OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

October 4, 1983

Mr. Edward A. Nierengarten
Nierengarten Law Offices, Ltd.
P. O. Box 214
New Ulm, Minnesota 56073

Dear Mr. Nierengarten:

Thank you for your letter of September 1, 1983, regarding standards dealing with grain dust.

The Occupational Safety and Health Administration (OSHA) does not have a specific standard regulating occupational exposure to grain dust. Although there have been studies indicating that workers in grain handling facilities experience adverse health effects, additional data must be developed before a standard can be proposed. The issue is complicated by the fact that "grain dust" is not a single, definable entity, but rather a heterogeneous mixture of components such as various types of grain, pesticide residues, and insect parts. This mixture varies from batch to batch, so workers are always exposed to different "grain dusts." OSHA is now reviewing the information concerning the health effects associated with inhalation of grain dusts.

For compliance purposes, OSHA has applied its nuisance dust standard (29 CFR 1910.1000; Table Z-3) to grain handling facilities. This standard limits employee exposure to 15 milligrams per cubic meter of air averaged over an eight-hour work shift, measured as total dust. If only the respirable fraction is measured, the exposure is limited to 5 milligrams per cubic meter of air. There have been legal challenges to applying this standard to grain dust, since the table in which it appears is entitled, "Mineral Dusts" and grain dust does not fall into this category. You may wish to contact your local OSHA area office for more information concerning OSHA's compliance policy with regard to grain dust at the following address:


Robert Hanna, Area Director
U.S. Department of Labor - OSHA
801 Butler Square Building
100 North 6th Street
Minneapolis, Minnesota 55403
Telephone: (612) 725-2571

We hope this information will be helpful to you. If we can be of further assistance, please do not hesitate to contact us.


R. Leonard Vance, Ph.D.
Health Standards Programs