Whether impelled by profit, legislation or altruism, lubricants which are considered to be less environmentally-damaging than their predecessors continue to increase in use. While these products generally demonstrate improved biodegradability and lowered eco-toxicity, and are based largely on "renewable" ingredients, there is not yet complete agreement as to the criteria for such designation, nor regarding the test procedures and resulting data required for inclusion in this category.

While various base fluids have received the most scrutiny as alternatives to mineral oil, appropriate additive packages must be developed for each, as well. Advances in the field continue to be made, based on a variety of factors. Perhaps the most-challenging lubrication application is in an engine crankcase; this environment also provides unique opportunities for indirect lubricant "greenness."

By far the greatest impediment to more widespread adoption of environmentally-benign lubricants is their significantly higher cost over conventional ones. This disadvantage is expected to gradually lessen, based on continuing pressure from the combination of technology advances, legislative restrictions and tax incentives, coupled with the possibility of further increases in crude-oil costs.