What Counts as a Hazardous Chemical Under OSHA?

A hazardous chemical is one that has been classified as hazardous — and you are not the one who classifies it. 29 CFR 1910.1200 defines the term in one sentence, puts the classifying duty on the manufacturer or importer, and then lists what the standard leaves out. Get those three things straight and the question does this product need a safety data sheet stops being a judgement call.

Below: the definition itself, who decides and how you check, the twelve things the standard excludes — and the exclusions that are narrower than they look, which is where inventories go wrong.

1. The definition

Paragraph (c) of 1910.1200 defines it:

“Hazardous chemical means any chemical which is classified as a physical hazard or a health hazard, a simple asphyxiant, combustible dust, or hazard not otherwise classified.”

Two things follow from that sentence. First, the starting universe is enormous: the same paragraph defines a chemical as any substance, or mixture of substances. Water is a chemical. What narrows the field is classification, not chemistry.

Second, four categories sit alongside the familiar physical and health hazards, and they are the ones people leave off an inventory:

• Simple asphyxiants — the nitrogen, argon or carbon dioxide cylinder that displaces oxygen without being toxic at all.
• Combustible dust — produced by a process, not bought in a container, which is why it is so often missed.
• Hazards not otherwise classified, for adverse effects that do not fit an existing class.

One inconsistency inside the standard is worth knowing about, because it decides what your training has to cover. The definition above does not name pyrophoric gas; the training paragraph, 1910.1200(h)(3)(ii), does — it requires employees to be informed of the physical, health, simple asphyxiation, combustible dust, and pyrophoric gas hazards, as well as hazards not otherwise classified, of the chemicals in the work area. Appendix B classifies a pyrophoric gas as a flammable gas that ignites spontaneously in air at or below 54 °C (130 °F), so it reaches the definition as a physical hazard either way. If you keep pyrophoric gases, name them in the training regardless of which list you read.

2. Who decides — and the two-second check

Classification is the supplier’s job. 1910.1200(d)(1) puts it plainly:

“Chemical manufacturers and importers shall evaluate chemicals produced in their workplaces or imported by them to classify the chemicals in accordance with this section. Employers are not required to classify chemicals unless they choose not to rely on the classification performed by the chemical manufacturer or importer”

So the answer is already written down for you, in Section 2 of the product’s safety data sheet. If Section 2 gives a hazard class and category, a signal word, a pictogram or a hazard statement, the product is a hazardous chemical in your workplace. If Section 2 says the mixture is not classified as hazardous, it is not — keep the sheet if you like, but it does not have to be on the list you maintain under 1910.1200(e).

Two practical consequences. A supplier sometimes issues a sheet for a product that is not classified as hazardous, so the arrival of a sheet is a prompt to read Section 2, not a verdict in itself. And the duty in 1910.1200(g)(1) is scoped the same way: Employers shall have a safety data sheet in the workplace for each hazardous chemical which they use.

3. What the standard does not apply to

Paragraph (b)(6) lists what is outside the section altogether. Condensed, it is:

• Hazardous waste regulated under RCRA, and CERCLA hazardous substances during a remedial or removal action;
• Tobacco and tobacco products;
• Wood and wood products where the only hazard is flammability or combustibility;
• Articles — defined below;
• Food and alcoholic beverages sold, used or prepared in a retail establishment, and food employees bring in for themselves;
• Drugs in solid final form for direct administration (tablets and pills), over-the-counter drugs packaged for retail sale, and first-aid supplies employees use on themselves;
• Cosmetics packaged for retail sale or brought in for personal use;
• Consumer products used the way a consumer would use them;
• Nuisance particulates, ionizing and non-ionizing radiation, and biological hazards.

An article is the exclusion people lean on hardest, and paragraph (c) defines it tightly: a manufactured item other than a fluid or particle, formed to a specific shape or design, whose end use depends on that shape, and

“Which under normal conditions of use does not release more than very small quantities, e.g., minute or trace amounts of a hazardous chemical…and does not pose a physical hazard or health risk to employees.”

A steel bracket sitting on a shelf is an article. The same bracket being welded, ground or cut is releasing more than trace amounts, and the exclusion stops applying to that operation.

4. The exclusions that are narrower than they look

This is where inventories go wrong, and all three traps are in the text itself.

Wood. The wood exclusion carries its own parenthetical: wood treated with a hazardous chemical, and wood which may be subsequently sawed or cut, generating dust, are not exempted. A lumber rack is out of scope; a saw is not.

Consumer products. The exclusion at 1910.1200(b)(6)(ix) applies where the employer can show the product is used for the purpose the manufacturer intended and the use results in a duration and frequency of exposure no greater than a consumer could reasonably experience. A janitor spraying disinfectant for six hours a shift is not using it as a consumer does, so the sheet and the training are back.

Labelling exemptions are not scope exemptions. Paragraph (b)(5) is a separate, shorter list, and it begins This section does not require labeling of the following chemicals — pesticides under FIFRA, substances under TSCA, FDA-regulated products, beverage alcohol, consumer products under CPSC rules, and treated seed. Those products keep their own agency’s label instead of a GHS one. Everything else in 1910.1200 still applies to them: the written program under paragraph (e), the safety data sheet under paragraph (g) and the training under paragraph (h). A pesticide in a workplace is squarely inside the standard; it just wears an EPA label.

5. Sorting your own shelf

Walk the building with three buckets in mind.

1. In. Anything whose Section 2 classifies it: cleaners, degreasers, fuels, paints, adhesives, compressed gases, disinfectants, pool and process chemicals. These go on the list your written program has to contain under 1910.1200(e), and their sheets have to be accessible under 1910.1200(g).
2. Out. Sealed articles, the coffee in the break room, employees’ own medicines, lumber you will not cut, waste already manifested under RCRA.
3. Ask. Anything a process changes — sawing, welding, grinding, heating, mixing — and anything used far harder than a household would use it. Dust, fume and vapour generated in your workplace are the classic gap, and they are the reason combustible dust is named in the definition at all.

When the answer is genuinely unclear, the cheap resolution is to request the sheet and read Section 2. The supplier has already done the classification; you are only reading the result.

Frequently asked questions

What counts as a hazardous chemical under OSHA?

29 CFR 1910.1200(c) defines it as any chemical which is classified as a physical hazard or a health hazard, a simple asphyxiant, combustible dust, or hazard not otherwise classified. The same paragraph defines a chemical as any substance, or mixture of substances, so it is the classification that narrows the field rather than the chemistry.

Who decides whether a product is hazardous?

The manufacturer or importer does. 29 CFR 1910.1200(d)(1) requires chemical manufacturers and importers to evaluate the chemicals they produce or import and classify them, and it says employers are not required to classify chemicals unless they choose not to rely on that classification. In practice you read the result in Section 2 of the safety data sheet.

Does every product in the building need a safety data sheet?

No. 29 CFR 1910.1200(g)(1) requires employers to have a safety data sheet in the workplace for each hazardous chemical which they use, so a product whose Section 2 shows no hazard classification does not need to be on that list. Paragraph (b)(6) also puts twelve categories outside the section altogether, among them articles, tobacco, untreated wood that will not be cut, food and drink in a retail setting or brought in by employees, solid-form drugs, retail-packaged cosmetics, consumer products used as a consumer would use them, ionizing and nonionizing radiation, and biological hazards.

Is a metal part or a machine component a hazardous chemical?

Not while it is an article. 29 CFR 1910.1200(c) defines an article as a manufactured item other than a fluid or particle, formed to a specific shape or design, whose end use depends on that shape, and which under normal conditions of use does not release more than very small quantities of a hazardous chemical and does not pose a physical hazard or health risk. Welding, grinding, cutting or heating that item releases more than trace amounts, and the exclusion stops covering that operation.

Do pesticides and other EPA-labelled products need safety data sheets at work?

Yes. The list in 29 CFR 1910.1200(b)(5) exempts pesticides, TSCA substances, FDA-regulated products, beverage alcohol, consumer products and treated seed from the labelling requirements of this section, because they carry another agency's label instead. It does not exempt them from the section itself: the written hazard communication program under paragraph (e), the safety data sheet under paragraph (g) and the training under paragraph (h) all still apply.

What about dust and fumes generated by our own work?

They are easy to miss on a chemical inventory, because nobody buys them in a container. Combustible dust is named in the definition of a hazardous chemical in 29 CFR 1910.1200(c), and the wood exclusion in paragraph (b)(6)(iv) expressly does not cover wood which may be subsequently sawed or cut, generating dust, or wood treated with a hazardous chemical. Where a process creates the hazard, the process is what you assess.

Related guides

• How to build a chemical inventory
• The 16 sections of a safety data sheet
• The consumer product exemption, and its limits
• GHS pictograms explained
• Does HazCom apply to a small business?
• When a manufacturer will not send the sheet
• HazCom for Schools, Daycares & Childcare Centers