Duty to conform with safety case
5.—(1) Where a person has prepared and has had accepted a safety case pursuant to these Regulations he shall ensure, so long as he conveys gas in the network to which the safety case relates or remains a network emergency co-ordinator, as the case may be, that the procedures and arrangements described in the safety case and any revision thereof are followed.
(2) In criminal proceedings for a contravention of paragraph (1) it shall be a defence for the accused to prove that—
(a)in the particular circumstances of the case it was not in the best interests of health and safety to follow the procedures or arrangements concerned and there was insufficient time to revise the safety case pursuant to regulation 4; or
(b)the commission of the offence was due to a contravention by another person of regulation 6 and the accused had taken all reasonable precautions and exercised all due diligence to ensure that the procedures or arrangements were followed.