Electrical maintenance is important for appropriate of Major Accident Prevention Policy MAPP at Seveso sites. At Seveso sites, many accidents include in the causes an electrical failure, due usually to a poor maintenance. Power outages, in particular, originate cascade effects, leading to a possible loss of hazardous materials. The repository of the minor incidents and near misses recorded at Seveso sites is a valuable source for investigating electrical failures, causes, effects and possible prevention and mitigation measures. The present paper discusses a number of incident records, gathered at Seveso establishments, during the mandatory inspections, required by the Seveso Directive. Gathered documents cover different types of plant, including refineries, oil terminal, LPG depots and chemical plants. They have been analysed, using advanced method, including machine learning. The results of this analysis have been exploited to provide the establishments’ operator with a few recommendations, essential to improve electrical safety and prevent major accidents.