This standard describes a method for the determination of total carbon, hydrogen and nitrogen contents in solid biofuels. Instrumental methods for the analysis of carbon, hydrogen and nitrogen are now in widespread and in regular use, often in preference to formerly developed chemical methods for which International Standards exist. The reliable determination of carbon, hydrogen and nitrogen is important for quality control and the results can be used as input parameters for calculations applied to the combustion of solid biofuels. The environmental importance of the nitrogen content is linked to emissions of NOx (formation of fuel NOx). Hydrogen content is important for calculation of the net calorific value. Carbon content is required for the determination of CO2-emissions. It is recognized that the Kjeldahl method is most reliable for determining nitrogen contents with a concentration lower than 0,1 %. Possible suitable methods are summarized in the bibliography. This document has been prepared by Technical Committee ISO/TC 238 "Solid biofuels" in collaboration with Technical Committee CEN/TC 335 "Solid biofuels" the secretariat of which is held by SIS (Sweden). The responsible German body involved in its preparation was the DIN-Normenausschuss Materialprüfung (DIN Standards Committee Materials Testing), Working Committee NA 062-05-82 AA "Biogene Festbrennstoffe" ("Solid biofuels").