Changes Under OSHA’s GHS Revision 7 Alignment – November 2026 Next Deadline

On May 20, 2024, the Occupational Safety and Health Administration published a final rule substantially revising the Hazard Communication Standard, 29 C.F.R. § 1910.1200. The rule—generally referred to as HCS 2024—became effective July 19, 2024. Hazard Communication Standard, 89 Fed. Reg. 44,144 (May 20, 2024). Its principal purpose is to align the federal standard with Revision 7 of the United Nations’ Globally Harmonized System of Classification and Labelling of Chemicals. (OSHA)

HCS 2024 is not, however, a verbatim adoption of GHS Revision 7. OSHA also incorporated selected concepts from GHS Revision 8, addressed implementation problems arising under HCS 2012, and improved coordination with the Department of Transportation, Environmental Protection Agency, Health Canada and other regulatory authorities. (OSHA)

Expanded hazard-classification obligations

The most legally significant change appears in 29 C.F.R. § 1910.1200(d)(1). Chemical manufacturers and importers must continue to determine the hazard classes and categories applicable to the chemicals they produce or import. HCS 2024 now expressly provides that the classification must include hazards associated with the chemical’s intrinsic properties, including:

1. Hazards resulting from a change in the chemical’s physical form; and
2. Hazards created by chemical reaction products associated with known or reasonably anticipated uses or applications.

Thus, a manufacturer may be required to consider whether a solid product will create a combustible-dust hazard when it is cut, ground or pulverized, even though the product does not present that hazard in its original form. Similarly, a classifier may be required to evaluate hazardous substances produced when the chemical is used as intended or in a reasonably anticipated downstream process. (OSHA)

OSHA does not require manufacturers to anticipate every conceivable downstream use. The obligation extends to uses known to the classifier or reasonably capable of being anticipated based on product literature, customary applications, product-stewardship information and other reliable sources. OSHA has stated that the classification should provide downstream employers with sufficient information to conduct a workplace-specific hazard assessment. (OSHA)

New and revised physical-hazard classifications

Appendix B to § 1910.1200 contains several important changes.

Flammable gases

The former Category 1 flammable-gas classification is divided into Categories 1A and 1B, while Category 2 remains available. Category 1A generally encompasses the more hazardous gases, including pyrophoric and chemically unstable gases. Category 1B permits certain gases with a higher lower-flammability limit or a comparatively low burning velocity to be distinguished from the more severe Category 1A gases. In the absence of sufficient data supporting Category 1B, a gas meeting the Category 1 criteria generally defaults to Category 1A. (OSHA)

This division may change the signal word, hazard statement or other label elements assigned to certain gases and may require corresponding revisions to SDSs and labels.

Desensitized explosives

OSHA added desensitized explosives as a distinct physical-hazard class. These materials possess explosive properties but are stabilized or “desensitized” with water, alcohol, plasticizers or other substances to suppress those properties during normal handling.

The classification is important because the material may regain its explosive characteristics if the desensitizing agent evaporates, is removed or falls below the concentration necessary to maintain stabilization. Manufacturers must therefore evaluate the material under the criteria in Appendix B and provide the corresponding warnings and handling instructions. (OSHA)

Aerosols and chemicals under pressure

OSHA revised the aerosol classification provisions and added a less hazardous Aerosol Category 3. The standard also separately addresses chemicals under pressure, meaning certain liquids or solids—such as pastes or powders—pressurized with gas at specified pressures in receptacles other than aerosol dispensers. Chemicals under pressure are divided into three categories based principally on their flammable-component content and heat of combustion. (OSHA)

These changes are intended to prevent products from being inaccurately classified as flammable gases, flammable liquids or gases under pressure when the aerosol or chemicals-under-pressure criteria more appropriately describe the product.

Revised health-hazard criteria

Appendix A was revised to improve consistency with GHS Revision 7, particularly for skin corrosion and irritation and serious eye damage and eye irritation. OSHA also incorporated selected GHS Revision 8 non-animal testing methods into the skin-corrosion and irritation provisions, thereby permitting greater use of scientifically validated alternative methods. (OSHA)

These revisions do not eliminate the requirement to evaluate the available evidence as a whole. Manufacturers and importers must still apply the mandatory classification criteria and use scientifically defensible professional judgment when the available data do not produce an automatic classification.

Small-container labeling

HCS 2024 formally addresses the practical problems associated with labeling very small containers. These accommodations apply only where the manufacturer, importer or distributor can demonstrate that using a pull-out label, fold-back label or tag containing the complete information is not feasible.

For containers with a capacity of 100 milliliters or less, the immediate-container label must include, at minimum:

• The product identifier;
• Applicable pictograms;
• The signal word;
• The manufacturer’s name and telephone number; and
• A statement that the complete label information appears on the immediate outer package.

For containers with a capacity of 3 milliliters or less, the container may bear only the product identifier when the regulated party can demonstrate that any additional label would interfere with the normal use of the container. (OSHA)

In either case, the immediate outer package must contain the complete shipped-container label and a statement instructing users to store the small container in the outer package when it is not in use. These provisions are broadly consistent with Health Canada’s WHMIS requirements. (OSHA)

Containers already released for shipment

OSHA added a definition of “released for shipment”: a chemical that has been packaged and labeled in the form in which it will be distributed or sold.

When a manufacturer, importer, distributor or other employer obtains significant new hazard information, it ordinarily must revise the label. Under HCS 2024, however, the regulated party is not necessarily required to reopen and physically relabel every container that was previously released for shipment and is awaiting distribution. If the container is not relabeled, the updated label must accompany each individual container when it is shipped. 29 C.F.R. § 1910.1200(f)(11). (OSHA)

This accommodation reduces the burden of reopening packaged inventory while preserving the downstream recipient’s right to receive current hazard information.

Bulk-shipment coordination with DOT

The rule provides additional flexibility for bulk shipments in tanker trucks, railcars and intermodal containers that may be regulated simultaneously by OSHA and the Department of Transportation. OSHA revised the rules governing label placement and the interaction between OSHA pictograms and DOT transportation markings.

The revisions do not eliminate OSHA’s hazard-communication requirements. Rather, they permit greater coordination of the required information so that duplicative or potentially conflicting markings can be avoided while employees and emergency responders continue to receive the necessary warnings. (OSHA)

Mandatory trade-secret concentration ranges

HCS 2024 materially changes the manner in which ingredient concentrations may be withheld as trade secrets.

A manufacturer or importer may continue to protect an exact concentration or concentration range where the requirements for a trade-secret claim are satisfied. However, the SDS must disclose the concentration through one of OSHA’s prescribed concentration ranges. The regulated party must generally use the narrowest applicable range, although a narrower range may be disclosed voluntarily. 29 C.F.R. § 1910.1200(i)(1)(iv)–(vi). (OSHA)

This change improves the usefulness of SDS information to employers, industrial hygienists, health professionals and emergency responders while continuing to protect legitimate confidential business information. The prescribed ranges also promote greater consistency with Canada’s WHMIS system. (OSHA)

Safety Data Sheet revisions

Appendix D includes revisions affecting SDS Sections 1, 2, 3, 8, 9, 10, 11 and 14, although OSHA identifies Sections 2, 3, 9 and 11 as the principal GHS-alignment changes.

Among the practical consequences:

• Section 2 must accurately reflect new or revised hazard classifications and label elements.
• Section 3 must include appropriate ingredient identities and concentrations or permissible concentration ranges.
• Section 9 contains revised physical and chemical property terminology and expressly addresses particle characteristics.
• Section 10 must provide useful stability, reactivity and hazardous-reaction information.
• Section 11 must contain the required toxicological information under the revised health-hazard criteria.

The revised provisions are intended to make SDS information more consistent, complete and useful throughout the supply chain. (OSHA)

Current compliance deadlines

OSHA extended the original HCS 2024 compliance dates by four months in January 2026. The operative federal schedule is:

During the applicable transition period, regulated parties may comply with HCS 2012, HCS 2024 or both. Once the applicable deadline has passed, OSHA may enforce the corresponding HCS 2024 requirements. (OSHA)

Operational significance

The principal compliance burden falls on chemical manufacturers and importers because they are responsible for classification and for preparing compliant labels and SDSs. Distributors must transmit that information downstream. Employers that merely use hazardous chemicals ordinarily may rely on classifications supplied by manufacturers and importers, but they remain responsible for maintaining current SDSs, ensuring appropriate workplace labeling, revising their written Hazard Communication Programs and providing additional employee training when newly received information identifies a new or changed hazard. (OSHA)

Accordingly, HCS 2024 should not be treated merely as a document-format revision. It expands and clarifies the hazards that must be evaluated, establishes new physical-hazard categories, changes small-container and trade-secret practices, and may require substantive changes to workplace hazard assessments, labeling, SDS management and employee training.