| The Home page of ILPI's Safety Data Sheet (SDS) Resource, the leader in SDS information since 1995! | |
| The history and philosophy behind this resource. | |
| A curated collection of books and reference materials concerning Safety Data Sheets and closely related topics. | |
| Paste your plain text SDS into the SDS-Demystifier, and it will be converted into a hypertext-enriched document with links to detailed explanations of each key term. | |
| An extensive list of frequently asked questions about Safety Data Sheets including regulations, content, compliance, and more. | |
| A humorous take on Safety Data Sheet jargon. Fill in the blanks on our entry form to generate a personalized Unsafety Data Sheet to share with your coworkers. | |
| Since 1995, we've maintained this massive curated list of the best places to find Safety Data Sheets on the Internet. | |
| Way more than a glossary, this hypertext-enhanced resource covers hundreds of SDS-related terms and expert knowledge. Each entry includes both the SDS relevance and links to additional authoritative resources. | |
| Archived results of Safety Data Sheet related polls taken by some of our millions of site visitors | |
| You are here! The OSHA regulations behind SDS regulations, including the inspection guidelines and over 400 official interpretations letters under the Hazard Communication Standard | |
| Commercial suppliers of SDS authoring and management software as well as cloud compliance services. | |
| Commercial companies that will create SDS's for your specific needs as well as SDS translation companies. |
Safety signs, banners, and scoreboards? Get yours at Safety Emporium!
OSHA Hazard Communication Letters of Interpretation
Hazard Communication Standard.
- Issued
- Record type
- Interpretation
- Historical standard
- 1910.1200, 1987 expanded rule (PDF)
- Current standard
- HCS 2024, as amended
ILPI assessment: Downstream cutting matters; old universal cancer threshold is not current
This letter addresses the obsolete 1987 version of the Hazard Communication Standard (HCS). Its central conclusion remains useful: normal downstream cutting that releases crystalline silica cannot be dismissed because only a fraction of customers or operations create exposure. The letter does not establish the present classification of a particular insulation product.
Under the current HCS, apply hazard classification, anticipated uses and physical-form changes, carcinogenicity criteria, and mixture rules. The old “greater than 0.1%” summary is not a universal modern label rule; the current criteria distinguish category, cutoff, and in some cases SDS versus label obligations. See ingredient disclosure, dust, and shipped-container label elements and Appendix C. Applicable construction silica controls remain separate.
Last reviewed: .
About this ILPI assessment
This comparison with current requirements is not a finding that OSHA has formally withdrawn this letter. This assessment reflects editorial judgment informed by human review and AI assistance. It is an opinion, may contain errors or omissions, and is not an official OSHA determination. For guidance on how OSHA requirements apply to your circumstances, contact your local OSHA office.
OSHA's notice about interpretation letters
The following notice is published on OSHA's interpretation pages; it is general guidance, not a letter-specific withdrawal notice.
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.
Source: OSHA's original letter page.
April 3, 1990
Michael G. Michaelson, M.D.
Covington & Burling
1201 Pennsylvania Avenue, N.W.
Washington, D.C. 20044
Thank you for your letter of February 23, to the Occupational Safety and Health Administration (OSHA) regarding the application of the Hazard Communication Standard (HCS), 29 CFR 1910.1200 [ILPI: Original HCS 1987 context (PDF) · Current HCS], to your client's product, calcium silicate pre-molded insulation materials.
You were specifically interested in whether the labeling requirements of the HCS would apply to your client's product which, under normal conditions of use, (i.e., cutting operations conducted during fabrication applications of the product) emits crystalline silica. The specific determination regarding coverage for a product is to be made by the chemical manufacturer or importer, which in this case is your client. If the crystalline silica is available for exposure, the rule applies. According to the test data you presented, crystalline silica was detected in the samples your client took which simulated the types of exposures that would occur under normal conditions of use. In your letter, you described sampling operations conducted by your client at three of four worksites where, in one case, "crystalline silica appeared to be present at levels greater than 0.1%" of the dust sampled. The crystalline silica emitted is, therefore, "available for exposure." Your client believes that exposure to dust containing more than 0.1% crystalline silica would occur "fewer than 10%" of the time in normal downstream uses of his product.
Because of this information, you requested that your client be allowed to warn of the carcinogenic hazard due to the presence of crystalline silica in his product only on the MSDS but not on the label. It is the Agency's policy that hazard warnings must appear on the MSDS and the label of a chemical product when a carcinogenic substance is present in amounts greater than 0.1%. Exposure calculations are not permitted in determining whether a hazard must appear on a label in that if there is a potential for exposure (other than in minute trace, or very small quantities), the hazard must be included. Additionally, suppliers may not exclude hazards based on presumed levels of exposure downstream (i.e., omitting a carcinogenic hazard warning because, in their estimate, presumed exposures will not be high enough to cause the effect).
[ILPI note: At issuance: 1910.1200, 1987 expanded rule (PDF). Do not use this old threshold as a complete current test. Apply current mixture cancer criteria, classification, and modern shipped-label elements; consider the actual product and anticipated cutting operations.]
In the situation you described in your letter, a warning may not be excluded from the label just because exposure to the hazardous substance may only occur in 10% of downstream operations.
As you are aware, and as stated in your letter, "the purpose of the HCS is communication." Employees have a right to know about the presence of hazardous substances in the materials they are required to work with. The purpose of the label is to serve as an immediate hazard warning of the health or physical hazard(s) that employees may be exposed to while working with the chemical. With this information, employees can take the proper precautionary measures necessary to protect themselves from exposure. Labels also provide a link to the more detailed information available on the MSDS. However, just because a hazard is detailed on the MSDS does not mean that information does not have to appear as a warning on the label.
I hope this helps clarify the concerns raised by your client regarding this issue. Please feel free to contact us again if we can be of further assistance.
Sincerely,
Gerard F. Scannell
Assistant Secretary
The original official public domain version of this document is available from OSHA at https://www.osha.gov/laws-regs/standardinterpretations/1990-04-03.