These are set out in the Gas Safety (Management) Regulations 1996. Government has indicated that there will be no scope for any change to the current specifications until at least 2020. As such, import gas that does not conform to the gas quality specifications will not be suitable for supply to consumers without being treated. The likely variable composition and energy content of such gas has lead to a series of Government-initiated reviews into the need for adjustment to imported gas to ensure continuing security and stability of gas supplies. The owner and operator of the GB gas transmission network, National Grid Gas plc (National Grid), acting in accordance with its regulatory obligations, will not allow the entry of non-specification gas into the network. This means that off-specification imports will need to be blended or processed prior to entry into the network in order to comply with existing limits.