An Assessment of the 5-mA 60-Hz Contact Current Safety Level

This paper is an investigation into the research basis of the 5-mA electrical safety standard. Although Dalziel´s let-go current research is generally considered to be the basis of this standard, the 5-mA level actually predates Dalziel´s investigations. Nevertheless, in spite of some limitations in experimental design, Dalziel´s let-go current experimental series is basically sound and well supports the 5-mA level as an occupational electrical safety standard. However, its applicability to the general population is questionable. Dalziel´s data were developed from generally young, healthy subjects, and the standard´s applicability to vulnerable populations such as children, the elderly, and the infirm is not known.