Key Terms

There are several key terms that are important to know when discussing asbestos awareness.

Asbestos-containing material (ACM) refers to any material comprised of more than one percent of asbestos.

Authorized person is any person authorized by the employer and required by work duties to be present in regulated areas.

Certified Industrial Hygienist (CIH) is a certified person in the practice of industrial hygiene by the American Board of Industrial Hygiene.

Competent person refers to someone who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees and who has authorization to take prompt corrective measures to eliminate them. A competent person should also be able to identify existing asbestos hazards in the workplace and select the appropriate control strategy.

Critical barrier is one or more layers of plastic sealed over all openings into a work area or any other similarly placed physical barriers. The critical barrier must be sufficient to prevent airborne asbestos in a work area from migrating to an adjacent area.

Excursion limits ensure that no employee is exposed to an airborne concentration of asbestos in excess of 1.0 fiber per cubic centimeter (f/cm³) of air as averaged over a sampling period of thirty minutes.

Fiber means a particulate form of asbestos, five micrometers or longer, with a length-to-diameter ratio of at least three to one.

Permissible Exposure Limits (PELs) are legal limits in the United States for exposure of an employee to a chemical substance or physical agent. For chemicals, the chemical regulation is usually expressed in parts per million (ppm) or in milligrams per cubic meter (mg/m³). Cal/OSHA has established an extensive list of PELs that are enforced in workplaces under its jurisdiction. Of all the states that have OSHA approved plans, California has the most extensive list of PELs.

Presumed asbestos-containing material (PACM) means thermal system insulation and surfacing material found in buildings constructed before 1980.

Regulated area is an area established by the employer where Class I, II, and III asbestos work is conducted.

Time-weighted average ensures that no employee is exposed to an airborne concentration of asbestos in excess of 0.1 (f/cm³) of air over an eight-hour period.

To learn more about Asbestos Awareness visit our Cal/OSHA Asbestos Awareness Online Training web page.