The following are the main differences between UL 60601-1
and IEC 60601-1. Please note that not all differences are listed here.
You should consult UL 60601-1 for full information.
Certain components must comply with the relevant ANSI/UL standards for those components, e.g. Lithium batteries must comply with UL 1642, fuseholders
with UL 512, etc. In general UL will only accept components which have been approved by UL itself, though other NRTL's (National Recognized Testing Laboratories)
may have more flexible policies concerning component approvals.
Leakage current: UL 60601-1 has more stringent leakage current requirements than IEC 60601-1
Moving parts: Where moving parts may cause injury, the maximum travel of those part must be limited by end stops or other mechanical means.
There are additional constructional requirements for medical devices that are used with oxygen or oxygen enriched atmospheres.
Nonmetallic surfaces of enclosures with conductive coatings generally have to comply with UL 746C. Both the materials and the process used have to be approved by UL.
Flammability: Polymeric enclosures and covers generally have to comply with flammability requirements.
If appropriate "Hospital Grade" or "Hospital Only" mains plugs exist for the electrical rating of the medical device, these are used.
Power Supply Cords:
UL 60601-1 specifies the power supply cord types that may be used.
Markings: There are various additional markings requirements.