2.3.0 Introduction

Hydrogen is a colourless, odourless gas that is lighter than air. The use of odorants to detect leaks [8] is being investigated, however, all the odorant chemicals so far considered have been rejected due to concerns regarding their potential to ‘poison’ the fuel cell membrane catalysts. Furthermore, they may have limited effectiveness for small leaks, as the odorant molecules will inevitably be much larger than the hydrogen molecules.

Hydrogen has many characteristics which are significantly different from conventional fuels, and which it is important to take into account when designing and installing a fuel cell system.