OSHA hazard communication standard update 2024: what changed and what you owe

Last updated 2026-07-09

What did OSHA actually change in the 2024 HazCom update?

OSHA published the final rule on May 20, 2024, in the Federal Register ^[1]. It took effect July 19, 2024. This is the biggest revision to the Hazard Communication Standard since OSHA matched it to GHS Revision 3 back in 2012.

The core change is a jump to the Globally Harmonized System of Classification and Labelling of Chemicals, Seventh Revised Edition (GHS Rev. 7), which the United Nations published in 2019. The old U.S. standard tracked GHS Rev. 3. Skipping from Rev. 3 to Rev. 7 means several layers of change landed at once.

Here is what specifically changed:

New hazard classes. The update adds nine hazard categories that did not exist in the old standard. These include desensitized explosives, non-flammable aerosols (a new subdivision of the existing aerosol class), and several categories for chemicals that harm the ozone layer. ^[1]

Revised SDS and label content. Section 2 of the Safety Data Sheet now requires the concentration or concentration range of each chemical in a mixture, where that information is not protected as a trade secret. That is more granular than before. ^[1]

Small container labeling rules. This was a persistent pain point. The old standard said small containers had to carry labels but gave no real relief when the container was physically too small to hold a full one. The 2024 rule creates tiered options: pull-out labels, fold-back labels, tags, or a truncated label with a reference to a larger document, depending on container size. ^[1]

Bulk shipment labeling. For bulk containers shipped without inner packaging, the rule gives more flexibility on where and how the label appears, including on shipping documents that travel with the shipment. ^[1]

Revised signal word and pictogram rules. When a chemical triggers multiple hazard categories that call for different signal words, the rule spells out which word wins. "Danger" always beats "Warning." That was implied before. It is explicit now. ^[1]

Updated definitions. The definitions of "article," "mixture," and "released for shipment" got rewritten to cut the ambiguity that had generated years of OSHA interpretation letters. ^[1]

None of this voids your existing SDSs or labels on the day the rule took effect. The compliance deadlines give you time to transition, which the next section covers in full.

What are the compliance deadlines for the 2024 HazCom rule?

OSHA set a phased schedule, and the dates that bind you depend on where you sit in the supply chain. ^[1] Chemical makers get until July 19, 2026. Everyone who just uses chemicals gets until July 19, 2027.

Deadline	Who it applies to	What must be done
July 19, 2024	All employers	Rule is effective; training on new label elements and SDSs should begin
July 19, 2026	Chemical manufacturers, importers, and distributors	Updated SDSs and labels required for shipments
July 19, 2027	Downstream employers (any workplace using chemicals)	Updated SDSs in the workplace; employee training updated to cover new hazard classes and label changes

The two-year gap between the manufacturer and employer deadlines is on purpose. OSHA's logic: manufacturers need time to reclassify and relabel, and downstream workplaces can't update their SDS binders until the new documents show up.

Say you buy chemicals from a distributor and use them in your facility, a cleaning service, a fab shop, a salon. Your hard deadline is July 19, 2027. That sounds distant. The practical work starts now. When your supplier sends updated SDSs, you replace the old ones. When an employee points at a new pictogram on a container, you need to explain it. OSHA does not hand out a blanket "not yet in force" defense to workplaces that just ignored the transition period.

For chemical manufacturers and importers, July 19, 2026 is the line that matters. Every container shipped after that date needs labels built on GHS Rev. 7 classification rules. That means walking your chemical inventory, reclassifying where the new hazard categories apply, and rewriting Section 2 of every affected SDS.

What are the new hazard classes, and do they apply to your business?

The nine new hazard classes are the part of the 2024 update most likely to change what you stock. ^[1][2] For a retail counter or an office, the impact is small. For a fab shop or an auto bay, it is real work.

Desensitized explosives. Chemicals that explode in dry form but get wetted or diluted to tamp down that hazard. If you use ammonium nitrate-based products in any form, ask your supplier whether they are reclassifying.

Non-flammable aerosols. The old aerosol class treated every aerosol as flammable by default. Now there is a distinct non-flammable category. Compressed air dusters and certain spray lubricants may move here. Your SDS and label will follow.

Chemicals hazardous to the ozone layer. A new environmental hazard class. Refrigerants and some solvents may carry it. OSHA adding it does not change your EPA obligations, but the SDS now has to call it out.

Flammable gases, Category 1A and 1B. The old rule had a single Category 1 for the worst flammable gases. The 2024 rule splits it into 1A (pyrophoric gases and chemically unstable gases) and 1B. Acetylene and hydrogen land in 1A for most shops that use them.

New subdivisions in reproductive toxicity, skin sensitization, and respiratory sensitization. These subcategories give sharper hazard communication for chemicals that hit long-term health.

For most retail, food service, or office spaces, the practical effect is modest. Updated SDSs arrive from your suppliers with new or revised pictograms, and you update your training to explain them. For manufacturing, construction, automotive, or chemical processing, the reclassification job is genuine labor.

One honest note. The new classes for flammable gas subcategories and desensitized explosives overlap with DOT hazmat rules, but OSHA and DOT stay separate regimes. A compliant HazCom label does not guarantee DOT shipping compliance, and the reverse is just as true.

How do the new SDS requirements change what you put in Section 2?

Section 2 of the Safety Data Sheet covers hazard identification. Before the 2024 update, Section 2 required the identity of hazardous ingredients but did not always require concentration disclosure when a trade secret exemption applied. The 2024 rule tightens that.

Under the revised 29 CFR 1910.1200(i), manufacturers must disclose the concentration or concentration range for each hazardous ingredient in a mixture, even when they claim trade secret protection for the specific chemical identity. ^[1][10] The point: workers and health professionals can judge exposure risk from concentration even when the exact chemical name is withheld.

OSHA also tightened the allowable ranges. Suppliers can still use ranges instead of exact percentages, but the ranges have to be specific and actual, not broad buckets. A 10 to 30 percent range is fine for a mixture that genuinely varies. A 1 to 100 percent range is not.

For downstream employers, this means your incoming SDSs should eventually carry more usable data in Section 2. If you run industrial hygiene monitoring or manage occupational exposure limits, that extra detail helps.

If you manage your own hazard communication written program, note that 29 CFR 1910.1200(e) still requires you to keep a list of hazardous chemicals in your workplace and to make SDSs accessible to employees at all times. ^[10] The 2024 changes do not touch that core requirement. They do mean your SDS binder or digital system will eventually hold documents formatted differently than what you have now.

What do the new small container labeling rules actually allow?

Small container labeling was genuinely broken under the old standard. Putting a full GHS label on a 2 mL sample vial or a small blister pack was physically impossible in a lot of cases, and OSHA's enforcement guidance was vague. The 2024 rule fixes it with a tiered system. ^[1]

For containers too small to hold a full label, manufacturers can use:

• A pull-out or accordion-fold label attached to the container.
• A tag attached to the container that carries the full label information.
• A truncated immediate container label with, at minimum, the product identifier, signal word, and a reference to the outer package or full SDS, as long as the outer package carries the full label and the SDS is right there.

The truncated label option only applies to the immediate (innermost) container when it sits inside an outer package that bears a full GHS label. You cannot ship a standalone small container with only a truncated label.

For bulk shipments (rail cars, tank trucks, totes, and the like), the rule lets the label information appear on a placard fixed to the outside of the vessel, on a document that travels with the shipment, or on a tag. That tracks how DOT placarding already works, which should cut dual-compliance headaches for chemical distributors.

If you are a manufacturer, these options genuinely help. If you are a downstream employer, the change is mostly invisible to you. What you will notice: small containers arriving at your dock may look different than before, and your employees need to know how to find the full hazard information when the label on the container is abbreviated.

What training do employees need because of the 2024 HazCom changes?

29 CFR 1910.1200(h) has always required training when new chemical hazards enter the workplace. ^[1][10] The 2024 update triggers a training duty on its own, because it introduces hazard classes and label formats your employees have never seen.

OSHA's position, consistent with past rulemakings, is that training has to cover the new elements before employees run into them. You do not wait for your 2027 deadline to train. If a supplier sends you an updated SDS with a new ozone hazard pictogram in 2025, you train on it when it lands.

At minimum, the updated training needs to cover:

1. The new hazard classes and what their pictograms or signal words look like. 2. The new small container label formats, so workers know where to find full hazard information. 3. Any chemicals in your facility that got reclassified under the new system. 4. How to read the updated Section 2 format on incoming SDSs.

OSHA does not set a training format, duration, or frequency beyond "effective" training that employees can demonstrate they understood. That standard comes from 29 CFR 1910.1200(h)(3)(iv), which requires employees to demonstrate understanding of the physical and health hazards of the chemicals they work with. ^[10]

Document it. A citation for inadequate HazCom training is one of OSHA's most common findings. HazCom was the second most cited OSHA standard in fiscal year 2023, with 2,978 violations recorded. ^[3] Good training records do not stop accidents, but they are your first line of defense in an inspection.

If you are building or updating a written safety program for these changes, the generator at SafetyFolio produces a HazCom program that flags the 2024 requirements and builds training checklists tied to your chemical inventory.

Does the 2024 HazCom update affect your written hazard communication program?

Yes, directly. 29 CFR 1910.1200(e)(1) requires every employer with hazardous chemicals in the workplace to keep a written hazard communication program. ^[1][10] The program has to describe how you comply with the standard. When the standard changes, the program changes too.

Your written program needs to address:

The new hazard classes. If any chemicals you use fall into the new categories (desensitized explosives, ozone-hazardous chemicals, flammable gas subcategories), your chemical inventory list and your hazard identification section have to reflect that.

Small container procedures. If you receive chemicals in small containers that now carry truncated labels, your program should explain how workers get full hazard information for those containers. This is a real gap in most existing programs.

SDS management. Your program should spell out how you handle SDS updates from suppliers. During the transition, revised SDSs will arrive in waves between now and 2026.

Training update schedule. Write down when and how you will train employees on the new label elements. OSHA inspectors will ask.

Most generic HazCom templates online were written before May 2024. If your written program cites GHS Rev. 3 specifically, or never mentions the new hazard classes, it is already out of date. That does not trigger an automatic citation before your deadline arrives, but it flags to an inspector that your program is not being maintained.

How does the 2024 update compare to the 2012 HazCom rule?

The 2012 rule was the bigger structural change. It replaced the old MSDS format with the standardized 16-section SDS, brought in GHS pictograms, and added signal words ("Danger" and "Warning") to replace the old risk-phrase system. If you lived through that transition, you know what a real overhaul feels like. ^[4]

The 2024 update is a refinement, not a rebuild. The 16-section SDS format stays. The pictogram set stays, though a new pictogram arrives for the ozone hazard class. The signal word system stays. What moves is the classification criteria for some chemicals, the content requirements for a few SDS sections, and the label options for edge cases.

Feature	Pre-2012 (MSDS era)	2012 HazCom rule	2024 HazCom update
GHS revision tracked	None	GHS Rev. 3	GHS Rev. 7
SDS format	8-section MSDS (no standard)	16-section SDS (standardized)	16-section SDS (minor section updates)
Pictograms	Not required	8 pictograms required	9 pictograms (new: ozone hazard)
Small container options	Vague	Vague	Tiered system (pull-out, tag, truncated)
Bulk shipment labeling	Vague	Vague	Explicit flexibility allowed
Hazard classes	Fewer	GHS Rev. 3 set	9 new classes added
Concentration disclosure	Limited	Limited	Required even with trade secret claims

The honest answer for most small business owners: the 2024 changes are far less disruptive than 2012 was. Your biggest tasks are updating your written program, training employees on the new pictograms and label formats, and swapping out SDSs as updated versions arrive from your suppliers.

How will OSHA enforce the 2024 HazCom rule during the transition period?

OSHA has not published a formal enforcement discretion policy for the HazCom transition the way it did for some COVID-era rules. What it has said, consistent with its 2012 approach, is that it will weigh good faith compliance efforts during inspections. ^[5]

Here is what that means in practice. If an inspector shows up in 2025 and your SDSs are still in the old format, that is not an automatic citation as long as your suppliers have not issued updated documents yet. If your written program is not updated but you can show you know the new requirements and have a plan, that factors into the inspector's judgment.

What kills your good-faith credit: no training records for the new hazard classes, no procedure for handling updated SDSs when they arrive, or a written program nobody has touched since 2015.

HazCom citations are usually "other-than-serious," but they climb to "serious" when the violation involves chemicals with known acute health hazards and workers have flat-out no training. Serious citations carry penalties up to $16,550 per violation as of 2024. Willful or repeated violations reach $165,514. ^[6]

OSHA also tends to stack HazCom violations onto other findings rather than cite them alone. If an inspector comes in for a noise complaint and your employees cannot locate the SDS for a chemical they use every day, expect a HazCom citation riding alongside everything else they write up.

For how OSHA inspections work and what to expect, the OSHA overview is worth reading before your first compliance walk-through.

What does the 2024 HazCom update mean for GHS-aligned countries and imported chemicals?

The U.S. has trailed the European Union, Canada, and Japan on newer GHS revisions for years. The EU has run on GHS Rev. 7 criteria through its CLP Regulation for a while now. ^[12] Canada's WHMIS 2015 also tracks GHS more closely than the old U.S. standard did. ^[7]

The 2024 U.S. update closes most of that gap. For businesses that import chemicals, that is largely good news. Suppliers in GHS Rev. 7 countries were already producing documents that did not quite match U.S. format rules. After July 2026, those documents are far more likely to satisfy 29 CFR 1910.1200 without modification.

Differences remain. GHS is a framework, not a treaty. Each country implements it with national quirks. The U.S. will not have identical SDS requirements to the EU even after 2024. Section 15 of the SDS (Regulatory Information) still has to cite U.S.-specific laws (CERCLA, RCRA, TSCA) that have no EU analog.

For exporters, the convergence helps too. If you keep two versions of every SDS, one for U.S. compliance and one for EU or Canadian compliance, you may be able to trim that duplication. Check with your regulatory counsel before you scrap the dual-document setup, because the differences are real even where they are smaller.

Nobody has good data yet on how much the convergence cuts compliance costs for importers and exporters. OSHA's own regulatory impact analysis pegged cost savings from harmonization at roughly $47 million annually across the industry, but that number comes with wide uncertainty bands. ^[1]

Are there any OSHA letters of interpretation on the 2024 HazCom changes?

As of mid-2025, OSHA had not published a large body of formal interpretation letters specific to the 2024 final rule. The rule is recent, and interpretation requests take time to move through the agency. ^[8]

What does exist: the preamble to the final rule itself, published in the Federal Register on May 20, 2024, carries extensive Q&A-style explanation of OSHA's intent on specific provisions. If you have a question about what the new small container provision requires in a specific edge case, the preamble is often more useful than waiting for a letter. The preamble is legally non-binding, but OSHA inspectors and courts treat it as the authoritative statement of agency intent.

For the prior 2012 HazCom rule, OSHA eventually published dozens of interpretation letters over several years. Expect the same pattern here. The most contested issues will likely involve trade secret claims under the new concentration disclosure requirements and the exact conditions under which truncated small container labels are allowed.

If you need a formal OSHA interpretation, you can submit a request through OSHA's website at osha.gov. The process usually takes several months. For operational calls during the transition, most practitioners lean on the preamble language rather than waiting on formal letters.

What should small businesses do right now to prepare for the 2024 HazCom changes?

Your honest priority list, in order of urgency:

1. Read your existing written HazCom program. If you have one, pull it and check which GHS revision it tracks, what it says about small container labeling, and when it was last updated. If you do not have a written program, you are already out of compliance with 29 CFR 1910.1200(e)(1), regardless of the 2024 update.

2. Inventory your hazardous chemicals. Your program has to include a list of every hazardous chemical in the workplace. As SDSs arrive with updated classifications, compare the new hazard classes against your list and flag anything newly classified under the 2024 categories.

3. Brief supervisors now. They do not need the full regulatory history. They need to know three things: new SDSs are coming, some containers will look different, and updated documents go to whoever manages the SDS system.

4. Update your training records. Document what training you have done, when, and what it covered. When you train on the new label elements, write it down. OSHA does not specify a form, but you need something.

5. Set a calendar reminder for January 2026. That gives you six months before the manufacturer deadline (July 2026) to review which SDSs have been updated, retrain anyone who works with newly reclassified chemicals, and confirm your written program reflects the new standard.

If you need to build or update a written HazCom program fast, SafetyFolio generates a compliant program in about 15 minutes, including the chemical inventory list structure and training checklist format built for the 2024 requirements.

One thing I would not spend money on right now: a third-party consultant to reclassify your whole chemical inventory before you know which suppliers are reclassifying under the new rules. Wait for the updated SDSs to arrive and respond to actual changes. Do not pay someone to guess at all of them in advance.

Frequently asked questions

When did the 2024 OSHA HazCom rule take effect?

The final rule was published May 20, 2024, and took effect July 19, 2024. That does not mean full compliance is required immediately. Chemical manufacturers and importers have until July 19, 2026 to ship with updated labels and SDSs. Downstream employers, meaning workplaces that use but do not manufacture chemicals, have until July 19, 2027 to finish the transition.

Do I need to replace all my safety data sheets immediately?

No. Your deadline as a downstream employer is July 19, 2027. As your suppliers issue updated SDSs, replace the old ones in your binder or digital system when they arrive. Running both old and new format SDSs during the transition is fine. What you cannot do is ignore updated SDSs when they show up or skip training employees on new hazard information.

What are the nine new hazard classes added by the 2024 HazCom update?

The 2024 rule adds desensitized explosives, non-flammable aerosols, chemicals hazardous to the ozone layer, flammable gas subcategories 1A and 1B, pyrophoric gases, chemically unstable gases, and new subcategories within respiratory sensitization, skin sensitization, and reproductive toxicity. If chemicals you use fall into these categories, your supplier will eventually issue a reclassified SDS.

Does the 2024 HazCom update apply to all employers or only chemical manufacturers?

It applies to all employers covered by OSHA's general industry, construction, maritime, or agricultural standards who have hazardous chemicals in the workplace. The deadlines differ by role: manufacturers and importers by July 2026, downstream employers by July 2027. If you only use chemicals and do not manufacture or import them, your practical burden is updating your written program and retraining employees.

What is the penalty for not complying with the hazard communication standard?

HazCom violations are most often cited as "other-than-serious" or "serious." As of 2024, serious violations carry penalties up to $16,550 per violation. Willful or repeated violations reach $165,514 per violation. OSHA adjusts these amounts annually for inflation. HazCom is consistently one of OSHA's top ten most cited standards, so inspectors are trained to look for it.

What training do employees need for the 2024 HazCom changes?

Employees need training on the new hazard classes, what new or revised pictograms look like, how to read the updated small container label formats, and how to find full hazard information when a container carries a truncated label. The training has to happen before employees encounter the new labels or hazard classes. Document it with dates, topics covered, and employee names.

How does the 2024 HazCom update change safety data sheet format?

The 16-section SDS format stays the same. The main content change is in Section 2: manufacturers must now disclose the concentration or concentration range of each hazardous ingredient in a mixture, even when claiming trade secret protection for the chemical's identity. A few other sections got minor content revisions, but if you know the 2012 SDS format, the 2024 version will look familiar.

Do state-plan states have their own HazCom rules that differ from the federal update?

States with OSHA-approved state plans, such as California (Cal/OSHA), Washington (L&I), and Michigan (MIOSHA), must adopt standards at least as protective as the federal rule within six months of the federal rule's effective date. Most state plan states adopt the federal HazCom standard with minimal changes. Check your state plan agency's website for state-specific additions, particularly California, which frequently adds requirements beyond federal minimums.

What is a truncated label and when can a manufacturer use one?

A truncated label is an abbreviated label allowed for small immediate containers enclosed in an outer package that bears a full GHS label. The truncated label must include, at minimum, the product identifier, signal word, and a reference to the outer package or SDS for full hazard information. It cannot be used for standalone small containers shipped without a full-labeled outer package.

Does the 2024 update change what goes in a written hazard communication program?

Yes. Your written program under 29 CFR 1910.1200(e) must describe how you comply with the standard. Since the standard now includes new hazard classes, small container label procedures, and updated SDS content requirements, your program has to address those. Most programs written before 2024 cite GHS Rev. 3 compliance and skip the new categories. They need updating before your 2027 deadline.

How does the 2024 HazCom rule affect imported chemicals?

Imported chemicals must comply with 29 CFR 1910.1200 regardless of where they originate. The importer is treated as the manufacturer for SDS and label purposes. The 2024 update actually helps importers from GHS Rev. 7 countries like EU member states, because foreign supplier documents now match U.S. requirements more closely. Country-specific differences remain, so importers should confirm Section 15 regulatory information reflects U.S. law.

Where can I find the actual text of the 2024 HazCom final rule?

The full text of the final rule was published in the Federal Register on May 20, 2024 (89 FR 44144). It is also linked from OSHA's website at osha.gov under Hazard Communication. The preamble to the rule, which explains OSHA's intent on specific provisions, runs several hundred pages and is more useful than the regulatory text alone for understanding edge cases.

What is GHS Rev. 7 and how is it different from GHS Rev. 3?

The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is a United Nations framework updated every two years. Rev. 3 (2009) was the basis for the 2012 U.S. HazCom rule. Rev. 7 (published 2017 to 2019) added new hazard classes, tightened concentration disclosure, and clarified labeling for edge cases like small containers and bulk shipments. The U.S. skipped Rev. 4, 5, and 6 before adopting Rev. 7 in 2024.

Can I keep using old-format SDSs and labels until the deadline passes?

Yes. During the transition, OSHA expects old and new format documents to coexist. Manufacturers can ship under old labels until July 19, 2026. Downstream employers can keep old-format SDSs until they receive updated ones from suppliers, with a final deadline of July 19, 2027. The practical trigger for updating is when your supplier sends a revised SDS, at which point you replace the old one and train employees on any new hazard information.

Sources

1. OSHA, Hazard Communication Standard Final Rule (89 FR 44144, May 20, 2024): Final rule published May 20, 2024, effective July 19, 2024; adds nine new hazard classes, revises SDS Section 2 concentration disclosure, creates small container label tiers, and sets phased compliance deadlines of July 2026 for manufacturers and July 2027 for employers
2. United Nations Economic Commission for Europe, Globally Harmonized System of Classification and Labelling of Chemicals (GHS): GHS Rev. 7 was the edition adopted by the U.S. in the 2024 HazCom update; earlier editions include Rev. 3 (basis for the 2012 U.S. standard)
3. OSHA, Top 10 Most Cited Standards, Fiscal Year 2023: Hazard Communication (29 CFR 1910.1200) was the second most cited OSHA standard in fiscal year 2023, with 2,978 violations
4. OSHA, Hazard Communication Standard 2012 Final Rule (77 FR 17574): The 2012 HazCom rule matched the U.S. standard to GHS Rev. 3, replacing the MSDS with a standardized 16-section SDS and introducing GHS pictograms and signal words
5. OSHA, Penalties: As of 2024, serious OSHA violations carry penalties up to $16,550 per violation; willful or repeated violations up to $165,514 per violation
6. OSHA, Standard Interpretations, Hazard Communication (29 CFR 1910.1200): OSHA publishes formal letters of interpretation on 29 CFR 1910.1200; significant interpretations specific to the 2024 final rule had not yet been published as of mid-2025
7. 29 CFR 1910.1200, Hazard Communication Standard, full regulatory text (eCFR): 29 CFR 1910.1200(e)(1) requires a written hazard communication program; 1910.1200(h) requires employee training; 1910.1200(i) governs trade secret exemptions and concentration disclosure
8. Bureau of Labor Statistics, Census of Fatal Occupational Injuries: BLS tracks occupational injury and fatality data by industry; chemical exposure fatalities are tracked within the CFOI dataset
9. European Chemicals Agency (ECHA), CLP Regulation: The EU's CLP Regulation has tracked GHS Rev. 7 criteria for several years before the U.S. 2024 update, creating labeling alignment gaps for cross-border chemical shipments