IEEE, the Institute of Electrical and Electronics Engineers, recently produced a paper1 reviewing 100 years of research on shock and arc injuries. Going back, the first recognized hazard to workers was the shock hazard. In the 1990s the arc flash hazard became a worker protection issue. Both shock and arc flash hazards have been the focus of NFPA 70E and OSHA standards since the late 1970s.
A century of research shows many thousands of fatalities have occurred due to power frequency shock, according to the IEEE paper’s authors -- four from Los Alamos National Laboratory and one from the Department of Energy.