The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) uses nine pictograms - red-bordered diamonds with black symbols on white backgrounds - to communicate the types of hazards a chemical poses. Under OSHA's Hazard Communication Standard (HazCom 2012, 29 CFR 1910.1200), every chemical container in the workplace must display the appropriate GHS pictograms on its label. Understanding what each symbol means is essential for anyone who handles, stores or works near hazardous chemicals.

This guide covers all nine GHS pictograms, the hazard classes each one represents and practical guidance on how to use this information to protect workers and maintain compliance.

How GHS Pictograms Work

Each GHS pictogram appears as a black symbol inside a red-bordered diamond (formally called a "red-bordered diamond-shaped" symbol set on a point). The red border with a white background is mandatory - pictograms printed in black and white without the red border do not meet GHS labeling requirements.

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A single chemical product can display multiple pictograms because one substance can present several types of hazards simultaneously. For example, a flammable solvent that is also acutely toxic might show both the flame and skull-and-crossbones pictograms. The pictograms on a label are determined by the chemical's hazard classification, which is documented on its Safety Data Sheet (SDS).

GHS Pictograms vs. Old NFPA/HMIS Systems

Before GHS adoption, many U.S. workplaces used the NFPA 704 diamond or HMIS color-bar system. These older systems are still allowed for facility-level marking, but they do not replace GHS labeling requirements on individual chemical containers. GHS pictograms are the required format on manufacturer labels and workplace container labels under OSHA HazCom 2012.

All 9 GHS Pictograms Explained

1. Flame (GHS02)

The flame pictogram indicates that a substance is flammable or pyrophoric. It covers the following hazard classes:

Workplace implication: Store away from heat sources, open flames and oxidizers. Use grounding and bonding when transferring flammable liquids. Ensure adequate ventilation to prevent vapor accumulation.

2. Flame Over Circle (GHS03)

This pictogram shows a flame sitting on top of a circle and indicates an oxidizer. Oxidizers do not necessarily burn themselves, but they intensify fires by supplying oxygen or other reactive elements. Hazard classes include:

Workplace implication: Never store oxidizers near flammable or combustible materials. Even materials that do not normally burn easily (like clothing or wood) can ignite violently in the presence of strong oxidizers. Use dedicated storage cabinets and maintain separation distances per your GHS hazard classification guide.

3. Gas Cylinder (GHS04)

The gas cylinder pictogram indicates gases stored under pressure. This includes:

Workplace implication: Pressurized containers can explode if exposed to heat or physical damage. Store cylinders upright and secured with chains or straps. Keep away from heat sources and direct sunlight. Use appropriate regulators and never modify cylinder valves.

4. Corrosion (GHS05)

The corrosion pictogram shows a chemical burning through material and skin. It indicates substances that cause:

Workplace implication: Wear chemical-resistant gloves, aprons, face shields and splash goggles. Ensure emergency showers and eyewash stations are accessible within 10 seconds of travel. Store corrosives in compatible containers and secondary containment. Separate acids from bases.

5. Skull and Crossbones (GHS06)

The skull and crossbones is the most universally recognized hazard symbol. Under GHS, it specifically indicates acute toxicity of high severity (Categories 1, 2 and 3). Routes of exposure include:

Workplace implication: These substances can cause death or serious harm from a single exposure or short-term exposure. Implement strict engineering controls (ventilation, enclosure), require specific PPE and maintain emergency response materials including antidotes where applicable. Restrict access to trained and authorized personnel only.

6. Exclamation Mark (GHS07)

The exclamation mark is the broadest pictogram, covering less severe versions of several hazard types:

Workplace implication: While less immediately dangerous than skull-and-crossbones chemicals, these substances still require appropriate PPE and ventilation. Repeated exposure to irritants and sensitizers can lead to chronic health effects including occupational asthma and dermatitis.

7. Health Hazard (GHS08)

The health hazard pictogram shows a silhouette of a human torso with a starburst on the chest. It indicates chronic or systemic health effects:

Workplace implication: These are among the most serious long-term health hazards. Many effects are irreversible and may not appear for years. Implement exposure monitoring, medical surveillance, engineering controls and respiratory protection. Maintain thorough records of worker exposure. This pictogram demands the highest level of attention in your hazard communication program.

8. Environment (GHS09)

The environment pictogram shows a dead tree and dead fish, indicating substances that are hazardous to the aquatic environment:

Workplace implication: Prevent releases to drains, waterways and soil. Maintain spill containment and response materials. This pictogram is not required by OSHA HazCom 2012 on workplace labels (OSHA did not adopt the environmental hazard classification), but it frequently appears on manufacturer labels because GHS is an international system and many manufacturers label for global compliance.

9. Exploding Bomb (GHS01)

The exploding bomb pictogram indicates substances and mixtures that can detonate or explode:

Workplace implication: Store in designated, purpose-built explosive magazines or storage areas. Maintain strict quantity limits, separation distances and access controls. Follow all ATF and DOT requirements in addition to OSHA standards. Eliminate all ignition sources in storage and handling areas.

Reading a GHS Label

Pictograms are just one element of a complete GHS label. Every compliant label must also include:

When a chemical displays multiple pictograms, read all of them together with the hazard statements to understand the full risk profile. A substance with both the flame and health hazard pictograms, for example, needs controls for both fire risk and chronic health effects.

Training Workers on GHS Pictograms

OSHA requires that all employees who work with or near hazardous chemicals receive HazCom training that includes how to read GHS labels and Safety Data Sheets. Effective pictogram training should accomplish three things.

First, workers should be able to identify all nine pictograms by sight and state the general hazard category each represents. Second, they should know where to find additional information (the SDS) when a pictogram indicates a hazard they are unfamiliar with. Third, they should understand what immediate protective actions each pictogram demands - the PPE to wear, the storage requirements to follow and the emergency response steps to take.

Deliver this training using toolbox talks with visual aids. Post pictogram reference charts in chemical storage areas, mixing rooms and near SDS binders. Reinforce the training whenever new chemicals are introduced to the workplace.

Common GHS Labeling Mistakes

Even workplaces with good intentions make labeling errors that can lead to OSHA citations.

Start Building a Stronger HazCom Program

Understanding GHS pictograms is the foundation of chemical safety in any workplace. Pair that knowledge with organized SDS management, documented training records and regular label audits to build a HazCom program that protects workers and passes inspections. Request a demo of Make Safety Easy to see how our platform helps you manage chemical safety documentation, deliver pictogram training and track compliance across your entire operation, or view our pricing plans to get started today.