CLP Hazard Pictograms Explained
Chemical products sold in the European Union must follow the CLP Regulation, which defines how substances and mixtures are classified, labelled and packaged. A key part of this system is the set of nine hazard pictograms used to communicate risks clearly and consistently. These symbols help users understand whether a product is flammable, toxic, corrosive, pressurised, environmentally harmful or presents other safety concerns.
This guide explains all nine CLP pictograms in detail, including what each symbol means, when it applies and how businesses should interpret these hazards when preparing labels, SDS documents and technical files. For related guidance, see our page on chemical testing and our overview of SDS documentation.
The Nine CLP Hazard Pictograms
1. Oxidising
Meaning and typical risks
This pictogram appears on chemicals that release oxygen or otherwise intensify combustion. Oxidising substances do not burn on their own, but they can cause other materials to ignite more easily or burn more intensely. They may react dangerously with fuels, organic matter or reducing agents.
Common examples
Peroxides, nitrates, chlorates and oxygen-generating compounds. These are often found in laboratory reagents, industrial bleaching agents or speciality cleaning products.
2. Acute Toxicity
Meaning and typical risks
The skull-and-crossbones symbol indicates severe short-term toxicity. Exposure by inhalation, skin contact or ingestion can quickly cause serious health effects or death. Even very small quantities may be dangerous.
Common examples
Certain pesticides, laboratory reagents, industrial chemicals and concentrated poisoning agents. These substances require strict handling and protective equipment, especially when preparing technical documentation or safety labels.
3. Gas Under Pressure
Meaning and typical risks
This symbol is used on compressed, liquefied or dissolved gases. Pressurised containers can explode if heated or damaged. Some gases may cause frostbite from rapid release, while others may displace oxygen and cause suffocation in confined spaces.
Common examples
CO₂ cylinders, propane tanks, helium bottles, aerosol propellants and industrial gas cylinders.
4. Flammable
Meaning and typical risks
This symbol covers materials that ignite easily, produce flammable vapours or react strongly with air or water. The risks include fire, explosion, rapid ignition or flashback from vapour clouds.
Common examples
Ethanol, acetone, flammable solvents, aerosols, certain adhesives, fuels and volatile organic compounds. For brands selling consumer products, correct labelling is essential for EU market compliance.
5. Explosive
Meaning and typical risks
The exploding-bomb symbol indicates unstable or explosive substances that can detonate under heat, shock, friction or contamination. These chemicals may undergo violent decomposition or rapid gas release.
Common examples
Blasting agents, detonators, certain metal azides, unstable peroxides and some self-reactive industrial compounds.
6. Serious Health Hazard
Meaning and typical risks
This symbol covers long-term or severe health effects. The risks include carcinogenicity, mutagenicity, reproductive toxicity, respiratory sensitisation or organ damage from prolonged exposure. It is one of the most critical health classifications in the CLP system.
Common examples
Some industrial solvents, formaldehyde, certain isocyanates, specific epoxy resins and substances linked to chronic health effects. Businesses handling these materials should follow structured processes such as the GPSR risk analysis process.
7. Hazardous to the Environment
Meaning and typical risks
This symbol alerts users that a chemical is harmful to aquatic organisms or ecosystems. Some products cause immediate toxicity, while others accumulate in the environment and cause long-term damage.
Common examples
Pesticides, biocides, certain oils, heavy-metal compounds and substances that persist in water or soil. Environmental classifications often appear in warning labels under GPSR.
8. Corrosive
Meaning and typical risks
The corrosion symbol indicates chemicals that can destroy metals or cause severe skin burns and eye damage. These substances react aggressively and require PPE, controlled storage and careful handling.
Common examples
Strong acids, caustic bases, industrial cleaners, descalers and concentrated laboratory reagents. Corrosive substances require precise documentation, often included in a product’s technical file.
9. Health Hazard (Irritant)
Meaning and typical risks
The exclamation-mark symbol applies to chemicals that may cause irritation, allergic reactions, dizziness or mild toxicity. It also appears on products that cause respiratory discomfort or skin sensitisation in certain individuals.
Common examples
Detergents, mild solvents, adhesives, resins, coatings and household cleaning chemicals. These hazards are frequently addressed when preparing labelling for GPSR compliance.
Why CLP Pictograms Matter for Compliance
Accurate classification and labelling help protect users and ensure products can move legally across EU markets. Incorrect or missing pictograms can lead to regulatory action, product recalls or marketplace delistings. Businesses must ensure that labels remain readable, durable and correctly structured with hazard statements, precautionary statements and supplier identification. For full guidance, see our article on handling product recalls and our overview of non-compliance consequences.
For mixtures, the classification must consider the combined hazards of all components. Updated SDS documents from suppliers should be reviewed regularly, especially when formulations change or when EU rules are amended. If you need structured support, explore our services at What We Offer or contact our team directly via Contact Us.
Official CLP Pictogram Source
For the official EU reference list of CLP hazard pictograms, visit: https://echa.europa.eu/regulations/clp/clp-pictograms