(1) An employer or self-employed person must ensure during work in a confined space that—
(a) so far as is reasonably practicable, the concentration of any flammable gas or vapour in the atmosphere of the space is below 5% of its LEL; or
(b) if it is not reasonably practicable to comply with paragraph (a) and the concentration of any flammable gas or vapour in the atmosphere of the space—
(i) is, or is likely to be, equal to or greater than 5% but less than 10% of its LEL, any employee is removed immediately from the space unless a suitably-calibrated, continuous-monitoring, flammable gas detector is used in the space while the employee is in the space; or
(ii) is equal to or greater than 10% of its LEL, any employee is removed immediately from the space.
Note
Act compliance—sections 21, 23 and 24 (see regulation 7).
(2) In this regulation, "LEL" (lower explosive limit) of a flammable gas or vapour means the concentration of that gas or vapour in air below which the propagation of a flame does not occur on contact with an ignition source.