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Hazard symbols, properly called hazard pictograms, are the red diamonds on the labels of chemicals and products such as cement, solvents, fuels and cleaning products. In Great Britain they are set by the CLP Regulation, which stands for Classification, Labelling and Packaging. There are nine of them, and each tells you about a different type of hazard.
This guide explains every symbol, the products you are likely to see it on, and how the rest of the label fits together.
The nine hazard pictograms at a glance
| Pictogram | Official name and code | What it warns about | Examples you may see |
|---|---|---|---|
| Exploding bomb | Explosive (GHS01) | Explosives, self-reactive substances and some organic peroxides | Cartridges for powder-actuated tools, some fireworks |
| Flame | Flammable (GHS02) | Flammable gases, aerosols, liquids and solids, and substances that ignite or give off flammable gas | Petrol, solvents, spray paints, expanding foam, LPG |
| Flame over circle | Oxidising (GHS03) | Oxidisers that can cause or intensify a fire | Oxygen cylinders, some pool chemicals and bleaching agents |
| Gas cylinder | Gas under pressure (GHS04) | Gases stored under pressure, which may explode if heated, or cause cold burns if refrigerated | Welding gases, propane, nitrogen, CO2 cylinders |
| Corrosion | Corrosive (GHS05) | Substances that cause severe skin burns, serious eye damage, or corrode metal | Wet cement and some mortars, drain cleaners, brick acid |
| Skull and crossbones | Acute toxicity (GHS06) | Substances that can be fatal or toxic in small amounts if swallowed, inhaled or in contact with skin | Some pesticides and rodenticides, methanol |
| Exclamation mark | Harmful or irritant (GHS07) | Less severe health hazards: harmful, skin or eye irritant, skin sensitiser, drowsiness or respiratory irritation | Many paints, adhesives, cleaning products and sealants |
| Health hazard | Serious health hazard (GHS08) | Serious longer-term effects: cancer, damage to genes or fertility, respiratory sensitisation, organ damage, aspiration hazard | Some solvents, isocyanate products, petrol, products containing crystalline silica |
| Environment | Hazardous to the environment (GHS09) | Toxic to fish and aquatic life | Fuels, some wood preservatives, some biocides |
The examples are typical, not guaranteed. Always check the label on the product you actually have, because the same type of product can be classified differently depending on its formula.
Exclamation mark or health hazard? The one people mix up
The exclamation mark (GHS07) covers less severe, usually short-term effects such as irritation or drowsiness. The health hazard pictogram (GHS08), the silhouette of a person with a star on the chest, covers serious and often long-term effects such as cancer or asthma. If you see the health hazard symbol, treat the product with particular care and check the safety data sheet before use.
Reading the rest of the label
| Label element | What it tells you |
|---|---|
| Signal word | Danger for the more severe hazards, Warning for the less severe ones. |
| Hazard statements (H codes) | Standard phrases describing the hazard, such as H315 Causes skin irritation. |
| Precautionary statements (P codes) | How to use, store and dispose of the product safely, and first aid, such as P280 Wear protective gloves. |
| Product identifier | The name of the product and the hazardous substances it contains. |
| Supplier details | Who to contact for more information, including the safety data sheet. |
Old orange symbols
Before CLP, Europe used square orange and black symbols. CLP replaced them, and the old symbols should no longer appear on new products. If you still find old stock with orange labels, check whether it is still needed and get an up-to-date safety data sheet.
Transport labels are different
Diamond labels on vehicles, tankers and outer packaging are transport labels under the carriage of dangerous goods rules, not CLP pictograms. They look similar but use coloured backgrounds and class numbers.
Before you use a product with a hazard symbol
- Read the label and the safety data sheet.
- Check the COSHH assessment for the task, or make sure one is done.
- Ask whether a less hazardous product or method could be used instead.
- Use the controls specified, such as extraction or ventilation, and the right PPE.
- Store, handle and dispose of it as the label and data sheet say.
- Know the first aid and spill arrangements before you start.
Our guide to what COSHH means explains the assessment and controls in more detail.
Training that helps
Our classroom COSHH awareness training and COSHH awareness eLearning teaches workers to read labels and data sheets and use controls properly, and our chemical spills eLearning covers what to do when something goes wrong. Where flammable substances are stored or used, our DSEAR eLearning covers fire and explosion risks. For managers, hazardous substances are covered in depth in the NEBOSH National General Certificate.
Where this fits in SMSTS and SSSTS
Naming hazard pictograms is a question on the SSSTS paper, and hazardous substances come up on both. Our free SMSTS mock test and SSSTS mock test let you check your knowledge before the course or a refresher, and you can email yourself the results sheet at the end.
When you are ready, the five day SMSTS course is for site managers and the two day SSSTS course is for supervisors. If your certificate is due, the SMSTS refresher and SSSTS refresher keep it current.
Frequently asked questions
How many hazard symbols are there?
There are nine CLP hazard pictograms, each a black symbol on a white background inside a red diamond.
What does the exclamation mark symbol mean?
It warns of less severe health hazards, such as skin or eye irritation, skin sensitisation, drowsiness or harm if swallowed.
What is the difference between Danger and Warning?
They are signal words. Danger is used for the more severe hazards and Warning for less severe ones.
Are COSHH symbols the same as CLP symbols?
People often call them COSHH symbols, but the pictograms come from the CLP Regulation. COSHH is the law on controlling exposure to hazardous substances at work.
Read the source
The CLP Regulation (EC) No 1272/2008 as retained in Great Britain (GB CLP), including Annex V on hazard pictograms; HSE guidance on CLP labelling and hazard pictograms; and the Control of Substances Hazardous to Health Regulations 2002. Facts checked on 6 October 2026.
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