semiatic

GHS04

Gas cylinder

Gas held under pressure.

A black gas cylinder lying at a slant, with its valve end to the upper right.

GHS code
GHS04
Name
Gas cylinder
Signal word
Warning
Old orange symbols (not one-to-one)
none: new with GHS

What it warns about

The gas cylinder marks a gas stored under pressure: compressed, liquefied, refrigerated (very cold liquid) or dissolved. The hazard is the pressure itself: the container can burst if heated, and a refrigerated liquefied gas can cause cold burns. It says nothing about whether the gas burns or is toxic; other pictograms cover that.

The pictogram only names the kind of hazard; follow the product’s label and safety data sheet for how to use, store and dispose of it.

The hazard classes it stands for

EU and GB: CLP Regulation, Annex V

  • Gases under pressure: compressed gases
  • Gases under pressure: liquefied gases
  • Gases under pressure: refrigerated liquefied gases
  • Gases under pressure: dissolved gases

US: OSHA Hazard Communication Standard, Appendix C

  • Gases under pressure
  • Chemicals under pressure

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 for gases under pressure. OSHA’s chemicals under pressure take Danger or Warning by category.

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

Camping gas and blowtorch cartridges, soda-maker carbon dioxide cylinders, and helium balloon canisters. Aerosol cans do not carry it: aerosols are a separate class.

At work

Welding and cutting gases (oxygen, acetylene, argon mixtures), refrigerants, laboratory gas cylinders, and liquid nitrogen.

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

  • OSHA also puts chemicals under pressure (liquids or solids pressurised with a gas, other than aerosols) under this symbol; the CLP copy cited here has no such class.
  • Under CLP, the gas cylinder is optional when the flame or the skull and crossbones already applies (Article 26(1)(e)), so a flammable gas such as propane may show only the flame.
  • In transport, the green non-flammable gas label (49 CFR 172.415 in the US) also shows a gas cylinder. It is a transport label, not the GHS pictogram.

The old orange symbol it replaced

It replaced nothing. The 67/548/EEC system had no symbol for gases under pressure; this pictogram arrived with GHS.

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

Sources

Written in our own words from these official texts and checked on the date shown. The CLP text is the UK National Archives copy on legislation.gov.uk (EUR-Lex and unece.org did not answer a plain request from this host); it carries EU amendments made up to the end of 2020, and later EU changes may not be reflected. OSHA’s own pages refused the request, so the US text is the eCFR copy of the regulation.