The European Committee for Standardization, CEN (TC335) is currently preparing 30 technical specifications for solid biofuels. The two most important technical specifications being developed deal with classification and specification (CEN/TS 14961) and quality assurance for solid biofuels (CEN/TS 15234). The classification of solid biofuels is based on their origin and source. The fuel production chain of fuels shall be unambiguously traceable back over the whole chain. The biofuels are divided into the following sub-categories for classification: (1) woody biomass, (2) herbaceous biomass, (3) fruit biomass and (4) blends and mixtures. The purpose of classification is to allow the possibility to differentiate and specify biofuel material based on origin with as much detail as needed. The quality classification in a table form was prepared only for major traded solid biofuels: briquettes, pellets, exhausted olive cake, wood chips, hog fuel, wood logs, sawdust, bark, and straw bales. Additionally, a general table was compiled for other biofuels. The most significant properties are normative, and shall be stated in the fuel specification. The classification is flexible, and hence the producer or the consumer may select from each property class the classification that corresponds to the produced or desired fuel quality. This so-called "free classification" does not bind different characteristics with each other. An advantage of this classification is that the producer and the consumer may agree upon characteristics case-by-case. To protect household consumers, examples of so-called "high-quality" fuels are given as an informative annex A of CEN/TS 14961. This paper describes the fuel specifications and classes of solid biofuels, which was published in April 2005. (c) 2006 Elsevier Ltd. All rights reserved.