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Silica in gaskets and hazard communication

Summary A gasket maker asked whether products containing crystalline silica needed a material safety data sheet. OSHA said the manufacturer must determine the product’s hazards and whether it meets the rule’s article exemption. If handling or use releases more than minute or trace amounts of silica that workers can be exposed to, the gasket would not qualify as an exempt article and its health effects must be reported on the sheet.
Document
Federal opinion letter
Agency
Occupational Safety and Health Administration (OSHA)
Document number
1999-11-01-1
Date issued
November 1, 1999
Status
Active
Status last verified October 9, 2026

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About this page: The full text below is the official document from Occupational Safety and Health Administration (OSHA). Ezel adds the plain-English summary and tracks the document's status. The official source linked on this page is authoritative for any reliance.

November 1, 1999

Ms. Michele Sabulsky
HSE Associate
EPI
[Recipient address omitted]

Dear Ms. Sabulsky:

Thank you for your letter of August 17, 1999 to the Occupational Safety and Health Administration (OSHA) regarding the carcinogenicity of silica and its classification on Material Safety Data Sheets (MSDSs) for gaskets. Your question has been referred to the Directorate of Compliance Programs for response.

OSHA does not make hazard determinations on a case-by-case basis, since it is the manufacturer who is most familiar with a product's composition, its intended uses, and the potential downstream exposures. We are not generally involved in the hazard determination process until it is brought to our attention that the manufacturer's MSDS may be incomplete or inadequate.

Your letter seems to ask whether or not the gaskets your company produces are an "article" under the Hazard Communication Standard (HCS). Articles do not present a hazardous exposure to employees and are exempt from coverage under the standard. Hopefully, the following guidance will be of assistance to you in making the determination of whether your product is an "article" or a "hazardous chemical."

A hazardous chemical is any chemical which is a health hazard or a physical hazard. Crystalline silica is considered a Group 1 carcinogen by the International Agency for Research on Cancer (IARC). According to the HCS, any hazardous chemical determined to be a carcinogen by IARC, the National Toxicology Program (NTP), or regulated as a carcinogen by OSHA is considered a carcinogen for the purposes of the HCS and must be designated as such on the MSDS. Crystalline silica is clearly a hazardous chemical.

An "article" under the HCS is any manufactured item other than a fluid or particle which, 1) is formed to a specific shape or design during manufacture, 2) has end use function(s) dependent in whole or in part upon its shape or design during end use, and 3) which under normal conditions of use does not release more than very small quantities, e.g., minute or trace amounts of a hazardous chemical and does not pose a physical hazard or health risk to employees (29 CFR 1910.1200(c)).

Therefore, if at any time during employee handling of your product (for example, shipping, packaging, installation, or final use), the silica in your product is available for employee exposure (in quantities other than minute or trace amounts), then your product would not be considered an article and the potential health effects must be reported on the MSDS.

I hope that this provides the clarification you were seeking. If you require further assistance, please contact the Office of Health Compliance Assistance at 202-693-2190. Thank you for your interest in occupational safety and health.

Sincerely,

Richard E. Fairfax, Director
Directorate of Compliance Programs

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