Tradefox

Tradefox – Build Skills

Learn Construction

Tradefox Reference

Gas cylinder colours.Read the label. Use the colour as a clue.

Cylinder colours tell you a lot from across a workshop, but the code changes from country to country. Europe colours the shoulder by hazard, Australia and Japan paint the whole cylinder by gas, and the US leaves industrial colours to each supplier. Pick a scheme to see each gas drawn out, then compare them side by side.

Read a cylinder. Top to bottom.

Every cylinder carries the same clues in the same places. The label is the one you can rely on; the rest help you spot a problem from a distance.

NN123456
  1. Valve and guard Outlet threads differ between gas families, so the wrong regulator will not fit. Many fuel gases use left-hand threads.
  2. Shoulder colour In Europe, the UK and the Gulf this is the coded part: it shows the main hazard, or the gas itself for a few common gases.
  3. The letter N Stamped twice on cylinders repainted during the European changeover. It is optional in the UK and no longer needed on Australian medical stock.
  4. Label The legal identifier. It names the gas or mixture and carries the hazard diamond, UN number, warnings and supplier details.
  5. Stamped markings Serial number, test pressure, test dates and owner are stamped into the shoulder. Test rings, if fitted, show the next test year.
  6. Body colour Free in Europe except for medical (white) and acetylene (maroon). In Australia, India, Japan and China the whole cylinder is coloured by gas.

Europe’s four hazard colours

Under EN 1089-3, a gas without its own colour takes the colour of its main hazard on the shoulder. Two hazards can mean two colours.

Toxic or corrosive

Yellow. Ammonia, chlorine, carbon monoxide. RAL 1018

Flammable

Red. Hydrogen, methane, propane mixes, argon/hydrogen. RAL 3000

Oxidising

Light blue. Oxygen-rich mixtures that feed a fire. RAL 5012

Inert

Bright green. Krypton, neon, most welding shielding mixes. RAL 6018

Seven common gases have their own shoulder colour instead:

OxygenWhite · RAL 9010NitrogenBlack · RAL 9005ArgonDark green · RAL 6001Carbon dioxideGrey · RAL 7037HeliumBrown · RAL 8008AcetyleneMaroon · RAL 3009Nitrous oxideBlue · RAL 5010

Colour codes. 10 schemes, 15 gases.

Choose a scheme. Each gas is drawn with its shoulder and body colour; a hatched area means the scheme leaves that colour to the supplier. On-screen colours are approximate.

EN 1089-3 Europe and UK, shoulder colour by hazard

Verified

The shoulder colour tells you the main hazard from a distance, before the label is close enough to read. A handful of common gases have their own colour; everything else takes the colour of its hazard. LPG, refrigerants, fire extinguishers and bundles are outside the standard.

Where
EU, EEA and UK (adopted as BS EN 1089-3)
Issued by
CEN (European Committee for Standardization)
Edition
EN 1089-3:2011 (replaced the 2004 edition)
Status
Current, under its periodic review in 2026
What is coloured
Shoulder (the curved top). Body colour is free, except medical (white).
Legal basis
European standard; shipping and supply law makes the label, not the colour, the legal identifier.
OxygenO₂Shoulder White (RAL 9010)Body Set by the supplierMedical oxygen: white shoulder on a white body.
NitrogenN₂Shoulder Black (RAL 9005)Body Set by the supplier
ArgonArShoulder Dark green (RAL 6001)Body Set by the supplier
Carbon dioxideCO₂Shoulder Grey (RAL 7037)Body Set by the supplier
AcetyleneC₂H₂Cylinder Maroon (RAL 3009)Acetylene bodies are maroon as well. The UK uses the darker RAL 3007.
HydrogenH₂Shoulder Red (RAL 3000)Body Set by the supplierTakes the flammable colour.
HeliumHeShoulder Brown (RAL 8008)Body Set by the supplier
Propane / LPGNot covered: LPG is excluded from EN 1089-3. The supplier sets its colours.
Nitrous oxideN₂OShoulder Blue (RAL 5010)Body Set by the supplier
Compressed airShoulder Bright green (RAL 6018)Body Set by the supplierIndustrial air is inert, so bright green. Medical air is white and black.
Argon welding mixesAr/CO₂, Ar/O₂Shoulder Bright green (RAL 6018)Body Set by the supplierArgon/CO₂ and argon/O₂ shielding mixes are inert, so bright green. Argon/hydrogen mixes are flammable, so red.
Toxic or corrosiveAny gas with this hazardShoulder Yellow (RAL 1018)Body Set by the supplierToxic and flammable: yellow and red. Toxic and oxidising: yellow and light blue.
FlammableAny gas with this hazardShoulder Red (RAL 3000)Body Set by the supplier
OxidisingAny gas with this hazardShoulder Light blue (RAL 5012)Body Set by the supplier
InertAny gas with this hazardShoulder Bright green (RAL 6018)Body Set by the supplierNon-toxic, non-flammable and non-oxidising (below 23.5% oxygen).
  • Colours are RAL references. The most serious hazard decides the colour: toxic, then flammable, then oxidising, then inert.
  • Cylinders repainted during the changeover carried the letter N twice on opposite sides of the shoulder. The UK never required the N.
Sources and confidence

Verified Confirmed from an authoritative source such as a standard, regulator or official industry body.

  1. EN 1089-3:2011 catalogue entry (iTeh Standards, CEN catalogue) (opens in a new tab)Title, July 2011 publication, scope (industrial, breathing and medical gases; LPG excluded), supersedes the 2004 edition, letter "N" twice on the shoulder (normative Annex C).
  2. BCGA Technical Information Sheet 6, Gas cylinder identification: label and colour code requirements, Revision 3 (2018) (opens in a new tab)Shoulder colours and RAL numbers by hazard and for specific gases; label is the primary identifier; medical bodies white; UK acetylene RAL 3007 body and shoulder; hydrogen red by UK custom; "N" not needed in the UK; LPG excluded; dip-tube stripe.
  3. BOC Special Products, Cylinder colour change (via University of Glasgow) (opens in a new tab)Shoulder colours by hazard and specific gas under BS EN 1089-3; body colour stays the supplier's choice; labels are the primary identifier.
  4. IGV Industriegaseverband, Druckgasflaschen: Farbkennzeichnung (leaflet) (opens in a new tab)"N" means new and is stamped twice on the shoulder where the colour changed; technical oxygen changed from blue to white in Germany; body grey or shoulder colour for industrial, white for medical; hazard label is binding.
  5. Messer Specialty Gases, Cylinder and bundle markings (opens in a new tab)EN 1089-3 hazard colours with examples: argon/hydrogen and other flammable mixtures red; inert gases bright green.
  6. Woikoski (Finland), How to identify gas cylinders (opens in a new tab)Body graphite grey for industrial and white for medical gases in that fleet; shoulder colours per EN 1089-3.
  7. Middle East Gases Association, Industrial gas cylinders colour coding (TD 08/15/E) (opens in a new tab)EN 1089-3 shoulder colours with RAL numbers for MEGA members (outside Saudi Arabia); body not mandated, grey recommended; label primary; conversion by 31 Dec 2019.

Checked 9 Nov 2026

Side by side. Same gas, different paint.

Every gas in every scheme on one table. Select a scheme name to open its details. Cells marked “check” are not confirmed from an official source.

Swipe the table sideways to see every scheme.

Gas cylinder colours by gas and scheme
GasEuropeUKMedicalUSAAustralia / NZIndiaSouth AfricaJapanChinaGulf (MEGA)
OxygenO₂White shoulderWhite shoulder, black bodyWhiteGreen shoulderBlackBlackBlackBlackLight blue, black textWhite shoulder
NitrogenN₂Black shoulderBlack shoulder, grey bodyBlack shoulder, white bodyBlack shoulderPewterFrench grey shoulder, french grey body, black bandCheck supplierGreyBlack, white textBlack shoulder
ArgonArDark green shoulderDark greenNot coveredNo standard colourPeacock bluePeacock blueCheck supplierGreySilver grey, dark green textDark green shoulder
Carbon dioxideCO₂Grey shoulderGrey shoulder, black bodyGrey shoulder, white bodyGrey shoulderSilverBlack shoulder, black body, white bandCheck supplierGreenAluminium white, black textGrey shoulder
AcetyleneC₂H₂MaroonMaroon (black red)Not coveredNo standard colourMaroonMaroonMaroonBrownWhite, bright red textMaroon
HydrogenH₂Red shoulderRedNot coveredNo standard colourSignal redSignal redCheck supplierRedLight green, bright red textRed shoulder
HeliumHeBrown shoulderBrownBrown shoulder, white bodyBrown shoulderMiddle brownMiddle brownCheck supplierGreySilver grey, dark green textBrown shoulder
Propane / LPGNot coveredRedNot coveredNo standard colourSilverSignal redCheck supplierNot coveredCheck supplierNot covered
Nitrous oxideN₂OBlue shoulderBlue shoulderBlue shoulder, white bodyBlue shoulderUltramarine shoulder, white bodyNot coveredCheck supplierGreyCheck supplierBlue shoulder
Compressed airBright green shoulderBright green shoulder, grey bodyWhite / Black shoulder, white bodyYellow shoulderBlack / White shoulder, white bodyFrench greyCheck supplierGreyBlack, white textBright green shoulder
Argon welding mixesAr/CO₂, Ar/O₂Bright green shoulderBright green shoulderNot coveredNo standard colourCheck supplierCheck supplierCheck supplierGreyNot coveredBright green shoulder
Toxic or corrosivehazard classYellow shoulderYellow shoulderNot coveredNo standard colourYellowWhite shoulder, white body, golden yellow bandYellow shoulderGreyLight yellow shoulderYellow shoulder
Flammablehazard classRed shoulderRed shoulderNot coveredNo standard colourSignal redWhite shoulder, white body, signal red bandRed shoulderGreyBright red shoulderRed shoulder
Oxidisinghazard classLight blue shoulderLight blue shoulderNot coveredNo standard colourBlackNot coveredCheck supplierGreyLight blue shoulderLight blue shoulder
Inerthazard classBright green shoulderBright green shoulderNot coveredNo standard colourPeacock blueWhiteCheck supplierGreyDark green shoulderBright green shoulder
Verified official source openedCorroborated two independent sourcesCheck local rules best-known practice

The 2006 change. Why old cylinders look different.

Europe moved from national codes to one shoulder code in the 2000s. Cylinders last for decades, so you can still meet old colours, odd repaints and the letter N.

  1. Before 1997

    National codes

    Each country had its own scheme. The UK used BS 349, and Germany painted technical oxygen blue.

    Sources: BCGA Guidance Note 2 (opens in a new tab) IGV Industriegaseverband (opens in a new tab)

  2. 1997 to 2004

    EN 1089-3 published

    A single European shoulder code by hazard. Revised in 2004 and again in 2011.

    Sources: BCGA Guidance Note 2 (opens in a new tab) EN 1089-3:2011 catalogue entry (iTeh Standards (opens in a new tab)

  3. Autumn 2005

    Repainting starts

    Major suppliers begin repainting shoulders as cylinders come back for refilling.

    Sources: University of Manchester safety circular 17/2005 (opens in a new tab) gasworld (opens in a new tab)

  4. 1 July 2006

    Deadline

    The harmonised scheme applies across Europe. Repainted cylinders carry an N (for new) twice on the shoulder. Germany kept the N until 2009; the UK never required it.

    Sources: University of Manchester safety circular 17/2005 (opens in a new tab) gasworld (opens in a new tab) IGV Industriegaseverband (opens in a new tab) BCGA Technical Information Sheet 6 (opens in a new tab)

  5. 2006 to 2011

    Old stock leaves

    Cylinders in the old colours take about five years to work out of circulation.

    Sources: University of Manchester safety circular 17/2005 (opens in a new tab) BOC Special Products (opens in a new tab)

  6. 2016 onwards

    White medical bodies

    Australia removes the N from medical cylinders. The UK continues converting medical cylinders to white bodies under BCGA policy.

    Sources: NSW Health safety notice SN 010/16 (opens in a new tab) BCGA TIS 20 (opens in a new tab) University of Portsmouth (opens in a new tab)

Colour is a clue. The label is the answer.

A cylinder holds a lot of energy in a small space. These basics apply whatever colour it is painted. Always follow the supplier’s safety data sheet and your site rules.

Read the label every time

The label is the legal identifier. Colours fade, get repainted and differ between suppliers and countries. If the label is missing or unreadable, do not use the cylinder: send it back.

Based on BCGA Technical Information Sheet 6 (opens in a new tab), CGA C-7-2020 (opens in a new tab), BOC New Zealand (opens in a new tab)

Store upright and secured

Chain or strap cylinders so they cannot fall. Keep them outdoors or in a well-ventilated store, away from heat, drains, exits and vehicle routes. Keep full and empty cylinders apart, and treat empties as full.

Based on Government of Jersey (opens in a new tab), University of Portsmouth (opens in a new tab), HSE INDG297 (opens in a new tab)

Keep oxygen away from fuel

Store oxygen apart from acetylene, propane and other fuel gases. US rules ask for 6.1 m (20 ft) or a 1.5 m half-hour fire-rated wall; New Zealand guidance gives 3 m or a wall 1 m above the tallest cylinder.

Based on OSHA 29 CFR 1910.253 (opens in a new tab), BOC New Zealand (opens in a new tab), Government of Jersey (opens in a new tab)

No oil or grease near oxygen

Oxygen can make oil and grease ignite violently. Use only oxygen-rated regulators and hoses, never use oxygen to blow dust off or to freshen the air, and check leaks with a proper oxy-fuel leak spray.

Based on HSE INDG297 (opens in a new tab)

Acetylene needs extra care

Keep acetylene upright. If it has been laid down, stand it before use (HSE says at least an hour; some suppliers say longer). Keep working pressure at or below 0.62 bar and fit flashback arrestors on both oxygen and fuel lines.

Based on HSE INDG327 (opens in a new tab), HSE INDG297 (opens in a new tab), BOC New Zealand (opens in a new tab)

Hot or vibrating acetylene: get out

An acetylene cylinder caught in a flashback or fire can start to decompose inside. If it gets hot or vibrates, evacuate and call the fire service.

Based on HSE INDG297 (opens in a new tab)

Inert gases can suffocate

Nitrogen, argon, helium and CO₂ give no warning. Use them with good ventilation, and fit oxygen or CO₂ alarms where large volumes are used.

Based on University of Portsmouth (opens in a new tab)

Transport in the open

Use an open vehicle where possible and never carry cylinders in the cab. Close valves, remove regulators, fit caps and strap cylinders upright. A closed van needs proper load-space ventilation.

Based on HSE INDG327 (opens in a new tab), BOC New Zealand (opens in a new tab), Government of Jersey (opens in a new tab)

Plan the job. Then weld it.

Work out how much shielding gas you need, what a run will cost and whether a part is safe to lift, with Tradefox’s welding and fabrication calculators.

Secret Link