Environment Committee Update
June 3, 2013

Contact: Darren Suarez

DOH Determines Building Material with Greater Than 10% Vermiculite is an ACM

In June of 2012, the New York State Department of Health (“DOH”) issued an "informational letter" to provide additional guidance regarding the State’s interpretation of standard requirements pertaining to vermiculite. The informational letter represents a significant departure from prior regulatory requirements. The letter stated due to no reliable method for determining the presence of asbestos in vermiculite, all vermiculite must be assumed to contain asbestos fibers, and therefore be handled as asbestos containing material (ACM). In addition, NYSDOH went on to say, any material containing 10% vermiculite or more must be treated as ACM, due to the limitations of the current testing. This determination could have significant unforeseen financial and legal consequences.


Vermiculite is a naturally occurring mineral mined in the United States, Brazil, Argentina, Mexico, South Africa, Zimbabwe, Kenya, Uganda, Egypt, India, Russia, China, Japan, and Australia. Mined vermiculite ore is milled to produce vermiculite concentrate of various sizes and grades. When rapidly heated, vermiculite concentrate expands to form small, light-weight, accordion-shaped granules.

Vermiculite is used in construction products (loose-fill attic insulation, acoustic finishes, spray-on fireproofing, gypsum plaster, concrete mixes for swimming pools), consumer products (packing materials, adsorbent in laboratories), agricultural and horticultural products (animal feed, bulking agent, fertilizers, pesticides, hydroponics, potting mixes, soil conditioners), and in industrial products (brake shoes and pads, drilling muds, furnaces, filters, insulator blocks, paints, and sealants).

Historically, much of the world's supply of vermiculite came from a mine near Libby, Montana. The Libby mine also had a natural deposit of asbestos, and the vermiculite from Libby is contaminated with asbestos.

In the 1970’s the W.R. Grace and Company reformulated its Monokote fireproofing spray by removing the asbestos fibers, and substituting about 30 percent of the mineral vermiculite. By 1977 Monokote had risen from a relatively small market share to become America’s leading fireproofing material, according to reports 60 to 80 percent of the 150,000 steel-frame building built during the 1970s and 1980s used Monokote.

“Informational Letter”

The stated intent of the June 22, 2012 informational letter and August 27, 2012 amendment was to clarify the April 8, 2011, list of frequently asked questions (FAQs) regarding asbestos/fibers analysis. The DOH stated in the letter “we have received numerous inquiries regarding the State’s interpretation of requirements pertaining to the testing for asbestos fibers in materials that contain vermiculite.”  Specific, the information letter provides guidance and revises FAQ # 10 regarding the State’s interpretation of standard requirements pertaining to vermiculite. Below is a copy of the revised answer to FAQ# 10 as of August 27, 2012:

How can I tell if vermiculite contains asbestos or what sampling methods should be used?

According to the EPA, you should assume that vermiculite insulation contains asbestos (http://www.epa.gov/asbestos/pubs/verm_questions.html.) Historically, the majority of the world's supply of vermiculite came from the mine located near Libby, Montana, that was closed in 1990 due to high levels of asbestos contamination. Since there is no mechanism to visually distinguish between vermiculite from the Libby mine versus other mines, as well as evidence of inaccuracies by methods used to rule out asbestos contamination, EPA’s guidance continues to emphasize caution when a building is being remediated especially when the origin of the vermiculite material is unknown. Accordingly, NYS Industrial Code Rule 56 lists vermiculite as a suspect miscellaneous asbestos-containing material. Since vermiculite’s asbestos contamination typically ranges from 1% to 5%, vermiculite’s contribution to asbestos content of vermiculite materials used for thermal system insulation, surfacing materials and other miscellaneous ACM (e.g., pipe lagging, sprayed-on fireproofing) may be assumed to be less than 1% if the vermiculite constitutes less than 10% of the total material. If vermiculite is determined to be present at less than 10% of the material content, analysis must continue to determine if asbestos fibers are present. If vermiculite is determined to be present at greater than 10% of the material content, the inaccuracies of currently available testing methods may lead to a false negative result for asbestos; therefore the material should be assumed to be ACM. (Please refer to the decision tree above for more laboratory testing guidance.)

Determination if Vermiculite Contains Asbestos

The informational letter clarified DOH position’s is that there is no reliable analytical method to test for the presence of asbestos in vermiculite. DOH goes on to distinguish between two categories of vermiculite materials: (1) “loose” vermiculite such as attic fill, block fill, and other loose bulk vermiculite materials (more common in residential homes) which must always be treated as ACM; and (2) vermiculite-containing materials used for thermal system insulation and surfacing materials. If the vermiculite comprises less than 10% of the material, testing of the material’s asbestos must continue to be tested to determine if the material is 1% or less asbestos. If, however, the material contains 10% or more vermiculite, it is presumed to be ACM. The presumption cannot be overturned by laboratory analysis of the vermiculite’s actual asbestos content (although there are provisions to exclude such materials from the asbestos regulations if it can be documented that the source of the vermiculite was not the Libby mine pursuant to August 27th amendment).