Medical Gases

Medical Gases, with their associated equipment, are widely used for treating patients.

Medical gases are classified as a medicine and, as such, within a medical environment they shall always be managed and controlled by an appropriately qualified healthcare professional. In a hospital this will be the Pharmacist. Information on managing medical gases by Pharmacists is provided by the Specialist Pharmacy Service.

Medical gases are administered by healthcare professionals in hospitals, clinics and care homes, by para-medics within the emergency services or are self-administered by the patient at home (having received appropriate training).

All medical gases and much of the associated equipment is regulated by UK legislation. UK and European legislation are generally aligned. The gases are classified as medicinal products for administration to a patient and the associated equipment is classified as a medical device when used to administer the gas. Some gases used for medical purposes can also be classified as medical device gases where they do not have a specific therapeutic outcome for the patient.

Manufacture, distribution and sales

Medical gases, like other medicinal products, are required to have a Marketing Authorisation (product licence) in order to be sold. The Marketing Authorisation defines the quality specification, when a gas can be used and how it should be administered to a patient. For patient treatment, all medical gases must be supplied with an appropriate Marketing Authorisation.

Although medical gases are similar to non-medical gases, medical gases are not to be used for non-medical purposes. Equally, non-medical gases must not be used as a medical gas. The UK Regulator for medical gases is the Medicines and Healthcare products Regulatory Agency (MHRA), who are an Executive Agency of the Department of Health and Social Care (DHSC). The MHRA protects and promotes public health and patient safety by ensuring that medicines, healthcare products and medical equipment meet appropriate standards of safety, quality, performance and effectiveness, and are used safely.

Any organisation that wishes to manufacture medical gases must have a Manufacturer’s Authorisation issued by the MHRA for the manufacture of medical gases. The organisation is required to operate a quality management system which complies with the basic principles and practices of Good Manufacturing Practice (GMP) for medicinal products and specifically for medical gases. Any organisation that wishes to supply and / or distribute medical gases must have a Wholesale Dealer’s Authorisation issued by the MHRA. The organisation is required to comply with the basic principles and practices of Good Distribution Practice (GDP). BCGA GN 32 was developed with the MHRA to ensure compliance with good distribution practice for medical gases.

Some equipment, such as medical gas regulators, demand valves and medical gas flow meters, that are associated with the administration of medical gases, are classified as medical devices. Medical devices must carry an appropriate certification mark. This can be either the UK CA mark or the European CE mark, this is a declaration by the manufacturer that the equipment complies with the relevant Medical Devices Regulations. Any organisation that wishes to manufacture medical devices (including medical gases classified as medical device gases) must conform to the requirements laid down in the relevant Medical Device Regulations and must be registered with the MHRA.

Storage and supply

Every site where medical gases are routinely used must have a suitable storage area with appropriate security provision. All personnel required to handle, move or use medical gases must have received appropriate information, instruction, training and, as required, be under supervision. The appropriately qualified health care professional / Pharmacist must provide written policies and Standard Operating Procedures for the management and safe use of all aspects of medical gas supply and administration.

As with all medicines, medical gases have a defined shelf life which is specified within the relevant Marketing Authorisation. Where the medical gas is supplied in a gas cylinder it will have a label that will show the expiry date as well as the batch number of the medicinal product. Do not use medical gases once this shelf life has expired; upon expiry the gas cylinder should be returned back to the owner (normally the gas supplier).

Within medical facilities the primary method of supply for a medical gas is for it to be supplied into a bulk storage tank(s), from where it is delivered through a medical gas pipeline system (MGPS) into the facility. The MGPS can include vacuum systems, dental systems and dental air vacuum systems (DAVS). These MGPS have to be compliant with various standards, including those required by the Department of Health and Social Care (DHSC). Compliance is required, for example, with:

Health Technical Memorandum (HTM) 02 – Medical Gas Pipeline Systems

  1. Part A, Design, Installation, Validation and Verification.
  2. Part B. Operational Management

HTM – 2022 Supplements:

  1. Dental Compressed Air and Vacuum.

Copies are available here.

Some medical facilities may utilise on-site gas generation systems. Where these systems are in use they must meet the requirements for the manufacture of medical gases, including compliance with GMP and the site quality management system.  

Gas cylinder storage

Within medical facilities an alternative method of supply is through the use of transportable medical gas cylinders. Where a MGPS is in use, gas cylinders are a secondary source of supply. Gas cylinders contain dangerous substances. Individual gases have hazardous properties and the gas is contained under pressure. Gas cylinders must always be stored and handled with care. When not in immediate use all gas cylinders must be kept:

  • in a designated store, being appropriately marked with safety signs and warning notices;
  • in a well ventilated store, away from any sources of ignition, excessive temperatures, flammable materials and from any incompatible products;
  • in a secure location where access is controlled;
  • under cover, in a clean condition suitable for use in a medical environment.

When choosing a cylinder for use, good stock management principles should be applied, for example, by selecting those with the shortest life remaining first, ‘first-expired, first-out’ (FEFO).

NOTE: Gas cylinders are attractive to thieves and are frequently stolen, both for the value of the materials they are made from and for their contents. This is particularly true of medical gases. Each store must incorporate appropriate security features and be included within the site security plan.

For more information, refer to BCGA CP 44The storage of gas cylinders.

The use of medical gases

Only medical gases, which are connected to suitable medical devices, shall be used to administer medical gases to a patient.

Each person who administers a medical gas to a patient must be trained and be competent to administer the gas, as well as being trained and competent in the use of medical gas cylinders and their associated medical gas devices. All personnel who store, handle or use medical gases shall be competent to do so, including being appropriately trained in manual handling, local security measures, general gases safety, as well as the safe management of any associated medical devices.

The gas suppliers will provide information on the safe and appropriate use of their medical products. Equipment manufacturers / suppliers will provide information on the safe and appropriate use of their medical devices. This information will include ‘Instructions for use (IFU)’.

WARNING: Do not smoke or use naked flames close to gas containers or any areas where medical gases are in use. When oxygen is in use there is the potential for localised oxygen enrichment, leading to an increased risk of fire. Always carry out local risk assessment and implement suitable and sufficient controls, in particular for the management of electrical equipment. Refer to BCGA Leaflet 16.

Domiciliary use of medical gases

Medical oxygen is supplied to patients in their home, care home or other domiciliary facility.

Medical oxygen is provided by a Homecare Service Provider along with the associated therapy equipment. The medical oxygen may be supplied from cylinders, cryogenic containers or oxygen
concentrators. There is a range of associated therapy equipment available, including Continuous Positive Airway Pressure (CPAP) machines, dependant on the patient’s needs. The Homecare Service Provider will work with the patient and, as appropriate, with those providing care for the patient, to install the oxygen equipment and to provide literature and training for safe management and use. Refer to BCGA GN 29Medical gases. The management of medical oxygen in domiciliary use.

Cryogenic gases

Gases at cryogenic temperatures are used by and for the treatment of patients. As examples, liquid nitrogen is used within cryotherapy to treat skin conditions and for some specialist medical procedures. Storage of oxygen as a liquid provides a bulk source which converts to a large quantity of gas, this can be beneficial for patients who are travelling or who require larger quantities for domiciliary use.

Cryogenic liquids are at extreme cold temperatures and require to be kept and used from specialist containers. All those handling and using cryogenic gases need specific training and competence.

For liquid nitrogen, refer to BCGA CP 30The safe use of liquid nitrogen dewars.

For liquid oxygen, refer to BCGA GN 29Medical gases. The management of medical oxygen in domiciliary use, and BCGA Leaflet 13Medical gases. Medical oxygen in a vehicle.



See below for further information regarding medical gasses.


Within BCGA, all aspects of medical gases are managed by Technical Sub-Committee (TSC) 7.

The primary objective of BCGA TSC7 is to safeguard patients by ensuring that all products provided by BCGA member companies are safe to use and fit for their intended purpose. This is achieved by promoting safety, producing best practice guidance, liaising with the MHRA and other government departments and participating in relevant standards work.



CP30 The safe use of liquid nitrogen dewars. Revision 3: 2019

01/09/2019 Codes of Practice CP30

Covers the storage, maintenance, handling, filling and use of dewars. Specifically addresses the use of liquid nitrogen in open dewars and dewars fitted with liquid withdrawal devices operating at less than 0.5 bar.

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CP36 Cryogenic liquid storage at users’ premises. Revision 2: 2013

01/09/2013 Codes of Practice CP36

This document covers the installation of cryogenic liquid storage tanks and associated equipment at customer sites. For liquid oxygen, nitrogen and argon. Tank sizes range from 0 to 125000 litre water capacity.

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CP44 The storage of gas cylinders. 2016

01/09/2016 Codes of Practice CP44

This document defines the principles of safe practice for the storage of gas cylinders and bundles. It promotes the use of an external store, in a secure location, with good natural ventilation and away from any sources of ignition.

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GN26 Medical gases. Selection and maintenance of seals used on high pressure cylinders. Revision 1: 2019

01/05/2019 Guidance Notes GN26

Provides information on best practice for users of medical gas cylinders when they are connecting approved medical equipment to gas cylinders. It provides advice on non-pressure regulated cylinder valves, the selection of a suitable seal and the correct procedure for the preparation of connections prior to fitting them to a cylinder.

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CP29 The design and operation of cylinder and tube trailers (battery vehicles) and multiple-element gas containers for the safe transport of compressed gases by road. Revision 2: 2013

01/09/2013 Codes of Practice CP29

Provides practical guidance on the design, construction, examination, testing and certification, and the filling/discharging of cylinder vehicle/trailers used for the domestic conveyance of compressed, but not liquefiable gases.

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GN31 Medical gases. The use of valves incorporating residual pressure devices 2017.

20/07/2017 Guidance Notes GN31

This document provides guidelines for the selection, installation and use of valves which incorporate a residual pressure device in medical gas cylinders, such that common practices are established across the gas industry. It is intended for those who are involved in the specification of cylinder valves and cylinder operations, as well as providing information to those using these valves.

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GN32 Medical gases. Good distribution practice. Revision 1: 2017

05/05/2017 Guidance Notes GN32

Medical products require effective management control during their distribution to ensure quality and integrity are maintained.

This document provides guidance on good distribution practice as required by the medical regulators

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GN37 Medical Gases. Data integrity. 2017

24/10/2017 Guidance Notes GN37

Data integrity is fundamental in a pharmaceutical quality system. This document provides guidance on compliance with the data integrity requirements for batch documentation relating to medicinal gases.

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GN39 Medical Gases. Responsible Person. 2020

09/01/2020 Guidance Notes GN39

Sets out the duties, roles and responsibilities of a Responsible Person within an organisation that distributes medicinal gases.

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GN40 Medical Gases. Quality management systems. Corrective and preventative actions. 2019

01/05/2019 Guidance Notes GN40

Any company manufacturing or distributing medical gases has to operate a quality management system. This document provides information on possible corrective and preventative actions.

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GN42 Medical gases. Incident reporting. 2021

20/04/2021 Guidance Notes GN42

Provides information on the reporting systems available in the UK if there is an incident with, or a problem is identified with, a medicinal gas or its associated medical device.

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L7 The dangers of misusing gases. Revision 4: 2016

15/09/2016 Leaflets L7

Highlights the dangers of misusing gases and the potential hazards that can occur if gases are used irresponsibly.

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L13 Medical gases. Medical oxygen in a vehicle. Revision 3: 2020

22/07/2020 Leaflets L13

This leaflet highlights the key safety information for patients and drivers where medical oxygen cylinders or medical liquid oxygen equipment is used and / or transported for personal use in a vehicle.

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L16 The safe use of electronic cigarettes and other electronic devices used near medical oxygen. Revision 1: 2020

03/03/2020 Leaflets L16

This leaflet highlights key safety information where medical oxygen and associated oxygen equipment is in use and where people may want to use electronic devices or electronic cigarettes.

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TIS6 Gas cylinder identification. Label and colour coding requirements. Revision 3: 2018

11/04/2018 Technical Information Sheets TIS6

An explanation of the content of a typical gas cylinder label and a guide to the colour coding system used on gas cylinders.

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TIS20 Medical gases. BCGA policy on colour coding. Revision 2: 2019

31/07/2019 Technical Information Sheets TIS20

This document sets out the BCGA policy for the colours used on a medical gas cylinder, for both the body and the shoulder, to differentiate medical gases from other gases and to assist in the identification of the gas within. It then details the conversion program to implement the changes required.

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TIS21 Medical gases. BCGA policy on valve outlets. Revision 2: 2019

13/05/2019 Technical Information Sheets TIS21

This document details the BCGA policy, agreed with the MHRA, on rationalising the number of different valve outlets available for medical gases to minimise the risk of administering the wrong gas to a patient and discusses the conversion program in place to implement the changes required.

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TIS36 Medical gases. The safe handling and use of gas cylinders fitted with valves with integrated pressure regulators. 2017

05/01/2017 Technical Information Sheets TIS36

Some medical gas cylinders integrate pressure regulators within the cylinder valve. TIS 36 provides advice on the safe handling and use of such cylinders.

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TIS37 Medical Gases. Gas cylinder cleanliness standards. Revision 2: 2019

18/06/2019 Technical Information Sheets TIS37

Details the requirement to keep medical gas cylinders clean and covers the methods used to either clean the external surface or to return a cylinder in protective packaging. It does not address the internal condition of a gas container or the quality of the gas within.

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TIS39 Medical Gases. Quality control and QP batch certification of bulk medical liquid oxygen. 2016

01/12/2016 Technical Information Sheets TIS39

Details both the practical and scientific justification for a concession allowed by the medical regulatory authorities for the retrospective release by a qualified person (QP) of bulk medical liquid oxygen.

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TIS42 Medical gases. Data Integrity Policy. 2018

17/01/2018 Technical Information Sheets TIS42

Data integrity is fundamental in a pharmaceutical quality system. This document provides guidance on compliance with the data integrity requirements for batch documentation relating to medicinal gases.

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EIGA held an oxygen safety workshop in January 2012. The following presentations may be of interest: