​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Chesterton 425 is manufactured with a virgin PTFE filament and a white oil lubricant. It is perfectly suited for use in valves and also in rotating equipment such as blenders, mixers, agitators and other rotating equipment. Chesterton 425 complies with the USDA requirements for minimal food contact and FDA specification 21 CFR, 178.3620 for lubricants with incidental food contact as well as 177.1550 perfluorocarbon resins.​​