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Erionite is a fibrous mineral whose properties are similar to those of asbestos.

What is erionite?

Erionite is a naturally occurring fibrous mineral that belongs to a group of minerals called zeolites. It forms fibrous masses in the hollows of rock formations. Some of the mineral’s properties are similar to those of asbestos; for example, the fibers pose a hazard only if they are disturbed and become airborne.

How are people exposed to erionite?

In the past, occupational exposure occurred during erionite mining and production operations, but erionite is no longer mined or marketed for commercial purposes. Erionite-related disease has been reported most often among road construction and maintenance workers who may have been exposure to erionite-containing gravel used in road surfacing.

Little is known about current exposures experienced by workers in the United States. However, erionite is found in some other commercial zeolite products. Therefore, the use of other zeolites may result in exposure to erionite among workers and members of the general population who use the zeolites in various processes and products. The commercial uses of other natural zeolites include pet litter, soil conditioners, animal feed, wastewater treatment, and gas absorbents.

Which cancers are associated with exposure to erionite?

Exposure to erionite is associated with increased risks of lung cancer and mesothelioma.

How can exposures be reduced?

There are no regulatory or consensus standards or occupational exposure limits for airborne erionite fibers. The U.S. Occupational Safety and Health Administration’s guidance for working with asbestos could serve as a model for limiting the generation and inhalation of dust known or thought to be contaminated with erionite.

Selected References:

  • National Toxicology Program. Erionite, Report on Carcinogens, Fifteenth Edition. Triangle Park, NC: National Institute of Environmental Health and Safety, 2021. Also available online. Last accessed December 5, 2022.
  • Weissman D and Kiefer M. Erionite: An Emerging North American Hazard. NIOSH Science Blog, November 22, 2011. Available online. Last accessed February 13, 2019.
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