A guide to the nine hazard pictograms you'll see on UK chemical containers, what each one warns of, and how the system replaced the older orange CHIP symbols.
If you've ever picked up a bottle of bleach, a can of paint or a bag of dry cement and noticed a red-bordered diamond with a black symbol inside, you've already seen a COSHH symbol. There are nine of them in current use across the UK, and they cover the full range of chemical hazards — from acute poisoning and corrosive burns through to long-term effects like cancer and reproductive harm.
These are CLP hazard pictograms, often informally called COSHH symbols. GB CLP applies in Great Britain; EU CLP continues in Northern Ireland. The pictograms identify physical, health and environmental hazards, while COSHH addresses relevant health risks at work.
For an overview of how the symbols fit into the wider picture, see what COSHH is. This page covers the symbols themselves.
How the current symbols came to be
The pictograms originate from the United Nations' Globally Harmonised System of Classification and Labelling of Chemicals (GHS), which the UN adopted in 2003. The system was designed to give every country in the world the same chemical hazard symbols, so that a chemical labelled "flammable" in Birmingham reads the same way in Bilbao, Brisbane and Bangkok. Before GHS, the UK used the orange-square CHIP symbols (Chemicals (Hazard Information and Packaging for Supply) Regulations), the US used a different system altogether, and the international trade in chemicals was a mess of conflicting hazard communication.
EU CLP introduced the GHS-based system, with substance classification and labelling from 1 December 2010 and mixtures from 1 June 2015, subject to transitional provisions for existing stock. GB CLP now applies in Great Britain, while EU CLP continues in Northern Ireland.
Current pictograms have a red border, white background and black symbol. Old CHIP labels may remain on historic stock. Check the substance’s current hazards and workplace identification arrangements rather than assuming old information remains adequate indefinitely.
The nine pictograms
The nine pictograms have identifiers GHS01 to GHS09. The number shown depends on classification and label-precedence rules. Signal words appear where the applicable hazard category requires them.
GHS01 — Explosive (exploding bomb)
The exploding bomb pictogram warns of substances that can detonate, explode in a fire, or undergo a violent self-reactive decomposition. It covers unstable explosives, mass-explosion hazards, and self-reactive substances and mixtures in certain categories. Most workplaces won't encounter true explosives, but the symbol also appears on some organic peroxides used in industrial processes and on some self-reactive chemicals used in research labs. Substances carrying this symbol require special storage and handling beyond ordinary COSHH controls, and may also fall under explosives licensing or DSEAR.
GHS02 — Flammable (flame)
The flame indicates specified flammable hazards and other categories such as pyrophoric, self-heating or water-reactive substances. Use the particular classification and hazard statements to identify the risk. DSEAR may apply, and storage must suit the substance and quantities; BS EN 14470-1 is not universally mandatory.
GHS03 — Oxidising (flame over a circle)
The flame over a circle identifies specified oxidising hazards. Suitable concentrations of hydrogen peroxide, nitric acid and potassium permanganate are examples. Do not assume every bleach product carries it: use the actual product label and SDS. Keep incompatible oxidisers away from flammables and other reactive materials.
GHS04 — Gas under pressure (gas cylinder)
The cylinder symbol identifies gases under pressure, including compressed and refrigerated liquefied gases. Nitrogen and helium are not harmless: they can displace oxygen. Assess pressure, temperature, asphyxiation and any chemical hazards, and use storage appropriate to the cylinders and location.
GHS05 — Corrosive (chemical corroding skin and metal)
The corrosion symbol can indicate skin corrosion, serious eye damage or corrosion to metals. Read the hazard statements to determine which applies. Select compatible gloves, eye or face protection and other controls for the actual substance and task.
GHS06 — Acute toxicity (skull and crossbones)
The skull and crossbones denotes the more severe acute-toxicity categories: fatal or toxic effects by the specified route. The signal word is Danger for these categories. The less severe harmful category normally uses GHS07. Monitoring and emergency arrangements depend on the substance and assessment, not this pictogram alone.
GHS07 — Health hazard (exclamation mark)
The exclamation mark covers specified less severe acute toxicity, irritation, skin sensitisation, respiratory irritation, narcotic effects and ozone-layer hazards. Read the hazard statements rather than assuming every product with this symbol has the same effects.
GHS07 can include skin sensitisation, so it is not confined to immediate effects. Respiratory sensitisation and several other serious health hazards use GHS08.
GHS08 — Serious health hazard (silhouette with star burst)
GHS08 includes carcinogenicity, mutagenicity, reproductive toxicity, respiratory sensitisation, aspiration hazard and specified target-organ toxicity after single or repeated exposure. Process-generated dust or fume can present these health risks without having a supplier label.
Controls depend on the classification, exposure and task. COSHH requires ALARP exposure for carcinogens, mutagens and asthmagens in addition to the other adequate-control requirements. Health surveillance follows Regulation 11 criteria; the pictogram alone does not decide it.
GHS09 — Hazardous to the environment (dead tree and dead fish)
The environmental symbol identifies specified aquatic hazards. Preventing pollution involves relevant environmental duties. A substance hazardous solely to the environment is not automatically within COSHH, although the same product may also have health hazards.
"Danger" and "Warning" — what the signal words mean
Where required, Danger denotes more severe categories and Warning less severe categories within a hazard class. Some classifications require neither signal word. The word alone cannot describe the full risk from a task.
If Danger is required, Warning is not also shown. Read all the hazard statements, because a product can have several hazards with different classifications.
Choose controls using the actual hazards and exposure. A Warning label is not an assurance that basic PPE is sufficient, and a Danger label does not by itself prescribe one universal emergency or surveillance arrangement.
Where you'll see the pictograms
The pictograms appear in several places in a working environment, and the consistency between them is part of the system's value:
- On supplier labels for any container of a classified substance, applied at the point of supply
- In Section 2 of the Safety Data Sheet for each substance, alongside the hazard statements and precautionary statements — the SDS is your primary reference for risk assessment
- On workplace containers or storage warnings where required by the applicable safety-sign and labelling rules
- In COSHH assessments themselves, where you transfer the pictograms across from the SDS as part of identifying the hazards
For storage area signage specifically — what symbols to display on a COSHH cabinet, signage for incompatible substance segregation — see our guide on COSHH storage requirements.
Dangerous-goods transport uses its own labels and markings. Hazard-class labels are diamond shaped and use several colours; orange plates are a different marking. Workers handling both systems should understand the relevant labels.
Legal duties around the symbols
Two sets of duties apply.
Suppliers must meet the applicable GB or EU CLP classification, packaging and labelling duties. SDS supply follows REACH Article 31, with its criteria and exceptions; not every product carrying a pictogram has an identical supply obligation.
Employers receiving hazardous substances must keep the labels intact and visible, ensure containers in use are also clearly labelled if substances are decanted or transferred, display appropriate signage at storage areas, and train workers to recognise and respond to the symbols. The training duty falls under Regulation 12 of COSHH. Where workers handle substances that carry GHS06, GHS08 or GHS05 labels, the training needs to be more substantive than a wall poster — properly delivered COSHH Training typically covers symbol recognition alongside the wider compliance picture.
Frequently asked questions
How many COSHH symbols are there?
There are nine CLP pictograms, GHS01 to GHS09. GB CLP applies in Great Britain and EU CLP in Northern Ireland. They communicate specified physical, health and environmental hazards.
What's the difference between "Danger" and "Warning"?
Both are signal words used alongside the pictograms. "Danger" is used for the more severe hazard categories within each hazard class; "Warning" is used for the less severe. If a substance has more than one hazard at different severity levels, the label uses "Danger" (the more severe always overrides).
Are the orange CHIP symbols still valid?
Current supply uses CLP rather than CHIP. Historic containers may still have old labels, but check current safety information and ensure workplace identification and training remain adequate.
What's the difference between GHS06 and GHS08?
GHS06 covers the more severe acute-toxicity categories. GHS08 covers specified serious health hazards, including cancer, respiratory sensitisation, aspiration hazards and some target-organ effects after single or repeated exposure.
Where do the COSHH symbols come from?
They derive from the UN GHS system first published in 2003. The UK adopted them through EU CLP; GB CLP now applies in Great Britain and EU CLP continues in Northern Ireland.
Do COSHH symbols apply to mixtures as well as substances?
Yes. Both substances and mixtures are classified and labelled under CLP. Mixtures are classified by reference to the hazards of their components, with specific rules for how component classifications combine to produce the mixture's overall classification.
Where should COSHH symbols appear in the workplace?
Use the correct supplier labels and SDS information and provide workplace container identification and storage warnings as required. Including pictograms in an assessment can help communication, but COSHH does not prescribe a pictogram on every assessment form.
Related guides
- COSHH Cleaning Colour Codes Explained
- The 8 Steps to COSHH Compliance
- The COSHH Hierarchy of Control: How to Choose Controls in the Right Order
Make sure your team can recognise the hazard symbols and work safely with substances covered by COSHH.
Explore the COSHH Training Course →Sources & references
- HSE: hazard pictograms
- HSE: labelling and packaging
- HSE: CLP regulation
- HSE: safety signs and signals
- HSE: flammable-liquid storage
Mark writes about workplace health & safety, COSHH and accredited online training for COSHH Training, part of Online CPD Academy.