A Guide to UL94 Horizontal and Vertical Burning Standards

For electrical and electronic products entering the markets of Russia and the Eurasian Economic Union (EAEU), the fire safety of materials is a mandatory requirement. In addition to the internationally recognized UL94 standard, products must typically comply with the relevant fire safety regulations within the GOST R certification system. A thorough understanding of the UL94 rating system is the foundational step for ensuring products successfully pass local safety certifications.

The UL94 standard is a globally accepted test method for assessing the flammability of plastic materials. Its procedures are highly aligned with Russian national standards such as GOST R IEC 60695-11-10 and GOST R IEC 60695-11-20. The standard comprises the following 12 primary classifications:

• HB: Horizontal Burning
• V-0. V-1. V-2. 5VA, 5VB: Vertical Burning
• VTM-0. VTM-1. VTM-2: Applicable to plastic films
• HBF, HF-1. HF-2: Applicable to foamed materials

Key Classifications Explained:

• UL94 HB (Lowest Rating): A material that burns slowly in a horizontal orientation but does not self-extinguish. This rating is often considered when a vertical classification (V-0. V-1. V-2) cannot be achieved.
• UL94 V-0 / V-1 / V-2 (Vertical Burning): These ratings evaluate a material's ability to self-extinguish after the ignition flame is removed. V-0 represents the highest commercial rating, with the most stringent requirements (shortest after-flame time, no burning drips that ignite cotton). V-2 allows for burning drips that ignite cotton positioned below the specimen.
• UL94 5V (Most Stringent Rating): Designed for more demanding applications. The test procedure permits no flaming drips, significant distortion, or burn-through holes.

Our Horizontal and Vertical Burning Test Chambers are engineered to strictly adhere to UL94 test protocols. They accurately perform all UL94 HB and UL94 V series tests, providing reliable data to support the efficient compliance of your products with safety certifications for the Russian and international markets.