Exclamation mark

The hazard classes it stands for

EU and GB: CLP Regulation, Annex V

• Acute toxicity (oral, dermal, inhalation), category 4
• Skin irritation, category 2
• Eye irritation, category 2
• Skin sensitisation, categories 1, 1A and 1B
• Specific target organ toxicity, single exposure, category 3 (respiratory tract irritation; narcotic effects)
• Hazardous to the ozone layer, category 1 (Annex V, Part 4)

US: OSHA Hazard Communication Standard, Appendix C

• Irritant
• Dermal sensitizer
• Acute toxicity (harmful)
• Narcotic effects
• Respiratory tract irritation
• Hazard not otherwise classified (non-mandatory)

A category number is the severity inside a class: category 1 (or type A) is the most severe. The hazard statements on the label (H-codes in the EU, such as H225 “Highly flammable liquid and vapour”) say exactly which class and category applies.

Signal word

Warning.

A label carries one signal word for the whole product: if any hazard calls for Danger, Warning does not appear as well.

Where you see it

At home

Washing-up liquid, laundry and dishwasher detergents, many surface cleaners, descalers, some paints and wood stains, glues, and nail-polish remover (for drowsiness, with the flame).

At work

Epoxy resins and hardeners and some paints (skin sensitisers), solvents that cause drowsiness, dilute acids and alkalis, and many cleaning chemicals.

Examples of typical products, not a list of what any brand is classified as; the label on the product in your hand is what counts.

Where the rules differ

• It is left off when a stronger pictogram already covers the same hazard: the skull and crossbones for acute toxicity, the corrosion pictogram for skin or eye irritation, and the health hazard (for respiratory sensitisation) for skin sensitisation or irritation (OSHA Appendix C, C.2.1.2 to C.2.1.4; CLP Article 26(1)(b) to (d)).
• OSHA allows it for a hazard not otherwise classified (HNOC) only with the words ‘Hazard Not Otherwise Classified’ or ‘HNOC’ under it (C.2.3.3).
• CLP also uses it for chemicals hazardous to the ozone layer; OSHA does not cover that hazard.
• Transport rules have no class for these milder health hazards on their own, so a product that carries only this pictogram usually travels with no transport hazard label.

The old orange symbol it replaced

Replaced most of the orange Xn (Harmful) and Xi (Irritant) squares, which both showed a black St Andrew’s cross. Not one-to-one: Xn for organ damage and lung damage if swallowed became the health hazard, Xi with R41 (serious eye damage) became the corrosion pictogram, and N with R59 (ozone layer) became this pictogram.

The mapping from the orange squares of Directive 67/548/EEC to the GHS pictograms is not one-to-one: CLP Annex VII translates each old classification separately, and some have no direct translation at all. All ten old symbols and what replaced them.

The other eight pictograms

• GHS01 exploding bomb: can explode, or react violently by itself
• GHS02 flame: catches fire easily
• GHS03 flame over circle: oxidiser: makes a fire burn hotter
• GHS04 gas cylinder: gas held under pressure
• GHS05 corrosion: burns skin, damages eyes, eats metal
• GHS06 skull and crossbones: toxic or fatal in small amounts
• GHS08 health hazard: serious or long-term harm to health
• GHS09 environment: toxic to fish and water life