'PFC-free' - Meets EPA 537.1, EPA 533, EPA 8327 and ISO 21675 requirements for PFC-trouble free usage when testing for PFAS related compounds. This PFC-free polypropylene cap is designed to work with our 'uniquely' designed 2 mL screw style clear polypropylene vial with an approximate fill volume of 1.5-1.7 ml (part number ).