Asbestos as a Hazardous Air Pollutant

Asbestos is a hazardous air pollutant, within the meaning of section 112 of the 1970 Clean Air Act¹. When it is in dry form, asbestos may be ‘friable’ or ‘non-friable,’ according to whether or not it is likely to release fibers into the air upon disturbance. Inhalation of asbestos fibers is strongly linked to a variety of severe lung diseases including bronchial cancer, mesothelioma, and asbestosis. Despite the early recognition of the risks associated with asbestos, for many years the EPA considered asbestos regulation impracticable: in part because the technology for detecting and measuring asbestos was not yet advanced enough, and in part because, as reported by a foundational National Academy of Sciences' study, "asbestos is too important in our technology and economy for its essential use to be stopped…” Until the NESHAP revisions implemented by the amended Clean Air Act of 1990, asbestos was ubiquitous in the production of many vital building components, including thermal insulation, joint compound (also known as “mud”), spray-on fireproofing, adhesives (e.g. tile mastic) and cement roofing (e.g. fibro).² All of these applications of asbestos are typically friable or likely to become friable over time. The manufacture and distribution of these products was effectively prohibited after 1990, but the asbestos introduced during the last few decades of construction wasn’t going anywhere.

With the exception of AHERA’s requirement for public school facilities, there are no regulations compelling proactive inspection and abatement of asbestos-containing materials. Instead, this is addressed by Occupational Safety and Health Administration (OSHA) regulations on permissible ambient air pollution which hold employers accountable for the exposure of employees. It stipulates that employees must not be exposed to “an airborne concentration of asbestos in excess of 0.1 fiber per cubic centimeter of air as an eight hour time-weighted average,” or “in excess of 1.0 fiber per cubic centimeter of air as averaged over a sampling period of thirty minutes.”³ Additionally, the US Environmental Protection Agency (EPA) and the Maine Department of Environmental Protection (MEDEP) require that abatement professionals take air clearance samples which register less than 0.01 fibers per cubic centimeter of air before they ‘release’ suspect areas to reoccupancy, and to clean areas that fail these tests pursuant to stringent regulation.⁴ Beyond that, many of the fundamental decisions determining the management of extant asbestos are left up to the discretion of building managers and of environmental health and waste management professionals. In the case of state-owned buildings, local government officials act as surrogate buildings managers. This report uses Maine’s Cultural Building as a case study to show that asbestos management strategies employed by the state could be reformed to better promote long-term safety.

¹ 42 U.S. Code § 7412
² 40 CFR § 721.11095
³ OSHA 29 CFR 1910.1001(c)(1)-(2), 1926.1101(c)(1)-(2), and 40 CFR Part 763, Subpart G – Asbestos Worker Protection which applies the previous statutes to state and local government employers who would otherwise be exempt.
⁴ Maine DEP Chapter 425 — Asbestos Management and Regulations