GHS uses nine pictograms, each a red-bordered diamond holding a black symbol on white. The code identifies the pictogram, the symbol gives the visual cue, and the meaning states the hazard class.
The Globally Harmonized System defines nine hazard pictograms used in hazard labelling and, in the EU, under CLP. Each is a diamond with a red border and a black symbol on a white field.
Overview#
| Code | Symbol | Meaning |
|---|---|---|
| GHS01 | Exploding bomb | Explosive |
| GHS02 | Flame | Flammable |
| GHS03 | Flame over circle | Oxidising |
| GHS04 | Gas cylinder | Gas under pressure |
| GHS05 | Corrosion | Corrosive to skin, eyes, and metals |
| GHS06 | Skull and crossbones | Acute toxicity |
| GHS07 | Exclamation mark | Irritant, skin sensitiser, harmful |
| GHS08 | Health hazard (person silhouette) | Carcinogen, mutagen, reprotoxic, respiratory sensitiser |
| GHS09 | Environment | Hazardous to the aquatic environment |
GHS07 covers lower-level health effects, while GHS08 marks the more serious longer-term ones. GHS09 is the only environmental pictogram.
Why a label shows fewer pictograms than the classification#
The table above tells you what each pictogram means. It does not tell you which ones reach the label, and that is the question most people actually have. A mixture can be classified in six hazard classes and still print three diamonds.
Article 26 of CLP sets out rules of precedence whose stated purpose is "to reduce the number of hazard pictograms required". A stronger pictogram suppresses a weaker one that would say something the reader has already been told.
A second rule sits under those five. Where a substance or mixture would produce more than one pictogram within the same hazard class, the label carries the one for the most severe hazard category in that class.
Two labels with three diamonds each can sit on very different chemicals, and a suppressed pictogram does not mean a suppressed hazard: the classification behind the label is unchanged, and the hazard statements still spell it out. Section 2 of the safety data sheet is the honest source, not the front of the drum.
Danger, Warning, and the signal word#
Alongside the pictograms, a CLP label carries exactly one signal word, and it works on the same suppression logic. "Danger" marks the more severe hazard categories, "Warning" the less severe ones, and where "Danger" is used, "Warning" must not also appear. So a label showing "Warning" tells you something real: nothing on it reached the more severe categories.
A CLP label is not a transport label#
The hazard diamonds on the outside of a pallet or a tanker, the ones the transport rules require, are not GHS pictograms, and confusing the two is one of the most common label mistakes. CLP does not apply to the transport of dangerous goods by air, sea, road, rail or inland waterways. It re-enters through one article, and that article is about packaging rather than about transport.
If the outer packaging meets the transport labelling rules, the inner and any intermediate packaging must be labelled under CLP. The outer may be as well, but a CLP pictogram covering the same hazard as the transport label need not appear on it.
A single package that meets the transport labelling rules must be labelled under both CLP and the transport rules. Again, a CLP pictogram covering the same hazard as the transport label need not appear.
So the practical reading is: if the outer packaging is bare of GHS diamonds, open it. The CLP label is on the bottle inside.
Note: Educational summary maintained by the Pareo team. The precedence rules quoted here are Articles 20, 26 and 33 of Regulation (EC) No 1272/2008 (CLP); verify against the consolidated text before relying on them.