Diving cylinders contain large amounts of stored energy. It is vital that they are made to appropriate standards and used and maintained to ensure the
safety of both the divers who use them and the people who fill them. In the EU a cylinder used with diving apparatus cannot be put on the market
unless it conforms to the Pressure Equipment Directive (PED),2 which is implemented in UK legislation by the Pressure Equipment Regulations
1999,3 as amended.
All diving cylinders manufactured to the PED will bear the CE mark. Cylinders made before the application of the PED will not bear the CE mark but
may continue to be used as long as they have been manufactured in accordance with an appropriate standard and are maintained in serviceable
In-service inspections and tests
It remains a requirement of health and safety law4 that equipment used at work or in connection with work is properly maintained. Diving cylinders
used at work or filled by a person who is at work must therefore be subject to a suitable inspection and test regime to ensure they are safe.
Recreational divers should note that this applies to their cylinders where they are filled by a person at work. It is, however, strongly recommended that
all cylinders, whether used at work or not, are subject to such a test regime. Aside from the obvious safety issues, personal insurance cover might
well be prejudiced if they are not.
The relevant European Standards describing the inspection requirements for diving cylinders are:
steel cylinders BS EN 1968;5
aluminium cylinders BS EN 1802;6
composite cyinders BS EN ISO 11623.7
These European Standards require that the inspection and test is carried out by a competent person. There is no unique legal definition of competence
for cylinder testing. However, HSE considers that the following provide a suitable level of confidence in a cylinder inspectorsí competence for this task:
appointment by the Secretary of State for Transport for the purposes of inspection of gas cylinders;
working within the terms of an industry accredited scheme such as that operated by the Scuba Industries Trade Association (SITA) and the
Inspectorate for Diving Equipment Servicing and Testing (IDEST).
The appointment or accreditation should be for the specific type of cylinder concerned.
Details of those test house/cylinder inspectors meeting these criteria are provided on the following websites:
Department for Transport Appointment:
Stamp marking and labelling
European Standards require a diving cylinder to be stamp marked, to show that it has been subject to the relevant inspection/test, and labelled to
show the next test date. A test report should also be given to the owner. It is recommended that cylinder owners retain these test reports as proof, in
addition to the stamp mark, that the test has been conducted by a suitably competent person.
The hazards posed by cylinders containing high-pressure gas are considerable. People involved in their handling, particularly the emergency services
responding to an incident, need to be able to identify these hazards. Diving cylinders should continue to be labelled in accordance with the European
Standard EN 1089-2,8 namely with a label displaying the green compressed-gas hazard diamond, an additional yellow hazard diamond if the gas has
an oxygen content greater than 21%, plus the UN name and number of the gas contained in the cylinder.