Red diamond symbols appear on chemical containers across Singapore workplaces, including factories, laboratories, warehouses, construction sites, and cleaning stores.
These symbols are GHS pictograms. Each one gives workers an immediate warning about a chemical’s hazards. Therefore, recognising them can help prevent fires, poisoning, chemical burns, and long-term illness.
However, a pictogram never tells the whole story. Workers must also read the label, check the Safety Data Sheet, and follow workplace procedures before starting work.
This guide explains all nine symbols and shows workers how to use them within Singapore’s safety framework.
What are GHS pictograms?
GHS means the Globally Harmonised System of Classification and Labelling of Chemicals. The United Nations developed it to improve hazard communication across countries.
Each pictogram uses a black symbol, a white background, and a red border. Therefore, workers can quickly recognise hazards across different suppliers.
In Singapore, SS 586 covers chemical hazard communication. Parts 2 and 3 address GHS classification, labelling, and Safety Data Sheets.
The revised Parts 2 and 3 took effect on 6 February 2025. The joint MOM, NEA, and SCDF circular confirms this date.
Therefore, employers should make pictogram knowledge a core part of chemical safety training.
Quick answer: What do GHS pictograms mean?
GHS pictograms identify physical, health, or environmental hazards. The nine symbols cover explosions, fires, oxidisers, pressurised gases, corrosion, toxicity, health damage, irritation, and aquatic harm.
However, the exact risk depends on the task, quantity, concentration, exposure route, and control measures. Therefore, always use the pictogram together with the complete label and Safety Data Sheet.
The nine GHS pictograms and their meanings
1. Exploding bomb: Explosion hazard
The exploding bomb warns about chemicals that may explode. Heat, flames, friction, or impact can trigger a dangerous reaction.
This symbol may cover explosives, certain self-reactive substances, and some organic peroxides. Therefore, keep these materials away from ignition sources and physical shock.
Also, use approved storage areas and procedures. Workers should know the emergency plan before handling the product.
2. Flame: Fire hazard
The flame identifies materials that can ignite or release flammable gas. It can appear on liquids, solids, gases, aerosols, and self-heating chemicals.
For example, solvents, fuels, and some cleaning products may carry this pictogram.
Therefore, remove ignition sources and provide ventilation. Also, use an appropriate cabinet or designated storage area.
3. Flame over circle: Oxidising hazard
The flame-over-circle identifies oxidisers. These chemicals may not burn, but they can start or intensify another material’s fire.
Consequently, keep oxidisers away from fuels, paper, cloth, wood, and reducing agents. Small contamination events can cause serious reactions.
Before storage, check the SDS compatibility information. Also, use separate containment when required.
4. Gas cylinder: Gas under pressure
The gas cylinder warns about gas under pressure. Heat can raise pressure, while valve damage can turn a cylinder into a projectile.
Furthermore, refrigerated gas may cause cold burns. Escaping gas can also displace oxygen or create other hazards.
Therefore, secure cylinders upright, protect their valves, and maintain ventilation. Always use the correct regulator and a suitable trolley.
5. Corrosion: Severe burns or metal damage
The corrosion pictogram shows liquid attacking a hand and a metal surface. It warns about severe skin burns, serious eye damage, or corrosion of metals.
First, prevent splashes through safer equipment. Next, wear the gloves, eye protection, and clothing that the SDS specifies.
Moreover, provide nearby washing facilities. Store corrosives in compatible containers with secondary containment.
6. Skull and crossbones: Severe acute toxicity
The skull and crossbones signals severe acute toxicity. A small exposure may cause serious poisoning or death through inhalation, swallowing, or skin contact.
Therefore, use enclosure, extraction, and controlled access. Only trained workers should handle the chemical.
If exposure occurs, follow the emergency instructions. Then obtain medical help and give responders the label or SDS.
7. Health hazard: Serious or long-term health effects
The health hazard symbol shows a person with a star-shaped mark on the chest. It warns about severe effects that may appear slowly.
Effects can include cancer, genetic damage, reproductive harm, respiratory sensitisation, or organ damage. Consequently, never use smell as a safety test.
Instead, control fumes, vapours, and dusts at their source. In addition, follow exposure limits and task-specific precautions.
8. Exclamation mark: Harmful or irritating effects
The exclamation mark often indicates skin irritation, eye irritation, skin sensitisation, respiratory irritation, drowsiness, or harmful acute toxicity.
Although these hazards may seem less severe, they still require proper controls.
Therefore, avoid breathing vapour, mist, or dust. Also, prevent contact, provide ventilation, and wear the required PPE.
9. Environment: Aquatic toxicity
The environment symbol shows a dead tree and fish. It warns about harm to aquatic life.
Therefore, never pour the chemical into sinks, drains, soil, or waterways. Instead, use suitable spill containment and follow approved waste disposal procedures.
Singapore’s National Environment Agency also controls certain hazardous substances. Therefore, review NEA’s guidance for relevant requirements.
How to read a GHS label correctly
A pictogram provides a fast warning, but the complete label guides action. Therefore, check every label element before use.
A GHS label includes the product identifier, pictograms, signal word, hazard statements, precautions, supplementary information, and supplier details.
The signal word “Danger” generally marks more severe hazards. In contrast, “Warning” generally marks less severe categories.
Hazard statements explain the danger. Meanwhile, precautionary statements cover prevention, response, storage, and disposal.
One product may display several pictograms. For example, a solvent may present both fire and health hazards.
GHS pictograms show hazards, not the full risk
A hazard describes a chemical’s ability to cause harm. In contrast, risk considers possible harm during a specific task.
For example, quantity, concentration, temperature, exposure time, ventilation, and handling method can change the risk.
Therefore, employers need task-specific risk assessments, effective controls, and clear work procedures.
PPE remains important. However, use engineering or process controls whenever practical.
What should workers do before handling chemicals?
First, confirm the product’s identity. Do not use a container with a missing or unreadable label.
Next, read the label and current SDS. Check handling, storage, exposure controls, first aid, spill response, and compatibility.
Then, review the risk assessment. Check ventilation, emergency equipment, washing facilities, and spill supplies.
Finally, wear the specified PPE and follow the approved method. Never use an unlabelled or food container.
Safety Data Sheet requirements in Singapore
Manufacturers and suppliers must prepare an SDS for products that meet GHS hazardous criteria. Users should keep it accessible.
According to
MOM’s SDS guidance, organisations must review each SDS within five years of its issue date. They must also review it when new chemical information becomes available.
Therefore, check SDS dates during inventory reviews. Replace outdated copies and brief workers about important changes.
Build a stronger chemical safety culture
GHS pictograms help workers recognise danger. However, protection also requires training, labels, Safety Data Sheets, safe storage, and emergency preparation.
Therefore, include pictogram recognition in induction and refresher training. Supervisors should confirm understanding through workplace checks.
Most importantly, encourage workers to stop and ask when information remains unclear. A short check before work can prevent a serious incident later.
For help with GHS labels, chemical safety products, or workplace safety solutions, contact our sales team.
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Frequently asked questions about GHS pictograms
There are nine main GHS pictograms. They communicate physical hazards, health hazards, and environmental hazards linked to chemical products.
Not always. The chemical’s classification and hazard category determine the required label elements. Therefore, read the hazard statements and SDS even when no pictogram appears.
Yes. A chemical may create several hazards, so its label may show more than one pictogram. Workers must consider every displayed symbol.
No. The pictogram identifies a hazard, but it does not specify exact glove materials or respirator types. Check the SDS and workplace risk assessment.
Do not use the chemical. Isolate it safely, warn nearby workers, and inform your supervisor or workplace safety representative immediately.
Companies should review an SDS within five years of its issue date. They should review it sooner when new information or property changes arise.
Not always. The systems may use similar symbols, but transport rules can require additional labels, marks, and documentation. Check the applicable transport requirements separately.
This article provides general workplace safety information. It does not replace Singapore legislation, SS 586, a product-specific Safety Data Sheet, or a workplace risk assessment.
