I-EPA Vial, eyaziwa nangokuthi i-Environmental Protection Agency agency, uhlobo lwesampula le-vial eklanyelwe ukucubungula kwezemvelo, ikakhulukazi umongo wamanzi nokuhlolwa kwenhlabathi. I-EPA isisungule amazinga athile kanye nemithetho yokuhlolwa kwemvelo, kanti ne-EPA Vavials yakhelwe ukufeza lezi zidingo.
I-EPA Vials ngokuvamile yenziwa ngezinto zokuhlanza, njengengilazi ye-borossilte, ukunciphisa ukusebenzisana phakathi kwesampula kanye ne-vial. Ziyatholakala ngosayizi ohlukile, ngokujwayelekile zisukela ku-20 ml kuya ku-40 ml, ukwamukela amavolumu ahlukahlukene wesampula.