The use of hydrogen containing impurities can cause damage to fuel cells after a short period of time. To counter this, guidelines for appropriate hydrogen purity have been established in International Standards ISO 14687:2019 and SAE J2719, which specify the maximum allowable impurity levels for compounds such as H₂O, O₂, He, N₂, Ar, CO, CO₂, TS, THC, HCHO, HCOOH, NH₃, HBr, HCl and Cl₂.

Typical application: purity testing of hydrogen for PEM fuel cells.