No.
Even though most brominated FRs require the usage of Antimony Tri-oxide as a synergist, there are several cases in which synergists are not necessary, like FR-1524 (TBBA) in Printed Circuit Boards (PCBs), FR-1206 (HBCD) in Polystyrene foams (EPS/XPS) and FR-370 in V-2 Polypropylene.