This document specifies the requirements, test methods, inspection rules, marking and accompanying documents, packaging, transportation and storage of 20% 2-acrylamido-2-methylpropanesulfonic acid aqueous solution. This document applies to 20% 2-acrylamido-2-methyl obtained by separation of the aqueous solution produced during the production of 2-acrylamido-2-methylpropanesulfonic acid using acrylonitrile, concentrated sulfuric acid and isobutylene as raw materials. Aqueous solution of propanesulfonic acid.