I typically prefer silicone or flourosilicone for the sealing applications I'm involved with. Recently someone mentioned EPDM Rubber. From the technical data I have found on vendor websites it seems this should perform equally as well as silicone over temperature and have added resistance to chemicals. I am mainly trying to achieve IP67, however maintaing a gas seal in our system is not a requirement, but if we can achieve gas tight seals it is added value for our product. I'm looking for feedback from anyone that has used EPDM in their design and anyone with experience on long term performance of this material as an oring and what their experiences have been.