Because of the many desirable physical properties of this natural mineral, asbestos was often used in all types of construction products including insulation materials like insulation seals. These were used to seal boilers, furnaces, door and window frames, and on roofs. Insulation seals when made with asbestos in general have between 10 and 30 percent of the material in them.
Even though it came to be known that there health dangers associated with asbestos, the mineral was widely used in construction applications. During the mid 20thcentury, the period of its widest use, it was not regulated in any manner. This did not happen until the 1970s. As long as asbestos products remain intact in the home, they do not pose a threat, but if the material of the seals is damaged or flaking, asbestos fibers can be released into the air.
Exposure to asbestos can result in lung scarring as well as mesothelioma, which is a rare cancer that most often affects the pleural lining of the chest or abdominal cavity. Diseases associated with asbestos have very long latency periods so the symptoms may not even reveal themselves for decades after exposure. Those who worked in factories where these asbestos products were made are at greatest risk.