What to Know About Gas Cylinder Colour Codes

Gas cylinder colour codes are useful for identifying the properties of the gas contained within (such as flammability) or what the gas is (such as oxygen). You can see colours on the top of the cylinder and they may also be seen on the body of the cylinder, which is the curved part of the gas bottle.

Why Do We Need Gas Bottle Colour Coding?

Colour coding for industrial gases exists to improve safety standards in industrial settings where gas cylinders are in use.

Some of the benefits of using colour coding over simple labels include the fact that colours are easy to distinguish from one another, they do not peel off or fade, and they do not have to rely on a person being able to understand the language of a written description.

Colour coding promotes health and safety in many commercial, industrial, healthcare, and scientific settings. Major safety benefits of using a colour coding system include:

  • Lack of confusion and a lower risk of using the wrong gas, which could cause an equipment malfunction or an accident.
  • Prevention of mixing potentially volatile gases, such as flammable gases and oxidising gases that can merge to create dangerous combinations.
  • Avoiding the use of any fixings of incompatible cylinder devices, such as valves, regulators, governors, changeover kits, or other accessories.

In the UK, the standard for gas cylinder colour codes is known as EN 1089-3, which has replaced the old cylinder colour scheme BS349 and sets a more convenient and international standard for compressed gas cylinders. Suppliers can vary the gas cylinders within this framework slightly.

As leading providers of gas bottle storage and handling products, we are a good source of information on gas cylinder colour codes and other industrial practices. Browse and buy online with free UK delivery and feel free to get in touch with us if you have a product query. 

How Do the Gas Cylinder Colour Codes Work?

Below, we have provided a breakdown of how colour coding works for compressed gas cylinders, which includes two main categories – gas cylinder colour codes for the properties of the gas and codes for identifying the gas itself. There may be other warning signs and symbols on a cylinder, too.

Gas Cylinder Colour Codes by Gas Properties

The colour coding system for the properties of a specific gas is set out as follows:

  • Red – Flammable: A flammable substance can ignite with the slightest spark, such as a flame, but also potentially the electrical components within a mobile phone. As a result, the bold red colour is used for flammable gas substances in every case.
  • Blue – Oxidising: Oxidising substances can be exceedingly dangerous, especially when combined with flammable ones. Not only do they intensify combustion, but they can be lethal when inhaled (one exception being oxygen) so they are dangerous.
  • Yellow – Toxic: Yellow means that a gas is toxic or corrosive, toxic either to humans, plant or animal life, and corrosive to surfaces such as metal or plastic. Toxic gases may not seem toxic or cause a reaction when inhaled; a good example is carbon monoxide.
  • Bright green – Inert: Inert gases can be quite dangerous, despite not reacting with other chemicals. Although inert and not flammable, oxidising, or toxic, gases such as compressed argon can cause nervous system disorders and many other health problems.

The colours represent the properties of gas that present the most danger, but they may have others.

Gas Cylinder Colour Codes by Gas Type

Cylinders with different types of liquid gas

The gas cylinder codes for bottles containing specific gases are as follows:

  • White – Oxygen: Compressed oxygen is one of the most widely-used gas cylinders, most often in a healthcare setting. Illnesses including chronic obstructive pulmonary disorder (COPD) and surgeries which require anaesthesia need it frequently.
  • Grey – Carbon dioxide: The grey colour indicates another common gas, and a close cousin of oxygen, carbon dioxide. It also has medical applications, such as keeping organ transplants cold, but is also used industrially for large-scale refrigeration.
  • Black – Nitrogen: A black colour on the top of the cylinder is indicative of nitrogen. Many dentists will use nitrogen as part of sedation, in combination with oxygen, but it is also used for pressure testing and removing oxygen in vacuum-sealed packages.
  • Brown – Helium: Many people are aware of helium as a compressed gas for filling party balloons. However, there are many other industrial applications, such as welding, where people use mixes of helium and other gases to accurately cut or weld metals.
  • Dark green – Argon: Argon is used extensively in the lighting industry. Almost every type of lightbulb is filled with argon, which is highly desirable for its inert properties. Though potentially dangerous as a compressed gas, argon in light bulbs is harmless.
  • Dark red – Acetylene: A deep, maroon-coloured red indicates that the gas cylinder contains acetylene. Most of the uses for acetylene also revolve around welding and metal cutting. It may be used when certain metals require a different chemical flame.

These are the most commonly used gases, which is why they have their own colour codes.


Gas Cylinder Colour Codes Explained

A flammable gas may include colour coding on the cylinder while also having a โ€˜flammableโ€™ symbol applied to the shoulder, as well as a neck colour. Similarly, an argon gas bottle may have the chemical symbol stamped on the body alongside the dark green-coloured top.
We hope you understand the ins and outs of gas cylinder colour coding a bit more distinctly now. Feel free to browse our gas bottle storage and handling products and buy online with free UK delivery. You can also get in touch with us if you have any questions about a product.

Leave a Reply