What causes fomblin vacuum diff pump oil to turn white?

Fomblin vacuum pump oil can turn white due to the presence of moisture or contamination, leading to the formation of emulsions or precipitates. When the oil absorbs water, it can create a milky appearance as the water and oil do not mix well. Additionally, prolonged exposure to high temperatures or certain chemical reactions may also contribute to this discoloration. It's important to regularly monitor and maintain vacuum oils to prevent such issues.