A low chemical background makes PTFE filters ideal for sampling low concentration contaminants. Naturally hydrophobic, PTFE filters feature a low tare mass for accurate gravimetric determinations SKC PTFE filters are temperature-stable to 527 F (275 C). The maximum operating temperature for Teflon filters with PMP support ring is 464 F (240 C). PTFE filters are prone to static effects. For the most accurate sampling use a static eliminator.