HCS Final Rule Updated from HCS 2012 Standard - Effective 7-19-24; 1-19-26; 7-19-27

OSHA has released a final rule updating the Hazard Communication Standard (HCS) to align primarily with revision 7 of the United Nations’ Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The final rule was published on May 20, 2024, and will take effect on July 19, 2024.
The revisions to the HCS include:
Adding classification categories for aerosols, desensitized explosives, and flammable gases. Select hazard and precautionary statements have been updated to provide clearer and more precise information on how to safely handle, store, and dispose of hazardous chemicals. The final rule also addresses issues that have arisen since the implementation of the 2012 standard:
Labelling requirements for small containers have been updated to be more comprehensive and readable. Labelling requirements for packaged containers released for shipment or that constitute bulk shipping have been revised. The rule now allows withholding concentration ranges of substances for trade secret reasons. The updated HCS also aims to improve alignment with other federal agencies and Canada. OSHA has provided a redline strikeout version of the regulatory text and appendices for stakeholders which can be found here.
Transition period
Substances:

Substances must comply with the final rule by January 19, 2026.

Employers must update alternative workplace labeling, hazard communication programs, and provide additional employee training by July 20, 2026.
Mixtures:

Mixtures must comply with the final rule by July 19, 2027.

Employers must update alternative workplace labeling, hazard communication programs, and provide additional employee training by January 19, 2028.