NPR-ISO/TR 19601 describes methods for producing aerosols of nano-objects and their aggregates and agglomerates (NOAA) for in vivo and in vitro air exposure studies. The purpose of this document is to aid in selecting an appropriate aerosol generator to fulfil a proposed toxicology study design. This document describes characteristics of aerosol generation methods, including their advantages and limitations. This document does not provide guidance for aerosolization of specific nano-objects.