The FAR 25.253 is a standard of the Federal Aviation Administration (FAA) for determining the flammability of aircraft seat cushions that serves as a source of guidance when complying with the Federal Aviation Regulations (FAR). The purpose is to establish maximum burn rate for materials used in these applications to reduce the instances and severity of burn injuries while increasing evacuation time.
The scope of testing involves subjecting three test specimens to a vertical Bunsen burner flame for either a 60 second duration (method i), or a 12 second duration (method ii). The test is concluded after either time duration has expired, and the test specimens are evaluated for flame time, ignition time, burn length, and drip flame time. The results from the test are recorded and the specimens pass or fail based on the following criteria:
| 60 seconds | Flame Time <15 seconds Average Drip Extinguishing Time <3 seconds Average Burn Length <6” (152 mm) |
| 12 seconds | Flame Time <15 seconds Average Drip Extinguishing Time <5 seconds Average Burn Length <8” (203 mm) |