No employer or user shall use or permit the use of a portable light where the operating voltage exceeds 50 V unless -
(a) it is fitted with a substantial handle which is made of non-hygroscopic, non-conducting material;
(b) all live metal parts or parts which may become live owing to a faulty circuit are completely protected against accidental contact;
(c) the lamp is protected by means of a substantial guard firmly fixed to the insulated handle; and
(d) the cable lead-in is such that the insulation can withstand rough use.