{"id":21013,"date":"2026-02-05T09:20:02","date_gmt":"2026-02-05T15:20:02","guid":{"rendered":"https:\/\/ulprospector.ul.com\/?p=21013"},"modified":"2026-03-25T10:04:14","modified_gmt":"2026-03-25T16:04:14","slug":"what-is-ul-746","status":"publish","type":"post","link":"https:\/\/ulprospector.ul.com\/21013\/what-is-ul-746\/","title":{"rendered":"What is UL 746?"},"content":{"rendered":"

Additional Languages: Korean<\/a>, Deutsch<\/a>, Japanese<\/a>, Chinese\u00a0<\/a><\/p>\n

What is UL 746?<\/strong><\/p>\n

It\u2019s\u00a0an important question<\/strong>\u2014whether\u00a0you\u2019re\u00a0new to the plastics industry, planning to launch products worldwide, or simply curious to learn more about the tests behind the standards your materials are certified to. Understanding these standards helps you make informed choices,\u00a0verify\u00a0compliance, and build products that meet global safety and performance expectations.<\/p>\n

UL\u202f746 refers to a set of standards developed by Underwriters Laboratories (UL)\u2014a leading global safety science organization. These standards define requirements for evaluating the safety and performance of plastic materials used in electrical and electronic products. They cover aspects like\u00a0mechanical,\u00a0ignition\u00a0resistance, electrical\u00a0properties, short-term\u00a0thermal\u00a0and long-term aging\u00a0to ensure materials meet strict safety criteria.<\/p>\n

UL standards are grouped into series, each focusing on a specific category of products or hazards. UL\u202f746 is part of the plastics series, helping manufacturers\u00a0meet\u00a0compliance\u00a0requirements\u00a0and market acceptance across regions.<\/p>\n

The\u00a0series is divided into several parts, each focusing on specific aspects of material evaluation: UL746A, UL746B, UL 746C, UL 746D, UL 746E, UL 746F, UL 746G, UL 746H UL 746R and UL 746S.<\/p>\n

Let\u2019s\u00a0dive into the\u00a0UL746 series and each of their\u00a0key components.<\/p>\n

UL 746A –\u00a0Short-term property evaluations<\/strong><\/p>\n

\"\"UL\u202f746A is all about testing plastics for short-term performance. It sets the rules for checking how a material holds up when it comes to strength, electrical properties, chemical resistance, and\u00a0ignition resistance\u2014basically, how\u00a0safe and reliable it is under different conditions. These tests\u00a0help make sure the plastics used in electrical and electronic products meet safety standards before they hit the market.<\/p>\n

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UL 746B – Long-term property evaluations<\/strong><\/p>\n

UL\u202f746B looks at how plastics perform over the long haul.\u00a0It\u2019s\u00a0all about understanding how materials age and break down over time\u2014especially when\u00a0they\u2019re\u00a0exposed to heat for extended periods. These tests help predict durability and safety so manufacturers know their products will last and stay reliable.<\/p>\n

UL 746C –\u00a0Use in electrical equipment<\/strong><\/p>\n

\"\"UL\u202f746C is about testing plastics used inside electrical equipment. It checks how well these materials hold up in real-world conditions\u2014things like outdoor exposure, UV light, and water. Part of this includes environmental ratings like\u00a0F1<\/strong>\u00a0(good resistance to sunlight and water) and\u00a0F2<\/strong> (less\u00a0demanding conditions). These evaluations help ensure the materials stay safe and durable wherever\u00a0they\u2019re\u00a0used.<\/p>\n

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UL 746D\u00a0– Traceability of polymeric materials<\/strong><\/p>\n

UL 746D establishes requirements to confirm full traceability of polymeric materials throughout the manufacturing process. The standard covers every stage\u2014from\u00a0initial\u00a0material handling and\u00a0molding\u00a0or fabrication through to the shipping of the finished parts.\u00a0In addition to traceability,\u00a0it\u00a0outlines the evaluation criteria that apply when a\u00a0molder\u00a0modifies\u00a0a material that has already been tested and certified.\u00a0This\u00a0maintains\u00a0confidence that any adjustments during processing will not compromise safety, operational performance, or compliance obligations.<\/p>\n

UL 746E –\u00a0Industrial laminates and printed wiring boards<\/strong><\/p>\n

UL\u202f746E sets the standards for materials used in things like industrial laminates, filament-wound tubing, vulcanized\u00a0fiber, and printed wiring boards. One key part of this standard is testing how well the protective coating (called conformal coating) resists ignition from electrical sources. In short, it helps make sure these materials stay safe and reliable in demanding electrical environments.<\/p>\n

UL 746F –\u00a0Flexible dielectric film materials<\/strong><\/p>\n

\"\"UL\u202f746F covers flexible materials used in printed wiring boards and flexible circuit connections\u2014think thin films like polyimide that provide insulation and help with conductivity. These materials are key for flexible electronics, and the standard makes sure they meet safety and performance requirements.<\/p>\n

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UL 746G –\u00a0<\/u><\/strong>Per- and polyfluoroalkyl substances (PFAS) and non-fluorinated materials<\/strong>\u00a0<\/a><\/p>\n

\"\"UL\u202f746G is all about addressing the growing demand for plastics that don\u2019t contain PFAS (per- and polyfluoroalkyl substances). It sets clear guidelines for testing and verifying materials\u2014both virgin and recycled\u2014to make sure they meet strict limits for fluorine and PFAS content.<\/p>\n

Here\u2019s\u00a0what it means in practice:<\/p>\n