49.—(1) A vehicle which is—
(a)a motor vehicle which first used gas as a fuel for its propulsion before 19th November 1982; or
(b)a trailer manufactured before 19th November 1982 to which there is fitted a gas container,
shall be so constructed that it complies with either Schedule 4 or 5.
(2) A vehicle which is—
(a)a motor vehicle which first used gas as a fuel for its propulsion on or after 19th November 1982; or
(b)a motor vehicle first used on or after 1st May 1984 or a trailer manufactured on or after 19th November 1982 which is in either case equipped with a gas container or a gas-fired appliance,
shall comply with Schedule 5.
(3) The requirements of this regulation are in addition to, and not in derogation from, the requirements of any regulations made under section 6 of the Petroleum (Consolidation) Act (Northern Ireland) 1929, Article 17 of the Health and Safety at Work (Northern Ireland) Order 1978(1), or any other Act or of any codes of practice issued under the said Order of 1978.
(4) In this regulation “gas container” has the meaning given in Part I of Schedule 4 where compliance with that Schedule is concerned and otherwise has the meaning given in paragraph 1 of Schedule 5.