The colour applied to the shoulder, or curved part at the top of the cylinder, signifies the European standard colour coding.
The aim of the new standard (EN 1089-3), which has replaced the old cylinder colour scheme (BS349), is to help improve safety standards within the gases industry.
A number of gases have been assigned a specific colour and some of these are shown below:
The colour of the body of the cylinder may differ for the same gas among different gas companies. The BOC cylinder body colours are displayed below: