OSHA HazCom Standard: Key Updates & GHS Rev 7 Transition

Overview of the 2024 HazCom Rule Changes

On May 20, 2024, OSHA published a final rule updating the Hazard Communication Standard (29 CFR 1910.1200) to align with the seventh revision of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS Rev 7). It is the first major revision of HazCom since 2012, when OSHA first adopted GHS.

The rule impacts every employer in the United States who uses, stores, or handles hazardous chemicals—from construction sites to manufacturing plants, laboratories to warehouses. Understanding these changes is critical for maintaining compliance and avoiding costly citations.

Why OSHA Updated the Standard

OSHA's primary motivations for this update include:

• International harmonization — Aligning with trading partners that use later GHS revisions
• Improved hazard communication — New categories provide more granular classification of chemical hazards
• Worker protection — Updated criteria better reflect current scientific understanding of chemical risks
• Trade facilitation — Reducing barriers for chemical manufacturers who export globally

GHS Revision 7: What Changed

New Hazard Categories for Flammable Gases

Under the updated HazCom criteria, flammable gas Category 1 is divided into two subcategories — 1A and 1B:

What this means for you: "Pyrophoric gas" and "chemically unstable gas" are descriptors within Category 1A — they are not the definitions of 1A and 1B. If you use welding, cutting, or specialty gases on construction sites, check with your supplier for updated SDSs reflecting the 1A/1B subcategorization and any pyrophoric or chemically-unstable designations.

Aerosols Reclassified

The old "flammable aerosol" category has been replaced with a broader "Aerosols" classification that includes three categories:

• Category 1 — Extremely flammable aerosol
• Category 2 — Flammable aerosol
• Category 3 — Non-flammable aerosol (new)

This affects common construction products like spray adhesives, lubricants, and coatings. Even "non-flammable" aerosols now require GHS labeling under Category 3.

Desensitized Explosives (New Class)

GHS Rev 7 adds an entirely new hazard class for desensitized explosives (Appendix B.17): explosives diluted or wetted to suppress their explosive properties, such as nitrocellulose wetted with water or alcohol. On a construction site it can show up in specialty nitrocellulose lacquers and coatings.

Updated Skin Corrosion/Irritation Criteria

The classification criteria for skin corrosion and irritation have been refined to:

• Better distinguish between corrosive and irritant effects
• Provide clearer guidance on animal test data interpretation
• Allow for weight-of-evidence approaches using existing data

SDS Format Changes Under Rev 7

Section 2: Hazard Identification

SDSs must now include:

• New hazard statements for the added categories (flammable gas 1A/1B, aerosol Category 3, desensitized explosives)
• Updated precautionary statements reflecting revised hazard criteria.

Section 3: Composition

When a concentration is withheld as a trade secret, the SDS must give one of the prescribed concentration ranges of 29 CFR 1910.1200(i)(1)(iv)–(vi), as Appendix D now states.

Section 9: Physical and Chemical Properties

Appendix D to 29 CFR 1910.1200 now lists 18 items, (a) to (r):

• Particle characteristics (item (r)) are new
• Viscosity is now kinematic viscosity (item (l))
• Physical state and color are listed separately where the 2012 list had "appearance"

Section 11: Toxicological Information

Appendix D asks for, among other items:

• Interactive effects, where relevant and readily available (item (e))
• Whether the chemical is listed by NTP or IARC, or found to be a potential carcinogen by OSHA (item (f))
• When chemical-specific data are missing, what alternative information was used and how (item (g))

Compliance Deadlines: The Critical Timeline

The November 20, 2026 Employer Deadline

This is the date that matters most for construction companies and general contractors (29 CFR 1910.1200(j)(2)(ii), applied to construction by 29 CFR 1926.59). By this date, you must:

1. Update your Written Hazard Communication Program to reference GHS Rev 7 criteria
2. Retrain employees on new hazard categories and label elements
3. Update workplace labels on secondary containers to reflect new classifications
4. Verify SDSs from suppliers are Rev 7 compliant
5. Document everything — training records, SDS receipt dates, label updates

Action Plan for Employers

Phase 1: Assessment (Start Now)

• Audit your SDS library — Identify which SDSs still predate the HCS 2024 revision using the gap-analysis method
• Inventory your chemicals — Create a comprehensive list using our Chemical Inventory Template
• Contact suppliers — Request updated Rev 7 SDSs for all chemicals

Phase 2: Update (3-6 Months Before Deadline)

• Revise your written HazCom program — Use our HazCom Program Generator to create a compliant written program
• Update secondary container labels — Use our GHS Label Generator for compliant labels
• Develop training materials — Focus on new hazard categories and classification changes

Phase 3: Train & Document (Before November 20, 2026)

• Conduct training sessions — Cover all new hazard categories, label changes, and SDS updates
• Document attendance — Use sign-in sheets with specific topics covered
• Test comprehension — Ensure workers understand the changes, not just attendance
• Store records — HazCom does not require training records, but keep them where you can show them during an inspection

Common Mistakes to Avoid

1. Assuming Old SDSs Are Still Valid

Many employers assume that if a chemical hasn't changed, the old SDS is fine. Manufacturers must reclassify chemicals under the new criteria, which may change hazard categories, pictograms, or signal words, and send the revised sheet; keep the latest one you receive (29 CFR 1910.1200(g)(6) and (g)(8)).

2. One-Time Training

GHS Rev 7 training isn't a one-and-done event. You must train again whenever a new chemical hazard the employees have not been trained on is introduced into their work area (29 CFR 1910.1200(h)(1)), which can happen with:

• A new product on site
• A revised SDS that shows a newly identified hazard
• A new role or a new site
• An annual refresher is good practice, not a HazCom requirement

3. Ignoring Multi-Employer Obligations

On a multi-employer site, each employer's written program must say how it gives the other employers access to its SDSs and informs them of precautions and of its labeling system (29 CFR 1910.1200(e)(2)), and a controlling employer is expected to exercise reasonable care to prevent and detect violations (CPL 02-00-124). In practice the GC asks every sub to:

• Provide SDSs for chemicals they bring on-site
• Use compatible labeling systems
• Train their workers on site-specific hazards

4. Not Planning for Offline Access

OSHA requires SDSs to be "readily accessible" during every work shift. On construction sites with poor connectivity, a cloud-only solution can fail this test where the signal drops. Ensure your SDS system works offline.

Penalties for Non-Compliance

Hazard Communication ranked second on OSHA's FY2025 list of most-cited standards. The 2026 civil-penalty maximums are unchanged from 2025 (no inflation increase was published), per 29 CFR 1903.15(d):

These caps are per violation — an out-of-date program, missing secondary labels, and stale training are separate items that stack, so a single inspection can total well into five or six figures. Estimate a specific scenario with the OSHA Fine Calculator.

How HazComFast Helps You Comply

HazComFast helps with the GHS Rev 7 transition:

• Offline SDS access: your jobsite's SDS load onto the phone on their own, with a count of how many are ready
• GHS Rev 7 label generator — Create compliant secondary container labels
• SDS Gap Analyzer — a 12-question self-audit that scores your program, with the gap-analysis method for naming the specific sheets to replace
• Training documentation — Digital sign-in sheets with topic tracking
• OSHA deadline calendar — Never miss a compliance deadline

The standard, tools & related reading

• The standard: Hazard Communication — 29 CFR 1910.1200 (construction via 1926.59)
• Go deeper: GHS Rev 7 Converter · HCS 2024 Deadlines: Complete Calendar · Mixtures 2027–2028 Transition · Complete OSHA HazCom 2026 Guide
• 2026 OSHA penalty schedule · penalties by state

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The November 20, 2026 deadline is approaching. Don't wait until the last minute. Start your free trial today and get audit-ready in under an hour.