Content and other characteristics of gas
8.—(1) A person shall not, subject to paragraphs (2) to (4), convey gas in a network unless the gas conforms with the requirements specified in Part I of Schedule 3.
(2) The network emergency co-ordinator may, where it is necessary to prevent a supply emergency and in accordance with the arrangements specified in his safety case pursuant to paragraph 3(d) of Schedule 2, authorise, for the period specified in the authorisation, gas not conforming with the requirements specified in Part I of Schedule 3 to be conveyed in the network if the gas conforms with the requirements specified in Part II of that Schedule.
(3) An authorisation under paragraph (2) may be given orally or in writing and may be withdrawn at any time.
(4) Where only one person conveys gas in a network, he may, where it is necessary to prevent a supply emergency and in accordance with the arrangements specified in his safety case pursuant to paragraph 19 of Schedule 1, convey gas which does not conform with the requirements specified in Part I of Schedule 3 if the gas conforms with the requirements specified in Part II of that Schedule.
(5) A person who conveys gas in a network shall ensure that suitable and sufficient tests are carried out to ensure that the gas conforms with the requirements of paragraph (1), (2) or (4), as appropriate.