What is vermiculite insulation? Vermiculite is a naturally occurring mineral that has the unusual property of expanding into worm-like accordion shaped pieces when heated. The expanded vermiculite is a lightweight, fire-resistant, absorbent, and odourless material. These properties allow vermiculite to be used to make numerous products, including insulation most commonly for attics. It can be purchased in various forms for various uses. Sizes of vermiculite products range from very fine particles to large coarse pieces nearly an inch long. Vermiculite that’s used in attics is a pour-in-place, gravel looking, insulation that’s usually light brown or gold in colour. Property owners, building maintenance personnel and those involved in real estate transaction process should be aware of the presence of vermiculite insulation and give careful consideration to its impact on the property and its occupants, now, in the past and in the future.
Vermiculite Insulation Sources
Vermiculite is used in a variety of products for both commercial and consumer use, including building materials. Processed raw ore was shipped to many plants in Canada for exfoliation or expanding where it was heated to about 1000°C causing it to expand into a lightweight granular looking material.
Almost all vermiculite insulation was sold under the trade name Zonolite. The loose fill insulation was used inside masonry block walls (the largest volume use), stove pipe and stack insulation, fire separations, cold rooms and in walls & attics (mostly of homes).
Asbestos Contamination – Prior to its closing in 1990, much of the world’s supply of vermiculite, according to the US Environmental Protection Agency (EPA), came from a mine near Libby, Montana owned by W.R. Grace. This mine had naturally occurring deposits of asbestos that contaminated the vermiculite. It is thought that most of their production contained at least trace amounts of asbestos fibre. Although vermiculite processed with a binder (such as concrete and plaster mixes, sprayed, fireproofing, etc.) is unlikely to ever release significant airborne asbestos, loose fill products do pose a risk, causing substantial asbestos exposure when disturbed. This asbestos-contaminated insulation from this mine was installed in many Canadian buildings, most of which were homes, but also in commercial, institutional and industrial buildings. Use in Canadian residential construction heightened with the CHIP Program between 1977 and 1984, the same program under which most Urea Formaldehyde Foam Insulation (UFFI) was installed.
How does asbestos cause health problems? Perhaps the most typical problem associated with asbestos comes from airborne particles that are inhaled. When asbestos is intact it is usually not a problem however when it is friable state, for example, readily crumbled, brittle, breaking down, deteriorating, damaged or disturbed) it can become airborne. As a result, persons may breathe in asbestos fibres. Continued exposure increases the amount of fibres that remain in the lung. Fibres embedded in lung tissue over time may result in lung diseases such as asbestosis, lung cancer, or mesothelioma. Smoking increases your risk of developing illness from asbestos exposure. Exposure to asbestos for prolonged periods or at high concentrations increases the risk of lung cancer and other respiratory diseases.
Health Canada states: “to be safe and in the absence of evidence to the contrary, it is reasonable to assume that if your building has older [pre-1990] vermiculite-based insulation, it may contain some amphibole asbestos”.
What to do if vermiculite insulation is present? According to the US EPA and ATSDR (Agency for Toxic Substances & Disease Registry) DO NOT DISTURB IT. Limit the number of trips made to your attic. Shortening the length of those trips can help limit your potential exposure. Any disturbance has the potential to release asbestos fibres into the air.
- Do not disturb vermiculite insulation.
- Do not store boxes or other items in your attic if retrieving the material will disturb the insulation.
- Do not allow children to play in open areas where vermiculite insulation is present.
- If you plan to remodel or conduct renovations that would disturb the vermiculite, hire professionals trained and certified to handle asbestos to safely remove the material.
- Do not attempt to remove vermiculite insulation yourself. Hire professionals trained and certified to safely remove the material.
It is important to note that some insurance companies may refuse to provide homeowner’s insurance on houses with vermiculite insulation or require, for example, additional / higher premiums, removal / modifications, and / or, further inspection(s) by experts to determine the presence of asbestos. Further professional advice from, for example, your homeowners’ insurance broker and an environmental specialist is recommended if you suspect the presence of this material in your home / building.