environmental VOA vials PTFE silicone septa with cap. Clear vial designed for water sample collection for volatile organic analysis (VOA) Vial shoulder slope optimized to prevent air bubble entrapment. Available in the standard 40mL size. Open-top white polypropylene cap bonded with 0.060in. thin PTFE-lined silicone septum. Septum permanently bonded to the cap for secure sealing. common use volatile organic analysis vials PTFE silicone