Understanding UL94v-0: Silicone Rubber

Probably, you are wondering why UL94V-0 is critical in silicone rubber applications. Well, this guide explores all the fundamental aspects you should know about UL94V-0 and how it related to silicone quality.

Besides, we shall also explain importance of UL94V-0 in silicone rubber quality.

What is UL94v-0?

UL94V-0 is a standard established by the Underwriters Laboratories for plastic materials used in devices and appliances. It measures the flammability of these materials assessing their resistance ignition and self-extinguishing ability upon exposure to a flame.

The designation UL94V-0 is representative of the following:

  • UL94 which describes the standard itself in general.
  • V asserts to the vertical flame used in the test.
  • 0, a digit representing the highest level of flame retardancy.
 Silicone Structure
Silicone Structure

Conducting UL94v-0 Testing for Silicone Rubber

Silicone rubber is a highly flexible, durable and temperature resistant synthetic polymer that finds wide usage where heat is a concern. UL94V-0 standard testing silicone rubber offers manufacturers and consumers valuable information concerning the material’s fire safety.

When subjecting silicone rubber to the UL94V-0 test procedure, it is conducted in a controlled laboratory environment.

This stabilizes the temperature and moisture content ensuring consistent and accurate test results. From this, you can develop silicone rubber UL94v 0 datasheet.

A standard test procedure takes the following form:

  • Five specimens of silicone rubber are prepared usually in the form of bars. These typically measure 125mm in length, 13mm in width and a maximum thickness of 13mm.
  • During testing, the silicone rubber specimen is vertically mounted in the test apparatus simulating real life conditions of exposure to a flame.
  • A Bunsen burner provides the test flame which should have a height of 20mm.
  • The flame is concentrated to the silicone rubber specimen’s bottom edge such that the burner’s top and specimen are 10mm apart.
  • This interaction is sustained for 10 seconds, ensuring the flame is directly below the silicone rubber at all times. You can achieve this by constantly moving the burner to accommodate the silicone specimen’s positional changes.
  • Upon exhaustion of the ten seconds, the flame interaction with the specimen is stopped. The duration the silicone rubber specimen continues to burn after removal of the flame is then recorded.
  • Soon after the silicone rubber extinguishes, the burner is reintroduced as before for ten more seconds.
  • After 10 second elapses, you can remove the burner. At this juncture, you will now examine how long the silicone rubber under test will continue to burn.

Success Determinants of a UL94v-0 Test on Silicone Rubber

Heat Resistant Silicone Washer
Heat Resistant Silicone Washer

When silicone rubber meets the test requirements of UL94V-0, it is considered to be of excellent flame retardancy and self-extinguishing. As such, it can be used in electronic devices and as a building material where fire safety is a priority.

Silicone rubber cannot be considered to have passed the UL94V-0 test until it meets the following key requirements:

  • For every silicone rubber specimen tested, the material shouldn’t support combustion for a duration exceeding 10 seconds after each flame application.
  • The combined duration of combustion after flame for the five silicone rubber specimen should be at most fifty seconds.
  • After flame removal, the silicone rubber material should not continue to smolder, to the extent it reaches the clamp. Furthermore, the material should not produce any glowing embers that could pose a fire hazard.
  • The silicone rubber specimen shouldn’t create flaming drips that ignite a cotton indicator positioned below it.
  • Upon subjecting the silicone rubber specimen to the first and second flame tests, the material should self-extinguish within thirty seconds.

Reasons for Subjecting Silicone Rubber to UL94v-0

Silicone finds extensive use across industries including the manufacture of cookware, automotive parts, seals, gaskets and electrical insulation. In these applications, a common issue is high temperature and the resultant heat which poses fire safety.

Consequently, you can identify the following reasons why testing silicone rubber for UL94V-0 compliance is necessary:

  • Fire Safety: Silicone rubber material finds use in electronic devices where overheating or malfunctions can occur posing risk of fires. Ensuring silicone rubber meets UL94V-0 standards enhances overall safety as it is less likely to contribute to fire spread.
  • Regulatory Compliance: Industries utilizing silicone rubber material have requirements that emphasize fire safety. Subjecting silicone material to UL94V-0 test ensures it meets these standards subject to industry approval.
  • Customer Confidence: Ensuring silicone rubber material meets UL94V-0 standards is demonstrative of product safety and quality. A customer therefore makes a purchase utilizing silicone rubber material with confidence on its safety.

Application of UL94v-0 Certified Silicone Rubber Products

Silicone rubber products cleared to be UL94V-0 certified find applications across various industries for their fire safety, reliability, and durability. Some of these applications are captured thus:

  • Silicone rubber is extensively used in the electronics industry for its electrical insulation quality. This allows for their use in high temperature and heat environments where fire safety is vital.
  • Aerospace and automotive applications implement silicon rubber material with UL94V-0 certification to insulate wires and cables. These applications require high fire resistance in case of accidents and emergencies.
  • Silicone rubber is used to make gaskets and seals which find wide usage across industries. Using UL94V-0 certified silicone rubber ensures these gaskets and seals offer superior heat and fire resistance.
  • Lighting fixtures such as LED strips and bulbs utilize UL94V-0 certified silicone materials for their high temperature tolerance. They can thus provide flame retardancy in lighting applications where fire safety is critical.


With UL94V-0 test standard, you can examine a wide range of silicone products. For instance, you can examine silicone sealant flammable properties or silicone rubber flammability properties.

At LEGENDAY, we have high grade silicone products, designed to meet strict quality standards and specifications.

More resources:

What are the Different Processing Methods for Silicone Rubber – Source: LEGENDAY

Polyurethane vs Silicone Rubber – Source: LEGENDAY

Liquid Silicone Rubber Overmolding – Source: LEGENDAY

What is Silicone Rubber Calendering – Source: LEGENDAY

What Is Medical Grade Liquid Silicone Rubber? – Source: LEGENDAY

What Is the Difference between Silicone Resin and Silicone Rubber – Source: LEGENDAY





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