How to create a safety data sheet: the steps OSHA requires

Chemical manufacturers and importers must obtain or develop an SDS for each hazardous chemical they produce or import (29 CFR 1910.1200(g)(1)). "Produce" is defined broadly: to manufacture, process, formulate, blend, extract, generate, emit, or repackage (§1910.1200(c)). A company that blends a cleaner from purchased ingredients, or splits drums into private-label bottles, is a chemical manufacturer for HazCom purposes. An importer is the first U.S. business with employees that receives chemicals produced abroad to supply them to distributors or employers.

"Obtain or develop" means someone else can write the sheet for you: a consultant, a toll blender, or software. The responsibility doesn't move. You, as the manufacturer or importer, must ensure the sheet meets the standard's content requirements and accurately reflects the scientific evidence used in the classification (§1910.1200(g)(2), (g)(5)). If you only use chemicals, you don't write SDSs. You may rely on your suppliers' classifications (§1910.1200(d)(1)).

Start with the formulation: every ingredient, its CAS number, and its concentration. Then collect each ingredient's current SDS from your suppliers. When you classify a mixture you make, you may rely on those ingredient SDSs unless you know, or with reasonable diligence should know, that one misstates or omits required information (§1910.1200(d)(3)(ii)).

You aren't required to test anything (§1910.1200(d)(2); Appendix A.0.2.1), but you must identify and consider the full range of available scientific literature and other evidence on the potential hazards (§1910.1200(d)(2)). Impurities, additives, and constituents that are themselves classified count when they exceed the cut-off for a hazard class (A.0.1.3). Physical hazards depend on the product's own properties: a liquid's flash point and initial boiling point decide whether it is flammable and in which category (Appendix B.6).

For each chemical, the manufacturer or importer determines which hazard classes apply and, where appropriate, the category within each class (§1910.1200(d)(1)). Health hazards are classified under Appendix A and physical hazards under Appendix B (§1910.1200(d)(2)). The classification includes hazards from a change in the chemical's physical form and from reaction products of its known or reasonably anticipated uses (§1910.1200(d)(1)(i)–(ii)).

For a mixture, Appendix A sets an order of precedence (A.0.4.1):

Carcinogenicity, germ cell mutagenicity, and reproductive toxicity are the exception: those are classified from the ingredients unless a case-by-case justification supports using data on the mixture as a whole (A.0.4.2). Cut-offs aren't the last word in either direction. If you know an ingredient presents a health risk below its cut-off, the mixture is classified accordingly (A.0.4.3.2), and you must take into account available information on synergistic effects between ingredients (A.0.4.4). In the other direction, conclusive data can justify a lower classification, but only in exceptional cases (A.0.4.3.3).

Some rules are blunt. In the absence of other information, a mixture with a pH of 2 or below, or 11.5 or above, is considered corrosive to skin and to cause serious eye damage, both Category 1 (A.2.3.1.3, A.3.3.1.2), though its buffering capacity can justify further evaluation. For many classes, though, the criteria are semi-quantitative or qualitative and need expert judgment to apply (A.0.1.2). Those judgment calls are hard to get right on your own.

The SDS must be in English and use the 16 headings in order, with at least the information Appendix D's Table D.1 lists for Sections 1–11 and 16 (§1910.1200(g)(2)). The 16-section guide walks through every heading. Three rules trip up first-time authors:

If an ingredient of unknown acute toxicity makes up 1% or more of a mixture you haven't classified by testing it as a whole, the label and the SDS must state what percentage of the mixture consists of ingredients of unknown acute toxicity, by route of exposure (Appendix C.3.3).

Every container of a hazardous chemical you ship needs a label with the product identifier, signal word, hazard statements, pictograms, precautionary statements, and your name, U.S. address, and U.S. phone number (§1910.1200(f)(1)), with limited relief for small containers (§1910.1200(f)(12)). Those elements come from Appendix C for each hazard class and category you assigned (§1910.1200(f)(2)), and the label must use the same product identifier as the SDS (Appendix C.1). Build the label and Section 2 from one classification, and they can't disagree.

Your customers' own workplace labels can be simpler (the labeling guide covers what they need), but the label on what you ship must be complete.

Provide the SDS with each customer's initial shipment, and with the first shipment after the sheet is updated (§1910.1200(g)(6)(i)), and on request (§1910.1200(g)(6)(iv)). When you learn significant new information about the hazards, or about ways to protect against them, add it to the SDS within three months (§1910.1200(g)(5)); if it concerns the hazards, revise the label within six months (§1910.1200(f)(11)). If the product isn't currently being made, the update goes in before it is shipped or used again.

If your sheets predate the 2024 update: sheets for substances had to comply by May 19, 2026, and sheets for mixtures must comply by November 19, 2027. Until then, either the current or the pre-2024 rule is acceptable (§1910.1200(j)(2)(i), (j)(3)(i), (j)(4)). The 2024 update guide covers what changed.

SDS HQ's authoring takes the software route. You enter the formulation, and the engine classifies its health hazards under HazCom 2024 using concentration limits, the additivity formula, and summation. From the physical data you supply, it also classifies flammable liquids, oxidizing liquids, and corrosivity to metals; gases, aerosols, and other physical hazard classes aren't covered. It writes all 16 sections, including Section 2's label elements, and shows the method, the reference, and the ingredient that drove each hazard. It costs $79 per SDS, with updates to that sheet included. It covers U.S. OSHA only, and the result is yours to review. The methodology states what it does and doesn't cover.