4.—(1) Without prejudice to regulation 5 of the General Duties Regulations, and subject to paragraphs (2) to (4), these Regulations apply in relation to —
(a)hazardous chemical agents that are or may be present on United Kingdom ships, giving rise to risks or the likelihood of risks to the health and safety of workers on those ships whether as a result of that presence or as a result of any work activity involving such agents; and
(b)United Kingdom ships on which such agents are or may be present.
(2) Where—
(a)a ship is being used in the course of public service activities or activities for the purpose of the civil protection services, and
(b)characteristics peculiar to those activities inevitably conflict with a provision of these Regulations,
that provision does not apply in relation to that ship to the extent of that conflict.
(3) To the extent that a provision of these Regulations does not apply in relation to a ship because of paragraph (2) there is in relation to that ship a duty on the employer to ensure, so far as is reasonably practicable, the health and safety of workers who are or who are likely to be exposed to risks from chemical agents as a result of their work.
(4) This regulation (other than paragraph (1)) and regulations 5, 19 and 21 apply where hazardous chemical agents are present or may be present on ships other than United Kingdom ships which are for the time being in United Kingdom waters giving rise to risks or the likelihood of risks to the health and safety of workers on those ships, whether as a result of that presence or as a result of any work activity involving such agents.
(5) In paragraph (2)—
(a)“civil protection services” includes the fire and rescue and ambulance services and search and rescue services provided by any other person; and
(b)“public service activities” includes the activities of the armed forces, HM Coastguard, HM Revenue and Customs, immigration officers, police, prison officers and the security and intelligence services.