Hazard pictograms are the red-bordered, white diamond symbols with a black image in the centre that appear on chemical product labels. Under the CLP (Classification, Labelling and Packaging) rules there are nine of them, and each one signals a type of hazard: explosive, flammable, oxidising, gas under pressure, corrosive, acute toxicity, health hazard, serious health hazard and hazardous to the environment. A single product can carry more than one.
For businesses, these hazard symbols are often the first visible clue that a product, and the waste it leaves behind, may need extra attention. This guide explains what each pictogram represents and how they connect to waste classification.
What are CLP hazard pictograms?
According to the Health and Safety Executive (HSE), hazard pictograms alert people to the presence of a hazardous chemical and help show that a chemical might cause harm to people or the environment. The GB CLP pictograms are diamond shaped, with a distinctive red border and a white background.
HSE also explains that a hazard label is made up of pictograms and written warnings. These are set out in law, and chemical suppliers must use them where hazardous properties have been identified.
The pictograms are not a UK invention. CLP adopts the United Nations Globally Harmonized System of classification and labelling of chemicals (GHS), which is designed so that the same classifications and labels can, over time, be used around the world.
The nine hazard pictograms and what they mean
HSE lists each pictogram by hazard and by the name of its symbol. The short descriptions below draw on HSE's guidance and on the hazard classes set out in the Environment Agency's waste classification guidance.
- Explosive (symbol: exploding bomb). Covers explosives, self-reactive substances and organic peroxides.
- Flammable (symbol: flame). Covers flammable gases, liquids, solids and aerosols, as well as organic peroxides, self-reactive, pyrophoric and self-heating substances, and substances that emit flammable gas on contact with water.
- Oxidising (symbol: flame over circle). Covers oxidising gases, liquids and solids.
- Gas under pressure (symbol: gas cylinder). Relates to gases such as compressed, liquefied, refrigerated liquefied and dissolved gases.
- Corrosive (symbol: corrosion). Covers substances that cause severe skin burns and eye damage and serious eye damage.
- Acute toxicity (symbol: skull and crossbones). Used for severe acute toxicity.
- Health hazard or hazardous to the ozone layer (symbol: exclamation mark). Used for less severe effects such as skin irritation, serious eye irritation and harmful acute toxicity.
- Serious health hazard (symbol: health hazard). Shows a head and shoulders with a star over the chest, and covers respiratory sensitisers, mutagens, carcinogens, reproductive toxicity, specific target organ toxicity and aspiration hazards.
- Hazardous to the environment (symbol: environment). Shows a dead tree and fish, and relates to hazards to the aquatic environment.
These descriptions are for recognition only. Specific information about a product's hazards, and what to do in an emergency, is found on its Safety Data Sheet (SDS). In an emergency, contact the emergency services.
How CLP replaced the older CHIP symbols
Before CLP, chemical labels in the UK followed the Chemicals (Hazard Information and Packaging for Supply) Regulations 2009, known as CHIP. HSE states that CLP replaced CHIP on 1 June 2015.
The CLP pictograms are very similar in meaning to the old CHIP hazard symbols, but HSE notes that they have a new shape, a new design and a new colour. CLP also brought in hazard statements in place of CHIP risk phrases, precautionary statements in place of safety phrases, and a signal word of either "warning" or "danger" depending on how severe the hazard is.
Official waste guidance still refers to both orange and black danger symbols and red and white hazard pictograms, so either style may be seen on products and waste.
GB CLP and Northern Ireland
The EU CLP Regulation came into force on 20 January 2009 across EU Member States, including the UK at the time. HSE explains that the regulation, as amended, has been assimilated into GB law, so Great Britain continues to adopt GHS independently of the EU. This is known as GB CLP, and HSE is the GB CLP Agency.
The position in Northern Ireland is different. Substances and mixtures placed on the market in Northern Ireland are subject to the EU CLP Regulation. GB CLP applies to Northern Ireland suppliers who directly supply the GB market with qualifying Northern Ireland goods.
Waste rules also vary between the UK nations. Our guide to hazardous waste rules across the UK nations sets out where they differ.
Why hazard pictograms matter for waste
Product labels and waste classification are separate legal systems, but they are closely linked. The GOV.UK waste classification guidance notes that many products include orange and black danger symbols or red and white hazard pictograms to indicate they are hazardous. It also points out that some products, such as cosmetics and medicines, usually do not carry these labels, and refers readers to manufacturers' safety data sheets and the technical guidance.
That technical guidance is the Environment Agency's WM3 waste classification guidance. WM3 says that if a pictogram is present, a hazardous property is likely to apply. It is equally clear that the absence of a pictogram does not mean there are no hazardous properties.
WM3 includes a table linking each pictogram to CLP hazard classes and to the hazardous properties, known as HP codes, used to classify waste. For example, the flammable hazard classes link to HP 3 Flammable, and skin corrosion links to HP 8 Corrosive. Some hazard classes carry no pictogram at all but still relate to a hazardous property.
In practice, this means a label is a useful starting point, but it is not the whole picture. Classifying waste correctly is the legal responsibility of the waste producer, and our guides on what hazardous waste is and the duty of care cover the wider framework. Where a product's status is unclear, speak to our team.
Hazard pictograms on common workplace products
HSE publishes separate guidance on cleaning products under GB CLP, and the CLP hazard classes include everyday categories such as flammable aerosols and flammable liquids. When products like these become waste, the pictograms on their labels are one of the signs that the waste may be hazardous.
We provide chemical waste disposal, aerosol can recycling and solvent disposal for businesses that produce these types of waste.
Speak to our team
To discuss your waste, contact our team on 0845 366 9306 or email enquire@hazardousdisposal.co.uk.
This article is for general information only and does not constitute professional, legal or chemical advice. Waste producers are legally responsible for correctly classifying their waste. For guidance on your specific waste, please contact our team.