▁during ▁polym er isation . ▁One ▁method ▁is ▁to ▁include ▁a ▁relatively ▁small ▁amount ▁of ▁b rom in ated ▁mon omer ▁during ▁the ▁polym er isation ▁process . ▁For ▁example , ▁vin yl ▁b rom ide ▁can ▁be ▁used ▁in ▁the ▁production ▁of ▁poly eth yl ene , ▁poly vin yl ▁ch lor ide ▁or ▁poly pro py l ene . ▁Specific ▁highly ▁b rom in ated ▁mole cules ▁can ▁also ▁be ▁added ▁that ▁particip ate ▁in ▁the ▁polym er isation ▁process ▁For ▁example , ▁t et rab rom ob is phen ol ▁A ▁can ▁be ▁added ▁to ▁poly esters ▁or ▁epo xy ▁res ins , ▁where ▁it ▁becomes ▁part ▁of ▁the ▁polym er . ▁E po x ies ▁used ▁in ▁printed ▁circuit ▁bo ards ▁are ▁normally ▁made ▁from ▁such ▁fl ame ▁ret ard ant ▁res ins , ▁indicated ▁by ▁the ▁FR ▁in ▁the ▁abbre viation ▁of ▁the ▁products ▁( FR - 4 ▁and ▁FR - 2 ). ▁In ▁some ▁cases ▁the ▁b rom ine ▁containing ▁comp ound ▁may ▁be ▁added ▁after ▁polym er isation . ▁For ▁example , ▁dec ab rom odi phen yl ▁ ether ▁can ▁be ▁added ▁to ▁the ▁final ▁polym ers . ▁ ▁A ▁number ▁of ▁g ase ous ▁or ▁highly ▁vol atile ▁b rom in ated ▁hal om eth ane ▁comp ounds ▁are ▁non - to xic ▁and ▁make ▁superior ▁fire ▁suppress ant ▁agents ▁by ▁this ▁same ▁mechanism , ▁and ▁are ▁particular ▁effective ▁in ▁en closed ▁spaces ▁such ▁as ▁sub mar ines , ▁air plan es , ▁and