No employer or supervising agent of an employer shall require or permit an employee to, and no employee shall participate in the erection, maintenance, repair, construction or installation, whether or not such work is for emergency purposes, of high-voltage lines having a voltage differential in excess of nominally 13,200 volts between any pair of conductors or in excess of nominally 7,600 volts between any conductor and ground, unless any and all such conductors are de-energized before such work is commenced, or unless such work is performed on any energized conductor or equipment through approved hot stick methods which do not include handling such high-voltage lines with gloves or bare handed method.