Written By: Devin Golden

Asbestos Exposure for Insulation Workers

Asbestos exposure is a concern for insulation workers due to asbestos contaminating vermiculite, which was part of making insulation materials during the 20th century. Asbestos and vermiculite are naturally occurring minerals usually found in the same geographical areas. to insulation material through most of the 20th century.


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Important Facts About Asbestos Exposure for Carpenters

  • Asbestos and vermiculite are two naturally occurring minerals found close to one another in the earth’s soil. The use of vermiculite in insulation materials led to asbestos contamination.
  • There were various types of insulation used in homes, offices and other buildings. All types can present a risk of asbestos exposure to insulation workers.
  • While vermiculite and asbestos are no longer used for insulation work today, there’s still a risk of “legacy asbestos” in homes and offices built during the 20th century.

Why Asbestos Was Used in Insulation

Insulation is a key component in the construction of homes, office buildings, entertainment venues, government buildings and more. Installing insulation is a very common trade among Americans and has been for decades. However, this ordinary occupation is one of the most susceptible to being exposed to asbestos.

Asbestos is a naturally-occurring mineral that forms in close proximity to vermiculite, which means they often mix together. When heated, vermiculite expands rather than burns. Insulation companies used vermiculite for its expansive and fire-resistant properties.

Where Did Asbestos Insulation Come From?

Most vermiculite insulation sold in the United States originated from the Libby, Montana mine, which was active until 1990. The insulation the Libby mine produced was sold as Zonolite, the brand name coined by W.R. Grace & Co.

The Libby mine extracted not only vermiculite but also asbestos. Joining the two mining operations led to the contamination of vermiculite insulation and most insulation in American homes and buildings.

Asbestos was also added as an insulant around pipes. Since asbestos can absorb heat, it can protect pipes from overheating. So insulation materials added to pipes often contained asbestos as another safeguard.

For most of the 20th century, the relationship between asbestos and vermiculite was unknown. Even after its discovery, the connection was an afterthought for many vermiculite manufacturers and insulation companies. Meanwhile, insulation workers were being exposed daily to dangerous asbestos and placed in certain danger.

How to Know If Insulation Has Asbestos

Vermiculite is known to be found next to asbestos in its natural state. The likelihood of materials containing vermiculite and asbestos is extremely high. The chances of asbestos contamination are so high that the Environmental Protection Agency (EPA) states all vermiculite insulation should be assumed to contain asbestos.

Insulation produced with vermiculite is easily identifiable due to its loose pebbly characteristics. It can also resemble lightweight gravel or tiny packing peanuts. Vermiculite insulation can be identified by a nonprofessional because other types of insulation have opposite characteristics as they are typically fibrous or wooly.

This type of insulation is commonly poured inside framed walls, concrete walls or laid between attic rafters or below flooring to protect the structure from premature decay and heat damage.

Insulation With Asbestos 

There are several different types of insulation. The ones known to contain asbestos were:

  • Vermiculite insulation 
  • Loose-fill insulation
  • Spray-on insulation 
  • Block insulation
  • Blanket/wrapped insulation
  • Asbestos pipe insulation

When Was Asbestos an Issue for Insulation Workers?

Asbestos entered the market in the early 20th century and was overly used for nearly 80 years. It is estimated that any American home built between 1900 and 1980 contains asbestos insulation.

Insulation was used in American homes for its durability and heat resistance. It was used to insulate walls, floors, pipes, ductwork, boilers and to fireproof structural beams. Insulation companies knew traces of asbestos could be detected in their insulation products but failed to learn the health risks and protect their employees. Handling asbestos is extremely dangerous and can lead to cancer or other serious health problems.

The EPA began implementing regulations on asbestos in the late 1980s, preventing the widespread use of the toxic substance in homes, buildings and consumer products. However, the Libby mine, known for producing most vermiculite insulation, remained active until 1990.

Most American homes built before 1990 were – or still are – likely to contain asbestos in some way. This is referred to as “legacy asbestos.” This term describes any leftover asbestos in a home or office building built during an era when using asbestos was embraced.

The presence of legacy asbestos means insulation workers today still face a risk of asbestos exposure and disease. Anyone who worked or currently works in this trade should know the health risks associated with insulation.

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Asbestos Insulation Health Risks

Insulation contaminated with asbestos can have deadly effects on a person’s health. Asbestos insulation is one of the biggest hazards in American homes.

Asbestos is highly toxic due to its microscopic, needle-like fibers. Any slight disturbance of asbestos insulation can send asbestos fibers into the air, exposing anyone in the area.

Occupational asbestos exposure is responsible for most cases of asbestos disease, including the rare cancer mesothelioma, but it is possible to be exposed to the toxic substance at home. Any amount of exposure to asbestos is dangerous and can lead to a type of insulation cancer.

How Does Insulation Cause Cancer?

Insulation can become a hazard in the home, especially when repairing damage or remodeling older homes. While not dangerous when whole, asbestos particles can flake off with the slightest touch or movement around them.

The disturbance or movement of the insulation will cause tiny asbestos fibers to become airborne and potentially inhaled or ingested by occupants in the home. If the body does not clear out the particles, then they can irritate healthy cells and turn them into cancer.

Asbestos fibers are sharp. If inhaled or ingested, they can become lodged in the lungs, throat or abdomen, embedding themselves into the organ tissue. This can lead to serious illness, such as cancer.

There are several types of cancer caused by asbestos in insulation.

Mesothelioma Among Insulation Workers

Mesothelioma is a rare and aggressive type of cancer caused by exposure to asbestos. Mesothelioma forms in the thin linings of the lungs and abdominal cavity. These narrow linings can be infiltrated by sharp asbestos fibers, which irritate cells in the linings and cause cell mutation. This leads to a tumor.

In 1990, the Centers for Disease Control and Prevention (CDC) reported 278 “definite or suspected” mesothelioma cases among the 17,800 insulation workers in the United States and Canada. This type of cancer has an extensive latency period, often 20-50 years, which means insulation workers may not show any signs of mesothelioma for decades.

Another study from 1967 reviewed data on 17,800 insulation workers from the U.S. and Canada. Among them, 356 died of mesothelioma by 1984.

Lung Cancer Among Insulation Workers

Asbestos lung cancer is a malignancy of the lungs due to asbestos exposure. The flaky dust produced by asbestos can be easily inhaled, leading to lung tissue irritation. This causes cells to mutate and form tumors, which can grow and spread throughout the body.

Asbestos exposure is the main cause of roughly 7,000-11,000 new cases of lung cancer in the U.S. each year. The only difference in asbestos lung cancer is the root cause of lung cancer – exposure to asbestos.

In 1968, a study reported a significant link between occupational exposure to asbestos and cigarette smoking among 370 insulators in the New York metropolitan area. They estimated that insulators with a history of both exposures had a 90% increased risk of death due to lung cancer compared with never-smokers in the general U.S. population not occupationally exposed to asbestos.

In 1979, they followed 17,800 insulators from 1967-1976. There were at least 429 deaths due to lung cancer. A follow-up in 1991, reported over 1,000 deaths due to lung cancer and increasing risk with age.

Help for Insulation Workers With Asbestos Diseases

Insulation workers have a significantly increased risk for developing an asbestos disease or type of insulation cancer, especially mesothelioma. In the CDC study, almost half of the insulation workers with mesothelioma had latency periods of 30-39 years.

Asbestos is heavily regulated now, but there is a chance asbestos insulation still remains in older homes, offices or other buildings. The main risk today is knowing where legacy asbestos insulation could be hiding and following safety protocols.

If you currently work or used to work in insulation and have been diagnosed with mesothelioma, there is most likely a connection between the two. If you have questions about your diagnosis, contact our patient advocate and registered nurse Karen Ritter. She can answer any asbestos-related health questions. Email her at karen@mesotheliomaguide.com for the quickest contact.

Sources & Author

    1. Dangers of Asbestos Contaminated Vermiculite Insulation In Your Home. Today’s Homeowner. Retrieved from: https://todayshomeowner.com/dangers-of-asbestos-contaminated-vermiculite-insulation-in-your-home/. Accessed: 01/03/2023.
    2. What Does Asbestos Insulation Look Like? Identification & What to Do. The Spruce. Retrieved from: https://www.thespruce.com/how-to-identify-dangerous-asbestos-insulation-4119906. Accessed: 01/04/2023.
    3. Malignant mesothelioma in a cohort of asbestos insulation workers: clinical presentation, diagnosis, and causes of death. British Journal of Industrial Medicine. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1007965/. Accessed: 01/05/2023.
    4. Pathology of lung cancer among asbestos insulation workers. U.S. Department of Energy Office of Scientific and Technical Information. Retrieved from: https://www.osti.gov/biblio/7186685. Accessed: 01/05/2023.
    5. Pathology of malignant mesothelioma among asbestos insulation workers. Centers for Disease Control and Prevention. Retrieved from: https://www.cdc.gov/niosh/nioshtic-2/00198428.html. Accessed: 01/05/2023.
    6. Asbestos and Lung Cancer: What We Know. American Thoracic Society Journal. Retrieved from: https://www.atsjournals.org/doi/full/10.1164/rccm.201305-0885ED. Accessed: 01/05/2023.
Devin Golden

About the Writer, Devin Golden

Devin Golden is a content writer for Mesothelioma Guide. He produces mesothelioma-related content on various mediums, including the Mesothelioma Guide website and social media channels. Devin's objective is to translate complex information regarding mesothelioma into informative, easily absorbable content to help patients and their loved ones.