Fencing vessels, etc

(1) Every fixed vessel, structure, sump or pit of which the edge is less than three feet above the adjoining ground or platform shall, if it contains any scalding, corrosive or poisonous liquid, either be securely covered or be securely fenced to at least that height, or where by reason of the nature of the work neither secure fencing nor secure covering to that height is practicable, all practicable steps shall be taken by covering, fencing or other means to prevent any person from falling into the vessel, structure, sump or pit. (2) The Chief Factory Inspector may by order exempt from the requirements of this regulation any class of vessel, structure, sump or pit in the case of which he is satisfied that the requirements are unnecessary or inappropriate.