Pick the shoulder colour (and a second colour for two rings), or type a colour (white, maroon, RAL 9010) or a gas (oxygen, acetylene, argon, CO2). Below, the gas that equipment is offered for can be checked against the one wanted.
On the gas alone: the outlet thread, working pressure and approval of the equipment are checked separately.
Gas cylinders in Europe carry a shoulder colour to EN 1089-3. Some gases have a colour of their own (oxygen white, acetylene maroon, argon dark green, nitrogen black, carbon dioxide grey, helium brown, nitrous oxide blue); every other gas carries the colour of its main hazard: yellow toxic and/or corrosive, red flammable, light blue oxidising, bright green inert. Enter the shoulder colour or the gas and the reader draws the cylinder, names the gas or hazard group with the RAL numbers, checks the gas that equipment is offered for and writes an RFQ line.
The label on the cylinder identifies the gas; the colour is a secondary guide, seen from a distance. EN 1089-3 does not cover LPG, refrigerants or fire extinguishers, and older cylinders may still carry former national colours.
The colour is on the shoulder, the curved top of the cylinder. Seven gases and one medical mixture have a colour of their own; any other gas shows its main hazard, in descending order of hazard: toxic and/or corrosive (yellow), flammable (red), oxidising (light blue), inert (bright green). Two colours, as rings or quarters, show a mixture or a second hazard.
EN 1089-3 does not fix the body colour of industrial gas cylinders; a white body is kept for gases for medical use. Two letters N, opposite each other on the shoulder, marked the new colours during the changeover from the former national colours; they are no longer required but may still be seen.
The label required for carriage is the main means of identifying the gas; the colour helps to tell cylinders apart from a distance. Former colours are still seen: in Germany oxygen was blue and acetylene yellow, and yellow now means toxic and/or corrosive. The change of colours did not change valve outlets.
| Colour | RAL | Meaning (one colour on the shoulder) |
|---|---|---|
| White | RAL 9010 | Oxygen |
| Maroon | RAL 3009 | Acetylene |
| Dark green | RAL 6001 | Argon |
| Black | RAL 9005 | Nitrogen |
| Grey | RAL 7037 | Carbon dioxide |
| Brown | RAL 8008 | Helium |
| Blue | RAL 5010 | Nitrous oxide |
| Turquoise blue | RAL 5018 | Nitric oxide in nitrogen, medical (NO below 1000 ppm) |
| Yellow | RAL 1018 | Toxic and/or corrosive gas |
| Red | RAL 3000 | Flammable gas |
| Light blue | RAL 5012 | Oxidising gas |
| Bright green | RAL 6018 | Inert gas |
| Gas or group | Shoulder | RAL |
|---|---|---|
| Oxygen | White | RAL 9010 |
| Acetylene | Maroon | RAL 3009 |
| Argon | Dark green | RAL 6001 |
| Nitrogen | Black | RAL 9005 |
| Carbon dioxide | Grey | RAL 7037 |
| Helium | Brown | RAL 8008 |
| Nitrous oxide | Blue | RAL 5010 |
| Nitric oxide in nitrogen, medical (NO below 1000 ppm) | Turquoise blue | RAL 5018 |
| Toxic and/or corrosive gas | Yellow | RAL 1018 |
| Flammable gas | Red | RAL 3000 |
| Oxidising gas | Light blue | RAL 5012 |
| Inert gas | Bright green | RAL 6018 |
| Toxic and/or corrosive, and flammable gas | Yellow and red | RAL 1018, RAL 3000 |
| Toxic and/or corrosive, and oxidising gas | Yellow and light blue | RAL 1018, RAL 5012 |
| Air or synthetic air, medical or breathing | White and black | RAL 9010, RAL 9005 |
| Oxygen and helium, medical or breathing | White and brown | RAL 9010, RAL 8008 |
| Oxygen and carbon dioxide, medical or breathing | White and grey | RAL 9010, RAL 7037 |
| Oxygen and nitrous oxide, medical | White and blue | RAL 9010, RAL 5010 |
| Mixture of inert gases: argon and nitrogen | Dark green and black | RAL 6001, RAL 9005 |
| Mixture of inert gases: argon and carbon dioxide | Dark green and grey | RAL 6001, RAL 7037 |
| Mixture of inert gases: argon and helium | Dark green and brown | RAL 6001, RAL 8008 |
| Mixture of inert gases: nitrogen and carbon dioxide | Black and grey | RAL 9005, RAL 7037 |
| Mixture of inert gases: nitrogen and helium | Black and brown | RAL 9005, RAL 8008 |
| Mixture of inert gases: carbon dioxide and helium | Grey and brown | RAL 7037, RAL 8008 |
| Hydrogen (flammable gas) | Red | RAL 3000 |
| Methane (flammable gas) | Red | RAL 3000 |
| Ammonia (toxic and/or corrosive gas) | Yellow | RAL 1018 |
| Chlorine (toxic and/or corrosive gas) | Yellow | RAL 1018 |
| Carbon monoxide (toxic and/or corrosive gas) | Yellow | RAL 1018 |
| Sulphur dioxide (toxic and/or corrosive gas) | Yellow | RAL 1018 |
| Krypton (inert gas) | Bright green | RAL 6018 |
| Xenon (inert gas) | Bright green | RAL 6018 |
| Neon (inert gas) | Bright green | RAL 6018 |
| Welding shielding gas mixture (inert gas) | Bright green | RAL 6018 |
| Compressed air, industrial (inert gas) | Bright green | RAL 6018 |
| Oxygen and nitrogen, more than 23.5 % oxygen (oxidising gas) | Light blue | RAL 5012 |
Every colour assignment and RAL number here is confirmed by two independent sources. Left out for want of two agreeing sources: the former German colours of nitrogen, argon and helium; the UK body colours of acetylene and hydrogen cylinders; the former UK colours; the permission to colour industrial argon, nitrogen, carbon dioxide or helium cylinders bright green in place of their own colour; the colours of cylinder bundles, valve guards and caps; diving mixtures. Gases shown with a group colour are examples of that group.
EN 1089-3:2011 on the colour coding of transportable gas cylinders, clauses 5 to 7 and Annexes A to D (as published in the Austrian Federal Law Gazette); the British Compressed Gases Association information sheet TIS 6 on cylinder labels and colour codes; the German industrial gases association leaflet on DIN EN 1089-3; the German statutory accident insurance article on the changed colour coding; a trade magazine article on the marking of gas cylinders; the colour guides of a German and a Finnish gas supplier; a gas supplier’s EN 1089-3 awareness sheet; the German Wikipedia article on gas cylinders. Every assignment is in at least two of them.
Under EN 1089-3 the shoulder shows a colour of the gas itself or the colour of its main hazard. Oxygen is white, acetylene maroon, argon dark green, nitrogen black, carbon dioxide grey, helium brown and nitrous oxide blue. Other gases are yellow if toxic and/or corrosive, red if flammable, light blue if oxidising and bright green if inert. The label, not the colour, identifies the gas.
EN 1089-3 sets the shoulder colour. For industrial gases the body colour is left to the gas company, as long as it does not misstate the hazard, and a white body is kept for gases for medical use. In Germany oxygen cylinders were blue before EN 1089-3, so a blue body under a white shoulder is still seen.
Two letters N, opposite each other on the shoulder, marked cylinders painted in the EN 1089-3 colours during the changeover from the former national colours. Germany and Austria no longer require them and in the UK they are not needed, but they may remain on older cylinders.
The gas as named on the cylinder label, the shoulder colour, the valve outlet thread or a photograph of the outlet, the equipment needed (regulator, cylinder valve, hose, flashback arrestor), the working pressure and the quantity.
A decoded colour is a guide, not an identification of the gas. Attach a photograph of the cylinder label and the valve outlet, and Vessel Core checks the equipment against them before an offer goes back.
