Sch 1 para 35 Explosive atmospheres caused by air and dust mixtures
(1) Equipment must be designed and constructed so that ignition of air and dust mixtures is prevented, even in the event of frequently occurring disturbances or equipment operating faults which normally have to be taken into account. (2) With regard to surface temperatures, sub-paragraph 33(5) applies. (3) With regard to protection against dust, sub-paragraph 33(3) applies. (4) With regard to the safe opening of equipment parts, sub-paragraph 34(3) applies.