40ml EPA/TOC Vial (ND24) Porefil® EPA/TOC Vials Porefil® offers a range of certified EPA Screw Vial Convenience Kits compatible with all TOC instruments, including Sievers, Shimadzu, OI Analytical and Teledyne-Tekmar. All vials are certified to contain <10 ppb carbon and fitted with Teflon-lined caps & protective dust covers.