For years, lagging cloth has been used by the HVAC industry to seal cracks and openings in heating and cooling systems within homes, offices and other buildings. A lagging adhesive is applied to any area along the duct system that is experiencing, or could encounter, an outflow of air—be it from a gap at the joint or an imperfection in the actual unit. It is then wrapped with the lagging cloth. In the prime of asbestos usage, this cloth was typically, if not always, made with asbestos fibers as part of the material. Manufactures of lagging cloth found that using asbestos as one of the components reduced costs and increased both the durability and insulative properties of the product. Since asbestos-containing lagging cloth was basically the only variety on the market, it would be found in almost any building with a heating and cooling system built or installed prior to the 1980s.
Even after the correlation was made between asbestos-containing products and the development of mesothelioma and other asbestos-related illnesses in workers who had handled and were exposed to the carcinogenic fibers, manufacturers still continued to produce and distribute products without a change in their composition. Not until the Consumer Product Safety Commission (CPSC) banned its use in 1977 did companies cease including it as a component of many products, including lagging cloth, even though they had originally been well aware of the health risks to the general public. If this wasn’t enough of an issue, the ban itself didn’t recall those products already in the market, so their use continued into the ‘80s—making it difficult to pinpoint an exact date when asbestos use ended.
Lagging cloth, when intact and in good condition, does not present itself as a major health hazard. However, if it becomes fragile or is damaged in any way, the asbestos contained in the lagging cloth may be released into the environment. Exposure to the dust created by the disturbance could pose health risks. When potential asbestos-containing lagging cloth is found on old HVAC systems and other heating or cooling units, a skilled abatementprofessional should be brought in to inspect—and, if damaged, remove—any product in question. Standard heating and cooling contractors should not be hired for any sort of removal of units containing asbestos. Only certified individuals should be utilized as secure methods, as precautions must be employed for the safety of both the worker and occupants of the building.