Table 1: Biodegrable fluids

Mineral Oil Glycols Vegetable oils Synthetic Esters
Density at 20C (Kg/M3) 880 1100 940 930
Viscosity index 100 100 to 200 100 to 200 120 to 220
Shear stability Good Good Good Good
Pour point (C) -15 -40 to +20 -20 to +10 -60 to 20
Cold flow properties Good Very good Poor Very good
Miscibility with mineral oil Not Miscible Good Good
Solubility in water Not Miscible Very good to poor Not miscible Not miscible
Seal swelling tendency Slight Shrinking Indifferent Fair
Behaviour against paint Good Poor Good Good
Biodegradability (CEC) % 10 to 30 10 to 99 70 to 100 10 to 100
Oxidation stability Good Good Fair Good
Hydrolytic stability Good Poor Fair
Sludge forming tendency Good Poor Fair
Relative cost (Mineral oil = 1) 1 2 to 4 2 to 3 4 to 20