FRP cable trays (fiberglass cable trays) are a new type of cable support device made primarily of glass fiber reinforced plastic, combined with flame retardants, stainless steel shielding mesh, and other materials. Fire resistance testing evaluates how well cable trays can withstand fire and prevent flames from spreading. This includes checking their flammability, smoke production, toxic gas emissions, and ability to block heat and fire. Why Does. Through these tests the aim was to learn more about thermal conductivity properties in fire conditions and what effects it would have on the tray itself and how long the installed cable could maintain circuit integrity. This is a test for electric cable systems that are required to maintain circuit integrity, so is therefore written around and is dependent on the cables themselves, but containmen of 90 minutes (the maximum time covered by DIN 4102-12). Only use fireproof trays for flame containment or isolation, not for unrelated functions.