Several substances have established PELs due to their carcinogenic properties. Examples include: - Benzene: Used in the production of plastics and resins, benzene has a PEL of 1 ppm (part per million) over an 8-hour workday. - Asbestos: Common in construction materials, asbestos has a PEL of 0.1 fibers per cubic centimeter of air over an 8-hour period. - Formaldehyde: Used in manufacturing and embalming, formaldehyde has a PEL of 0.75 ppm.
