A contentious point of debate continues to revolve around the health concerns of fiberglass insulation. Health and safety research on fiberglass has been ongoing for nearly 60 years. Member companies with NAIMA, the trade association of North American manufacturers of fiberglass, rock wool, and slag wool insulation products, have committed tens of millions of dollars in research projects with leading independent laboratories and universities in the United States and abroad. Recent studies have presented results that suggest that the carcinogenic concerns about fiberglass may only have an impact under extreme exposure conditions. An Occupational Safety and Health administration (OSHA) report in 1994 stated that fiberglass insulation is carcinogenic, but results indicated that there was virtually no risk to home occupants. The greatest risk was the exposure to installers during installation.11
In 1997, the American Conference of Governmental Industrial Hygienists (ACGIH), representing over 1600 academic and government professionals engaged in occupational safety and health programs, concluded that the “available evidence suggests that [fiberglass]…is not likely to cause cancer in humans except under uncommon or unlikely routes or levels of exposures.” The ACGIH designated fiberglass as an “A3, animal carcinogen.” The A3 designation indicates that the substance may cause cancer in experimental animals at relatively high doses and by routes of exposure that “are not considered relevant” to workers.12
The Canadian government classified fiberglass as “unlikely to be carcinogenic to humans” and concluded that glass wool “is not entering the environment in quantities or under conditions that may constitute a danger in Canada to human life or health.” The CPSC (1992) also has found that “fibrous glass is carcinogenic in animals only when surgically implanted into the lung or abdomen. In tests where animals were exposed by inhalation, the expected route of human exposure, the animals did not develop tumors. Therefore, the animal implantation studies do not establish a hazard to humans.”13
Nevertheless, fiberglass as a simple irritant is well documented. Workers in fiberglass manufacturing plants, as well as people working with or using materials that contain fiberglass, may develop a skin irritation. This mechanical irritation is a physical reaction of the skin to the ends of fibers that have rubbed against or become embedded in the skin’s outer layer. Any skin irritation caused by fiberglass is temporary. Washing the exposed skin gently with warm water and mild soap can relieve it. The vast majority of workers and consumers, however, can control skin irritation by following recommended work practices when handling the material. Fiberglass is also a catalyst for eye irritation if deposited in the eye by the user’s fingers or through fibers in the air. If this should happen, the eyes should not be rubbed but rinsed thoroughly with warm water, and a doctor should be consulted if irritation persists.12
Fiberglass released into the air during its manufacture or handling also may create temporary upper respiratory irritation. Like skin irritation, upper respiratory irritation is a mechanical reaction to the fibers. It is not an allergic reaction, and the irritation generally does not persist. Such exposures to high concentrations of airborne fiberglass may result in temporary coughing or wheezing. These effects will subside after the worker is removed from exposure.12
As will be discussed later in this chapter, proper clothing and handling and the use of approved respiratory protection can effectively control exposure to airborne fibers and therefore reduce the likelihood of skin or upper respiratory tract irritation.