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UK Gas Safety (Management) (Amendment) Regulations 2023 come into force

11 April 2023

New laws related to the transmission and distribution of gas in Great Britain came into force on April 6 following a government review of gas quality regulation and a public consultation on changes to the Gas Safety (Management) Regulations 1996.

Changes will see new values for the content and characteristics of gas that may be conveyed in the gas network, an extension of the co-operation duties to liquified natural gas import facilities, the creation of an Emergency Reporting Service to take over the functions and responsibilities of the gas emergency telephone service for gas escapes and additional regulatory requirements for pipelines conveying biomethane in gas networks, the HSE has said.

The Gas Safety (Management) (Amendment) Regulations 2023 (GSMAR) apply to gas transmission and distribution, providing for the safe management of gas flow through a network; gas quality specifications; arrangements for dealing with gas escapes and arrangements for managing gas supply emergencies, and will play an important role in the continued supply of gas and resilience in our supply mix, and in the health and safety of gas conveyance.

The regulatory changes include:

- Gas that is permitted in gas networks in Great Britain must have a relative density of =0.700. The incomplete combustion factor and sooting index values are no longer required in order to comply with Schedule 3

- Gas that is permitted in gas networks in Great Britain may have an oxygen content of =1% (molar) so long as it is conveyed at pressures =38 barg. The permitted oxygen content for gases conveyed at pressures above 38 barg will remain =0.2% (molar)

- Liquified natural gas import facilities will be subject to the co-operation requirements set down by the regulations

- The gas emergency telephone service is now known as the Emergency Reporting Service. The function of the service is remaining the same however no gas network may operate without an emergency reporting service provider in place and a new schedule has been created outlining the particulars to be included in the safety case of the emergency reporting service provider


- The lower Wobbe Number limit for gas permitted in gas networks in Great Britain will change to  =46.5MJ/m3 on 6 April 2025

- Pipelines conveying biomethane must be operated with a safety case – this came into force on 6 April 2023. However, dutyholders will have until 6 October 2024 to prepare and submit a safety case to HSE if they are not already operating with one. Biomethane can continue to be conveyed to treatment or blending points if the gas requires them in order to bring it into conformity with Schedule 3 gas quality specifications

For more information on the changes, please see these useful links:

- The Gas Safety (Management) (Amendment) Regulations 2023
- GSMAR consultation 
- GSMAR consultation response (.PDF)
- GSMAR impact assessment 

HSE will also be publishing updated L80 guidance on the regulations in due course.

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