Health issues related to vermiculite insulation

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Health issues related to vermiculite insulation

Source: Lynch Building Inspection Services Ltd. of Nelson, BC
Originally appeared in The Nelson Express

I think I have vermiculite insulation in my attic. Recently I heard that it is a health hazard and I’m wondering if I should remove it. What is your opinion?

First, it is a good idea to positively identify that it is vermiculite. This type of insulation is grey in colour and shaped like small pellets. Some vermiculite is harmless; however, according to a CBC National news article entitled “Deadly Dust” by Fredrick Zalac, the product sold under the brand name Zonolite, produced at the Libby mine, was contaminated with tremolite asbestos, a significantly toxic form of asbestos fiber.

It is impossible to tell if the vermiculite in your attic was produced at the Libby mine. If you find empty Zonolite paper bags in your attic, and the bags state that the product was processed by WR Grace Canada, Grant Industries or F. Hyde & Co., the vermiculite is probably from Libby and likely contaminated with tremolite asbestos. The only sure way to tell is to collect a small quantity and have it analyzed at a laboratory.

The good news is that according to Zalac’s article, if left undisturbed this type of insulation poses minimal or no health risk at all. The asbestos fibers must be air borne to be inhaled. Therefore, leaving it undisturbed in your attic or sealed in a wall or floor assembly is a cost free, effective strategy. If you are going to renovate and cannot avoid disturbing the insulation, wear a proper respirator and a disposable full body suit. Ensure the fibers do not spread to other areas of your home. It is recommended to hire a contractor qualified to work with asbestos because specialized equipment such as vacuum cleaners equipped with highly sensitive HEPA filters may be required to effectively control the asbestos during the removal operation.