Guanidine hydrochloride consists of a networkof guanidinium cations and chloride anions linked by NHCl hydrogen bonds,it is a strong chaotropic agent. Guanidine HCl may agglomerate upon storage. It may appear as a free-flowing crystalline powder, a free flowing powder with solid material dispersed throughout, or a solid. The quality of the product does not appear to be affected and solutions prepared from the free-flowing and lumpy guanidine HCl appear identical.