UL 94 vs. UL 746C Flammability Testing Standards:

UL 94:

The UL 94 regulation describes the test for evaluating and classifying the ignition characteristics of plastic materials.

These requirements cover tests for the flammability of polymeric materials used for parts in devices and appliances. They are intended to serve as a preliminary indication of their acceptability concerning flammability for a particular application.

UL 746C:

The UL 746C regulation sets standards for polymeric materials used in electrical equipment, required by UL50.

These requirements cover parts made of polymeric materials that are used in electrical equipment and describe the various test procedures and their use in the testing of such parts and equipment.

If all the materials are classed as UL 94-5VA in molded parts, UL 746C flammability testing is not required for the equipment.

As an alternative to materials with the UL 94 classification 5VA, the UL 50 Regulation also permits material that has the classification UL 94 HB but have passed the flame test according to UL 746C.

UL 50:

The UL 50 standard applies to enclosures for electrical equipment intended to be installed and used in non-hazardous locations and covers the non-environmental construction and performance requirements for enclosures to provide a degree of protection to personnel against incidental contact with the enclosed equipment.

For more information on UL 94 flame ratings, check out our blog posts:

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