The objective of the ISO 17225 series is to provide unambiguous and clear classification principles for solid biofuels and to serve as a tool to enable efficient trading of biofuels and to enable good understanding between seller and buyer as well as a tool for communication with equipment manufacturers. It will also facilitate authority permission procedures and reporting. Part 1: General requirements; Part 2: Graded wood pellets; Part 3: Graded wood briquettes; Part 4: Graded wood chips; Part 5: Graded firewood; Part 6: Graded non-woody pellets; Part 7: Graded non-woody briquettes. This document was prepared by Technical Committee ISO/TC 238 on Solid biofuels. It cancels and replaces the first edition ISO 17225:2014.