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King County has purchased re-refined motor oil since 1992. This helps the environment by reducing the impacts of refining and also conserves a non-renewable resource. Engine lubricating oil does not "wear out." Producers can re-refine oil to remove contaminants introduced during its use and replace the "additive packages" that confer its specific properties, such as viscosity. Current technologies allow used oil to be re-refined into a high-quality base-stock and several oil companies manufacture products that have been certified by the American Petroleum Institute (API).

Biobased lubricants are derived from plants and other renewable agricultural, marine, and forestry materials and also conserve resources. These can be used in the same systems as petroleum based products. Equipment usually includes a label that identifies that biobased lubricants have been used.

King County’s Renton Maintenance Facility of the Fleet Administration Division (Fleet) has purchased vegetable-based hydraulic oils for use in their equipment, from lawn mowers to dump trucks, since 2001.


Policy and Goals:

As stated in King County's Sustainable Purchasing Executive Policy (CON 7-22-EP),

  • Purchase re-refined, bio-based, or long life lubricants


  • re-refined motor oil (minimum 25% recycled content)
  • biobased lubricants


  • virgin (new) oil and lubricants
  • used oil burning for heat

End of Life

  • recycle with vendor

An EPA checkmark indicates a certification or standard is recommended by the U.S. Environmental Protection Agency (EPA).

Other Guidance


American Petroleum Institute (API) – API Certification is the basis for warranty requirements of motor vehicle manufacturers and is used in specifications of motor oil buyers. “Resource Conserving” or “Energy Conserving” oils apply to oils intended for gasoline-engine cars, vans, and light trucks. Widespread use of these designated oils may result in an overall savings of fuel in the vehicle fleet as a whole.

Technical Specification Language

Sustainable Facilities: SF Tool Green Procurement Compilation (GPC) tool

Contact Us

Phone: 206-263-9400

TTY Relay: 711

Fax: 206-296-7676