PREPARATION AND PROVISION OF HIGH ASSAY DECABROMODIPHENYLETHANE

High assay reaction-derived decabromodiphenylethane product is produced a nd provided. The process comprises feeding diphenylethane, a partially bromi nated diphenylethane, or both subsurface into the liquid phase of a reaction mixture formed from components comprising excess liquid bromine and aluminu m-based Lewis acid bromination catalyst. The temperature of the reaction mix ture, the catalyst concentration in the excess bromine in the reaction mixtu re, and the feed time are coordinated in the processes to produce high assay reaction-derived decabromodiphenylethane product. Ways of effecting such co ordination are described.