Cal. Health & Safety Code § 25250.7
(b) A used oil transfer or recycling facility authorized by the department pursuant to Section 25200, 25200.5, or 25201.6 may mix used oil with a contaminated petroleum product or with an oily waste other than wastes listed as hazardous under the federal act, if all of the following conditions are met:
(c) A generator or transporter may mix used oil with one or more contaminated petroleum products if the mixture is managed in accordance with Section 25143.2 or if all of the following conditions apply:
(2)