NFPA 701: Standard Methods of Fire Tests for Flame Propagation of Textiles and Films, is the federal standard, however your local Fire Department may have more strict rules, so definitely check with them. As for the length of the flame proofing, check with the original goods manufacturer. The goods may be inherently flame resistant so they may bee good for the life of the goods. If they are treated, such as some of mine, the substance that treated the goods would be what you need to check on. For example the stuff we used, Fire Block, is good indefinitely or 3 washes, and as I don't own a washer that can fit 672 sq.ft. of material I should never have to worry about re-treating them.