Thermal spray-on products are used for insulation as well as for soundproofing. They are used in building bridges and in the construction of large commercial buildings such as skyscrapers and parking garages. Up until about 1980, thermal sprays that contained asbestos was frequently used for fireproofing in these large structures. It was also used to coat the walls of boilers on Navy submarines and boiler rooms and even sprayed on the inside of boilers for insulating and fire-retardant purposes.
Applying thermal spray coatings results in the release of high levels of asbestos dust into the air. Anyone without a respirator or other protective equipment can easily inhale asbestos fibers. These coatings have been in use since long before the dangers of asbestos were generally known and, therefore, long before protection as minimal as paper masks was worn. Asbestos fibers are small enough to be breathed in even through paper masks.
Thermal coatings are dangerous even long after application such as during any type of maintenance or renovation. In order to remove spray on coating, it must be sanded, and this act releases asbestos into the air in high concentrations. Perhaps the best-known danger of inhaling asbestos fibers is pleural mesothelioma, which can develop when these fibers become lodged in the lining of the lungs.