Table 12. Comparison of ISO and NIFoS graded of wood chips from logging residues by harvesting and processing methods.

Harvesting and processing methods
Property class	CTL-unscreened		CTL-screened		WT-unscreened		WT-screened
Property class	ISO 17225-4 (2021)	NIFoS (2020)	ISO 17225-4 (2021)	NIFoS (2020)	ISO 17225-4 (2021)	NIFoS (2020)	ISO 17225-4 (2021)	NIFoS (2020)
Origin and source	forest biomass
Particle size	P31S		P31S		P31, F10		P31S
Moisture	A1	First class	A1	First class	A2	Second class	A2	Second class
Ash	n.a.^a	n.a.^a	n.a.^a	Second class	n.a.^a	Second class	A1	First class
Bulk density	A2	First class	A2	First class	A2	First class	A2	First class
Elemental (N, S and Cl)	n.a.^b	First class	n.a.^b	First class	n.a.^b	First class	n.a.^b	First class
Inorganic substance (As, Cd, Cr, Pb and Hg)	n.a.^b	First class	n.a.^b	First class	n.a.^b	First class	n.a.^b	First class
Final class	n.a.^a	n.a.^a	A2	Second class	n.a.^a	Second class	A2	Second class

n.a. : not available,
n.a. : not applicable