ABSTRACT
Lubricants are unique among all petroleum products in that often they are not consumed during use. Solid lubricants, such as greases, are not considered here as they are seldom in a form to be easily recovered at the end of their useful life. Most fluid lubricants, such as crankcase oil and transmission fluid, are collected and replaced as part of normal equipment service. These “used oils” are now available to become either a useful resource if handled properly or a potentially hazardous waste if ignored or discarded.
