What Changed

OSHA has pushed back all compliance deadlines for the updated Hazard Communication Standard (HCS) by four months. The revised HCS, published May 20, 2024, aligns U.S. chemical labeling and safety data sheet requirements with the seventh revision of the United Nations' Globally Harmonized System (GHS Rev 7). The original deadlines were already tight — the extension gives manufacturers, importers, distributors, and employers additional time to comply.

The New Compliance Deadlines

Until the applicable deadline arrives, companies may comply with either the 2012 or 2024 version of the HCS. After the deadline, only the updated 2024 standard applies.

What's Actually Changing in the HCS

The updated standard brings several significant changes that affect how chemicals are classified, labeled, and documented:

• New hazard class: Desensitized explosives are now a distinct classification category
• New hazard categories: Chemicals under pressure (within the aerosols class) and unstable gases (within the flammable gases class)
• Revised health and physical hazard criteria: Updated classification thresholds for several existing hazard categories
• SDS Section 9 updates: Physical and chemical properties must now be listed in the same order as in GHS Rev 7
• SDS Section 11 updates: New requirements for interactive effects data and alternative information sourcing when specific chemical data is unavailable
• Small container labeling: New provisions for labeling containers too small for full GHS labels
• Label update requirements: Revised rules for when and how labels must be updated after reclassification

Why This Matters for Chemical Buyers

If you purchase chemicals for manufacturing, water treatment, laboratory work, or any industrial application, this rule change affects you directly. Here's what to expect:

• Your SDS documents will change. Safety Data Sheets from your suppliers will be updated to match the new format. Make sure your files are current.
• Labels will look different. GHS Rev 7 may change pictograms, signal words, or hazard statements on products you already use.
• Training is required. Employers must train workers on any newly identified hazards before the employer compliance deadline.
• Your HazCom program needs updating. Written hazard communication programs must reflect the new classifications and labeling requirements.

What to Do Now

• Catalog your chemicals — Build or update your inventory of all hazardous chemicals on-site and verify which ones may be reclassified under the new criteria
• Contact your suppliers — Ask when they'll be shipping updated SDS documents and labels. A good supplier should already be working on this.
• Plan your training — Identify which employees need updated HazCom training and build it into your 2026 schedule
• Review your written program — Update your hazard communication program to reference the 2024 HCS and document any new hazard classifications
• Monitor OSHA guidance — OSHA is releasing implementation guidance materials throughout 2026. Check osha.gov/hazcom regularly.