1. The problem statement, all variables and given/known data Hospital operating theatres, floors are made out of conducting material and staff wear shoes made of conducting material not insulating material. How sis charge built up on insulating soles and how does using conducting material reduce charge & sparks? 2. Relevant equations none 3. The attempt at a solution No free movemen of electrons in insulating materials there for the charge is built up over time, by using conducting materials the electrons are free to move from one place to another therefor not building up charge.