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Asbestos Zonolite Insulation

Expert Fact Checked

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Jennifer Lucarelli Lawyer and Legal Advisor


Zonolite is a loose-fill insulation brand commonly used to insulate attics. The product was made of asbestos-contaminated vermiculite once mined in Libby, Montana. Zonolite insulation is no longer manufactured in the United States. However, the asbestos product may still be present in some homes.


01. Asbestos Use in Zonolite Insulation

Why Was Asbestos Used in Zonolite Insulation?

Zonolite is a brand name of loose-fill vermiculite attic insulation sold from the 1940s to the 1980s. The vermiculite used in Zonolite attic insulation came from a mine in Libby, Montana. The Libby mine was contaminated with tremolite asbestos. As a result, Zonolite attic insulation likely contains asbestos.

Vermiculite insulation is typically a silver-gold or gray-brown color. The insulation particles are approximately the size of pebbles and designed to be poured onto an attic floor.

Zonolite insulation was popular because it was lightweight and fire-resistant. In the United States, the product was used to insulate millions of homes.

Asbestos Zonolite Insulation History at a Glance

  • Other Names: Vermiculite insulation
  • Years of Manufacture: 1940 – 1984
  • Places Used: Attics
  • Asbestos Use Banned: No
  • Noteworthy Brands: W.R. Grace, Zonolite

The Zonolite Company was the first to manufacture Zonolite insulation. In 1963, W.R. Grace & Company bought the Zonolite Company and sold the insulation products until 1984.

During the 1980s, asbestos laws regulated asbestos use in the United States. Although Zonolite Attic Insulation is no longer manufactured, it may still be present in many homes.

Dangers of Vermiculite Insulation

On its own, vermiculite is not dangerous. However, a majority of vermiculite in the U.S. is contaminated with asbestos. Approximately 80% of America’s vermiculite was mined in Libby, Montana. The Environmental Protection Agency (EPA) says homeowners should assume all vermiculite insulation may be contaminated with asbestos.

In a 2012 study, researchers tested vermiculite attic insulation in 40 homes. Amphibole asbestos was present in all the insulation samples.

Comparing Vermiculite and Asbestos

Vermiculite and asbestos are naturally occurring minerals. Both minerals are also resistant to heat and chemical corrosion. These qualities make them popular additives in insulation products.

Zonolite attic insulation is friable and may be a health risk. The EPA recommends Zonolite insulation should only be removed by an asbestos abatement professional. To further prevent exposure, homeowners should avoid going into their attics or storing items in their attics. This could disturb the asbestos insulation.

If asbestos-containing materials are improperly removed, individuals nearby may be exposed to asbestos fibers. Inhaling or ingesting asbestos dust may lead to asbestosis, lung cancer or mesothelioma.

02. List of Asbestos Zonolite Products

Zonolite Products Made by W.R. Grace

From 1963 to 1990, W.R. Grace manufactured a variety of Zonolite brand products. Some products were also manufactured before 1963 by The Zonolite Company. While Zonolite’s insulation remains the main asbestos exposure concern, other Zonolite brand products have been noted to contain asbestos. Zonolite products manufactured by W.R. Grace include:

Asbestos Zonolite Products
List of Asbestos Zonolite Products

Product Name Start Year End Year
Ari-Zonolite Board Texture 1961 1964
Zonolite Acoustical Plaster 1945 1972
Zonolite Insulating Cement 1945 1972
Zonolite Mono-Kote (MK-3) 1959 1973
Zonolite Spra-Insulation 1960 1973
Zonolite Spra-Tex 1955 1972
Perltex Super-40 1966 1973

These products were made with asbestos-contaminated vermiculite. Individuals who come in contact with Zonolite products may risk asbestos exposure.

03. Zonolite Insulation & Asbestos Exposure

Who Is at Risk of Asbestos Exposure From Zonolite Insulation?

During a home renovation or demolition, contractors and other construction workers may risk exposure to Zonolite attic insulation. Today, the insulation product may still be present in millions of homes. This also puts homeowners at risk of exposure.

Occupations at Risk of Exposure From Asbestos Zonolite Insulation

Former W.R. Grace employees may have also experienced exposure. People who mined the vermiculite for the production of Zonolite insulation also risked exposure. The vermiculite mines in Libby to produce these products led to widespread contamination.

The EPA started cleaning up the Libby asbestos site in 1999 and completed cleanup in 2018. However, Libby residents and workers continue to be diagnosed with asbestos-related diseases because of the long latency periods.

Individuals with an asbestos illness from exposure to Zonolite insulation may be eligible to file a lawsuit.

04. Asbestos Lawsuits

Asbestos Lawsuits, Settlements & Other Compensation

Thousands of asbestos victims have filed lawsuits against W.R. Grace after exposure to Zonolite insulation. In 2001, W.R. Grace filed for Chapter 11 bankruptcy. Until the company’s bankruptcy filing, it had faced more than 65,000 asbestos-related lawsuits involving nearly 130,000 plaintiffs.

As part of W.R. Grace’s bankruptcy proceedings, the company established two trust funds:

  • W.R. Grace & Company Personal Injury Trust: Created to compensate current and future asbestos victims who developed mesothelioma or another asbestos illness.
  • The Zonolite Attic Insulation Trust: Created to partially cover encapsulation or abatement costs for homeowners to remove Zonolite attic insulation. The trust may reimburse claimants for up to 55% of the abatement cost.

W.R. Grace began accepting trust fund claims in 2014. Those exposed to Zonolite insulation who later develop asbestos illnesses may file a trust fund claim.

Together, the trusts are funded with more than $4 billion. Both trusts use a payment percentage to pay out eligible claimants. This ensures the trusts can maintain funds for future claimants.

The payout percentage for the personal injury trust is currently 31.7%. Compensation amounts will vary based on various factors. For instance, the claimant’s age, diagnosis and exposure history, as well as the law firm’s settlement history, can impact the award.

Financial compensation from an asbestos trust fund claim may help patients and their loved ones pay for treatment and other expenses.