▁neg ating ▁the ▁perce ived ▁benefits ▁of ▁fast ▁installation ▁and ▁" re - enter ability " ▁that ▁is ▁typically ▁pur port ed ▁to ▁be ▁provided ▁by ▁this ▁technology . ▁ ▁Int umes cent ▁fo am ▁rub ber ▁fir est ops ▁util ize ▁Bayer ▁F om ox ▁int umes cent ▁fo am , ▁which ▁can ▁be ▁extr ud ed ▁into ▁various ▁shapes . ▁For ▁countries ▁that ▁use ▁a ▁h ose - stream ▁test , ▁the ▁F om ox ▁is ▁rein for ced ▁with ▁int umes cent ▁graph ite , ▁whereas ▁for ▁those ▁who ▁do ▁not ▁use ▁a ▁h ose - stream , ▁this ▁ing red ient ▁is ▁omitted . ▁ ▁Rep airs / main ten ance ▁ ▁P ill ows ▁may ▁present ▁an ▁opportunity ▁for ▁v andal ism ▁if ▁not ▁properly ▁secured . ▁Rep airs ▁must ▁conform ▁to ▁the ▁original ▁cert ification ▁listing . ▁ ▁Sm oke proof ing ▁▁ ▁Field ▁install ations ▁of ▁fir est op ▁pill ows ▁do ▁not ▁offer ▁significant ▁resistance ▁to ▁air ▁pressure ▁differences ▁or ▁smoke ▁pen etr ation , ▁as ▁is ▁ev iden ced ▁by ▁the ▁L ▁ratings ▁of ▁North ▁American ▁cert ification ▁list ings ▁of ▁fir est ops . ▁ ▁Techn ical ▁concepts ▁▁ ▁The ▁int umes cent ▁res ins ▁in ▁batt - based ▁fir est op ▁pill ows ▁contains ▁hyd r ates , ▁or ▁chem ically ▁bound ▁water . ▁On ▁the ▁fire ▁side , ▁the ▁pl astic ▁bag ▁burn s ▁off ▁expos ing ▁the ▁int umes cent ▁to ▁the ▁fire , ▁which ▁releases ▁the ▁water ▁in ▁the