Story updated a few minutes ago. Two workers hurt in an arc flash. One with possible inhalation. Arc rated clothing dramatically reduce these injuries. Cotton clothing, if it ignites usually kills the worker. These type of incidents are covered by OSHA 1910.269. NSTAR is a leading company in arc flash safety. The NESC and OSHA require arc flash calculations and adequate protection for the calculated level but depending on work practices being followed or not, the energy level can be greater.