There are nine GHS pictograms, each a black symbol on a white background inside a red-bordered diamond, and each flags a physical, health or environmental hazard of the chemical in the container. In Great Britain they appear on labels under GB CLP, and they are the symbols you meet in COSHH assessments and safety data sheets. This guide explains what every symbol means, how it works with the signal word and hazard statements, and what to do when a label carries several at once.
TL;DR
- GHS uses nine pictograms, numbered GHS01 to GHS09: exploding bomb, flame, flame over circle, gas cylinder, corrosion, skull and crossbones, exclamation mark, health hazard and environment.
- In Great Britain they are diamonds with a red border and white background, and one chemical may carry more than one.
- The pictogram is only part of the label. Read the signal word (Danger or Warning), the hazard statements and the precautionary statements too.
- Great Britain follows GB CLP, overseen by the HSE. Northern Ireland follows the EU CLP Regulation.
- A pictogram tells you the type of hazard, not how to handle the substance. For that, use the safety data sheet and your COSHH assessment.
Table of Contents
- What GHS pictograms are and why labs rely on them
- The nine GHS pictograms and what each one means
- Signal words, hazard statements and precautionary statements
- When a label carries several pictograms
- GHS pictograms, COSHH and CLP: how they fit together
- Great Britain and Northern Ireland: which rules apply
- Practical tips for reading labels in the lab
- Perspective
- Handling research materials beyond the label
- Sourcing research peptides for your laboratory
- FAQ
- Sources
What GHS pictograms are and why labs rely on them
GHS stands for the Globally Harmonised System of Classification and Labelling of Chemicals. It exists so that a flammable solvent or a corrosive acid looks the same on a label wherever it was made. A researcher who cannot read a supplier's language can still recognise a flame or a skull and crossbones.
In the UK, the system is put into law through CLP. The EU CLP Regulation, as amended, is assimilated into GB law, and the HSE oversees GB CLP functions. That is the regulation behind the labels on most chemicals you buy for a bench.
The pictograms work as a quick first read. They are not a substitute for the full label or for training, but they let you sort a shelf of bottles in seconds and spot the ones that need extra care.
The nine GHS pictograms and what each one means
The table gives the code, the symbol and the hazard family it signals. The names follow the GHS list used by Safe Work Australia, and the nine symbols are the same ones the HSE describes for GB CLP.
| Code | Symbol | Hazard type | What it signals |
|---|---|---|---|
| GHS01 | Exploding bomb | Physical | Explosives, self-reactive substances, organic peroxides |
| GHS02 | Flame | Physical | Flammable gases, liquids and solids, self-heating or pyrophoric substances, substances that give off flammable gas on contact with water |
| GHS03 | Flame over circle | Physical | Oxidisers that can cause or intensify a fire |
| GHS04 | Gas cylinder | Physical | Gases under pressure: compressed, liquefied or dissolved |
| GHS05 | Corrosion | Physical and health | Corrosive to metals; skin burns and serious eye damage |
| GHS06 | Skull and crossbones | Health | Acute toxicity that can be fatal or toxic |
| GHS07 | Exclamation mark | Health | Less severe hazards such as irritation, skin sensitisation, harmful if swallowed |
| GHS08 | Health hazard | Health | Serious, often long-term effects on the body |
| GHS09 | Environment | Environmental | Harmful to aquatic life |
GHS01: exploding bomb
This marks materials that can explode through shock, friction, heat or spark. In a research lab it is relatively rare, but it turns up on certain peroxides and on some reagents that become unstable with age. Store them as the label directs, keep quantities small and never let a container dry out if the data sheet warns against it.
GHS02: flame
The flame covers anything that ignites readily, and several other fire-related properties. Common examples are acetone, ethanol, acetonitrile and diethyl ether. Keep these away from ignition sources and store them in a suitable flammables cabinet.
GHS03: flame over circle
An oxidiser does not necessarily burn itself, but it feeds a fire and can make a small one severe. Nitric acid, hydrogen peroxide at higher concentrations and many nitrates and perchlorates carry this symbol. Store them apart from flammables and organic materials.
GHS04: gas cylinder
The hazard here is the pressure. A cylinder can rupture or become a projectile if damaged, and liquefied gases can cause cold burns. Secure cylinders upright, cap them when not in use, and check regulators before connecting.
GHS05: corrosion
Corrosives cause severe skin burns and eye damage, and some attack metals. Strong acids and bases such as hydrochloric acid, sulphuric acid and sodium hydroxide are the familiar examples. Eye protection and suitable gloves are the baseline, and an eyewash should be within reach.
GHS06: skull and crossbones
This is the acute toxicity symbol. A small exposure by swallowing, skin contact or inhalation may be fatal or seriously harmful. Sodium azide and many cyanides are typical examples. Treat it as a prompt to check ventilation, containment and emergency arrangements before you open the bottle.
GHS07: exclamation mark
The exclamation mark is the most common symbol on a lab shelf and the one most often underestimated. It covers skin and eye irritation, skin sensitisation, respiratory tract irritation, drowsiness and harm if swallowed. Sensitisation is the one to watch: repeated contact can trigger an allergic response that gets worse over time.
GHS08: health hazard
This symbol flags serious and sometimes delayed effects. It indicates hazards including respiratory sensitisation, germ cell mutagenicity, carcinogenicity, reproductive toxicity, specific target organ effects after single or repeated exposure, and aspiration hazard. The same source notes that these effects may not be obvious straight away, which is why this symbol deserves respect even when the bottle looks harmless. Use it as a trigger for a careful COSHH assessment and, where required, health surveillance.
GHS09: environment
The dead tree and fish symbol means the substance is harmful to aquatic life. It has a practical consequence in the lab: do not pour it down the sink. Collect it as chemical waste and follow your institution's disposal route.
Signal words, hazard statements and precautionary statements
A pictogram never stands alone on a compliant label. Three other elements work with it.
Signal word. The signal words Danger and Warning indicate more and less severe hazards. Only one appears on a label. If both could apply, Danger is used.
Hazard statements. These describe the nature of the hazard in words, for example that a substance is highly flammable or causes serious eye damage. They carry the detail the symbol cannot, so two bottles with the same exclamation mark can differ in what they actually do to you.
Precautionary statements. Suppliers determine these, usually no more than six, based on the required hazard statements. They cover prevention, response, storage and disposal, such as keeping away from heat or rinsing cautiously with water if the substance gets in the eyes.
A useful habit is to read a label in this order: signal word, pictograms, hazard statements, precautionary statements. Then move to section 2 and sections 7 to 8 of the safety data sheet for storage and exposure controls.
When a label carries several pictograms
Multiple symbols are normal. One or more pictograms might appear on the labelling of a single chemical. Concentrated nitric acid, for instance, is typically both an oxidiser and a corrosive, so you would expect to see more than one symbol.
Two points help when reading them:
- Each symbol represents a separate hazard class, so you need to manage all of them, not just the most dramatic one.
- Labels may omit a lower-priority symbol where a more severe one already covers the hazard. For example, where the skull and crossbones applies, the exclamation mark is not normally added for the same type of effect. Never assume a missing symbol means a missing hazard; check the hazard statements.
GHS pictograms, COSHH and CLP: how they fit together
People often search for COSHH symbols and GHS symbols as if they were two systems. They are two layers of the same picture.
- CLP (classification, labelling and packaging) governs how suppliers classify and label chemicals. The pictograms come from here.
- COSHH (Control of Substances Hazardous to Health) is the UK regime for employers and labs managing the risk from those substances in use. You read the CLP label, then write a COSHH assessment that decides what controls apply.
In practice, the nine symbols on the bottle are the same nine symbols that COSHH training materials and chemical management tools call "COSHH symbols". The label tells you what the supplier has classified; the assessment tells you what you must do in your own work. If your lab handles a new substance, the pictogram prompts the assessment, it does not replace it.
Great Britain and Northern Ireland: which rules apply
The label looks nearly identical on both sides of the Irish Sea, but the legal source differs. GB CLP applies in England, Scotland and Wales and is overseen by the HSE. Substances and mixtures placed on the market in Northern Ireland are subject to the EU CLP Regulation, with the HSE for Northern Ireland publishing guidance on labelling and packaging.
If you move chemicals between sites in different parts of the UK, or buy from suppliers who serve both markets, check which regime the label was prepared under and consult the relevant regulator's current pages for any change in requirements.
Practical tips for reading labels in the lab
- Check labels on receipt. A damaged or unreadable label is a reason to relabel or quarantine the container before use.
- Decant with care. If you move a chemical into a secondary container, label it with the identity and the relevant hazard information. An unlabelled beaker is a classic cause of accidents.
- Do not ignore exclamation marks. They are common, which makes them easy to treat as background noise.
- Pair labels with the data sheet. The label is a summary. The safety data sheet holds exposure controls, first aid and disposal.
- Keep incompatible classes apart. Oxidisers away from flammables, acids away from bases, and so on.
- Train new starters on all nine. A one-page chart by the door is cheap and effective.
Perspective
Hazard pictograms are most useful when everything else about a product is just as clear. In our work supplying research peptides, we see how much a laboratory depends on documentation it can trust: a Certificate of Analysis, a stated HPLC purity of 99%+ and a clear statement of intended use.
We build our verification and quality control around that expectation, and we supply our products strictly for laboratory and scientific research, never for human or veterinary consumption. A researcher who reads labels carefully will also want to read the paperwork behind a product carefully, and we think that is exactly the right instinct.
When you assess any material for your bench, treat the label, the safety data sheet and the certificate as one package. That habit protects people, protects data and makes audits easier. It is also why we publish practical handling material alongside our range.
Neil
Handling research materials beyond the label
Hazard symbols cover the chemicals with a formal classification. Other research materials still need disciplined handling even when their labels are simple. Our guides cover peptide handling guidelines for UK research labs and laboratory reconstitution, including the solvents and diluents that bring their own pictograms into the workflow. If you are unsure what a research-use-only designation means on a product page, our explainer on research use only peptides sets it out for UK readers.
Sourcing research peptides for your laboratory
If you are a scientist, institution or laboratory looking for high-purity peptides with documentation you can file against your COSHH records, we supply precision research peptides at 99%+ HPLC purity, with Certificates of Analysis and a secure checkout. Everything is intended solely for laboratory research.
Read how we define and supply research use only products, or visit BioForgeUK to browse the range.
FAQ
How many GHS pictograms are there?
There are nine, coded GHS01 to GHS09. They cover explosive, flammable, oxidising, pressurised, corrosive, toxic, irritant, serious health and environmental hazards. The GB CLP set used in Great Britain has the same nine.
What does the exclamation mark pictogram mean?
It flags less severe hazards than the skull and crossbones or the health hazard symbol. Typical examples are skin or eye irritation, skin sensitisation, respiratory irritation and harm if swallowed. Read the hazard statement to see which one applies to your substance.
What is the difference between Danger and Warning on a label?
They are signal words that show severity. Danger indicates the more severe hazards and Warning the less severe ones. A label carries one or the other, not both.
Are the old orange hazard symbols still valid?
The older orange square symbols belong to the previous labelling system, and current labels use the red-bordered diamond. You may still find old stock in a lab cupboard. Check the safety data sheet and relabel or dispose of it according to your institution's procedures.
Do GHS labels replace a COSHH assessment?
No. The label classifies the hazard, and the COSHH assessment decides how you control the risk in your own work. Use the pictograms and statements as inputs, together with the safety data sheet and your local safety officer's advice.