ce ▁self - cont ained ▁breath ing ▁appar atus ▁( SC BA ). ▁A ▁crew ▁member ▁must ▁also ▁wear ▁bo ots ▁with ▁steel ▁to es ▁and ▁sh anks ▁on ▁the ▁outside ▁of ▁the ▁suit ▁and ▁spe cially ▁selected ▁chemical - res istant ▁glo ves ▁for ▁this ▁level ▁of ▁protection . ▁The ▁breath ing ▁appar atus ▁is ▁worn ▁inside ▁( enc aps ulated ▁within ) ▁the ▁suit . ▁To ▁qual ify ▁as ▁Level ▁A ▁protection , ▁an ▁intr ins ically ▁safe ▁two - way ▁radio ▁is ▁also ▁worn ▁inside ▁the ▁suit , ▁often ▁incorpor ating ▁voice - oper ated ▁micro ph ones ▁and ▁an ▁ear pie ce ▁speaker ▁for ▁monitoring ▁the ▁operations ▁channel . ▁Level ▁B ▁Level ▁B ▁protection ▁requires ▁a ▁gar ment ▁( including ▁SC BA ) ▁that ▁provides ▁protection ▁against ▁spl ash es ▁from ▁a ▁ha z ard ous ▁chemical . ▁Since ▁the ▁breath ing ▁appar atus ▁is ▁sometimes ▁worn ▁on ▁the ▁outside ▁of ▁the ▁gar ment , ▁Level ▁B ▁protection ▁is ▁not ▁v apor - prote ct ive . ▁Level ▁B ▁su its ▁can ▁also ▁be ▁fully ▁enc aps ulating , ▁which ▁helps ▁prevent ▁the ▁SC BA ▁from ▁becoming ▁cont amin ated . ▁It ▁is ▁worn ▁when ▁v apor - prote ct ive ▁cl othing ▁( Level ▁A ) ▁is ▁not ▁required . ▁W rist s , ▁an k les , ▁face pie ce ▁and ▁h ood , ▁and ▁wa ist ▁are ▁secured ▁to ▁prevent ▁any ▁entry ▁of ▁spl ashed ▁liquid . ▁Depending ▁on ▁the ▁chemical ▁being ▁handled , ▁specific ▁types