1.1 This guide suggests physical, chemical, and toxicological test methods for characterizing hydrocarbon lubricant base oils derived from various refining processes including re-refining, used oils, and refining crude oil. This guide does not purport to cover all tests which could be employed. It is the responsibility of the buyer and seller to determine and agree upon the implementation of this guide. 1.2 This guide applies only to base oils and not to finished lubricants.