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Lighting fixtures are certified for electrical safety by a Nationally Recognized Testing Laboratory (NRTL). Retrofit projects utilizing T-LED lamps designed for G13 fluorescent lamp holders and that require rewiring around the ballast (Type B) or installation of an external driver (Type C) are required to use kits that are UL Certified (Classified) for the purpose. Precautionary labeling must be applied to the lighting fixture to indicate that it has been modified from its original condition and will no longer support operation from a light source other than the specific type of T-LED replacement lamp with which it has been fitted. If the labels are missing or do not match other documentation, or if the LED product used is not UL Certified (Classified) for the purpose, the local inspector can reject the installation as non-compliant requiring further on-site UL inspections.
UL has certification options designed to allow for UL Certification of products utilizing the G6.6J Snap-Fit system. Manufacturers of GJ6.6 T-LED lamps and lamp holders now have a quick and low-cost certification process for gaining UL Certification of their products. The installation of their products and the legacy fixtures into which they are installed will conform to associated codes. This means that building owners can now safely implement Type B and Type C T-LED lamp retrofit projects with fewer risk for code violations or implicating warranties or insurance coverage.
For more information on certification options available to T-LED manufacturers, lampholder manufacturers, retrofit manufacturers, and luminaire manufacturers, please visit UL at or contact UL at


Official copies of GJ6.6 Standards are available through the American National Standards Institute.

ANSI C81.61-2019 Electric Lamp Bases

ANSI C81.62-2019 Electric Lampholders

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