Electrical oil formulation comprising a base oil component and an additive, wherein (i) at least 80 wt % of the base oil component is a paraffin base oil having a paraffin content of greater than 80 wt % paraffins and a saturates content of greater than 98 wt % and comprising a series of iso-paraffins having n, n+1, n+2, n+3 and n+4 carbon atoms and wherein n is between 20 and 35; and (ii) an anti-oxidant additive; wherein the base oil component has a flash point of at least 170° C., as determined by ISO 2592.