This glossary contains terms you may run across on this site or in some other safety context. Not included are very common words, words that usually have their ordinary dictionary meaning, and words that are topics on the site.
IARC—International Agency for Research on Cancer. IARC publishes “Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man.” This is one of the publications that is to be used when conducting the hazard determination. For more information go to http://www.iarc.fr/en/publications/list/monographs/index.php. ALSO SEE: CARCINOGENICITY.
Immediate use (OSHA)—“...means that the hazardous chemical will be under the control of and used only by the person who transfers it from a labeled container and only within the work shift in which it is transferred.” Employers are not required to label containers designated for an “immediate use” purpose.
Importer responsibility—SEE IMPORTER.
Importer (OSHA)—“...means the first business with employees within the customs territory of the United States which receives hazardous chemicals produced in other countries for the purpose of supplying them to distributors or employers within the United States.” Importers must evaluate chemicals for hazards, label containers, and develop SDSs in addition to the requirements as an employer.
Ingestion—Chemicals which enter the body by this route of entry may have local effects and/or may be absorbed into the bloodstream through the small intestine.
Inhalation—Chemicals which enter the body by this route of entry may have local effects and/or may be absorbed into the bloodstream through the lungs.
Inhibitor—A chemical which is added to another substance to prevent an unwanted chemical change from occurring.
Inspections by OSHA—SEE COMPLIANCE.
International Agency for Research on Cancer—SEE IARC.
Inventory—A list or inventory of hazardous chemicals known to be present in the workplace is a required component of the written hazard communication program. This list is to be cross referenced with the SDS and the label.
Irritant—A chemical that produces reversible damage to the skin following the application of a test substance for up to 4 hours.
Job hazard analysis—This is a process by which a job is studied to determine the hazards involved and ways to safely complete the job by procedures and/or personal protective equipment.
LC50—Lethal concentration 50. This is the concentration in air of a toxic substance that was required to cause the death of half the test animal population under controlled administration. This evaluates inhalation as a potentially harmful route of entry. LC50 data is used to assess the toxicity of a chemical.
LD50—Lethal dose 50. This is the dose or amount of toxic substance that was required to cause death in half the test animal population under controlled administration. Either ingestion or skin contact may be evaluated. LD50 data is used to assess the toxicity of a chemical.
LFL—The lowest concentration of a combustible or flammable gas or vapor in air that will produce a flash of fire. Mixtures below this concentration are too lean to burn. The LFL of toluene is 1.27%. ALSO SEE: FLASHPOINT, UFL.
Label (OSHA)—“...means an appropriate group of written, printed, or graphic information concerning a hazardous chemical that is affixed to, printed on, or attached to the immediate container of a hazardous chemical, or to the outside packaging.” Containers in the workplace must be labeled in accordance with section (f) of OSHA’s Hazard Communication Standard at 29 CFR 1910.1200. ALSO SEE: LABEL ELEMENTS
Label elements—“means the specified pictogram, hazard statement, signal word, and precautionary statement for each hazard class and category.” This definition refers to the Hazard Communication Standard at 29 CFR 1910.1200. ALSO SEE: LABEL.
Labeling systems—SEE HMIS, NFPA 704.
Labeling exemptions—SEE FIFRA, FDA, CONSUMER PRODUCTS, DISTILLED SPIRITS.
Language requirements—All labels and other forms of warning are to be in English. The label may also present the information in a different language in addition to English.
Lethal concentration—SEE LC50.
Lethal dose—SEE LD50.
Liquid, flammable (OSHA)—SEE FLAMMABLE LIQUID.
List of hazardous chemicals—SEE INVENTORY.
Lung agents (Appendix A 1910.1200)—Chemicals which irritate or damage lung tissue. Examples include asbestos, silica.
MSDS (OSHA)—SEE SDS. The MSDS, or material safety data sheet, has been replaced by the SDS, or safety data sheet, in accordance with OSHA’s 2012 revisions to its Hazard Communication Standard.
MSHA—Mine Safety and Health Administration.
Material safety data sheet—The material safety data sheet has been replaced by the safety data sheet in accordance with OSHA’s 2012 revisions to its Hazard Communication Standard. SEE SDS.
Medical surveillance—Many of the chemicals that are regulated by OSHA have requirements that the employer conduct medical surveillance on employees to assure that chemical exposure is within the acceptable limits..
Melting point—This is the temperature at which a solid changes state to a liquid. The melting point of toluene is -139°F.
Mixture (OSHA)—“means a combination or a solution composed of two or more substances in which they do not react.” This definition refers to the Hazard Communication Standard at 29 CFR 1910.1200.
Mutagen—A substance which causes genetic mutations. ALSO SEE: REPRODUCTIVE TOXINS.
NAICS Codes—North American Industry Classification System codes. NAICS codes use a six-digit hierarchical coding system to classify all economic activity into twenty industry sectors and 1,170 industries. OSHA began using NAICS codes in its data in 2003. ALSO SEE: SIC CODES.
NFPA—National Fire Protection Association. NFPA is a non-profit organization which provides information on fire protection and prevention. Among the publications the NFPA develops is the 704 Standard for the Identification of the Fire Hazards of Materials. This publication describes a hazard warning system suitable for labels on containers. See www.nfpa.org.
NFPA 704 System—SEE NFPA.
NIOSH—National Institute for Occupational Safety and Health. NIOSH is involved in research on health effects due to workplace exposures. Research is used to make recommendations for reducing or preventing worker exposures. NIOSH is also responsible for testing and certifying respirators. See www.cdc.gov/niosh.
NTP—National Toxicology Program. The Annual Report on Carcinogens is a result of work completed under the NTP. ALSO SEE: ANNUAL REPORT ON CARCINOGENS.
National Toxicology Program—SEE NTP.
National Fire Protection Association—SEE NFPA.
Nephrotoxins—Chemicals which cause damage to the kidneys. Trichloroethylene is an example of a nephrotoxin.
Neurotoxins—Chemicals which have their primary toxic effects on the central nervous system. Examples of neurotoxins include mercury and carbon disulfide.
North American Industry Classification System codes—SEE NAICS Codes.
OSHA—Occupational Safety and Health Administration.
Oral dose—SEE LD50.
Organic peroxide (OSHA)—“...means a liquid or solid organic chemical which contains the bivalent -0-0- structure and as such is considered a derivative of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals. The term organic peroxide includes organic peroxide mixtures containing at least one organic peroxide. Organic peroxides are thermally unstable chemicals, which may undergo exothermic self-accelerating decomposition.” The law considers organic peroxide to be a physical hazard. ALSO SEE: PHYSICAL HAZARD.
Oxidizer (OSHA)—“...means a chemical other than a blasting agent or explosive as defined in section 1910.109(a), that initiates or promotes combustion in other materials thereby causing fire either of itself or through the release of oxygen or other gases.” The law considers an oxidizer to be a physical hazard. ALSO SEE: PHYSICAL HAZARD.
Oxidizing agent—A chemical which gives off free oxygen in a chemical reaction.
ppb—parts per billion.
ppm—parts per million.
psi—pounds per square inch.
PEL—Permissible Exposure Limit. The PEL refers to the maximum air contaminant concentration a worker can be exposed on a repeated basis without developing adverse effects. The PELs are listed in 29 CFR 1910.1000 Tables Z-1, Z-2, Z-3. ALSO SEE: CFR 29 Section 1910 Subpart Z.
Penetration—This is the passage of a chemical through an opening in a protective material. Holes and rips in protective clothing can allow penetration as can stitch holes, space between zipper teeth, and open jacket and pant cuffs. ALSO SEE: CPC.
Permeation—Permeation is the passage of a chemical through a piece of clothing on a molecular level. If a piece of clothing is permeated, the chemical may collect on the inside, increasing the chance of skin contact with that chemical. Permeation is independent of degradation. Permeation may occur even though the clothing may show no signs of degradation. ALSO SEE: CPC.
Permissible Exposure Limit—SEE PEL.
Physical Hazard (OSHA)—“...means a chemical that is classified as posing one of the following hazardous effects: explosive, flammable (gases, aerosols, liquids, or solids); oxidizer (liquid, solid, or gas); self-reactive; pyrophoric (liquid or solid); self-heating; organic peroxide; corrosive to metal; gas under pressure; or in contact with water emits flammable gas.” This definition refers to the Hazard Communication Standard at 29 CFR 1910.1200. Any chemical which can be classified as a physical hazard is considered to be a hazardous chemical under the law. ALSO SEE: CLASSIFICATION, HAZARD CATEGORY, HAZARD CLASS HAZARDOUS CHEMICAL.
Pictogram (OSHA)—“means a composition that may include a symbol plus other graphic elements, such as a border, background pattern, or color, that is intended to convey specific information about the hazards of a chemical.” Eight pictograms are designated under OSHA’s Hazard Communication Standard for application to a hazard category. ALSO SEE: LABEL, LABEL ELEMENTS.
Placard—A placard is a notice or poster placed in a hazardous work area that can be observed and read by workers. The placard can be attached to stationary process containers as long as it contains the same information as a label would carry. ALSO SEE: LABEL.
Polymerization—A chemical reaction in which two or more small molecules combine to form larger molecules.
Portable containers—Portable containers need not be labeled if they are for “immediate use.” ALSO SEE: IMMEDIATE USE.
Precautionary statement (OSHA)—“means a phrase that describes recommended measures that should be taken to minimize or prevent adverse effects resulting from exposure to a hazardous chemical, or improper storage or handling.” This definition refers to OSHA’s Hazard Communication Standard at 29 CFR 1910.1200. ALSO SEE: LABEL, LABEL ELEMENTS, SDS.
Product identifier (OSHA)—“means the name or number used for a hazardous chemical on a label or in the SDS. It provides a unique means by which the user can identify the chemical. The product identifier used shall permit cross-references to be made among the list of hazardous chemicals required in the written hazard communication program, the label and the SDS.” This definition refers to OSHA’s Hazard Communication Standard at 29 CFR 1910.1200. ALSO SEE: LABEL, LABEL ELEMENTS, SDS.
Pulmonary agents—SEE LUNG AGENTS.
Pyrophoric gas (OSHA)—“...means a chemical in a gaseous state that will ignite spontaneously in air at a temperature of 130 degrees F (54.4 degrees C) or below.” Pyrophoric gases are considered to be hazardous chemicals under OSHA’s Hazard Communication Standard at 29 CFR 1910.1200. ALSO SEE: HAZARDOUS CHEMICAL.
Pyrophoric liquid (OSHA)—“means a liquid which, even in small quantities, is able to ignite within five minutes after coming into contact with air.” OSHA considers pyrophoric liquids to be physical hazards under its Hazard Communication Standard at 29 CFR 1910.1200. ALSO SEE: PHYSICAL HAZARD.
Pyrophoric solid (OSHA)—“means a solid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air.” OSHA considers pyrophoric solids to be physical hazards under its Hazard Communication Standard at 29 CFR 1910.1200. ALSO SEE: PHYSICAL HAZARD.
Safety Glossary Terms A through C
Safety Glossary Terms D through H
Safety Glossary Terms R through Z