For organisations operating in or with the UK, BSI recommends purchasing the adopted British Standard.
This document specifies the fuel quality classes and specifications of graded firewood. This document applies only to firewood produced from the following raw materials (see ISO 17225-1:2021, Table 1):
1.1.1 Whole trees without roots;
1.1.3 Stemwood;
1.1.4 Logging residues (thick branches, tops, etc.);
1.2.1 Chemically untreated by-products and residues from wood processing industry.