Natural Polyvinylidine Fluoride (PVDF) resin features translucent, off-white hemispheres. RoHS complaint and animal derivative free. High stability in harsh thermal, chemical and ultraviolet environments. High toughness and mechanical strength, low permeability, abrasion resistant. NK material can be autoclaved to 285 F (140 C) and meets USP Class VI requirements. Generally, these plastic fittings are chemically resistant to: Most acids, salts, weak bases, halogenated solvents, alcohols, nuclear and UV radiation, oxidants, ozone and deionized water.