20ml EPA glass vials with high quality gc headspace vials supplier. 20ml EPA glass vials with high quality gc headspace vials supplier Quality Sample Containers and Closures Since 1988- 20-ml and 30-ml Vials Manufactured in the VOA/EPA vials for water testing,these high-quality borosilie glass vials are available with either open-top septum caps or closed-top Teflon-lined caps. 24-414 black