less ▁steel ▁after ▁ 2 7 0 ▁minutes . ▁ ▁Studies ▁have ▁been ▁conducted ▁to ▁examine ▁the ▁E . ▁col i ▁O 1 5 7 : H 7 ▁b acter ic idal ▁eff ica cies ▁on ▁ 2 5 ▁different ▁co pper ▁allo ys ▁to ▁identify ▁those ▁allo ys ▁that ▁provide ▁the ▁best ▁combination ▁of ▁ant im icro b ial ▁activity , ▁cor ros ion / ox id ation ▁resistance , ▁and ▁fabric ation ▁properties . ▁Co pper ' s ▁ant ib acter ial ▁effect ▁was ▁found ▁to ▁be ▁intr insic ▁in ▁all ▁of ▁the ▁co pper ▁allo ys ▁tested . ▁As ▁in ▁previous ▁studies , ▁no ▁ant ib acter ial ▁properties ▁were ▁observed ▁on ▁st ain less ▁steel ▁( U NS ▁S 3 0 4 0 0 ). ▁Also , ▁in ▁confirm ation ▁with ▁earlier ▁studies ▁the ▁rate ▁of ▁drop - off ▁of ▁E . ▁col i ▁O 1 5 7 : H 7 ▁on ▁the ▁co pper ▁allo ys ▁is ▁faster ▁at ▁room ▁temperature ▁than ▁at ▁ch ill ▁temperature . ▁ ▁For ▁the ▁most ▁part , ▁the ▁b acter ial ▁kill ▁rate ▁of ▁co pper ▁allo ys ▁increased ▁with ▁increasing ▁co pper ▁content ▁of ▁the ▁al loy . ▁This ▁is ▁further ▁evidence ▁of ▁co pper ' s ▁intr insic ▁ant ib acter ial ▁properties . ▁ ▁E ffic acy ▁on ▁br ass , ▁bronze , ▁co pper - nick el ▁allo ys ▁Br ass es , ▁which ▁were ▁frequently ▁used ▁for ▁do ork n obs ▁and ▁push ▁pl ates ▁in ▁dec