Vacuum pumps often require specific oils due to the nature of the applications on which they run. Remember, vacuum pumps ingest all nature of chemicals resulting from the process itself. Some pass through the pump harmlessly, while others end up in the oil. Unlike compressors, which generally ingest mostly air, vacuum pumps may ingest water, solvents, acids, and so forth. The proper type of oil can be critical to the pump, so it is important to follow the pump manufacturer's recommendations very carefully. What works for one pump type not work for the other.
With laser applications, using the wrong type of oil may affect the output power of the laser if vapors or aerosols get into the laser.
Some applications