Compatible with all 9 mm screw-thread vials. Molded, 10 ml, solid, pierceable cap. PTFE-free—ideal for PFAS analysis (e.g., EPA 537) and other PFAS-sensitive methods. Note: Polypropylene vials and caps prevent sample contamination from PTFE coated septa. However, since polypropylene caps do not reseal, evaporation occurs after injection.