The other way oil seals work is by stopping outboard materials that can damage the machine or contaminate its lubricant. The outboard materials that the oil seal will need to stop depend on the application. However, the most common kinds are dirt, moisture, and the particles produced during manufacturing.
Automotive Gaskets: Diverse Applications and Materials

Maintenance and Replacement:

By far, nitrile is the most popularly used, but buyers who need seals for applications involving high-speed shaft rotation increased interest. Viton is another alternative for silicone and poly-acrylic because it’s more resistant to harmful chemicals and abrasion and works better in higher temperatures.
M
Leather is probably the oldest of the lip materials still in common use, but the move towards mass production methods has seen a massive increase in the development of synthetic rubbers which lend themselves to accurate and repeatable injection and compression moulding. Nitrile (NBR) is still by far the most common elastomer for “normal” use, whilst Viton® (FKM/FPM) is rapidly replacing Polyacrylate (ACM) and Silicone (VMQ) for high-temperature applications. Viton® also has high resistance to abrasion and chemical attack making it a preferred elastomer. Recent developments in the use of PTFE for Rotary shaft seals has caused widespread interest particularly for high-speed shaft rotation or poor lubrication applications.
Viton®
High level of chemical resistance
High temperature resistance