MEB Crystal Flux is a compound composed of Zinc Ammonium Chloride (ZnCl2.xNH4Cl), distinct from a mere mixture of zinc chloride and ammonium chloride.

It can be produced as either a 2-salt or 3-salt compound depending on customer requirements. This chemical is widely utilized in the hot-dip galvanizing industry for surface cleaning purposes.

The REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals) Regulation, which was passed by the European Parliament on 18 December 2006 and took effect on 1 June 2007, mandates that companies operating in European Union member countries and involved in the production or importation of chemicals must register these substances in a central database administered by the European Chemicals Agency (ECHA).