Globally Harmonized System (GHS) labels and transport labels are two of the most common chemical labels, and they often get confused. A GHS label tells the people who use a chemical how it can harm them and how to handle it safely, while a transport label tells the people who move it, and emergency responders, which hazard class it belongs to during shipping.
Both serve important purposes, but they are used in different situations and follow different rules. In the US, the Occupational Safety and Health Administration (OSHA) sets the rules for GHS labels, and the Department of Transportation (DOT) sets the rules for transport labels.
In this article, you'll learn what each label is, when a shipped container needs both, why the two systems don't always agree, and how to tell them apart.
Key Takeaways
- GHS labels warn the people who use a chemical about its hazards and how to handle it, while transport labels warn the people who move it, and emergency responders, about its hazard class in transit.
- In the US, OSHA's Hazard Communication Standard (29 CFR 1910.1200) governs GHS labels, and DOT's Hazardous Materials Regulations (49 CFR Parts 171-180) govern transport labels.
- A GHS label carries a signal word, hazard and precautionary statements and pictograms, while a DOT transport label is a colored diamond at least 100 mm (3.9 in) on each side with a class number and no statements.
- A shipped container of a regulated hazardous material carries both labels, but where the DOT label shows a hazard, OSHA does not require the GHS pictogram for that same hazard.
- The two systems classify chemicals differently, so a chemical can need a GHS label and no transport label, such as a combustible liquid shipped in a small pail.
- The safety data sheet (SDS) holds the data for both labels: Section 2 for the GHS label and Section 14 for transport.
What Are GHS Labels?
GHS labels come from the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), developed by the United Nations. In the US, these requirements are enforced under OSHA's Hazard Communication Standard (29 CFR 1910.1200), last updated in 2024.
- Purpose: To protect workers by providing clear hazard information about chemicals in the workplace.
- Where you see them: On shipped containers from the manufacturer, importer or distributor, and on secondary containers such as spray bottles or smaller jars once chemicals are transferred, where OSHA also allows a simpler workplace label.
- What they include:
- Product identifier (matches the SDS)
- Supplier details (name, address, phone)
- Signal word: "Danger" or "Warning"
- Hazard statements (e.g., "Causes skin irritation")
- Precautionary statements (storage, handling, first aid)
- GHS pictograms (black symbols in red-framed diamonds showing hazards such as flammability or toxicity)
Think of GHS labels as workplace-focused. They tell you how a chemical might affect your health and safety when you use it.
What Are Transport Labels?
Transport labels, also called hazard class labels or, in the US, DOT hazmat labels, are used during shipping and transport of dangerous goods. In the US, the Pipeline and Hazardous Materials Safety Administration (PHMSA), part of DOT, regulates them under the Hazardous Materials Regulations (49 CFR Parts 171-180), which follow the UN Recommendations on the Transport of Dangerous Goods. Air and sea shipments can also follow the International Civil Aviation Organization (ICAO) Technical Instructions and the International Maritime Dangerous Goods (IMDG) Code.
- Purpose: To keep everyone safe during shipping, including truck drivers, cargo handlers, airport staff and emergency responders.
- Where you see them: On shipping boxes, barrels, drums and other packages used for moving hazardous materials, and as larger placards on the trucks and rail cars that carry them.
- What they include:
- Square-on-point (diamond) labels at least 100 mm (3.9 in) on each side, under 49 CFR 172.407; OSHA sets no minimum size for GHS labels
- Class numbers (e.g., Class 3 for flammable liquids)
- UN numbers (four-digit codes such as UN1203 for gasoline), which DOT requires as a marking on the package next to the proper shipping name, not on the label itself
- Standardized colors (e.g., red for flammable liquids and gases, green for non-flammable gases, white for toxic materials, black and white for corrosives)
Transport labels are travel-focused since they warn anyone handling the shipment about hazards during movement, storage, or accidents.
Some small packages ship as limited quantities and carry a limited quantity mark instead of hazard class labels.
GHS Labels vs Transport Labels: Key Differences
One way GHS labels differ from transport labels is what they say. A GHS label spells out the hazards in words, with a signal word and hazard and precautionary statements, while a transport label shows a colored diamond with a symbol, a class number and, at most, a short hazard name such as "FLAMMABLE LIQUID." They also differ in who reads them, which agency regulates them, and where they appear.
| Feature | GHS Labels (workplace) | Transport Labels (in transit) |
|---|---|---|
| Purpose | Worker safety and hazard communication at the point of use | Carriage safety and emergency awareness during shipping |
| Regulated by | OSHA Hazard Communication Standard (29 CFR 1910.1200) | DOT/PHMSA Hazardous Materials Regulations (49 CFR Parts 171-180) |
| Where used | Shipped containers and workplace containers, including containers filled on site | Packages, intermediate bulk containers (IBCs), freight containers and vehicles during transport |
| How it looks | Black symbols in red-framed diamonds, signal word, H and P statements, supplier details | Colored diamonds with a class number, at least 100 mm on each side; UN number and shipping name marked separately; placards on vehicles |
| Hazards covered | Physical and health hazards, including long-term effects such as cancer | Hazards in transport, in nine classes; most long-term health hazards have no transport label |
| Where the data comes from | SDS Section 2 | SDS Section 14 |
| Primary focus | Health and safety for users handling the chemical | Safe carriage and emergency response |
When a Shipped Container Carries Both Labels
A drum of a hazardous chemical that is also a regulated hazardous material carries both labels while it is shipped: the GHS label required by OSHA and the transport label required by DOT.
OSHA doesn't require the same hazard symbol twice. Where a DOT pictogram appears on a shipped container, OSHA's standard says the GHS pictogram "for the same hazard is not required on the label."
A drum of acetone with a DOT Class 3 flammable liquid label therefore doesn't need the GHS flame pictogram as well, but it still needs the rest of the GHS label, including the exclamation mark pictogram for acetone's eye irritation hazard.
For bulk shipments, such as tank trucks and rail cars, OSHA lets the GHS label go on the immediate container, with the shipping papers or bills of lading, or, if the receiving company agrees, by electronic means.
A transport label never replaces the GHS label. Once the drum arrives and goes into use, its GHS label must stay in place and readable, and any container you fill from it needs its own workplace label.
Why GHS and DOT Classifications Don't Always Match
GHS and DOT classifications don't always match because each system sets its own criteria for its own reader. A chemical can need a GHS label and no transport label at all.
Take a liquid with a flash point of 75 °C (167 °F). OSHA classes it as a flammable liquid Category 4, so its GHS label carries the signal word "Warning" and no pictogram.
DOT classes the same liquid as a combustible liquid, and in non-bulk packaging, such as a 5-gallon pail, it isn't regulated as a hazardous material in transport unless it is also a hazardous substance, hazardous waste or marine pollutant.
Health hazards work the same way. A carcinogen carries the GHS health hazard pictogram, but DOT has no hazard class for cancer, so it ships without a transport label unless it also meets a transport class, such as flammable or toxic.
To avoid both mistakes, take each label's data from its own section of the current supplier SDS instead of working one label out from the other.
Why It's Important to Know the Difference
Confusing the two can lead to serious compliance issues. For example:
- A container in the workplace must have a GHS label so employees know how to handle it safely.
- A shipping drum being sent to another site must also have transport labels if its contents are a regulated hazardous material, so drivers and emergency teams know what's inside if there's an accident.
Both labeling systems work hand-in-hand to keep people safe, but they serve different audiences and different stages in a chemical's lifecycle.
A third system, the NFPA 704 diamond, goes on buildings, storage areas and tanks for firefighters, and it replaces neither label.
Making Labeling Easy
Creating labels by hand means copying Section 2 and Section 14 of every SDS, then checking them again each time a supplier revises the SDS.
For shipped containers, SDS Manager creates GHS transport labels in 12 sizes, each with the hazard pictograms, UN number, packing group and H- and P-statements taken from the SDS in your library.
For containers you fill on site, SDS Manager prints GHS-compliant secondary container labels, complete with pictograms, signal words and a QR code that links directly to the safety data sheet.
If you need a label for a single product, the transport label generator builds one from its SDS.
For the DOT hazard class labels, placards and package markings themselves, always refer to the Hazardous Materials Regulations so shipments meet legal standards.
Final Thoughts
When it comes to GHS labels vs transport labels, the difference comes down to where the chemical is and who needs the information.
- GHS labels: For employees handling chemicals in the workplace.
- Transport labels: For anyone shipping, moving, or responding to an accident with hazardous materials.
By understanding and applying both correctly, companies can keep workers safe, meet regulations, and prevent accidents both inside the facility and on the road.
Frequently Asked Questions
Do I Need Both a GHS Label and a Transport Label?
You need both a GHS label and a transport label on a shipped container of a hazardous chemical that is also a regulated hazardous material. Containers that stay in your workplace, including secondary containers, need only a workplace label.
Can a Transport Label Replace a GHS Label Once the Product Arrives?
A transport label cannot replace a GHS label once the product arrives. Transport labels are for shipping, so a container in use on site still needs its GHS label or another OSHA-compliant workplace label.
Where Do I Find the Right Info for Each Label?
You find the right info for each label on the SDS. Section 2 gives the GHS label elements (pictograms, signal word, hazard and precautionary statements), and Section 14 gives the transport details (UN number, proper shipping name, hazard class and packing group).
What's the Difference Between a UN Number and a CAS Number?
The difference between a UN number and a CAS number is that a UN number identifies a hazardous material, or a group of them, for transport, while a CAS number, assigned by the Chemical Abstracts Service, identifies one specific chemical substance. For example, UN1993 covers flammable liquids not otherwise specified.
Are the Symbols the Same on Both Labels?
The symbols on GHS and transport labels are similar but not the same. Both use diamonds and share symbols such as the flame, but a GHS pictogram is a black symbol in a red frame with text around it on the label, while a transport label is a colored diamond with a class number.