Hazard Communication: Labels and Safety Data Sheets

You have a right to know what you are working with. OSHA's Hazard Communication Standard, 29 CFR 1910.1200, is often called the "Right to Know" rule. It makes chemical makers classify hazards and pass that information down the line, and it makes your employer keep a written program, label containers, keep Safety Data Sheets where you can get to them, and train you. Cleaners, solvents, fuels, adhesives, coolants, paints and many other everyday products are covered.

What You Will Be Able to Do

• Read the six parts of a chemical label and say what each pictogram means.
• Find the right section of a Safety Data Sheet (SDS) in under a minute.
• Label a secondary container correctly.
• Read an NFPA 704 diamond and avoid mixing up its numbers with GHS categories.
• Name the ways a chemical gets into your body.

How Chemicals Get Into Your Body

Think about the route before you think about the chemical. The three main routes are:

• Inhalation: breathing in vapor, gas, mist, fume or dust. This is the most common route at work.
• Skin absorption: passing through skin or eyes. Some solvents do this without leaving a mark.
• Ingestion: swallowing it, usually from hands that touched food, a cigarette or a phone.

A sharp object can also inject a chemical through the skin. The route tells you which protection matters.

The Six Parts of a Label

OSHA's label system follows the Globally Harmonized System (GHS). A shipped container carries these elements:

1. Product identifier: the name that matches the SDS.
2. Signal word: Danger for the more severe hazards, Warning for the less severe. A label has only one, and Danger wins if both could apply.
3. Hazard statements: set phrases such as "Causes severe skin burns and eye damage."
4. Pictograms: red-bordered diamonds that show the hazard type.
5. Precautionary statements: what to do for prevention, response, storage and disposal.
6. Supplier information: name, address and phone number of the maker or importer.

The Pictograms

Two pairs trip people up. The plain flame means the product burns. The flame over a circle means it adds oxygen and can make other things burn harder, so it must be kept away from fuels. The corrosion symbol means permanent tissue damage on contact. The exclamation mark covers irritants, which cause redness and swelling that heal. A corrosive is a much bigger problem than an irritant.

Secondary Containers

Pouring from a labeled drum into a spray bottle or bucket makes a secondary container. It must show the product identifier and the hazards in words, pictures or symbols. "Cleaner" on a piece of tape does not do that.

There is one narrow exception. If you fill a portable container for your own immediate use, and it stays with you during your shift, it does not need a label. If it leaves your hands, goes to someone else or stays past your shift, it must be labeled. In practice, label it anyway. Most chemical mix-ups start with an unmarked bottle.

Safety Data Sheets

An SDS is the full information sheet for a chemical. It has 16 sections in a set order, so once you know one you know them all. Your employer must keep one for every hazardous chemical on site, and you must be able to reach it during your shift, on paper or electronically, without a barrier.

Sections 12 through 15 are required by the GHS format, but OSHA does not enforce them because other agencies cover those subjects.

Worked example: You are told to degrease parts with a product you have not used before. Before you open it:

1. Find the SDS by the name on the label.
2. Section 2 shows it is flammable and irritates skin, with signal word Warning.
3. Section 7 says keep it away from ignition sources and keep the lid closed.
4. Section 8 calls for nitrile gloves, splash goggles and good ventilation.
5. Section 10 lists strong oxidizers as incompatible, so you move it away from the pool chlorine stored on the same shelf.
6. Section 4 tells you to flush skin with water and get fresh air, so you check where the nearest eyewash and sink are.

That takes about a minute, and it answers the questions that matter before anything goes wrong.

NFPA 704 Diamonds

Many buildings and tanks also carry the NFPA 704 diamond, which tells emergency responders what they face.

Blue, red and yellow are each rated 0 to 4, with 4 the worst.

Warning: The numbers run the opposite way in the GHS. A GHS Category 1 is the most severe, while a 1 on an NFPA diamond is a slight hazard. Do not read one as if it were the other.

Your Training

Your employer must train you when you are first assigned and whenever a new chemical hazard comes into your work area. It must cover where the written program and SDS are, how to spot a release, the hazards in your area, the protective measures, and how to read labels and SDS. It must be in a language and vocabulary you understand.

OSHA updated the standard in 2024 to line up with a newer GHS edition. Compliance dates run in stages: manufacturers and employers working with single substances first, with employers reaching their deadline for substances on November 20, 2026, and for mixtures on May 19, 2028. You may see small-container labels with less on them and some changed wording on labels and sheets during that time. The way you read them stays the same.

Common Mistakes

• Trusting a chemical because it smells mild. Many dangerous chemicals have little odor, or they deaden your sense of smell.
• Reusing a marked container for something else. The old label now tells a lie.
• Mixing products to get more cleaning power. Bleach and ammonia, or bleach and acid, give off toxic gas.
• Reading only the front of the label. The precautionary statements tell you what to do.

Check Your Understanding

1. A drum label shows a flame over a circle and the word Danger. Where should it not be stored?

Near fuels, solvents, oils, wood or other combustibles. It is an oxidizer, which makes things burn harder.

2. You fill a squeeze bottle with solvent and set it on a bench for the next shift. Does it need a label?

Yes. It left your possession and will outlast your shift, so the exception no longer applies.

3. You spilled a product on your arm. Which SDS section do you go to first, and which one tells you what gloves to wear next time?

Section 4 for first aid. Section 8 for gloves and other protection.

4. A tank placard shows a 3 in the blue area. Is that a mild or serious health hazard?

Serious. On an NFPA diamond a higher number is worse, and 4 is the top of the scale.

Key Takeaways

• You have a right to know about the chemicals in your work area and to be trained on them.
• Danger is more severe than Warning, and pictograms show the hazard type at a glance.
• The SDS has 16 sections. Start with 2, 4, 7, 8 and 10.
• Label every secondary container that leaves your hands.
• NFPA numbers rise with severity, while GHS categories fall with it.