The National Institute for Occupational Safety and Health (NIOSH), reports that an estimated 5 to 10 arc flash accidents occur every day in the US.
An arc flash is the sudden release of electrical energy through the air when a high-voltage gap exists and there is a breakdown between conductors. An arc flash gives off thermal radiation (heat) and bright, intense light that can cause burns.
Temperatures have been recorded as high as 35,000 °F. High-voltage arcs can also produce considerable pressure waves by rapidly heating the air and creating a blast. This pressure burst can hit a worker with great force and send molten metal droplets from melted copper and aluminum electrical components great distances at extremely high velocities.
OSHA Standards 29 CFR, Parts 1910 and 1926. Occupational Safety and Health Standards. Part 1910, subpart S (electrical) §§ 1910.332 through 1910.335 contain generally applicable requirements for safety-related work practices.
On April 11, 2014, OSHA adopted revised standards for electric power generation, transmission, and distribution work at part 1910, § 1910.269 and part 1926, subpart V, which contain requirements for arc flash protection and guidelines for assessing arc-flash hazards, making reasonable estimates of incident heat energy from electric arcs, and selecting appropriate protective equipment (79 FR 20316 et seq., Apr. 11, 2014). All of these OSHA standards reference NFPA 70E.
This video addresses the problem of arc flash safety.