Standard for UL flame retardant labels

The UL flame retardant label standard is a series of testing standards for material flame retardancy developed by Underwriters Laboratories (UL) in the United States. These standards typically include various testing methods such as vertical combustion testing, horizontal combustion testing, and ultimate oxygen index testing to evaluate the flame retardant performance of materials under different conditions.

Specifically, the standards for UL flame retardant labels may involve the following aspects:

Vertical combustion test: a testing method for evaluating the combustion performance of materials when placed vertically, by observing indicators such as the combustion speed and flame spread length of the sample to assess the flame retardancy of the material.

Horizontal combustion test: a testing method for evaluating the combustion performance of materials when placed horizontally, which also evaluates the flame retardancy of materials by observing indicators such as the combustion speed and flame spread length of the sample.

Extreme Oxygen Index Test: A test method for evaluating the minimum oxygen concentration required for a material to maintain combustion at a specific oxygen concentration, used to determine the flame retardant performance level of the material.

It should be noted that the standards for UL flame retardant labels are not static. With the development of technology and the improvement of safety standards, UL will continuously update and improve its flame retardant testing standards. Therefore, in specific applications, it is necessary to refer to the latest UL flame retardant testing standards to evaluate the flame retardant performance of the product.

UL94 flame retardant rating classification

UL94 is currently the most widely used flame retardant performance evaluation standard for plastic materials internationally, with a total of 12 grades: HB V-0、V-1、V-2、5VA、5VB、VTM-0、VTM-1、VTM-2、HBF、HF-1、HF-2。

VTM-0, VTM-1, and VTM-2 are suitable for plastic films, while HBF, HF1, and HF2 are suitable for foam materials.

The equivalent flame retardant rating standard adopted by China is GBT2408 "Horizontal and Vertical Methods for Testing the Burning Behavior of Plastics".

The flame retardant grade of plastics increases gradually from HB to V-0: HB<V-2<V-1<V-0<5VB<5VA.

UL94 Common Test Methods

UL94 is used to evaluate the ability of materials to extinguish flames after being ignited. There are multiple evaluation methods based on combustion speed, combustion time, anti drip ability, and whether the drips are burning.