Asbestos in Caulking

Caulk is an all-purpose sealant used to fix cracks, fill joint gaps, and seal windows against drafts. Caulk must be weatherproof, heatproof, waterproof, and durable in order to be effective. Caulk manufacturers often used asbestos before the 1970s as a fire retardant. Common places in the home that may have asbestos-containing caulk are around ovens, fireplaces, boilers, pipe joints, ducts, brickwork, and exteriors.

Before the 1970s, all types of asbestos were used in caulk formulas. Some caulks can be close to 100 percent asbestos. After the 1970s, the only type of asbestos allowed in caulk compounds was chrysotile. Most types of asbestos feature sharp, needle-like fibers, while chrysotile has curly fibers that increase its malleability. This has a result of making chrysotile caulks less friable than caulks produced with other kinds of asbestos. Asbestos’ friability, or how easily the pressure of a hand can break it down, indicates how dangerous the caulk is. If the caulk is easy to break down, then there is a greater possibility that asbestos fibers can become airborne.

Asbestos fibers cannot be released from caulking unless the caulk is damaged in some way. Caulk can be damaged by aging, water, impact, drilling, sanding, scraping, or attempts to remove it. If you suspect the caulk in your home contains asbestos, it is better to leave it alone if it is in good condition. Otherwise, consult a professional contractor for safe removal.

Fibers released from improper removal of asbestos-containing caulk can cause serious health problems. When asbestos fibers become airborne, they can be inhaled and cause severe respiratory problems. They accumulate in the lungs where they can’t be broken down by the body. Repeated or prolonged exposure to areas contaminated with asbestos increases the risk of developing an asbestos-related illness. Asbestosis, mesotheliomas, and lung cancer are known to be caused by inhaling asbestos fibers.