Cal. Health & Safety Code § 25250.18

(a) Any person who transports recycled oil or oil exempted pursuant to paragraph (1) of subdivision (b) of Section 25250.1 shall maintain with each shipment a certification form, provided by the department, which contains all of the following information:
1. (1) The name and address of the used oil recycling facility or generator claiming the oil meets the requirements of Section 25250.1.
2. (2) The name and address of the facility receiving the shipment.
3. (3) The quantity of oil delivered.
4. (4) The date of shipment or delivery.
5. (5) A cross-reference to the records and documentation required under Section 25250.1.
(b) Certification forms required in subdivision (a) shall be maintained for three years and are subject to an audit and verification by the department or the board.