This document specifies the minimum safety requirements applicable for the functionality of compressed gaseous hydrogen (CGH2) and hydrogen/natural gas blends on-board fuel systems intended for use on the types of motor vehicles defined in ISO 3833.

It is applicable to vehicles using compressed gaseous hydrogen (CGH2), in accordance with ISO 14687‑1 or ISO 14687‑2, and hydrogen/natural gas blends using natural gas, in accordance with ISO 15403‑1 and ISO/TR 15403‑2. It is not applicable to the following:

1) liquefied hydrogen (LH2) fuel system components;

2) fuel containers;

3) stationary gas engines;

4) container mounting hardware;

5) electronic fuel management;

6) refuelling receptacles; and

7) fuel cell vehicles.

NOTE 1 It is recognized that miscellaneous components not specifically covered herein can be examined to meet the criteria of this document and tested according to the appropriate functional tests.

NOTE 2 All references to pressure in this document are considered gauge pressures unless otherwise specified.

All matters relating to the skills of installers and converters have been excluded from this document.