This part of ISO 17225 determines the fuel quality classes and specifications of graded non-woody pellets. This part of ISO 17225 covers only non-woody pellets produced from the following raw material (see ISO 17225-1, Table 1): – 2 Herbaceous biomass NOTE 1 – Herbaceous biomass is from plants that have a non-woody stem and which die back at the end of the growing season. It includes grains or seeds crops from food production or processing industry and their byproducts such as cereals. – 3 Fruit biomass – 4 Aquatic biomass – 5 Biomass blends and mixtures NOTE 2 – Group 5 Blends and mixtures include blends and mixtures from the main origin-based solid biofuel groups woody, herbaceous biomass, fruit biomass and aquatic biomass. Blends are intentionally mixed biofuels, whereas mixtures are unintentionally mixed biofuels. The origin of the blend and mixture is to be described using ISO 17225-1, Table 1. If solid biofuel blend or mixture contains chemically treated material it shall be stated. NOTE 3 – Thermally treated biomass pellets (e.g. torrefied pellets) are not included in the scope of this part of ISO 17225. Torrefaction is a mild pre-treatment of biomass at a temperature between 200 °C to 300 °C.