Subject to extreme temperatures, asbestos materials erode and break down over time. Boilermakers regularly replace boiler components by chipping away at the damaged asbestos, prying it loose with hand-held tools or welding torches – unknowingly releasing poisonous dust. This work is commonly accomplished in hot and cramped spaces, like basements and the tight lower decks of ships, where potentially lethal dust can accumulate. Not knowing to protect themselves, many boilermakers could have breathed in deadly asbestos fibers, or brought the asbestos dust home on their clothes, exposing family members to the dangerous toxin as well.
Because of its fire-resistant qualities, asbestos was used as the main heat-insulation medium of industrial and residential boilers. Many boilers contained thick slabs of asbestos-lined “block” insulation in boiler fire boxes or around the furnace walls and tube banks.
Asbestos was also used to make the following boiler components: