NEN-ISO 1762 describes the determination of the residue (ash content) on ignition of paper, board, pulps and cellulose nanomaterials at 525 ° C. It is applicable to all types of paper, board, pulp and cellulose nanomaterial samples. This document provides measurement procedures to obtain a measurement precision of 0.01% or better for residue (ash content) on ignition at 525 ° C. Determination of residue (ash content) on ignition at 900 ° C of paper, board, pulps and cellulose nanomaterials is described in ISO 2144. In the context of this document, the term “cellulose nanomaterial” refers specifically to cellulose nano-object (see 3.2 to 3.4 ). Owing to their nanoscale dimensions, these cellulose nano-objects can have intrinsic properties, behaviors or functionalities that are distinct from those associated with paper, board and pulps.