Globally Harmonized System (GHS) labels and National Fire Protection Association (NFPA) labels warn about the same chemicals for different readers. A GHS label is the hazard label the Occupational Safety and Health Administration (OSHA) requires on shipped chemical containers, written for the workers who handle them. An NFPA 704 diamond, often just called an NFPA diamond or NFPA label, is a four-color sign that fire codes use to show emergency responders the hazards of a building, room or tank at a glance.
The two systems also number hazards in opposite directions. On a GHS label, Category 1 is the most severe hazard, while on an NFPA diamond, 4 is the most severe. You can use NFPA labels on containers that stay inside your workplace, under conditions, but they never replace the GHS label on a container you ship.
In this article, you'll learn how GHS and NFPA labels differ, why their numbers can't be swapped, when OSHA accepts an NFPA label on a workplace container, and where Hazardous Materials Identification System (HMIS) labels fit.
Key Takeaways
- A GHS label is required by OSHA's Hazard Communication Standard on shipped chemical containers. An NFPA diamond is not required by OSHA, but a local fire code may require it at storage areas and on tanks.
- GHS labels are written for workers handling a chemical every day, while NFPA diamonds are read by firefighters and other responders during a fire or spill.
- GHS hazard categories start at 1 for the most severe hazard and go up to 4 at most under OSHA, while NFPA ratings run from 0 (least) to 4 (most hazardous).
- NFPA 704 does not cover chronic health effects such as cancer, which a GHS label shows with the health hazard pictogram.
- OSHA's comparison guide says not to fill in an NFPA diamond with the GHS category numbers from an SDS.
- NFPA or HMIS labels can serve as workplace labels on in-house containers if they agree with the GHS classification, chronic hazards are added, and workers are trained on both systems.
What Is the Difference Between GHS and NFPA Labels?
The main difference between GHS and NFPA labels is who they are for. A GHS label tells workers how a chemical can hurt them and how to handle it safely under normal use, while an NFPA 704 diamond tells emergency responders how a chemical behaves in a fire or spill. OSHA's NFPA 704 and HazCom comparison guide describes them that way.
| GHS label | NFPA 704 diamond | |
|---|---|---|
| Purpose | Hazards of a chemical under normal use, and how to work with it safely | Basic hazard information for responders to a fire or spill |
| Main reader | Workers and employers | Firefighters and other emergency responders |
| Where it goes | On each chemical container | At entrances to buildings, rooms and storage areas, and on tanks |
| Required by | OSHA Hazard Communication Standard (29 CFR 1910.1200) | Local fire codes, as enforced by the local fire official |
| Number scale | Category 1 is most severe; higher categories (up to 4) are less severe | 0 (least hazardous) to 4 (most hazardous) |
| Hazards covered | Physical and health (acute and chronic) hazards; environmental hazards optional in the US | Health (acute), flammability, instability and special hazards |
| Format | Text, signal word and red-framed pictograms | Four colored squares with numbers and symbols, no text |
What Does a GHS Label Show?
A GHS label on a shipped container shows the six GHS label elements set by OSHA's Hazard Communication Standard, which was last updated in 2024:
- the product identifier, matching the safety data sheet (SDS)
- the name, address and phone number of the manufacturer, importer or distributor
- a signal word, "Danger" or "Warning"
- hazard statements, such as "Causes serious eye irritation"
- pictograms, the red-framed symbols such as the flame or the skull and crossbones
- precautionary statements on prevention, response, storage and disposal
What Does the NFPA 704 Diamond Show?
The NFPA diamond rates a chemical from 0 to 4 in three colored squares and adds symbols in a fourth, according to the NFPA 704 standard of the National Fire Protection Association:
- Blue (health): how badly short-term exposure can harm a responder, from 0 (no hazard beyond ordinary combustible material) to 4 (very short exposure may cause death or major injury).
- Red (flammability): how easily the material burns, from 0 (will not burn) to 4 (vaporizes and burns readily at normal temperature).
- Yellow (instability): how likely the material is to react or explode, from 0 (normally stable, even in a fire) to 4 (may detonate at normal temperature and pressure).
- White (special hazards): only three symbols are part of the standard: OX for oxidizers, W with a line through it for materials that react dangerously with water, and SA for simple asphyxiant gases such as nitrogen.
Other white-square codes, such as COR or ACID, are not part of NFPA 704, and your local fire official decides whether they are allowed.
Why Do GHS and NFPA Numbers Run in Opposite Directions?
GHS and NFPA numbers run in opposite directions because each system was built for its own job. A GHS hazard category ranks how severe a hazard is within a hazard class, starting with 1 for the most severe, while an NFPA rating scores how dangerous the material is to a responder, ending with 4 for the most dangerous.
Acetone shows the trap. A US supplier SDS for acetone from Sigma-Aldrich (revised 2016) classifies it as a flammable liquid Category 2, with the signal word "Danger", and lists NFPA ratings of health 2, flammability 3 and instability 0 in Section 16. The same flammability hazard is "2" on the GHS side and "3" on the NFPA side, and neither number is wrong.
Ratings can also differ between sources. NOAA's CAMEO Chemicals database lists acetone as health 1, flammability 3 and instability 0, so check your ratings against the current supplier SDS before you print a sign.
Can You Fill In an NFPA Diamond From an SDS?
You cannot fill in an NFPA diamond from the GHS hazard categories on an SDS. OSHA's comparison guide says the category numbers are required in Section 2 of the SDS but "are NOT to be used to fill in the NFPA 704 diamond."
NFPA ratings come from the criteria in NFPA 704 itself, such as flash point and boiling point for the flammability rating. Many suppliers list NFPA ratings in Section 16 of the SDS, as Sigma-Aldrich does for acetone, and you can use those. Where the SDS gives no NFPA ratings, the person assigning them needs the NFPA 704 criteria and the chemical's test data.
Are NFPA 704 Labels Acceptable Workplace Labels?
NFPA 704 labels are acceptable workplace labels on containers that stay in your workplace, if they meet OSHA's conditions. A workplace label is the label on a container you fill or use inside your own workplace, such as a spray bottle you fill from a drum. OSHA accepts an NFPA label there on four conditions:
- the label must be consistent with the HazCom standard, with no conflicting hazard warnings or pictograms
- hazards that NFPA 704 does not cover, such as chronic health effects, must be added in words, pictures or symbols
- workers must be able to get the specific hazard information right away, for example from the SDS
- workers must be trained on both the GHS labels and the NFPA system
An NFPA diamond can never replace the GHS label on a container that leaves your workplace. Inside your workplace, it is one of several ways OSHA allows for labeling secondary containers.
Does OSHA Require NFPA Labels?
OSHA does not require NFPA labels. NFPA 704 is a standard of the National Fire Protection Association, and it becomes mandatory only where a fire code adopts it.
Many local fire codes do. A San Diego Fire-Rescue policy based on the California Fire Code, for example, requires NFPA 704 signs on stationary containers and at entrances to locations where hazardous materials are stored, dispensed, used or handled. The local authority having jurisdiction, such as the fire marshal, approves where the signs go and how large they are.
What About HMIS Labels?
HMIS labels, from the Hazardous Materials Identification System of the American Coatings Association, rate health (blue), flammability (red) and physical hazard (orange) from 0 to 4 in colored bars, and add a white bar with a letter for the protective equipment to wear. An asterisk next to the health rating marks a chronic health hazard.
According to ILPI's HMIS reference, HMIS is meant for employees and is not intended for emergencies, and its health ratings are scored differently from NFPA's.
HMIS is not required by OSHA either. Like NFPA labels, HMIS labels can serve as workplace labels on in-house containers under the same conditions, and like NFPA ratings, they must not be copied from GHS category numbers.
Print GHS, NFPA and HMIS Labels From One SDS Library
Keeping GHS labels, NFPA diamonds and HMIS labels consistent by hand means checking every rating against every revised SDS.
SDS Manager prints NFPA labels from the SDS in your library: you find the product, select "Print NFPA label", and set any ratings the SDS does not give.
The same library prints HMIS labels for in-house use, so your NFPA and HMIS ratings come from the same SDS.
SDS Manager also keeps your SDS library up to date with the latest supplier versions, so the ratings you print match the current SDS.
For your GHS workplace labels, SDS Manager prints secondary container labels with a QR code that opens the full SDS when a worker scans it.
Frequently Asked Questions
Does an NFPA Label Replace a GHS Label?
An NFPA label does not replace a GHS label on a shipped container, which always needs the full GHS label. On containers that stay in your workplace, an NFPA label can stand in for the GHS label if it agrees with the GHS classification, adds chronic hazards and your workers are trained on it.
Is NFPA 704 the Same as GHS?
NFPA 704 is not the same as GHS. GHS is a United Nations system for classifying chemicals and labeling containers, while NFPA 704 is a US fire-safety standard for signs that responders read during an emergency.
What Do the Four Colors on the NFPA Diamond Mean?
The four colors on the NFPA diamond mean blue for health, red for flammability, yellow for instability and white for special hazards. The first three carry a rating from 0 to 4, and the white square carries a symbol such as OX or W.
Are HMIS and NFPA the Same?
HMIS and NFPA are not the same. Both rate hazards from 0 to 4, but NFPA diamonds are signs for emergency responders, while HMIS labels use colored bars, show protective equipment and are meant for workers handling the chemical. The two can give the same chemical different numbers, because their criteria differ.