US OSHA Published Proposed HCS Update to Harmonize with the 7th Revision of the GHS

Posted on: February 12, 2021

by Caroline Miller, CIH, CSP

Hazard labels - US OSHA Published ProposedThe U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) issued a proposed regulation on February 5, 2021 to align the Hazard Communication Standard (HCS) with the seventh revision of the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The proposed rule is scheduled to be published in the February 16, 2021 Federal Register. OSHA will accept comments on the proposed rule until April 19, 2021.

The current HCS, published in 2012, follows the third revision of the GHS. Many of the trading partners of the U.S. are on or are preparing to align with the seventh revision. The United Nations published the eighth revised edition of the GHS in 2019.

The proposed rule includes changes to hazard classification and information on safety data sheets (SDSs) and labels. The proposed changes to HCS 2012 is summarized as follows:

  • New definitions
    • Combustible Dust
    • Exposure or exposed
    • Gas, Liquid, and Solid
    • Immediate outer package
    • Released-for-shipment
  • Addition of “under normal conditions of use and foreseeable emergencies” to Hazard classification
  • Addition of “Date chemical is released for shipment” to label requirements
  • New requirements for small container labeling
  • Addition of concentration ranges for trade secrets consistent with those used in Canada
  • Adoption of the revised health hazard definitions and classifications from the GHS Rev. 7 in appendix A. In addition, updates to terminology and mandatory language
  • Changes to Appendix B
    • Proposing certain corrections and clarifications for Explosives, Gases under Pressure, Flammable Liquids, Flammable Solids, Self-heating Chemicals, and Oxidizing Solids.
  • Changes Appendix B – Flammable Gases hazard class:
    • Subdividing Category 1 (extremely flammable gases) into two Subcategories:
      • Subcategory 1A – includes pyrophoric gases and chemically unstable gases
      • Subcategory 1B – includes flammable non-pyrophoric gases and chemically stable gases with a lower flammability hazard than 1A
    • Addition of definitions for “chemically unstable gas” and “pyrophoric gas”
  • Changes Appendix B – Flammable Aerosols hazard class:
    • Name change to “Aerosols”
    • Addition of Category 3 for non-flammable aerosols
    • Removal of “flammable aerosol” definition
    • Addition/deletion of provisions in regards to labelling and classification, including that products in the Aerosols hazard class do not fall within the scope of the Gases Under Pressure hazard class.
  • Addition in Appendix B –  Desensitized Explosives hazard class
    • Adoption of most of the classification language on desensitized explosives from Chapter 2.17 of the GHS Rev. 7
  • Updates to Appendix C
    • Addresses labeling requirements for the new hazard classes and categories in appendix B
    • Aligns the HCS labeling with the GHS Rev. 7
    • Improves alignment of the HCS and Health Canada’s labeling requirements
    • Revisions to label elements for OSHA defined hazards
  • Changes to Appendix D
    • Section 3 – Allows for concentration ranges to be withheld as a trade secret
    • Section 8 – Clarification that any ingredient or constituent identified in section 3 should have exposure limits list in Section 8, as applicable. A “range” of exposure limits must be included (i.e. control banding).
    • Section 9  – Proposing to align with GHS Rev. 7 by listing in same order that appears in GHS
    • Section 11 – Inclusion of interactive effects and alternative information
    • Section 14 – Changes subheading to “Transport in bulk according to IMO instructions”

Recommended Action Items:

  • Become familiar with the proposed regulatory changes to establish the impact on your products, substances, mixtures or materials.
  • Determine if any of your products, substances, mixtures or materials will need to be reclassified.
  • Identify the impact of the proposed regulatory changes to the SDS and product label.
  • Submit comments, if applicable, prior to April 19, 2021.


OSHA’s Notice of Proposed Rulemaking (NPRM) to modify the Hazard Communication Standard (HCS) to conform to the United Nations’ Globally Harmonized System of Classification and Labelling of Chemicals (GHS) Revision 7 (GHS, Rev. 7) 2020-28987.pdf (

OSHA News Release “US Department of Labor’s OSHA issues proposed rule to update hazard communication standard”


OSHA, Hazard communication, HazCom, HCS, GHS Revision 7, hazard classification, hazard communication label, Safety data sheet, SDS, labelling

Never Miss an Update:

UL’s global Regulatory Assurance Team contains more than 50 regulatory analysts worldwide, serving customers in six continents, with multi-lingual support in more than 30 languages. Our team can help you navigate the complex, ever changing regulatory landscape to understand and execute your compliance obligations.

For all of the latest regulatory news and the most important industry updates, sign up for our monthly Regulatory Round-Up Newsletter.


The views, opinions and technical analyses presented here are those of the author, and are not necessarily those of UL LLC. All content is subject to copyright and may not be reproduced without prior authorization from UL. While the editors of this site may verify the accuracy of its content from time to time, we assume no responsibility for errors made by the author, editorial staff or any other contributor.