Flammability – UL94

Setting Up a Flame Test
Many plastics are flammable by nature...

Their molecular density tends to make them burn longer and more easily. Plastic’s widespread presence in modern life means that this flammability problem must be addressed to keep consumers and products safe. Government regulations and industry standards were introduced to make plastic-containing products fire-safe as appropriate for their relevant applications. Now, manufacturers must subject their products to flammability testing in to abide by those expectations.

Applied Technical Services, provides flammability testing to manufacturers to keep their products standard-compliant. UL94 is a widely known standard testing method for plastics. ATS is especially qualified to handle your UL94 testing needs, as we are A2LA (ISO 17025) accredited to test to that standard.


About the Method

The test method involves burning a small sample of plastic material for a certain amount of time and noting the characteristics it displays while burning, such as: whether the sample burned, how long it glowed from the heat after the flame was removed, how long the sample burned after the flame was removed, how much of the material was lost, whether any material dripped off of the sample, whether those drips were on fire, and any unusual phenomena like melting or warping.

To start the UL94 method, our technicians will apply one of three kinds of burn test to the sample material, depending on the desired flammability rating. The test is performed, and the technician notes the burning characteristics of the sample. They then take these burning characteristics into account and either assign the material the appropriate rating or mark it as failing to meet criteria. The ratings break down like this, ordered from least to most fire-resistant:

  • HB: The only horizontal burn test in the method, measures burn rate as a function of mm/minute
  • V-2: Vertical burn test, allowed to drip burning material
  • V-1: Can drip non-burning material, must extinguish within 30 seconds once flame is removed
  • V-0: Must extinguish within 10 seconds once flame is removed
  • 5VB: Material is exposed to flame five different times, allowed to develop a burned-through hole
  • 5VA: Is not allowed to drip or develop a burned-through hole, must extinguish within 60 seconds once flame is removed


ATS and UL94

ATS is thoroughly experienced in performing flammability testing. For 50 years, we have provided consulting, inspection, engineering, and testing services to clients from a variety of industries. ATS provides its clients with the most accurate findings with a quick turn-around time; contact us today so we can supply the critical insight that will keep your products standard-compliant.

A2LA Certification

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