UL 101 applies to cord- and plug-connected household and similar appliances (see Definitions, Section 3) rated 20 A or less, nominal 50 or 60 Hz, having 3-wire (including equipment grounding conductor) or 2-wire cords, and intended for use on supply circuits not exceeding 150 V to ground.

This standard does not apply to:

• Appliances having a grounding connection made at the factory to the neutral terminal.
• Electronic measuring instruments not intended for household use.

The values in this standard do not provide protection against the minute currents which could cause ventricular fibrillation if applied directly to the heart, as via a heart catheter.

WEINBERG, D. I., J.L. ARTLEY, R.E. WHALEN, H.D. McINTOSH. Electric Shock Hazards in Cardiac Catheterization, An Engineering Analysis. Electrical Engineering 82:30-35. 1963 (American Institute of Electrical Engineers now the Institute of Electrical and Electronic Engineers).