According to National Fire Protection Association’s calculation, every 24 seconds, a fire department in the United States responds to a fire somewhere in the nation. Among them, 13% are electrical fires, which accounted for the highest share of civilian deaths (18%) and direct property damage (20%). Arcing was the heat source in approximately three of five home fires involving an electrical failure or malfunction. So it is crucial for electrical appliances to be made of fire-retardant materials that don’t turn arcing into open flames.
What Are Fire-Retardant Materials and How Do They Work
Fire-retardant materials are designed to burn slowly or even self-extinguish. Flame retardants inhibit or delay the spread of fire by suppressing the chemical reactions in the flame or by the formation of a protective layer on the surface of a material. They often have a high melting point and burning point, and drips no or few burning particles when they are lit. Common fire-retardant materials used in the electrical appliance industry are ABS+PC, PC, and PVC. They all have reached the UL94 V-0 fire-retardant level.
UL94 Plastic Flammability Test
Flammability is the ease with which a combustible substance can be ignited, causing fire or combustion or even an explosion. The degree of difficulty required to cause the combustion of a substance is quantified through fire testing.
UL 94, the Standard for Safety of Flammability of Plastic Materials for Parts in Devices and Appliances testing, is a plastics flammability standard released by Underwriters Laboratories of the United States. The standard determines the material’s tendency to either extinguish or spread the flame once the specimen has been ignited.
From lowest (Least flame-retardant) to highest (Most flame-retardant):
HB: slow burning on a horizontal specimen; burning rate < 76 mm/min for thickness < 3 mm or burning stops before 100 mm
V-2: burning stops within 30 seconds on a vertical specimen; drips of flaming particles are allowed.
V-1: burning stops within 30 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.
V-0: burning stops within 10 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.
5VB: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may develop a hole.
5VA: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may not develop a hole.
So next time you are choosing an electrical appliance or power delivering device, like a power strip, make sure to check its casing material and fire-retardant rating (UL94 V-0 or higher). If you have any questions regarding this blog or need any help choosing power strips, please comment below or send us an email to firstname.lastname@example.org.