Whether you are developing product to be sold locally or internationally, knowing the relevant product safety standard is important. Safety standards for industrial control equipment (ICE) are being harmonized to increase global market access.

The result of this harmonization process is detailed in the table below. The table identifies the affected product categories and the corresponding harmonized standard to which they will be transitioned, along with other information needed.

 Affected Category (CCN) from UL 508 or UL 508C Transition
Start / End Dates **
Bulletins /
Transition FAQs
Magnetic Motor Controllers – NLDXManual Motor Controllers – NLRV Combination Motor Controllers – NKJH Auxiliary Devices (Overload Relays ONLY) – NKCRIndustrial Control Switches, Intended for use in Power Circuits (direct connection to Mains) – NRNT UL 60947-4-1 Jan 26, 2012
/Jan 26, 2017
Latest  Communication(July 2015) FAQs
Programmable Logic Controllers – NRAQ UL 61010-2-201 (with no National Differences) Sept 10, 2013
/ April 1, 2016
Initial Communication
(Mar 19, 2012)2nd Communication
(Sept 9, 2013)3rd Communication
(Nov 11, 2014)
Proximity Switches – NRKH UL 60947-5-2 ## Mar 28, 2014
Power Conversion Equipment – NMMS UL 61800-5-1 Feb  1, 2016 / Feb 1, 2020 Initial Communication
(Aug 23, 2012)2nd Communication
(Apr 10, 2013)3rd Communication(May 19, 2015)
Auxiliary Devices (Excluding Overload Relays) – NKCR UL 60947-5-1 ## Mar 28, 2014
Motor Controllers, Mechanically Operated and Solid-state, Solid-State Controls for Motor Loads – NMFT UL 60947-4-2 Mar 21, 2014
/Mar 21, 2021
Initial Communication(July 16, 2015) TBD
Industrial Control Switches, Solid-state Controls for Non-Motor Loads – NRNT UL 60947-4-3 TBD TBD TBD
Industrial Control Switches, All-or-Nothing Relays – NRNT Magnetic Motor Controllers – NLDXAuxiliary Devices (Excluding Overload Relays) – NKCR UL 61810-1 ## TBD TBD TBD


** Start Date – Date when the new Standard(s) may be used for Certification; End Date = Date when UL 508/508C is no longer an option for new and alternate construction product investigations.

## – These Standards have been published and are available for use towards Certification. Details regarding the transition schedule, bulletins and associated FAQs will be provided in the future.

Action Required

Unless indicated in one of the above-mentioned transitions, if you currently have a product certified to UL 508 or UL 508C, under one of the affected categories, please contact UL by the requested date to convert your existing file to the appropriate harmonized standard(s). Contact your local sales representative to request a quotation, click here, or use the Contact UL button on this page.

Please note that if you have any product or sales literature that references UL 508 (or UL 508C), you should consider revising such literature to reference the new corresponding harmonized standard.

Please be certain to review this website regularly for updates to the current and new standard transitions.