IEC 62282-5-1:2012(E) covers construction, marking and test requirements for portable fuel cell power systems intended to produce electrical power. Applies to a.c. and d.c. type portable fuel cell power systems, with a rated output voltage not exceeding 600 V a.c., or 850 V d.c. for indoor and outdoor use. The major technical changes with respect to the first edition are as follows: - referencing an alternative test method; reduction of the limit on flammable atmospheres; - consideration of additional effluents and criteria to establish if a system is suitable for indoor or outdoor operation; - revision of specific criteria for oxygen detector sensor performance; - new test method and new drop heights; addition of a table giving limits on emission of effluents. Keywords: fuel cell