The IEC (International Electrotechnical Commission) and UL (Underwriters Laboratories Inc.) standards differ significantly.

IEC standards specify the minimum device safety requirements.

UL standards, in contrast, specify comprehensive technical details in terms of product safety and application.

The IEC and UL organizations also differ greatly in terms of their general approach.

In addition to standards development, the UL is also responsible for certification (general third-party certification) as well as field acceptance.

Compliance with the standards is monitored more strictly, for example through factory inspections of device manufacturers, to ensure that the framework conditions specified together with the certification are met.