS
Central Nervous System. The control center for the entire nervous system; consists of the brain
and spinal cord.
Code of Federal Regulations
See CFR
Colorimetric tube
An instrument for the chemical analysis of liquids by comparison of the color of the given liquid
with standard colors.
Combustible liquids
Any liquid having a flashpoint at or above 100°F (37.8°C) , but below 200°F (93.3°C), except
any mixture having components with flashpoints of 200°F (93.3°C), or higher, the total volume of
which make up 99% or more of the total volume of the mixture. Combustible liquids do not ignite
as easily as flammable liquids, but can be ignited under certain circumstances, and must be
handled with caution.
Compressed gas
• A gas, or mixture of gases, having, in a container, an absolute pressure that exceeds 40 psi at
70°F
(21.1°C),
7
• A gas, or a mixture of gases, having, in a container, an absolute pressure that exceeds 104 psi
at 130°F
(54.4°C), regardless of the pressure at 70°F (21.1°C), or
•
A liquid having a vapor pressure that exceeds 40 psi at 100°F (37.8°C).
Concentration
The relative amount of a substance when combined or mixed with other substances. Often
expressed in mg/m3, mg/kg, or ppm.
Containment (Biological)
Safe methods for managing infectious agents in the laboratory environment where they are being
handled or maintained.
Contamination Reduction Zone (CRZ)
The area on a site where decontamination takes place, preventing cross-contamination from
contaminated areas to clean areas.
Continuous Flow Respirator
A respiratory protection device that maintains a constant flow of air into the facepiece at all
times. Air flow is independent of user respiration.
Corrosive
A liquid or solid that causes visible destruction or irreversible alterations in human skin tissue at
the site of contact or, in the case of liquid from its package, a liquid that has a severe corrosion
rate on steel. A waste that exhibits characteristics of corrosivity may be regulated by the EPA as
a hazardous waste.
CPC
See chemical protective clothing.
CPR
Cardiopulmonary resuscitation. The artificial reestablishment of normal or near normal
respiration and circulation.
CPSC
Consumer Products Safety Commission. A federal agency with responsibility for regulating
hazardous materials when they appear in consumer goods. For CPSC purposes, hazards are
defined in the Hazardous Substances Act and the Poison Prevention Packaging Act of 1970.
Crazing
The formation of minute cracks (as in the lens of a facepiece).
CRC
Contamination Reduction Corridor. Contains decontamination stations for personnel and
equipment; located in the CRZ.
Cross-contamination
The transfer of a chemical contaminant from on person, piece of equipment, or area to another
that was previously not contaminated with that substance.
8
CRZ
Contamination Reduction Zone. Transition zone between contaminated and clean zones.
CSP
Certified Safety Professional. A properly qualified safety professional who has met the
requirements for certification.
Cutaneous toxicity
See Dermal toxicity.
CWA
Clean Water Act. Public Law PL 92-500, with regulations enacted by the EPA found at 40 CFR
100-140 and 400-470. The CWA regulates the discharge of nontoxic and toxic pollutants into
surface waters.
Decomposition
Breakdown of a material or substance (by heat, chemical reaction, electrolysis, decay, or other
processes) into parts or elements of simpler compounds.
Decontamination
The process of removing or neutralizing hazardous substances on personnel and equipment.
Decontamination line
A specific sequence of decontamination stations within the Contamination Reduction Zone for
decontaminating personnel or equipment.
Degradation
The physical breakdown of a protective material due to exposure to a chemical.
Demand respirator
A respiratory protection device that supplies air or oxygen to the user in response to negative
pressure created by inhalation.
Density
Ratio of the weight, or mass, of a material to its volume.
Department of Labor
See DOL.
Department of Transportation
See DOT.
Dermal
Used or applied to the skin.
Dermal toxicity
Adverse effects resulting from skin exposure to a substance. Effects may be local or result from
absorption through the skin (systemic).
Dermatitis
9
Inflammation of the skin.
Designated area
An area which may be used for work with “select carcinogens,” reproductive toxins or substances
which have a high degree of acute toxicity. A designated area may be the entire laboratory, an
area of a laboratory, or a device such as a laboratory hood (per 29 CFR 1910.1450).
DHHS
U.S. Department of Health and Human Services. This agency was created in 1980 to replace the
Department of Health, Education and Welfare (DHEW) as “parent” for NIOSH, the Public Health
Service, and other agencies related to safety.
Direct-reading instrument
A portable device that measures and displays, in a short time period, the concentration of a
contaminant in the environment.
DOD
Department of Defense.
DOL
U.S. Department of Labor. The DOL includes the Occupational Safety and Health Administration
(OSHA).
Dosimeter
An instrument for measuring doses of radioactivity or other chemical exposures based on
collection media.
DOT
U.S. Department of Transportation. Regulates transportation of materials to protect the public as
well as fire, law, and other emergency-response personnel.
Dressout area
A section of the Support Zone where personnel suit up for entry into the Exclusion Zone.
Dust
Solid particles suspended in air. Dusts may present inhalation, fire, or explosion hazards,
depending on the material.
Emergency
Any occurrence, such as, but not limited to, equipment failure, rupture of containers, or failure of
control equipment, which results in an uncontrolled release of a hazardous chemical into the
workplace.
Engineering controls
Systems that reduce potential hazards by isolating the worker from the hazard or by removing the
hazard from the work area. Engineering controls are preferred over personal protective
equipment and should be used in conjunction with administrative practices.
Environmental Protection Agency
See EPA
10
EPA
U.S. Environmental Protection Agency. A federal agency with environmental protection
regulatory and enforcement authority. Administers the Clean Air Act, Clean Water Act, FIFRA,
RCRA, TSCA, other federal environmental laws.
ERCS
Emergency Response Cleanup Services, under EPA contact.
Ergonomics
The study of human characteristics for the appropriate design of living and work environments.
ERT
Environmental Response Team. A team of EPA professionals trained to respond to environmental
emergencies.
Escape-only SCBA (ESCBA)
A type of self-contained breathing apparatus that is approved for escape purposes only. It does
not carry the safety features necessary for longer work periods.
Etiologic agent
A micro-organism that may cause human disease.
eV
Electron Volt.
Evaporation rate
The rate at which a particular material will vaporize (evaporate) when compared to the rate or
vaporization of a known material. The evaporation rate can be useful in evaluating the health and
fire hazards of a material. The known material is usually normal butyl acetate, with a vaporization
rate designated as 1.0. Vaporization rates of other solvents or materials are then classified as “fast
evaporating” (greater than 3.0), “medium evaporating” (0.8-3.0), or “slow evaporating” (less than
0.8).
Exclusion zone
The contaminated area of a site.
Explosive
A chemical that is capable of burning or bursting suddenly and violently.
Explosive Limits
Upper Explosive Limit (UEL) and Lower Explosive Limit (LEL). Same as Flammable Limits.
(See also LFL and UFL.)
Exothermic
Process that gives off heat.
Extinguishing media
The type of fire extinguisher or extinguishing method appropriate for a specific material.
f/cc
Fibers per cubic centimeter of air.
11
Federal Register
See FR.
FEMA
Federal Emergency Management Agency.
FID
Flame Ionization Detector. An air monitoring instrument which uses ionization, caused by a
hydrogen flame, as the detection method.
FIFRA
Federal Insecticide, Fungicide and Rodenticide Act. Regulations administered by EPA under this
Act require that certain useful poisons, such as chemical pesticides, sold to the public contain
labels that carry health hazard warnings to protect users.
Filter
A purifying device for an air-purifying respirator that removes particulates and/or metal fumes
from the ambient air as it is inhaled.
Flammable aerosol
An aerosol that, when tested by the method described in 16 CFR 1500.45, yields a flame
projection exceeding 18 inches at full-valve opening, or a flashback (a flame extending back to
the valve) at any degree of valve opening.
Flammable gas
• A gas that, at ambient temperature and pressure, forms a flammable mixture with air at a
concentration
of 13% by volume or less; or
• A gas that, at ambient temperatures and pressure, forms a range of flammable mixtures with
air wider
than 12% by volume, regardless of the lower limit.
Flammable limits
The minimum and maximum concentrations of a flammable gas or vapor between which ignition
can occur. (See also LFL and UFL.)
Flammable liquid
Per OSHA, any liquid having a flashpoint below 100°F (37.8°C), except any mixture having
components with flashpoints of 100°F (37.8°C) or higher, the total of which makes up 99% or
more of the total volume of the mixture. Per DOT, any liquid having a flashpoint below 140 F
(60.5 C), except any mixture having components with flashpoints of 140 F (60.5 C) or higher, the
total of which makes up 99% or more of the total volume of the mixture.
Flammable solid
A solid, other than a blasting agent or explosive, that is liable to cause fire through friction,
absorption of moisture, spontaneous chemical changes, or 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 hazard.
12
Flash point
The minimum temperature at which a liquid gives off vapor within a test vessel in sufficient
concentration to form an ignitable mixture with air near the surface of the liquid. There are
several flash point test methods, and flash points may vary for the same material depending on
the method used, so the test method is indicated when the flash points is given.
FM
Factory Mutual.
Fog
A visible suspension of fine droplets in gas.
FR
Federal Register. A daily publication that lists and discusses federal regulations. Available from
the U.S. Government Printing Office, Washington, DC.
Fume
Airborne particulate formed by the vaporization of solid materials; usually refers to metals. Fume
particles are usually less than 1 micron in diameter.
Freezing point
The temperature at which a material changes its physical state from liquid to solid.
g
Gram. A metric unit of weight. One U.S. ounce (avoirdupois) is about 28.4 grams.
g/kg
Grams per kilogram; an expression of dose used in oral and dermal toxicology testing to indicate
the grams of substance dosed per kilogram of animal body weight. Also see kg” (kilogram).
Gamma radiation
A type of ionizing radiation consisting of high-energy, short-wavelength, electromagnetic
radiation.
Gas
A state of matter in which the material has very low density and viscosity, diffuses easily into
other gases, and is readily distributed throughout any container. Examples of atmospheric gases
include oxygen, nitrogen, and carbon dioxide.
GC
Gas chromatograph or gas chromatography. A gaseous detection technique which involves the
separation of mixtures by passing them through a column that detains the components for varying
periods of time before they are detected and recorded.
GC/MS
Gas chromatography and mass spectroscopy. Mass spectrometers are used in conjunction with
GC to perform qualitative analysis by comparing the result to a library of spectra.
General exhaust/General ventilation
A system for removing contaminated air from a general work area and replacing it with clean air.
Also known as dilution ventilation. (See also Local Ventilation.)
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Generic material
Made from one type of polymer or polymer combination. Examples are neoprene, nitrile, and
polyvinyl alcohol. When products are manufactured from the polymer, additions of other
materials are included for various reasons during the manufacturing process.
GM
Geiger-Mueller. Used for beta-, gamma-, and x-radiation survey instruments because it is capable
of detecting very small amounts of radiation.
Grounding
A fire safety practice to conduct any electrical charge to the ground, preventing sparks that could
ignite flammable materials.
Groundwater
Water in a saturated zone, or formation beneath the surface of land or water.
HACS
Hazard Assessment Computer System. HACS, the computerized counterpart of Volume 3 of the
CHRIS manuals, makes it possible to obtain very detailed hazard evaluations through the
computer at Coast Guard Headquarters. The system is intended primarily for use by the OSC.
Hazard
Biological, chemical, or physical conditions that have the potential for causing harm to people,
property, or the environment (see also Risk).
Hazard classes
A series of nine descriptive terms that have been established by the UN Committee of Experts to
categorize the hazardous nature of chemical, physical, and biological materials. These categories
are flammable liquids, explosives, gases, oxidizers, radioactive materials, corrosives, flammable
solids, poisonous and infectious substances, and dangerous substances.
Haz Cat
A process of hazard categorization using a relatively simple kit and standard procedures to
determine the hazard class of an unknown chemical. It is not a full analysis, nor an identification
process. Always leaves you with the assumption of poison” because it cannot be disproved with
portable equipment.
Hazardous chemical
According to OSHA, a hazardous chemical is a chemical for which there is statistically
significant evidence based on at least one study conducted in accordance with established
scientific principles that acute or chronic health effects may occur in exposed employees.
Haz Mat, HM
See Hazardous Material.
Hazardous material
A term used by the DOT to describe a substance or material which has been determined to be
capable of posing an unreasonable risk to health, safety, and property when transported in
commerce, and which has been so designated.
Includes substances, and mixtures and solutions of substances that are:
14
• Listed in the appendix to the DOT Hazardous Materials Table
• Transported in one package in a quantity that is equal to or greater than the reportable
quantity (RQ)
listed in the appendix to the Hazardous Materials Table
• When in mixture or solution, is in a concentration that equals or exceeds the concentration
corresponding to the RQ of the material.
See also RQ and DOT.
Hazardous substance
According to CERCLA, any substance that is designated as a hazardous substance under Section
307 and 311 of the Clean Water Act and Section 112 of the Clean Air Act, or any substance
designated as a hazardous waste under RCRA (see also CAA, CWA, CERCLA, RCRA,
Hazardous waste).
Hazardous waste
RCRA describes a hazardous waste as any discarded material that is regulated under RCRA
because it exhibits the characteristic of ignitability, corrosivity, reactivity, or toxicity as described
in the Act (see also RCRA).
Hazardous waste number
An identification number assigned by the EPA, per RCRA, to identify and track wastes.
Health hazard
Includes chemicals that are carcinogens, toxic or highly toxic agents, reproductive toxins,
irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which act on the
hematopoietic systems, and agents which damage the lungs, skin, eyes, or mucous membranes
(per OSHA 29 CFR 1910.1200).
HEPA
High-efficiency particulate air filter. Used in ventilation systems; has a 99.97% removal
efficiency of 0.03 micron particles.
HNU
A brand of photoionization detector.
Hotline
The outer boundary of the Exclusion Zone on a site.
HP
Health physicist. A professional devoted to the protection of man and his environment from
radiation hazards.
IARC
International Agency for Research on Cancer. One of the three sources that OSHA refers to for
data on a material’s carcinogenicity (see also Carcinogen).
ID#, EPA
EPA identification number assigned to generators, transporters, and disposal sites. This number
is used on the manifest and elsewhere.
15
IDLH
Immediately Dangerous to Life and Health. Used to determine selection of a respirator. The
maximum concentration from which one could escape within 30 minutes without any escapeimpairing symptoms or irreversible health effects. IDLH values are listed in the NIOSH Pocket
Guide to Chemical Hazards.
Ignitable
Capable of being set afire.
Ignition temperature
The lowest temperature at which a combustible material ignites in air and continues to burn
independently of the source of heat.
Impervious
Describes a material, usually a piece of protective clothing, that does not allow another substance
to penetrate or pass through it.
Incompatible
Used to describe materials that could cause dangerous reactions and the release of energy from
direct contact with another material.
Inflammable
Capable of being easily set on fire and continuing to burn, especially violently. Identical in
meaning to flammable.
Ingestion
The taking in of a substance through the mouth.
Injection
The introduction of chemicals into the body through puncture wounds.
Inhalation
The breathing in of a substance in the form of a gas, vapor, fume, mist, or dust.
Inhibitor
A chemical that is added to another substance to prevent an unwanted chemical change from
occurring, e.g. polymerization.
International Agency for Research on Cancer
See IARC.
Ionizing radiation
High-energy radiation that causes irradiated substances to form ions, which are electrically
charged particles.
IP
Ionization Potential. Refers to the potential for one or more electrons to be removed from a
neutral atom by the action of radiation.
IR
16
Infrared. Those wavelengths of the electromagnetic spectrum longer than those of visible light
and shorter than radio waves (10-4 cm to 10-1 cm wavelength)
IRAP
Interagency Radiological Assistance Plan. IRAP is designed to assist in coping with radiation
emergencies. It operates through DOE, but works closely with other Federal, State, military, and
regional groups. If the spill or leak appears serious, a technical response team is dispatched and
the Nuclear Regulatory Commission is notified.
Irritant
A substance, which is not a corrosive, but which causes a reversible inflammatory effect on living
tissue by chemical action at the sight of contact as a function of concentration and duration of
exposure.
kg
Kilogram. A metric unit of weight, about 2.2 U.S. pounds. Also see “g/k,” and “g,” and “mg.”
L
Liter. A metric unit of capacity. A U.S. quart is about 9/10 of a liter.
Laboratory
As defined by OSHA in 29 CFR 1910.1450, a facility where the laboratory use of hazardous
chemicals occurs, where relatively small quantities of hazardous chemicals are used on a nonproduction basis.
Laboratory use
According to OSHA in 29 CFR 1910.1450, laboratory use of hazardous chemicals occurs when
all of the following conditions are met:
• Chemical manipulations are carried out on a laboratory scale
• Multiple chemical procedures or chemicals are used
• Procedures are neither part of, nor support, a production process
• Protective lab practices and equipment are available and in common use to minimize the
potential for
employee exposure to hazardous chemicals.
Landfill
Disposal of trash and waste products at a controlled location that is then sealed and buried under
earth. This is increasingly a less preferred method of disposal due to the long-term environmental
impact of waste.
LC
Lethal concentration. A concentration of a substance that will kill a test animal.
LC50
Lethal concentration 50. The concentration of a material in air which, on the basis of laboratory
tests, is expected to kill 50% of a group of test animals when administered as a single exposure
(usually 1 to 4 hours). The LC50 is expressed as parts of material per million parts of air, by
volume (ppm) for gases and vapors, or as micrograms of material per liter of air (ug/L) or
17
milligrams of material per cubic meter of air (mg/m3) for dusts and mists, as well as for gases and
vapors.
LD
Lethal dose. A concentration of a substance that will kill a test animal.
LD50
Lethal dose 50%. A single dose of a material which on the basis of laboratory tests, is expected to
kill 50% of a group of test animals. LD50 dose is usually expressed as milligrams of materials
per kilogram of animal body weight (mg/kg or g/kg).
LEL/LFL
Lower Explosive Limit/Lower Flammable Limit. The lowest concentration of a vapor or gas
which will explode, ignite, or burn in the presence of an ignition source. Mixtures below this limit
are too lean to burn. LELs are expressed in percent vapor or gas in air by volume; 1 percent
equals 10,000 ppm. (See also UEL/UFL.)
LNG
Liquid Natural Gas.
Local ventilation
The drawing off and replacement of contaminated air directly from its source. Examples include
glove boxes and laboratory fume hoods.
Lower Explosive/Flammable Limit
See LEL/LFL.
LPG
Liquified Petroleum Gas.
m3
Cubic meter, or stere. A metric measure of volume, about 35.3 cubic feet or 1.3 cubic yards.
Material Safety Data Sheet
See MSDS.
Melting point
The temperature at which a solid substance changes to a liquid state. For mixtures, the melting
range may be given.
mg
Milligram. A metric unit of weight. There are 1,000 milligrams in one gram (g) of a substance.
mg/kg
Milligrams per kilogram. An expression of toxicological dose. See g/kg.
mg/L
Milligrams per liter.
mg/m3
18
Milligrams per cubic meter. A unit for measuring concentrations of dusts, gases, or mists in air.
MIRAN
Trade name for series of Foxboro miniature infrared analyzers.
Mists
Aerosolized liquid droplets generated either by condensation of gases to liquids, or by fine
dispersion of a liquid through splashing or atomizing.
Mitigation
Actions taken to prevent or reduce the severity of harm.
Ml
Milliliter. A metric unit of capacity, equal in volume to one cubic centimeter (CC) or about 1/16
of a cubic inch. There are 1,000 milliliters in one liter (L).
mmHg
Millimeters (mm) of mercury (Hg); a unit of measurement of low pressure of partial vacuums.
mppcf
Million particles per cubic foot. A unit of measuring particles of a substance suspended in air.
Exposure limits for mineral dusts (silica, graphite, Portland cement, nuisance dusts, and others),
formerly expressed as mppcf, now are more commonl quoted in mg/m3.
mR/hr
MilliRoetgens per hour.
MS
Mass Spectroscopy. Highly useful tool for the identification of unknowns. Often coupled with
GC for separation and quantification of the different components.
MSDS
Material Safety Data Sheet. Information sheets (required by OSHA per 29 CFR 1910.1200)
containing data on a chemical’s physical properties, health hazards, toxic effects, fire hazards, etc.
MSHA
The Mining Safety and Health Administration of the U.S. Department of the Interior. Federal
Agency with safety and health regulatory and enforcement authorities for the mining industry.
Also see “OSHA.”
MUC
Maximum use concentration. The highest concentration, not exceeding IDLH concentration, of a
specific contaminant in which a respirator can be worn.
MUL
Maximum use limits.
Mutagen
Any substance that can cause a change (mutation) in the genetic material of a living cell.
19
National Contingency Plan
Policies and procedures that the Federal Government follows in implementing responses to
hazardous substances.
National Fire Protection Association
See NFPA.
National Institute for Occupational Safety and Health
See NIOSH.
National Response Center
See NRC.
NBUAC or n-BuAc
Normal butyl acetate. See “evaporation rate.”
NCP
National Contingency Plan.
NEC
National Electric Code.
NFPA
National Fire Protection Association. An international voluntary membership organization to
promote/improve fire protection and prevention and establish safeguards against loss of life and
property by fire. Best known for publishing the National Fire Codes, 16 volumes of codes,
standards, recommended practices, and manuals developed (and periodically updated) by NFPA
technical committees. Among these is NFPA 704M, the code for showing hazards of materials
using the familiar diamond-shaped label or placard with appropriate numbers or symbols.
NIOSH
National Institute for Occupational Safety and Health of the Public Health Service, U.S.
Department of Health and Human Services (DHHS). A federal agency that tests and certifies
respiratory protective devices, recommends occupational exposure limits for various substances
(RELs), and assists OSHA and MSHA in occupational safety and health investigations and
research.
N.O.S.
Not Otherwise Specified, as in “corrosive, n.o.s.;” has the properties of a Hazardous Class but is
not otherwise listed in the Haz Mat Table.
Nonflammable
Incapable of being easily ignited or burned with extreme rapidity when lighted.
Non-ionizing radiation
Includes infrared light, visible light, ultraviolet light, lasers, microwaves, and ultrasound. Does
not possess sufficient energy to displace electrons bound to atoms, but can damage the structure
of the atoms.
NPL
National Priority List.
20
NRC
National Response Center. A notification center that must be called when significant oil or
chemical spills or other environment-related accidents/incidents occur. The toll free telephone
number is 1-800-424-8802.
NRC/Nuclear Regulatory Commission
An independent federal agency responsible for licensing and inspecting nuclear power plants and
other commercial users of radioactive materials.
NTP
National Toxicology Program.
NTSB
National Transportation Safety Board.
Occupational Safety and Health Administration
See OSHA.
Olfactory
Relating to the sense of smell. The Olfactory organ in the nasal cavity is the sensing element that
detects odors and transmits information to the brain through the olfactory nerves.
Open-Circuit SCBA
A self-contained breathing apparatus in which the user exhales air directly to the atmosphere.
OPIM
Other potentially infectious material. Term defined by OSHA in 29 CFR 1910.1030 to include
the following:
• Human body fluids: semen, vaginal secretions, cerebrospinal fluid, synovial fluid, pleural
fluid, etc.
• Any body fluid visibly contaminated with blood
• All body fluids in situations where it is difficult or impossible to differentiate between body
fluids
• Any unfixed tissue or organ from a human
• HIV-containing cells or tissue cultures, organ culture, and HIV- HBV-containing culture
media or
other solutions
• Blood, organs, or other tissues from experimental animal infected with HIV or HBV.
Oral
Used in or taken into the body through the mouth or intragastrically.
Oral toxicity
Adverse effects resulting from taking a substance into the body via the mouth.
Organic peroxide
An organic oxidizer that can be shock- and heat-sensitive, flammable, and potentially explosive.
An organic compound that contains the bivalent —O—O— structure, and which may be
21
considered to be a structural derivative of hydrogen peroxide where one or both of the hydrogen
atoms has been replaced by an organic radical group.
OSC
On-Scene Coordinator.
OSHA
Occupational Safety and Health Administration of the U.S. Department of Labor; federal agency
with safety and health regulatory and enforcement authorities for most U.S. industry and
business.
Other potentially infectious material
See OPIM.
OVA
Organic Vapor Analyzer.
Overpack
An oversized drum into which a leaking drum can be placed and sealed; to overpack such a drum.
Oxidation
A reaction in which a substance combines with oxygen provided by an oxidizer or an oxidizing
agent.
Oxidizer
A chemical other than a blasting agent or explosive, that initiates or promotes combustion in other
materials thereby causing fire either of itself of through the release of oxygen or other gases.
Particulate
Small, separate pieces of airborne material. Dusts, fumes, smokes, mists, and fogs are examples
of particulates.
Particularly hazardous substances
These include “select carcinogens,” reproductive toxins, and substances that have a high degree
of acute toxicity (per 29 CFR 1910.1450).
Pathways of dispersion
The mode (water, groundwater, soil and air) by which a chemical moves through the
environment.
PCB
Polychlorinated biphenyl. Pathogenic and teratogenic compound used as a heat-transfer medium.
A total of 209 PCB molecules exist, differing in number (congeners) or location (isomers) of
attached chlorine. PCBs are hazardous and their handling is regulated by law (40 CFR Part 761).
PEL
Permissible Exposure Limit. Limits developed by OSHA to indicate the maximum airborne
concentration of a contaminant to which an employee may be exposed over the duration specified
by the type of PEL assigned to that contaminant. May be expressed as a time-weighted average
(TWA) or as a ceiling exposure limit that must never be exceeded instantaneously (see also
TWA, C or Ceiling and STEL).
22
Percent volatile
The percentage of a liquid or solid (by volume) that will evaporate at an ambient temperature of
70°F. (Unless some other temperature is stated).
Percutaneous
Effected or performed through the skin.
Permeation
As related to personal protective clothing, sorption of chemical into a protective clothing
material; diffusion of the chemical through the material; desorption of the chemical from the
clothing material.
Permeation rate
As related to personal protective clothing, the amount of chemical that permeates through a
protective material per unit area, per unit time; often given in micrograms per square centimeter
per minute ( g/cm2/min.).
Permissible Exposure Limit
See PEL.
Peroxide
See Organic peroxide.
Persistent chemicals
Substances that resist biodegradation and/or chemical oxidation when released into the
environment and tend to accumulate on land, in air, in water, or in organic matter.
Personal Protective Equipment
See PPE.
PF
Protection Factor.
pH
A scale from 0-14 that represents the acidity or alkalinity of an aqueous solution. Pure water has
a pH of 7. (See also Acid, Alkali, and Base.)
Physical hazard
A chemical for which there is scientifically valid evidence that it is a combustible liquid, a
compressed gas, explosive, flammable, an organic peroxide, an oxidizer, pyrophoric, unstable, or
water-reactive.
PID
Photoionization detector. A general survey instrument used to detect air contaminants.
Pollutant
A substance which resists biodegradation and/or chemical oxidation when released into the
environment and tends to accumulate on land, or in air, water, or organic matter.
23
Polymerization
A chemical reaction in which one or more small molecules combine to form larger molecules. A
hazardous polymerization is such a reaction which takes place at a rate which releases large
amounts of energy. If hazardous polymerization can occur with a given material, the MSDS u
sually will list conditions that could start the reaction.
PPB
Parts per billion. A unit for measuring the concentration of gas or vapor in air by indicating AL
parts (by volume) of the gas or vapor in a billion parts of air. Usually used to express
measurements of extremely low concentrations of usually toxic gases or vapors. Also used to
indicate the concentration of a particular substance in a liquid or solid.
PPE
Personal Protective Equipment. Devices or clothing worn to help protect a worker from direct
exposure to hazardous materials (e.g., gloves, respirators, laboratory coats).
ppm
Parts per million. A unit for measuring the concentration of gas or vapor in air by indicating parts
(by volume) of the gas or vapor in a million parts of air. Also used to indicate the concentration
of a particular substance in a liquid or solid.
Pressure-demand respirator
A respiratory protection device that supplies air to the user and maintains a slight positive
pressure in the facepiece at all times, and supplies additional air in response to the negative
pressure created by inhalation.
Protection factor
The ratio of the ambient concentration of an airborne substance to the concentration of the
substance inside the respirator at the breathing zone of the wearer. The protection factor is a
measure of the degree of protection that the respirator offers.
psi
Pounds per square inch. For MSDS purposes, a unit for measuring the pressure a material exerts
on the walls of a confining vessel or enclosure,. For technical accuracy, pressure must be
expressed as psig (pounds per square inch gauge) or psia (pounds per square inch absolute; that
is gauge pressure plus sea level atmospheric pressure or psig plus about 14.7 pounds per square
inch). Also see “mmHg”.
PSN
DOT Proper Shipping Name. Comes from paragraph 172.101 (the Hazardous Materials Table) of
CFR 49. If waste, then it is preceded by the word “waste”. Must be on package and shipping
paper. May be different from chemical name.
PVC
Poly vinyl chloride. A polymer which is commonly used in PPE or in air sampling media.
Pyrophoric
A chemical that ignites spontaneously in air at a temperature of 130°F (54.4°C) or
below.
QA/QC
24
Quality assurance/Quality control.
Radiation
Excessive nuclear energy emitted in the form of high-energy electromagnetic waves of particles
(see also Non-ionizing radiation and Ionizing radiation).
rDNA
Recombinant DNA. Molecules constructed outside living cells by joining natural or synthetic
DNA segments to DNA molecules that can replicate in a living cell; or DNA molecules that result
from the replication of those molecules.
RCRA
Resource Conservation and Recovery Act. Public Law PL 94-580, with regulations enacted by
the EPA found at 40 CFR 240-271. Federal environmental legislation, administered by EPA,
aimed at controlling the generation, treating, storage, transportation, and disposal of hazardous
wastes.
Reaction
A chemical transformation or change; the interaction of two or more substances to form new
substances.
Reactive material
A chemical substance or mixture that vigorously polymerizes, decomposes, condenses, or
becomes self-reactive due to shock, pressure, or temperature.
Reactivity
Describes a substance’s tendency to undergo chemical reaction either by itself or with other
materials with the release of energy. Undesirable effects, such as pressure buildup, temperature
increase, or formation of noxious, toxic, or corrosive by-products, may occur due to the reactivity
of a substance following heating, burning, direct contact with other materials or other conditions
of use or storage. A sold waste exhibits a “characteristic of reactivity,” as defined by RCRA, may
be regulated by EPA as a hazardous waste.
Reagent
A substance used in a chemical reaction to detect, measure, examine, or produce other substances.
Redress area
A section of the Exclusion Zone where decontaminated personnel put on clothing for use in the
Support Zone.
Reducing agent
In a reduction reaction (which always occurs simultaneously with an oxidation reaction) the
reducing agent is the chemical or substance which combines with oxygen, or loses electrons to
the reaction.
Reportable quantity
See RQ.
Reproductive toxins
25
Chemicals which affect the reproductive capabilities of adult males or females or the developing
fetus. Effects include infertility, sterility, and mutagenic effects on germ cells. (See also
Teratogen.)
Respirator
Any of a variety of devices that limit the inhalation of toxic materials. They include disposable
dust masks, supplied air respirators, and SCBAs.
Risk
The probability of incurring harm from a hazard.
Risk assessment
The use of a factual base to define the health effects of exposure to hazardous materials and
situations on individuals or populations.
Route of entry
The method by which a material enters the body; includes absorption (eye or skin contact),
ingestion, and inhalation.
RQ
Reportable Quantity.
CERCLA: quantity of substance designated under CERCLA as hazardous, and the release of
which must be reported to the NRC. RQs can be found in Section 311 of the CAA
DOT:
quantity specified for a substance in the appendix to the Hazardous Materials Table.
SARA:
quantity specified in Title III, Section 304, which requires specific reporting.
RRT
Regional Response Team
Salvage drum
Generic Term for over-pack drum. Applies not only to Recovery Drum” but also to any drum
legally used to over-pack leaking and damaged packages. See also 49 CFR 173.3 for rules.
SAR
Supplied Air Respirator. A type of respirator which provides an air supply to the user from a
source that is not worn by the user but is connected to the user by a hose. Also called an air-line
respirator.
SARA
Superfund Amendments and Reauthorization Act. A revision and extension of CERCLA,
administered by the EPA, intended to encourage and support local and state emergency planning
efforts. Title III of SARA is known as the Emergency Planning and Community Right-to Know
Act (EPCRA).
SCBA
Self-contained breathing apparatus. A respirator with full facepiece and an independent supply of
air or oxygen.
26
SDWA
Safe Drinking Water Act.
Sensitization
A state of immune response in which further exposure to the substance elicits an immune or
allergic reaction.
Sensitizer
A substance that on first exposure causes little or no reaction in humans or test animals, but that
on repeated exposure may cause a marked response not necessarily limited to the contact site.
Skin sensitization is the most common form of sensitization in the industrial setting, although
respiratory sensitization to some chemicals is also known to occur.
Site safety plan
Written site-specific safety criteria that establishes requirements for protecting the health and
safety of responders during activities conducted at an incident.
Skin notation
A notation used by OSHA and ACGIH indicating that the stated substance may be absorbed by
the skin, mucous membranes, and eyes, either by airborne or direct contact, and that this
additional exposure must be considered part of the total exposure to avoid exceeding the PEL or
TLV for that substance.
Smoke
Dry particles and droplets generated by the incomplete combustion of an organic material
combined with, and suspended in, the gases from combustion.
Solubility in water
A term expressing the percentage or a material (by weight) that will dissolve in water at ambient
temperature.
Solvent
A material that can dissolve other materials to form a uniform mixture.
Soot
Fine particles, usually black, formed by combustion and composed mostly of carbon.
SOP
Standard Operating Procedure. A set of established steps and guidelines which are followed for a
particular operation.
Sorbent material
A substance that takes up other materials either by absorption or adsorption.
SOSGs
Standard Operating Safety Guides. A guidance manual developed by the Environmental
Response Branch of EPA’s Office of Emergency and Remedial Response designed to provide
support for personnel performing spill containment, cleanup, and damage assessment.
SPCC
Spill Prevention, Control, and Countermeasure Plan.
27
Specific gravity
The weight of a material compared to the weight of an equal volume of water; a unitless
expression of the density (or heaviness) of the material.
Stability
An expression of the ability of a material to remain unchanged. For MSDS purposes, a material is
stable if it remains in the same form under expected and reasonable conditions of storage or use.
Conditions which may cause instability (dangerous change) are stated.
Staging area
An area in which items are arranged in some order.
Steady state permeation
The constant rate of permeation that occurs after the breakthrough when all forces affecting
permeation have reached equilibrium.
STEL
See TLV-STEL.
Superfund
A common name for the Comprehensive Environmental Response, Compensation, and Liability
Act (CERCLA) of 1980.
Supplied air respirator
A respiratory protection device that supplies air to the user from a source that is not worn by the
user but is connected to the user by a hose. Also called an air-line respirator.
Support zone
The uncontaminated area of a site where workers will not be exposed to hazardous conditions.
Swipe
A patch of cloth or paper that is wiped over a surface and analyzed for the presence of a
substance.
Target organ effects
Chemically caused effects from exposure to a material on specifically listed organs and systems,
such as the liver, kidneys, central nervous system, lungs, skin, and eyes.
Teratogen
A substance or agent to which exposure of a pregnant female can result in physical defects. (See
also Reproductive Toxin.)
Threshold Limit Value - Short Term Exposure Limit
See TLV-STEL.
Threshold Limit Value - Time Weighted Average
See TLV-TWA.
TLV-STEL
28
The airborne concentration to which workers can be exposed for a short period of time without
suffering from irritation, chronic or irreversible tissue damage, or narcosis of sufficient degree to
increase the likelihood of accidental injury, impair self-rescue or materially reduce work
efficiency (provided the daily TLV-TWA is not exceeded). A 15-minute TWA exposure should
not occur more than four times per day, or occur more than once during a 60-minute period;
defined by ACGIH.
Threshold Limit Value - Ceiling (TLV-C)
See “C” or ceiling limit.
TLV-TWA
Threshold limit value-time-weighted average. The time-weighted average airborne concentration
of a contaminant to which nearly all workers may be exposed, for a normal 8-hour workday and a
40-hour workweek without adverse effect. Defined by the American Conference of Governmental
Industrial Hygienists (ACGIH).
Toxicity
The sum of adverse effects resulting from exposure to a material. (See also Acute Toxicity and
Chronic Toxicity.)
TSCA
Toxic Substances Control Act. Public Law PL 94-469, with regulations enacted by the EPA
found in 40 CFR 700-799. Federal environmental legislation, administered by EPA, for
regulating the manufacture, handling, and use of materials classified as “toxic substances.”
TSDF
Treatment, Storage or Disposal Facility permitted by EPA or by a state with interim
authorization.
UEL/UFL
Upper explosive limit/upper flammable limit. The highest concentration of a vapor or gas which
will explode, ignite, or burn in the presence of an ignition source. Mixtures above this limit are
too rich to burn. LELs are expressed in percent vapor or gas in air by volume; one percent equals
10,000 ppm. (See also LEL/LFL.)
Ultrasound
Mechanical vibrations at frequencies above the limit of human audibility (approximately 16 kHz).
Universal precautions
A method of infection control that treats all human blood and body fluids as infectious for
bloodborne pathogens (per 29 CFR 1910.1030.)
UN/NA ID#
Two-character and four-digit number assigned to each DOT Proper Shipping Name. Use on
cargo tanks to enable emergency response services to recognize hazards. Also required on
packages. Required on manifest.
Unstable
Describes a chemical that, in the pure state, or as produced or transported, vigorously
polymerizes, decomposes, condenses, or becomes self-reactive under conditions of shock,
pressure, or temperature.
29
Upper Explosive/Flammable Limit
See UEL/UFL.
USCG
United States Coast Guard.
UV
Ultraviolet. The region of the electromagnetic spectrum between visible light and x-rays.
Vapor
The gaseous form of materials that are normally liquids or solids at room temperature and
pressure, e.g., steam.
Vapor density
The weight of a vapor or gas compared to the weight of an equal volume of air; an expression of
the density of the vapor or gas. Materials lighter than air have vapor densities less than 1.0.
Materials heavier than air have vapor densities greater than 1.0. All vapors and gases will mix
with air, but the lighter materials will tend to rise and dissipate (unless confined). Heavier vapors
and gases are likely to concentrate in low places.
Vapor pressure
The pressure exerted by a saturated vapor above its own liquid in a closed container.
Water reactive
A chemical that reacts with water and may release gases that are either flammable or present a
health hazard. Usually flammable solids will react in varying degrees with water or humid air.
A substance that takes up other materials either by absorption or adsorption.
SOSGs
Standard Operating Safety Guides. A guidance manual developed by the Environmental
Response Branch of EPA’s Office of Emergency and Remedial Response designed to provide
support for personnel performing spill containment, cleanup, and damage assessment.
SPCC
Spill Prevention, Control, and Countermeasure Plan.
Specific gravity
The weight of a material compared to the weight of an equal volume of water; a unitless
expression of the density (or heaviness) of the material.
Stability
An expression of the ability of a material to remain unchanged. For MSDS purposes, a material is
stable if it remains in the same form under expected and reasonable conditions of storage or use.
Conditions which may cause instability (dangerous change) are stated.
Staging area
An area in which items are arranged in some order.
30
Steady state permeation
The constant rate of permeation that occurs after the breakthrough when all forces affecting
permeation have reached equilibrium.
STEL
See TLV-STEL.
Superfund
A common name for the Comprehensive Environmental Response, Compensation, and Liability
Act (CERCLA) of 1980.
Supplied air respirator
A respiratory protection device that supplies air to the user from a source that is not worn by the
user but is connected to the user by a hose. Also called an air-line respirator.
Support zone
The uncontaminated area of a site where workers will not be exposed to hazardous conditions.
Swipe
A patch of cloth or paper that is wiped over a surface and analyzed for the presence of a
substance.
Target organ effects
Chemically caused effects from exposure to a material on specifically listed organs and systems,
such as the liver, kidneys, central nervous system, lungs, skin, and eyes.
Teratogen
A substance or agent to which exposure of a pregnant female can result in physical defects. (See
also Reproductive Toxin.)
Threshold Limit Value - Short Term Exposure Limit
See TLV-STEL.
Threshold Limit Value - Time Weighted Average
See TLV-TWA.
TLV-STEL
The airborne concentration to which workers can be exposed for a short period of time without
suffering from irritation, chronic or irreversible tissue damage, or narcosis of sufficient degree to
increase the likelihood of accidental injury, impair self-rescue or materially reduce work
efficiency (provided the daily TLV-TWA is not exceeded). A 15-minute TWA exposure should
not occur more than four times per day, or occur more than once during a 60-minute period;
defined by ACGIH.
Threshold Limit Value - Ceiling (TLV-C)
See “C” or ceiling limit.
TLV-TWA
Threshold limit value-time-weighted average. The time-weighted average airborne concentration
of a contaminant to which nearly all workers may be exposed, for a normal 8-hour workday and a
31
40-hour workweek without adverse effect. Defined by the American Conference of Governmental
Industrial Hygienists (ACGIH).
Toxicity
The sum of adverse effects resulting from exposure to a material. (See also Acute Toxicity and
Chronic Toxicity.)
TSCA
Toxic Substances Control Act. Public Law PL 94-469, with regulations enacted by the EPA
found in 40 CFR 700-799. Federal environmental legislation, administered by EPA, for
regulating the manufacture, handling, and use of materials classified as “toxic substances.”
TSDF
Treatment, Storage or Disposal Facility permitted by EPA or by a state with interim
authorization.
UEL/UFL
Upper explosive limit/upper flammable limit. The highest concentration of a vapor or gas which
will explode, ignite, or burn in the presence of an ignition source. Mixtures above this limit are
too rich to burn. LELs are expressed in percent vapor or gas in air by volume; one percent equals
10,000 ppm. (See also LEL/LFL.)
Ultrasound
Mechanical vibrations at frequencies above the limit of human audibility (approximately 16 kHz).
Universal precautions
A method of infection control that treats all human blood and body fluids as infectious for
bloodborne pathogens (per 29 CFR 1910.1030.)
UN/NA ID#
Two-character and four-digit number assigned to each DOT Proper Shipping Name. Use on
cargo tanks to enable emergency response services to recognize hazards. Also required on
packages. Required on manifest.
Unstable
Describes a chemical that, in the pure state, or as produced or transported, vigorously
polymerizes, decomposes, condenses, or becomes self-reactive under conditions of shock,
pressure, or temperature.
Upper Explosive/Flammable Limit
See UEL/UFL.
USCG
United States Coast Guard.
UV
Ultraviolet. The region of the electromagnetic spectrum between visible light and x-rays.
Vapor
The gaseous form of materials that are normally liquids or solids at room temperature and
pressure, e.g., steam.
32
Vapor density
The weight of a vapor or gas compared to the weight of an equal volume of air; an expression of
the density of the vapor or gas. Materials lighter than air have vapor densities less than 1.0.
Materials heavier than air have vapor densities greater than 1.0. All vapors and gases will mix
with air, but the lighter materials will tend to rise and dissipate (unless confined). Heavier vapors
and gases are likely to concentrate in low places.
Vapor pressure
The pressure exerted by a saturated vapor above its own liquid in a closed container.
Water reactive
A chemical that reacts with water and may release gases that are either flammable or present a
health hazard. Usually flammable solids will react in varying degrees with water or humid air.
33