Section 21: Vessels containing dangerous liquids

(1) Every fixed vessel, structure, sump or pit of which the edge is level with or less than 91 centimetres 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 covering nor secure fencing 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) As respects any plant mentioned in subsection (1) of this section, a warning notice in English and in such Nigerian languages as an instructor may direct, indicating the nature of the danger, shall be marked on or attached to the plant or, if this is not reasonably practicable, be posted nearby.