Environmental Health and Safety

MSDS Glossary

Clean Air Act was enacted to regulate/reduce air pollution. CAA is administered by the U.S. Environmental Protection Agency (EPA).
A substance or agent that has been demonstrated to cause or produce cancer in mammals, including humans. Carcinogens are regulated by OSHA and are listed in the National Toxicology Program Annual Report of Carcinogens.
Chemical Abstracts Service is an organization under the American Chemical Society. CAS abstracts and indexes chemical literature from all over the world in "Chemical Abstracts." "CAS Numbers" are used to identify specific chemicals or mixtures.
See Base.
Cubic centimeter is a volume measurement in the metric system that is equal in capacity to one milliliter (ml). One quart is about 946 cubic centimeters (0.946L).
Ceiling Limit (PEL or TLV)
The maximum allowable human exposure limit for an airborne substance which is not to be exceeded even momentarily. See also PEL and TLV.
Centigrade, a unit of temperature. To convert from centigrade to Fahrenheit, multiply the temperature given in centigrade degrees by 9, divide that number by 5, then add 32.
Central Nervous System
The brain and spinal cord. These organs supervise and coordinate the activity of the entire nervous system.
Comprehensive Environmental Response, Compensation, and Liability Act of 1980. The Act requires that the Coast Guard National Response Center be notified in the event of a hazardous substance release. The Act also provides for a fund (the Superfund) to be used for the cleanup of abandoned hazardous waste disposal sites.
Code of Federal Regulations. A collection of the regulations that have been promulgated under United States Law.
Chemical Cartridge Respirator
A respirator that uses various chemical substances to purify inhaled air of certain gases and vapors. This type respirator is effective for concentrations ten times or more times (depending on the type of respirator) the TLV of the contaminant, if the contaminant has warning properties (odor or irritation) below the TLV. See also Air-Purifying Respirator.
Chemical Family
A group of single elements or compounds with a common general name. Example: acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) are of the "Ketone" family; acrolein, furfural, and acetaldehyde are of the "aldehyde" family.
Chemical Pneumonitis
Inflammation of the lungs caused by accumulation of fluids due to chemical irritation.
Chemical Transportation Emergency Center is a national center established by the Chemical Manufacturers Association (CMA) to relay pertinent emergency information concerning specific chemicals on requests from individuals. CHEMTREC has a 24-hour toll-free telephone number (800-424-9300) to help respond to chemical transportation emergencies.
Chronic Effect
Adverse symptoms of chemical exposure that develop slowly over a long period of time (weeks, months or years) due to repeated long-term exposure to a substance. Examples include cancer or damage to certain internal organs. Also see Acute Effect.
Chronic Exposure
Repeated long-term contact with a substance.
Chronic Toxicity
Adverse effects resulting from repeated doses of or exposures to a substance over a long period of time.
Clean Air Act
Clean Air Act was enacted to regulate/reduce air pollution. CAA is administered by the U.S. Environmental Protection Agency.
Clean Water Act
Federal law enacted to regulate/reduce water pollution. CWA is administered by the U.S. Environmental Protection Agency.
For liquids, a liquid with a flash point above 100°F (37.8°C) but below 200°F (93.3°C). Non-liquid substances such as wood and paper are classified as "ordinary combustibles" by NFPA. Also see Flammable Liquid.
Common Name
A name used to identify a chemical other than its chemical name (e.g., code name, code number, trade name, brand name, or generic name). See Generic.
Compressed Gas:
  1. A gas or mixture of gases having, in a container, an absolute pressure exceeding 40 pounds per square inch (psi) at 70°F (21.1°C); or
  2. A gas or mixture of gases having, in a container, an absolute pressure exceeding 104 psi at 130°F (54.4°C) regardless of the pressure at 70°F (21.1°C); or
  3. A liquid having a vapor pressure exceeding 40 psi at 100°F (37.8°C) as determined by ASTM D-323-72.
The relative amount of a substance when combined or mixed with other substances. Examples: 2 ppm hydrogen sulfide in air, or a 50 percent caustic solution.
Conditions to Avoid
Conditions encountered during handling or storage that could cause a substance to become unstable.
Corrosive Material
Any solid, liquid, or gas that burns, irritates, or destroys organic tissues such as the skin, lungs, and stomach. Corrosives can also destroy metal and other building materials. The term corrosive includes both acids and bases.
Clean Water Act was enacted to regulate/reduce water pollution. It is administered by the Environmental Protection Agency (EPA).

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