This document determines the fuel quality classes and specifications of graded wood pellets for non-industrial and industrial use. This document covers only wood pellets produced from the following raw materials (see ISO 17225‑1:2021, Table 1):
—    1.1 Forest, plantation and other virgin wood;
—    1.2 By-products and residues from wood processing industry;
—    1.3.1 Chemically untreated used wood.
Thermally treated biomass pellets (e.g. torrefied pellets) are not included in the scope of this document.

ISO 17225-2:2021

Solid biofuels - Fuel specifications and classes - Part 2: Graded wood pellets