This part of ISO 15500 provides tests and requirements for the gas injector, a compressed natural gas fuel system component intended for use on the types of motor vehicles defined in ISO 3833.

This part of ISO 15550 is applicable to vehicles using natural gas in accordance with ISO 15403 (mono-fuel, bi-fuel or dual-fuel applications). It is not applicable to injectors intended for high-pressure injection to the combustion chamber, or to the following: liquefied natural gas (LNG) fuel system components located upstream of, and including, the vaporizer; fuel containers; stationary gas engines; container mounting hardware; electronic fuel management; refuelling receptacles.