Hazard Communication Basics

Four parts that work together

HazCom works like a relay. Chemical manufacturers and importers evaluate the hazards first. That information travels with the product, and your employer passes it to you.

OSHA aligned the standard with the United Nations' Globally Harmonized System (GHS) in 2012 and updated it again in 2024, so labels and data sheets look much the same around the world.

Reference: 29 CFR 1910.1200(a)(1) · 29 CFR 1910.1200(b)(1) · 77 FR 17785 (Mar. 26, 2012) · 89 FR 44356 (May 20, 2024)

How chemicals get into your body

A chemical can only hurt you if it reaches you. Knowing the route tells you which protection matters.

Reference: 29 CFR 1910.1200(c) "Exposure or exposed" · 29 CFR 1910.1200 Appendix D, Section 11(a)

What your employer must have in writing

Every employer whose workers can be exposed to hazardous chemicals needs a written hazard communication program, available to you on request. It must cover:

• A chemical inventory: a list of the hazardous chemicals present, using the same product identifiers that appear on the Safety Data Sheets
• Labels: how containers will be labeled and kept labeled
• Safety Data Sheets: how SDSs are kept and how you can get to them on every shift
• Training: how and when you will be trained
• Non-routine tasks: how you will be told about hazards of unusual jobs, like cleaning out a tank, and chemicals in unlabeled pipes
• Multi-employer sites: how contractors sharing a site exchange SDS access, labeling systems and precautions

Reference: 29 CFR 1910.1200(e)(1) · 29 CFR 1910.1200(e)(2) · 29 CFR 1910.1200(e)(4)

When you must be trained, and your part

Your employer must train you when you are first assigned and whenever a new chemical hazard you have not been trained on is introduced into your work area. Training must cover how to detect a release, the hazards of the chemicals, how to protect yourself, and how the labels and SDSs at your workplace work.

Your part

• Read labels before you use a product, every time
• Know where the SDSs are kept on your site
• Use the protective equipment the SDS and your employer call for
• Never use, or leave behind, an unlabeled container
• Report spills, leaks, damaged labels and symptoms right away

Reference: 29 CFR 1910.1200(h)(1) · 29 CFR 1910.1200(h)(3)

The six things on every shipped label

Labels on containers shipped by a manufacturer, importer or distributor must show six elements.

Pictograms

Red-bordered diamonds showing the type of hazard. Here: flame (flammable) and exclamation mark (irritant, drowsiness).

Product identifier

The name or number that matches the product on its Safety Data Sheet. This is how you find the right SDS.

Signal word

"Danger" or "Warning" tells you how severe the hazard is at a glance. Danger is the more severe.

Hazard statements

Standard phrases describing the nature and severity of each hazard.

Precautionary statements

What to do to prevent harm, how to respond to an exposure, how to store it, and how to dispose of it.

Supplier information

Name, U.S. address and U.S. phone number of the chemical manufacturer, importer or other responsible party.

Sample label for training only. The product and company are fictional.

Reference: 29 CFR 1910.1200(f)(1)

Signal words and workplace labels

Only two signal words

A label shows only one signal word. If "Danger" is used, "Warning" does not appear.

Labels inside your workplace

When chemicals are moved into containers at your workplace, those containers still need a label. Your employer can use the full shipped label, or a simpler workplace label that shows the product identifier and enough hazard information (words, pictures or symbols) to warn you, combined with the other information available to you.

Reference: 29 CFR 1910.1200(c) "Signal word" · 29 CFR 1910.1200 Appendix C, C.2.1.1 · 29 CFR 1910.1200(f)(6) · 29 CFR 1910.1200(f)(8) · 29 CFR 1910.1200(c) "Immediate use"

Eight symbols you must recognize

Each pictogram is a black symbol on a white background inside a red diamond. OSHA requires these eight. You may also see a ninth pictogram for environmental hazards; OSHA does not require it.

Reference: 29 CFR 1910.1200(c) "Pictogram" · 29 CFR 1910.1200 Appendix C, Figure C.1 · 29 CFR 1910.1200 Appendix C, C.2.3.2 and C.3

The 16 sections, always in the same order

Every SDS uses the same 16 sections in the same order, so once you learn the layout you can find answers fast on any product. Open a section to see what it holds.

The headings for Sections 12–15 must appear, but OSHA does not enforce their content because other agencies cover those areas.

Reference: 29 CFR 1910.1200(g)(2) and Notes 1–2 · 29 CFR 1910.1200 Appendix D, Table D.1

Common test questions

What is the difference between "Danger" and "Warning" on a label?

Danger is used for the more severe hazards; Warning is used for the less severe hazards.

Rule: 29 CFR 1910.1200(c)

Who has to figure out a chemical's hazards?

The chemical manufacturer or importer must evaluate the hazards of the chemicals it makes or imports.

Rule: 29 CFR 1910.1200(d)(1)

Must safety data sheets be easy for workers to get?

Yes. The employer keeps a safety data sheet for each hazardous chemical and makes it readily accessible to workers during each shift.

Rule: 29 CFR 1910.1200(g)(8)

When must workers be trained on hazardous chemicals?

When they are first assigned, and whenever a new chemical hazard is brought into their work area.

Rule: 29 CFR 1910.1200(h)(1)

Practice these in the course