On February 16, 2021, the Department of Labor’s Occupational Safety and Health Administration (OSHA) published in the Federal Register a notice of proposed rulemaking to update its Hazard Communication Standard (HCS). This standard, which applies nationally and preempts any state standards, requires chemical manufacturers or importers to classify and identify the hazards of any chemicals they produce or import and requires employers to provide information to employees regarding classified hazards present in the workplace.

The HCS provides rules for maintaining a workplace hazard communication program; labeling containers of chemicals in, or being shipped to, a workplace; the preparation and distribution of safety data sheets (SDS); and the development and implementation of employee training programs regarding chemical hazards and protective measures. OSHA’s proposal includes updates to provisions that may have broad impact on both manufacturers and employers.

The HCS was last updated in 2012 to align the United States standard with the United Nations’ Globally Harmonized System of Classification of Labeling of Chemicals (GHS) Revision 3. The GHS is revised every two years. OSHA’s new proposal intends to update the standard to align with GHS Revision 7.

Notable Changes for Manufacturers

Under the HCS, chemical manufacturers or importers must classify and provide information regarding the hazards of chemicals they produce or import. OSHA’s proposal includes significant revisions to these rules. Proposed revisions of note applicable to chemical manufacturers or importers include revised criteria and new categories for the classification of certain health and physical hazards, revised requirements for labeling small containers and relabeling chemicals released for shipment, new rules regarding the disclosure of concentrations claimed as trade secrets, and changes to the required contents of SDSs. The following highlights some of these changes:

• Skin Corrosion/Irritation: OSHA proposes to expand non-animal test methods for classification of chemicals in this hazard category, including in vitro test methods and computational and in silico techniques, and to reorganize the tiered approach to data evaluation when classifying for this hazard category. The proposal additionally revises the definitions of “skin corrosion” and “skin irritation” to remove specific exposure time constraints.

• Flammable Gases: OSHA proposes to subdivide Category 1 “Extremely Flammable” into two subcategories. Under the proposal, pyrophoric gases and chemically unstable gases are to be categorized as Category 1A, indicating that these gases exhibit a wide spectrum of flammable properties. For a gas to be categorized as Category 1B, data would have to show a flammability limit or fundamental burning velocity below specified rates. Such data could be established by literature or through testing.

• Aerosols: OSHA’s proposal would expand the existing “Flammable Aerosols” hazard class to include aerosols that are non-flammable. The proposal renames this hazard class “Aerosols,” adds a new Category 3 for non-flammable aerosols, and clarifies that aerosols are distinct form “gases under pressure” but may fall within the scope of other hazard categories.

• Desensitized Explosives: OSHA proposes to add a new physical hazard class titled “Desensitized Explosives,” to be labeled with the flame pictogram, for chemicals that have been treated or stabilized to reduce or suppress the explosive properties.

• Labeling Small Containers: OSHA’s proposal would limit labeling requirements on containers with 100ml or less capacity where a chemical manufacturer or importer can demonstrate it is not feasible to provide full label information on the immediate container. The proposal further streamlines requirements for containers with 3ml or less capacity. For any containers using these streamlined requirements, the full label information must be provided on the immediate outer package, which must also include a statement that the small containers must be stored within the immediate outer package when not in use.

• Relabeling Chemicals Released for Shipment: OSHA’s proposal clarifies that when new significant information becomes available, after the six-month grace period has passed, chemical manufacturers or importers do not need to relabel chemicals already released for shipment; however, manufacturers or importers must provide with shipment the updated label for each individual container.

• Disclosure of Concentration Claimed as Trade Secret: OSHA’s proposal permits the withholding of a chemical’s exact concentration or concentration range as a trade secret; however, the proposal requires that when such concentration is withheld, the SDS must include reference to a prescribed concentration range in lieu of the actual concentration or concentration range.

• Safety Data Sheets (SDS): OSHA’s proposal includes several changes to the content requirements of safety data sheets, including disclosure of information related to particle size and interactive effects. OSHA’s proposal additionally clarifies that SDSs may be “stored,” rather than “designed,” in a way that covers groups of hazardous chemicals in a work area.

​Notable Changes for Employers

The HCS requires employers to provide information to employees about hazardous chemicals to which they are exposed in the workplace. Employers provide this information through a hazard communication program, labeling and other forms of warning, SDSs, and training. Although the rules applicable to hazard classification and labeling are geared towards chemical manufacturers and importers, employers should review proposed changes to these rules for any updates that will have an impact on their hazard communication and training requirements.

OSHA is accepting written comment on its proposal through April 19, 2021.