Aijiren̻s EPA Vials. Aijiren’s 20-60 mL sample vials are certified to a TOC <0 ppb. After analysis and verification by our accredited laboratory, the silicone and PTFE lined caps and dust caps provide excellent con Rated 4.5 /5 based on 385 customer reviews. 24mm screw vial EPA Vial Sample Storage Vial.