Dichlorodimethylhydantoin

Dichlorodimethylhydantoin (CAS 118-52-5), commonly abbreviated as DDH and sold under trade names including Dactin and Halane, is a chlorine-releasing heterocyclic compound classified under HS code 29332100. It carries no assigned E-code and is recognised in regulatory frameworks under EC number 204-258-7.

In water treatment, DDH releases active chlorine slowly and consistently, providing sustained biocidal action against bacteria, algae, and fungi in cooling towers and process water systems. In personal care formulations, it functions as a preservation agent and skin conditioner, delivering controlled antimicrobial activity at low use concentrations without the stability limitations of liquid chlorine sources.

DDH is supplied as a crystalline powder suitable for direct dosing or blending. It falls under REACH regulation and suppliers should confirm compliance documentation including Safety Data Sheets aligned with EU GHS requirements. Procurement teams should request technical grade specifications and confirm suitability for intended application prior to ordering.