Compressed Gases
Main hazards associated with compressed gases
- Explosion of the cylinder due to mechanical damage, weakness or over-pressurisation.
- Exposure to released gas or fluid, which may have harmful properties (asphyxiant, toxic, corrosive). Oxygen is particularly dangerous as it can promote fires and explosion and sustains combustion.
- Fire due to escape of flammable gas/fluid.
- Over-pressurisation in the event of fire.
- Impact from falling cylinders.
- Manual handling injuries.
Standard Precautions to be Observed
No person should use a gas cylinder or change the cylinder regulator unless they have received appropriate training and are authorised to do so by their supervisor or line manager.
- Ensure the regulator and pipework is appropriate for the type of gas and pressure regime.
- Wear a suitable face visor or safety glasses (to protect against impact) when changing/fitting regulators.
- Do not use grease or PTFE tape on threads - this can present an explosion risk and indicates unsatisfactory seal being made which could leak.
- Check for leaks using leak detection fluid - proprietary sprays are recommended. (Tepol/water can be used as vegetable based but soapy water must not be used as it is oil-based).
- Use only brass spanners (these do not create sparks) when fitting regulators to cylinders of highly flammable gas.
- Ensure the cylinder is secured in a trolley or securely chained/strapped to the wall or bench.
- Transport cylinders in suitable trolleys with dust cowls in place.
- Wear suitable safety shoes when transporting cylinders.
- Store in a safe place outside or in a room that has adequate ventilation.
- Do not store flammable gases near any source of ignition.
Gas cylinders should be handled gently and used only with the correct fittings. In particular the materials from which any components of the system are made should be compatible with the gas being used. Detailed information on this is contained in British Compressed Gases Association publications (CP4 and CP5 are particularly). They should always be secured to prevent them being knocked over accidentally. Cylinder valves must not be lubricated.
Cylinders of compressed gases can be a hazard if fire breaks out. Wherever practicable all cylinders containing gas should be kept outside a building in a well-ventilated area.
Oxygen is particularly dangerous since it is more likely to promote fires or explosions than is air. Compressed air should be used with caution and never in the context of practical jokes.
Acetylene used at > 9 p.s.i. is subject to specific regulation and special notification to the appropriate agency is required. Contact Safety Office for details.
University Guidance
University guidance 
informs Schools/Departments of the key requirements for the safe operation and management of piped compressed gas systems attached to transportable gas cylinders and stand-alone transportable compressed gas cylinder installations (see related link to DRAFT guidance). The primary objective is to prevent danger from unintentional release of stored energy. Information on the competency requirements for the design, installation, operation and maintenance of systems is included as well as the frequency of maintenance; testing and examination regimes that are required for the various high and low pressure components which make up such systems.
Due to the increased dangers associated with the use of stand-alone transportable compressed gas cylinders located in buildings in the event of fire, the guidance also specifies the circumstances under which such stand-alone systems should be considered and the justification required for their use.
This guidance does not apply to domestic gas installations.
Inspection & Maintenance
University guidance informs Schools/Departments of the key requirements for the safe operation and management of piped compressed gas systems attached to transportable gas cylinders and stand-alone transportable compressed gas cylinder installations. The primary objective is to prevent danger from unintentional release of stored energy. Information on the competency requirements for the design, installation, operation and maintenance of systems is included as well as the frequency of maintenance; testing and examination regimes that are required for the various high and low pressure components which make up such systems.
National Guidance - BCGA
The main recognised body that issues national guidance and is referred to by the HSE, is the British Compressed Gas Association (BCGA). In particular, the following documents are useful reference and electronic and hard copies are available from the Safety Office:
- CP4 - Industrial gas cylinder manifolds and gas distribution pipe work: excluding acetylene.
- CP23 - Industrial & medical pressure systems installed at user premises.
- CP36 - Bulk cryogenic liquid storage.
- GN7 - The Safe Use of Oxy-Fuel Gas Equipment (Individual Portable or Mobile Cylinder Supply).
- GN2 - Guidance for the Storage of Gas Cylinders in the Workplace.
- GN7 - The Safe Use of Oxy-Fuel Gas Equipment.