It is self-evident that in order to determine the hazardous properties and the appropriate risk management measures for substances in different forms, it is necessary to characterise the substance in terms of its physical form, in particular regarding nanoforms, before determining the corresponding hazards and assessing the exposure of humans and the environment and the associated risk management measures.The characterisation of nanoforms of the substance is a per-requisite to the determination of all the hazardous properties and appropriate risk management measures concerning the registered substance.