This document specifies the quality characteristics of the NOx reduction agent AUS 32 (aqueous urea solution) which is needed to operate selective catalytic reduction (SCR) converter systems in motor vehicles with diesel engines. SCR converter systems are particularly suitable for selectively reducing the nitrogen oxide (NOx) emissions of diesel engines.Cross References:ISO 22241-2ISO 3696ISO 12185IATF 16949:2016ISO 4259 (all parts)ISO 3675ISO 22241-3Incorporates the following:Amendment, November 2019