These amber screw thread EPA vials without caps are for the collection and storage of water samples. They comply with the guidelines for establishing test procedures for the analysis of pollutants (Ref. EPA Methods 601, 602, 603 and 604). While vials are not "pre-cleaned," they are packaged in a plastic shrink wrap module, lehr-clean, as they come from the end of the production lehr and then are placed into a corrugated shelf-pack. Vials are manufactured from 51 expansion borosilicate amber glass conforming to ASTM E438, Type I requirements.