Interaction of carboxymethylchitosan and heavy metals in cement media

► Carboxymethylchitosan (CMCH) is employed as additive for S/S of heavy metals in cement matrices. ► CMCH minimises the detrimental effects provoked by the incorporation of toxic heavy metals (Cr, Pb, Zn) on the setting time. ► Leachability of Pb and Zn was significantly reduced when previously formed CMCH-metal complexes were incorporated into the cement mortars.