Race car drivers wear driving suits constructed of Nomex and or other fire retardant materials, along with Nomex gloves, long underwear, balaclavas, socks, helmet lining and shoes to protect them in the event of a fire. The FIA and the SFI Foundation provide specifications for flame-resistant drivers clothing to be used in racing. The standards range from single layer suits that provide some protection against flash fires to much thicker multilayer SFI-15 suits required by the National Hot Rod Association that can protect a driver for up to 40 seconds against the intense heat and almost invisible flames generated by the nitromethane, ethanol and methanol fuels that are used in championship drag racing.