4.1
Electrical equipment and wiring
All electrical equipment and wiring shall be of a certified safe type
for use in an explosive hydrogen and air mixturefootnote.
4.2
Ventilation arrangement
4.2.1 Electrical equipment and wiring, if installed
in any ventilation duct, shall be of a certified safe type for use in explosive
hydrogen and air mixtures and the outlet from any exhaust duct shall be sited in
a safe position, having regard to other possible sources of ignition.
4.2.2 The fans shall be designed such as to avoid
the possibility of ignition of hydrogen and air mixtures. Suitable wire mesh
guards shall be fitted over inlet and outlet ventilation openings.
4.3
Other ignition sources
Other equipment which may constitute a source of ignition of hydrogen
and air mixtures shall not be permitted.