OSHA revised the standard in a final rule published in the Federal Register on May 20, 2024 (89 FR 44144), effective July 19, 2024. A later rule (91 FR 1695, January 15, 2026) moved each compliance date back four months. For substances, the dates are May 19, 2026 for manufacturers, importers and distributors (this date has passed), and November 20, 2026 for employers. For mixtures it is November 19, 2027.
For a product-by-product update list, use our HCS 2024 checklist.
Informational, not legal advice. Check the primary source: 29 CFR 1910.1200 on eCFR and your regulatory professional.
Who the OSHA HazCom standard covers
Paragraph (b)(1) says the standard "requires chemical manufacturers or importers to classify the hazards of chemicals which they produce or import, and all employers to provide information to their employees about the hazardous chemicals to which they are exposed."
| Role | How 1910.1200(c) defines it | What it owes |
|---|---|---|
| Chemical manufacturer | "an employer with a workplace where chemical(s) are produced for use or distribution." "Produce" includes "manufacture, process, formulate, blend, extract, generate, emit, or repackage." | Classification (d), labels (f), SDSs (g) |
| Importer | The first business with employees in the U.S. Customs Territory to receive hazardous chemicals produced in other countries, for supply to distributors or employers | Same as a manufacturer |
| Distributor | "a business, other than a chemical manufacturer or importer, which supplies hazardous chemicals to other distributors or to employers" | Label shipped containers (f)(1); pass SDSs along (g)(7). Does not classify unless it repackages, blends or otherwise changes the product, in which case OSHA treats it as a chemical manufacturer (CPL X.C.12.a) |
| Employer | A business where chemicals are used, distributed, or produced | Written program (e), workplace labels, SDS access (g)(8), training (h) |
"Produce" is defined to include "formulate, blend... or repackage", so a company that does those things is a chemical manufacturer for this standard (1910.1200(c)). OSHA's inspection directive, CPL 02-02-079, says the same (X.C.12.a and X.C.27.a). Whether a specific operation counts is fact-specific; check with your regulatory professional.
Paragraphs (b)(5) and (b)(6) list chemicals exempt from labeling under this standard (for example, pesticides and food, drugs and cosmetics when they are subject to their own federal labeling laws) or from the standard altogether (for example, articles). Read those lists before assuming a product is in scope.
What authors must produce
Hazard classification: paragraph (d), Appendices A and B
Classification comes first, because the label and the SDS both report it. Paragraph (d)(1) says manufacturers and importers "shall determine the hazard classes, and where appropriate, the category of each class that apply to the chemical being classified." Health hazard criteria are in Appendix A; physical hazard criteria are in Appendix B. Under (d)(2), there is "no requirement to test the chemical."
For mixtures, (d)(3)(ii) lets you rely on ingredient SDSs, "except where the chemical manufacturer or importer knows, or in the exercise of reasonable diligence should know, that the safety data sheet misstates or omits information required by this section." Valenc's GHS classification runs the same step with a deterministic rules engine and shows the rule behind each result.
Labels: paragraph (f) and Appendix C
Each container of hazardous chemicals leaving your workplace must be labeled, tagged or marked with six elements ((f)(1)), subject to exceptions such as (f)(4) (certain solids), (f)(5) (transportation and bulk) and (f)(12) (small containers):
Product identifier
Signal word
Hazard statement(s)
Pictogram(s)
Precautionary statement(s)
Name, U.S. address, and U.S. telephone number of the manufacturer, importer, or other responsible party
Elements 1 to 5 must follow Appendix C and be "prominently displayed, and in English." The signal word, hazard statements and pictograms must be "located together on the label" ((f)(3)). Appendix C also settles details that trip up drafts:
If "Danger" appears, "Warning" shall not, and a pictogram "may only appear once on a label."
Precautionary statements may carry "minor textual variations," used consistently on label and SDS (C.2.4.7).
Where a mixture has an ingredient with unknown acute toxicity at 1% or more, and the mixture was not classified from whole-mixture testing, the label and the SDS must state the percentage of unknown acute toxicity (C.3.3).
Small containers. Paragraph (f)(12) applies where you "can demonstrate that it is not feasible to use pull-out labels, fold-back labels, or tags." Then:
A container of 100 ml or less must carry the product identifier, pictogram(s), signal word, the manufacturer's name and phone number, and a statement that the full label is on the immediate outer package.
A container of 3 ml or less, if any label "interferes with the normal use of the container," may carry only the product identifier.
In both cases the immediate outer package carries the full label information.
Label updates. Under (f)(11)(i), chemical manufacturers, importers, distributors or employers who "become newly aware of any significant information regarding the hazards of a chemical shall revise the labels for the chemical within six months of becoming aware of the new information." For chemicals already released for shipment and awaiting distribution, you may skip relabeling, but "they must provide the updated label for each individual container with each shipment."
Safety data sheets: paragraph (g) and Appendix D
Under (g)(1), manufacturers and importers "shall obtain or develop a safety data sheet for each hazardous chemical they produce or import." The SDS must be in English and include 16 sections in the order Appendix D sets, from 1 Identification through 16 Other information, including date of preparation or last revision.
OSHA's enforcement of Sections 12 to 15 is limited: Note 2 to (g)(2) says OSHA "will not be enforcing information requirements in sections 12 through 15," but Note 1 says the SDS must still include those headings in order. Appendix D calls the content of those sections "non-mandatory."
New significant hazard information "shall be added to the safety data sheet within three months" ((g)(5)). Distributors and employers must get an SDS "with their initial shipment, and with the first shipment after a safety data sheet is updated" ((g)(6)(i)).
Trade secrets and concentration ranges: paragraph (i)
You may withhold a chemical identity or an exact concentration from Section 3 if the claim "can be supported," the SDS still discloses the properties and effects, and the SDS says the information is withheld "as a trade secret." Withholding a concentration range is new in the 2024 rule. If the concentration is withheld, the SDS must give it as one of 13 prescribed ranges, from 0.1% to 1% up to 80% to 100% ((i)(1)(iv)).
The range used "must be the narrowest range possible" ((i)(1)(v)).
If the true range falls between 0.1% and 30% and does not fit inside one prescribed range, two consecutive prescribed ranges within that span may be combined, provided the combined range does not include a range that lies entirely outside the true range ((i)(1)(v)).
Manufacturers "may provide a range narrower than those prescribed" ((i)(1)(vi)).
A trade-secret claim does not end disclosure duties: (i)(2) to (i)(4) require disclosure to treating health professionals in emergencies and, on written request with a confidentiality agreement, in non-emergencies.
What employers must do
Employers who do not produce or import chemicals "need only focus on those parts of this rule that deal with establishing a workplace program and communicating information to their workers" ((b)(1)). The HCS 2024 checklist covers those employer tasks.
If your facility is in a State Plan state, your state's rule and dates control. State Plans with their own hazard communication standards must adopt provisions at least as effective as the federal rule (OSHA Q&A), and some state dates differ from the federal dates. Check your state agency.
What the 2024 HazCom update changed for SDSs and labels
OSHA's summary in the Federal Register says the update covers "revised criteria for classification of certain health and physical hazards, revised provisions for updating labels, new labeling provisions for small containers, new provisions related to trade secrets, technical amendments related to the contents of safety data sheets (SDSs)," and revised definitions. The items that matter to authors:
| Area | What the text now says | Where |
|---|---|---|
| Classification scope | The classification "shall include any hazards associated with the chemical's intrinsic properties including: (i) A change in the chemical's physical form; and (ii) Chemical reaction products associated with known or reasonably anticipated uses or applications." | (d)(1) |
| Label versus SDS | "Hazards not otherwise classified and hazards identified and classified under (d)(1)(ii) do not have to be addressed on the container." The SDS lists (d)(1)(ii) hazards in Section 2(c) and hazards not otherwise classified in Section 2(d). | (f)(1), App D |
| Physical and health hazards | Per OSHA's Q&A: expanded flammable gas categories, desensitized explosives, an additional aerosol category, and revised skin corrosion/irritation and serious eye damage criteria. | Apps A, B |
| Released for shipment | Option not to relabel, if the updated label goes with each container. | (f)(11) |
| Small containers | 100 ml and 3 ml provisions, with the full label on the outer package. | (f)(12) |
| Trade-secret concentrations | Prescribed ranges are mandatory when a concentration is withheld. | (i)(1)(iv) |
On downstream uses, OSHA's Q&A says classification "must account for downstream uses that are known to the classifier or can be reasonably anticipated by them." That is agency guidance, not the text of the standard.
Appendix D changes. OSHA's Q&A says the updates "include" Sections 2, 3, 9 and 11; the inspection directive names Sections 1, 2, 3, 8, 9, 10, 11 and 14. The specifics:
Section 1: the manufacturer, importer or other responsible party's name, U.S. address and U.S. telephone number (OSHA describes the U.S. requirement as clarifying an existing one).
Section 2: 2(a) classification excludes (d)(1)(ii) hazards; 2(c) covers "Hazards classified under paragraph (d)(1)(ii)."
Section 3: for mixtures, the CAS number or other unique identifier; if the CAS number is unavailable or a trade secret, the preparer must "indicate the source of unique identifier."
Section 8: 8(a) applies to all ingredients or constituents listed in Section 3.
Section 9: particle characteristics added to the property list.
Section 10: 10(c) includes hazardous reactions "associated with foreseeable emergencies."
Section 11: interactive effects, and, where specific data are missing, a statement of any alternative information used and the method used to derive it.
Section 14 (non-mandatory): 14(f) now reads "Transport in bulk according to IMO instruments."
The dates, and how to plan around them
The current dates are in 1910.1200(j), as extended by 91 FR 1695:
| Date | Who | What | Cite |
|---|---|---|---|
| July 19, 2024 | Everyone | Effective date of the 2024 rule | (j)(1) |
| May 19, 2026 (has passed) | Manufacturers, importers, distributors evaluating substances | In compliance with all modified provisions | (j)(2)(i) |
| November 20, 2026 | All employers, for substances | Update alternative workplace labeling (f)(6), the hazard communication program (h)(1) and training (h)(3), as necessary, for newly identified physical, health or other hazards | (j)(2)(ii) |
| November 19, 2027 | Manufacturers, importers, distributors evaluating mixtures | In compliance with all modified provisions | (j)(3)(i) |
| May 19, 2028 | All employers, for mixtures | Same as the substances row for employers | (j)(3)(ii) |
Until each date, paragraph (j)(4) lets manufacturers, importers, distributors and employers "comply with either this section or § 1910.1200 revised as of July 1, 2023, or both."
The date that applies turns on whether the product is a substance or a mixture ((j)(2), (j)(3)). A mixture SDS may rely on ingredient SDSs under (d)(3)(ii). Edge cases, such as companies making both or reaction products, are fact-specific; check with your regulatory professional.
One planning note, from OSHA's directive rather than the standard's text: it says a manufacturer or importer "may not partially implement the revised standard for a label or SDS for an individual product," and that it is "acceptable to have HCS 2012 labels and HCS 2024 SDSs or vice versa." This is a transition-period rule. It has ended for manufacturers, importers and distributors of substances, it still runs for mixtures to November 19, 2027, and it runs for employers to their (j)(2)(ii) and (j)(3)(ii) dates.
OSHA has issued correction documents to the 2024 text, including 89 FR 81829 (October 9, 2024), 91 FR 562 (January 8, 2026), and 91 FR 6760 (February 13, 2026), a one-page correction to a note in Appendix B. Dates are as extended by 91 FR 1695; work from the current eCFR text, not a copy of the May 2024 rule.
An authoring workflow for OSHA HazCom
This is a working sequence, not a legal requirement or a compliance guarantee. Do it per product.
Decide whether the product is a substance or a mixture, and your role.
Gather composition, supplier SDSs and measured properties.
Classify against Appendices A and B, recording the rule behind each result.
Draft the label from Appendix C and the 16 SDS sections in order.
Check that Section 2 matches the label: it reports the signal word, hazard statements and precautionary statements "in accordance with paragraph (f)" (App D, Section 2(b)), and any variation in precautionary wording must be used consistently on both (C.2.4.7).
Have a person approve, then ship the updated SDS.
For the product-by-product list, use the HCS 2024 checklist.
How Valenc's platform maps to the classification, drafting and review steps
Valenc's platform runs in a similar sequence: extract, enrich, classify, draft, review. AI agents extract data from supplier SDS PDFs with a confidence score on each field, and you review beside the source PDF. The data is enriched from a Valenc database of about 55,000 chemicals. Classification runs on a deterministic rules engine: same inputs, same result, with the rule behind each classification shown. The SDS is drafted from that classified record across all 16 sections, and Valenc also produces GHS labels.
A review agent flags items for a person's decision. Nothing publishes until a person approves, and there is a full audit trail from PDF to published SDS. Regulatory monitoring agents watch OSHA, EPA, REACH and CLP lists and flag affected SDSs in your library. Your compositions stay private and are never used to train AI models.
Weighing tools? See how to compare SDS authoring software and SDS authoring services versus software. Selling beyond the US: multilingual SDS authoring for regulatory teams. Managing the supplier SDSs you receive: SDS management software guide.
Frequently asked questions
What is the OSHA HazCom standard?
It is OSHA's Hazard Communication Standard, 29 CFR 1910.1200. It requires chemical manufacturers and importers to classify chemical hazards and pass them on through labels and safety data sheets, and requires employers to run a written program, keep SDSs accessible, and train workers.
Who has to write an SDS under HazCom?
Chemical manufacturers and importers. Paragraph (g)(1) says they "shall obtain or develop a safety data sheet for each hazardous chemical they produce or import." By 1910.1200(c)'s definitions, "produce" includes formulating, blending and repackaging.
What must be on a HazCom label?
Six things: product identifier, signal word, hazard statement(s), pictogram(s), precautionary statement(s), and the name, U.S. address and U.S. telephone number of the manufacturer, importer or other responsible party. Small containers have reduced-label options under (f)(12).
When do the 2024 HazCom changes take effect?
For substances: May 19, 2026 for manufacturers, importers and distributors (this date has passed), and November 20, 2026 for employers. For mixtures: November 19, 2027 for manufacturers, importers and distributors, and May 19, 2028 for employers. Until each date, (j)(4) lets you comply with the 2024 standard, the version revised as of July 1, 2023, or both. OSHA's directive says that once a date has passed, only the 2024 requirements are cited for the provisions covered (CPL X.J.2.a). For the update list, see the HCS 2024 checklist.
Can I write my SDS to a newer GHS revision than Rev. 7?
Not automatically. OSHA's inspection directive says HCS 2024 is based primarily on GHS Rev. 7 and some sections of Rev. 8, and that using Rev. 9 or a later revision "may result in non-compliance with HCS 2024 if it contradicts or casts doubt on OSHA-required information." OSHA says it evaluates each situation case by case (CPL X.A.1; see also 89 FR 44318). Confirm with your regulatory professional.
See it on your own supplier SDSs
If you author SDSs and labels for a US chemical manufacturing business, request a demo. Valenc sets up a walkthrough on your own supplier SDSs, so you see extraction, classification and a review-ready draft on chemistry you already know.
Informational, not legal advice. Check the primary source: 29 CFR 1910.1200.