What is the minimum requirement for cabin upholstery materials in current standard category airplanes?

The minimum requirement for cabin upholstery materials in current standard category airplanes is that they must be flame resistant. This requirement is crucial for safety in aviation, as it helps mitigate the risk of fire spreading within the cabin environment. The materials used in the upholstery are subjected to rigorous testing to ensure they meet specific flame resistance standards, which are established by aviation authorities. This is vital for protecting passengers and crew in the event of a fire, as the cabin space is confined and can pose serious risks if flammable materials are used. While the other options may offer benefits such as comfort or maintenance ease, flame resistance is a critical safety standard that must be adhered to in aviation.