It will therefore be more practical , rather than listing the commercial mixture C-PentaBDE under the Convention , to list brominated diphenylethers with 4 or 5 bromines . All mixtures with one of the isomers of tetrabromodiphenyl ether ( TetraBDE ) or pentabromodiphenyl ether ( PentaBDE ) will then be covered by the conditions in the Convention , except when they occur as trace .