Sealer and Asbestos Exposure

Sealers were simple and standby products commonly used in most parts of building construction and equipment manufacturing. Sealants did an excellent job of blending seams, patching holes and covering up mistakes in the installation of primary products.

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Many times, tradespeople took the view that close enough was good enough and finished joints with gobs of sealer. Although the building and manufacturing industries depended on sealants for a wide range of tasks, many end-users had no idea how dangerous sealants could be. That’s because, before the 1980s, almost every type of sealer on the American market contained harmful quantities of asbestos fibers.

Most sealants were semi-solid materials like caulking and adhesives. Malleability was the key to good sealers so they could be squeezed out or scooped from containers then beaded along cracks and porous surfaces. Workers applied sealants in all kinds of conditions. They placed sealers in high heat applications like chimneys and boilers. Sealants were spread on damp surfaces like water pipes and containers as well as on roofs and exterior walls. Sealers also helped insulate building products, stopped electrical contact and, most importantly, prevented fires.

That was a lot to ask from semi-liquid construction product. But almost every sealer seemed to be improved by adding asbestos fibers into the mix. From the early 1900s to the later twentieth century, most sealers on the American market contained asbestos particles. Asbestos was widely available, easy to manipulate and exceptionally cost-effective. And sealers with asbestos materials as an ingredient were stable. Asbestos fibers didn’t chemically react with other materials.

Asbestos Fibers in Sealers

Another significant advantage to adding asbestos materials in sealers was making the products pliable. Sealers needed the flexibility to do their job and asbestos was an excellent additive for enhancing sealant pliability. Many industrial sealants contained between 10 and 50 percent asbestos fibers. Content amounts depended on what purpose the sealer had. It also depended on what type of asbestos fiber the manufacturer blended into their sealant product.

The sealer industry primarily used two different types of asbestos fibers. Chrysotile asbestos was the most common additive. It was also called “white asbestos” due to its natural mineral color.

Chrysotile asbestos was commonly available and used in low-stress sealer applications like:

  • Residential, commercial and industrial building construction.
  • Automotive, aircraft and railroad equipment manufacturing.
  • Medical supplies and hospital settings.
  • Electrical components.
  • Household goods.

Chrysotile asbestos was also known as “good asbestos.” That’s because the health hazards from the other type of asbestos fibers used in sealant manufacturing were well-known. Amphibole asbestos belonged to a different classification of crystalline asbestos minerals than chrysotile. Amphibole colors ranged from blue, green and brown. High heat and pressure resistance were the main benefit sealant makers got from blending amphibole fibers into sealants.

Amphibole asbestos was useful for:

Exposure to Asbestos Fibers in Sealants

Sealants exposed workers to asbestos fibers in three ways. One was manufacturing the original sealer product. The second was applying sealants at a worksite. And third, workers maintaining, repairing or removing sealants were exposed to airborne asbestos fibers when old sealers were disturbed.

Once asbestos sealers were in placed and allowed to cure, they were stable and safe. Health risks occurred when asbestos fibers were added or handled in a factory setting or if sealants were disturbed during construction or demolition. Old sealants that turned dry and crumbly also presented severe exposure risk. Dried out sealers became friable where microscopic asbestos particles were released into the air as dust when broken down. When inhaled by workers, asbestos fibers turned deadly.

Asbestos Sealers and Mesothelioma

Did You Know?

Mesothelioma Justice Network Brief

A mesothelioma is a fatal form of lung cancer. Its only cause is exposure to airborne asbestos fibers. Inhaled asbestos particles bond to the lung lining or mesothelium. They remain permanently fixed and, over time, cause scar tissue that turns tumorous. There is no known cure for mesothelioma.

Compensation for Mesothelioma Victims

Compensation may be available for anyone who developed mesothelioma due to workplace asbestos exposure. Negligent manufacturers of asbestos-containing products like sealers are held accountable for personal injury, lost income and medical expenses. Families of mesothelioma victims can claim on members’ behalf. They are also entitled to file wrongful death lawsuits.

Mesothelioma Support Team
Stephanie KiddWritten by:


Stephanie Kidd works tirelessly as a dedicated advocate for the vulnerable and underrepresented. Stephanie worked as a copywriter for an agency whose focus was communicating safety procedures on construction work sites. With her extensive background in victim advocacy and a dedication to seeing justice done, Stephanie works hard to ensure that all online content is reliable, truthful and helpful.

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