GHS Pictograms: the Complete Visual Guide to All 9 Hazard Symbols

GHS pictograms are the nine standardized symbols the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) uses to communicate chemical hazards on labels and Safety Data Sheets (SDS). Each pictogram is a black symbol on a white background inside a red diamond border, and each one represents a specific hazard class, from flammability to acute toxicity to environmental harm. Under OSHA's Hazard Communication Standard (29 CFR 1910.1200), U.S. employers must use eight of these nine pictograms on labels for hazardous chemicals in the workplace; the ninth, Environment, is optional under U.S. law.

What Are GHS Pictograms?

"GHS" stands for the Globally Harmonized System of Classification and Labelling of Chemicals, a United Nations framework that standardizes how chemical hazards are classified and communicated worldwide. Every GHS pictogram follows the same visual format: a black hazard symbol centered on a white background, framed by a red diamond (technically a square rotated 45 degrees, or a "square set on point"). That consistency is intentional. A worker who recognizes the shape and color on one product recognizes it on any product, in any country that has adopted GHS.

It's worth clearing up a common point of confusion early: GHS pictograms are not the same thing as the NFPA 704 diamond, the numeric hazard rating often posted on facility doors and tanks, or an HMIS (Hazardous Materials Identification System) label. NFPA 704 and HMIS use numeric severity ratings inside colored fields, and they're built for different audiences and purposes, mainly emergency responders and internal facility hazard ratings, rather than the point-of-use container label required by HazCom. GHS pictograms, by contrast, are printed on the product label itself and travel with the chemical wherever it goes.

GHS pictograms show up in two places an EHS professional deals with constantly: the container label and Section 2, Hazard Identification, of the SDS.

The history is also worth getting right, since the two systems are often assumed to have arrived together. OSHA's original Hazard Communication Standard dates to 1983, decades before GHS existed. The United Nations did not publish the first version of GHS until 2003. OSHA aligned HazCom with GHS in its 2012 final rule, often called "HazCom 2012," which adopted GHS Revision 3. HazCom predates GHS; GHS didn't create HazCom, it reshaped it. OSHA has since updated the standard again: a 2024 final rule aligned HazCom with GHS Revision 7, effective July 19, 2024. That update revises how a few hazard classes are categorized (more on that below), but it does not change the nine pictograms themselves or which eight are mandatory in the U.S.

Why Do GHS Pictograms Matter for Workplace Safety?

Pictograms exist to be understood before anyone reads a word. A worker handling a drum in a warehouse should recognize "corrosive" or "flammable" from the symbol alone, faster than they could read and process a full hazard statement. That's the design premise: fast hazard recognition at the point of use, which drives real decisions, like which glove to put on, whether a spark-producing tool belongs nearby, or which chemicals can't be stored on the same shelf.

Pictogram accuracy is also a direct compliance issue, not a cosmetic one. OSHA's Hazard Communication standard is a perennial presence on the agency's list of most frequently cited standards. A mislabeled, faded, or missing pictogram on a container is exactly the kind of finding an inspector documents on a walkthrough.

Beyond citations, pictograms feed decisions that help prevent real exposure incidents: PPE selection, storage segregation (keeping oxidizers away from flammables, for example), and spill or emergency response. Getting the symbol wrong, or failing to update it after a chemical is reclassified, isn't just a paperwork gap; it's a break in the chain that's supposed to warn someone before they're exposed.

What Are the 9 GHS Pictograms and What Do They Mean?

Each pictogram below maps to a defined set of hazard classes under OSHA's Hazard Communication Standard, reflecting OSHA's current Hazard Communication Standard Pictogram QuickCard (OSHA 3491, 2024 edition).

1. Health Hazard. The Health Hazard pictogram shows a human silhouette with a starburst pattern over the chest. It covers longer-term or systemic health hazards: carcinogens, mutagens, reproductive toxicants, respiratory sensitizers, target organ toxicants, and aspiration toxicity. You'll see it on SDSs for materials like crystalline silica dust and many industrial solvents, where the risk isn't an immediate burn or acute poisoning but cumulative or delayed harm.

2. Flame. The Flame pictogram covers flammable liquids, gases, and solids, along with pyrophorics, self-heating substances, materials that emit flammable gas, self-reactive substances, organic peroxides, and, as of the 2024 update, desensitized explosives. Acetone and propane are common examples; so is any aerosol product with a flammable propellant.

3. Exclamation Mark. This is the "lower severity, still hazardous" pictogram: skin and eye irritants, skin sensitizers, acute toxicity at the harmful (not fatal) level, narcotic effects, and respiratory tract irritation. Two non-mandatory categories also fall under this symbol: hazardous to the ozone layer, and Hazard Not Otherwise Classified (HNOC), a catch-all for hazards that don't fit a formal GHS class but still require disclosure. It's one of the most common pictograms in a typical workplace, since it applies to many everyday cleaning products and solvents.

4. Gas Cylinder. The Gas Cylinder pictogram covers gases under pressure, including compressed, liquefied, dissolved, and refrigerated gases, and, as of the 2024 update, chemicals under pressure. Compressed nitrogen cylinders and welding gases like acetylene are typical examples.

5. Corrosion. Corrosion covers skin corrosion and burns, serious eye damage, and corrosivity to metals. Battery acid and sodium hydroxide (lye) both carry this pictogram, as does anything strong enough to eat through a metal container over time.

6. Exploding Bomb. This pictogram covers explosives, self-reactive substances, and organic peroxides. Certain industrial oxidizing agents and materials used in blasting or pyrotechnic applications carry this symbol.

7. Flame Over Circle. Flame Over Circle indicates an oxidizer: a substance that can intensify combustion even though it isn't flammable itself. Hydrogen peroxide and ammonium nitrate are common examples. It's easy to confuse with the plain Flame pictogram, but the underlying hazard mechanism is different (see the FAQ below).

8. Skull and Crossbones. This pictogram is reserved for acute toxicity severe enough to be fatal or seriously toxic at low doses, a higher severity than the acute toxicity covered by the Exclamation Mark. Certain pesticides and cyanide compounds are common examples.

9. Environment. The Environment pictogram, a dead fish beside a dying tree, indicates aquatic toxicity. It's part of the UN GHS framework but is not mandated by OSHA. You'll still see it on SDSs that include Section 12 ecological information, and on labels for products manufactured or sold outside the U.S., since many other countries with GHS-based systems do require it.

GHS Pictograms vs OSHA-Required Pictograms: What's the Difference?

The confusion here is understandable: the UN's GHS framework defines nine pictograms, but OSHA's Hazard Communication Standard requires only eight of them on U.S. workplace labels. The Environment pictogram is the one exception. OSHA does not require it on U.S. labels, though a manufacturer can include it voluntarily, and it's common on SDSs and on products sold internationally.

This isn't a U.S.-only quirk. Other countries and regions that have adopted GHS don't all implement it identically. The building-block structure of GHS lets each jurisdiction choose which hazard classes and label elements to adopt, so a label compliant under the EU's CLP regulation can look slightly different from a U.S. HazCom label, even for the same chemical.

The practical guidance for U.S. employers: confirm that labels include the applicable pictograms from OSHA's mandatory set of eight, based on the chemical's actual hazard classification (not every pictogram appears on every label, only the ones that apply). The Environment pictogram is worth checking for, since its presence signals ecological data beyond OSHA's minimum, but its absence is not itself a compliance gap. Appendix C to 1910.1200, Allocation of Label Elements, is the reference for which pictogram pairs with which hazard classification.

Where Do GHS Pictograms Appear on Labels and Safety Data Sheets?

On a container label, the pictogram never stands alone. OSHA's Hazard Communication Standard requires it to appear alongside a signal word ("Danger" or "Warning"), a hazard statement, a precautionary statement, the product identifier, and supplier information. The pictogram tells the reader what kind of hazard exists; the surrounding text tells them how severe it is and what to do about it.

On the SDS, pictograms live in Section 2, Hazard Identification, near the front of OSHA's standardized 16-section SDS format. That placement is deliberate: Section 2 is meant to be the fastest place to find "what am I dealing with" before moving into the more detailed sections on composition, handling, or exposure controls.

Secondary containers, the smaller bottles or bins workers fill from a larger source container, generally need their own label with the applicable pictograms, unless the same employee transfers the chemical and uses it entirely within the same work shift, the immediate-use exception. That exception is one of the most commonly misapplied parts of the standard; a container left on a shelf overnight, or handed off to another employee, no longer qualifies.

How Do EHS Teams Keep Pictogram Labeling Accurate and Compliant?

In practice, pictogram accuracy breaks down in a few predictable ways: labels that fade or get damaged in the field, secondary containers that never get labeled at all, and SDS records that don't get updated when a chemical is reclassified or reformulated. Any one of these can leave a pictogram on a container that no longer matches the current hazard classification, or no pictogram at all.

A chemical inventory and SDS management system helps close that gap by giving every material a single, current record instead of relying on whatever's printed on the container. EHS Insight's Chemical Management Module, for example, stores each material's hazardous properties and CAS number alongside its linked Safety Data Sheet in one Material List, and can be configured to require an attached SDS before a material is added to inventory. That gives EHS teams one place to check whether a chemical's documentation, including its current SDS, is on file and current, rather than relying on a label surviving a shift on the plant floor.

Frequently Asked Questions

What Are the 9 GHS Pictograms?

The nine GHS pictograms are Health Hazard, Flame, Exclamation Mark, Gas Cylinder, Corrosion, Exploding Bomb, Flame Over Circle (oxidizer), Skull and Crossbones (acute toxicity), and Environment. Each appears as a black symbol inside a red diamond border. OSHA requires the first eight on workplace labels; the Environment pictogram is part of the UN GHS system but not mandated by OSHA.

What Is the Difference Between GHS Pictograms and Hazard Symbols?

"GHS pictogram" and "hazard symbol" are often used interchangeably, but GHS pictograms specifically refer to the nine standardized red-diamond symbols defined by the Globally Harmonized System. Older systems like the NFPA 704 diamond or HMIS ratings use different visual formats and are not GHS pictograms, even though they also communicate chemical hazards.

Does OSHA Require All 9 GHS Pictograms?

No. OSHA's Hazard Communication Standard (29 CFR 1910.1200) requires eight of the nine GHS pictograms on workplace labels. The Environment pictogram, which indicates aquatic toxicity, is part of the broader UN GHS framework but is not required under U.S. OSHA regulations.

What Does the Exclamation Mark Pictogram Mean?

The Exclamation Mark pictogram indicates a lower-severity hazard category: skin or eye irritation, skin sensitization, acute toxicity at a less severe level, narcotic effects, or respiratory tract irritation, plus two non-mandatory categories (hazardous to the ozone layer and Hazard Not Otherwise Classified). It's one of the most commonly seen GHS pictograms because it applies to many everyday industrial and cleaning products.

Where Do GHS Pictograms Appear?

GHS pictograms appear on chemical container labels and in Section 2, Hazard Identification, of the Safety Data Sheet (SDS). Properly labeled secondary containers used in the workplace should also carry the relevant pictograms, along with the signal word and hazard statement.

What Is the Difference Between the Flame and Flame Over Circle Pictograms?

The Flame pictogram indicates flammability: flammable liquids, gases, solids, or self-reactive substances. The Flame Over Circle pictogram indicates an oxidizer, a substance that can intensify a fire or cause combustion even though it isn't flammable itself. They represent distinct hazard classes and often appear together on the same product.