Despite Limits, No Safe Level of Asbestos Exposure
Asbestos is extremely hazardous. According to the National Institute for Occupational Health and Safety (NIOSH) "all levels of asbestos exposure studied to date have demonstrated asbestos-related disease" and "there is no level of [asbestos] exposure below which clinical effects do not occur." Therefore, all avoidable exposures to asbestos should be prevented whenever possible.
The Occupational Safety and Health Commission (OSHA) has set a permissible asbestos exposure limit (PEL) of 0.1 fiber per cubic centimeter (f/cc) for work in all industries, including construction, shipyards, and asbestos abatement work. This standard has also been adopted by the Environmental Protection Agency. OSHA is quick to add, however, that the asbestos PEL is a target guideline for regulatory purposes only, and does not establish any level of "safe" asbestos exposure. As OSHA writes in its Asbestos Final Rule: "The 0.1 f/cc level leaves a remaining significant risk."
Construction and Asbestos Abatement Categories
OSHA divides construction and asbestos abatement work into categories based upon the threat of exposure, and provides work procedures for each category. For example, a high asbestos exposure danger exists in removing asbestos-containing material from thermal insulation systems. Such work has the most stringent safety requirements.
For all construction work, OSHA requires the use of vacuum cleaners with HEPA filters to collect asbestos-containing debris, wet methods during mixing and handling to minimize dust, and prompt disposal of asbestos-contaminated wastes in leak-tight containers. At the minimum, employers must provide either: local exhaust ventilation equipped with HEPA filter dust collection systems, enclosures for processes producing asbestos dust, or ventilation of regulated areas to move contaminated air away from an employee's breathing zone to a filtration or collection device. Respiratory protection includes glove bags, protective clothing and approved respirators.