Cal. Code Regs. tit. 8, § 3664
(b) Every employee who operates an agricultural or industrial tractor shall be instructed in the following procedures and in any other practices dictated by the work environment. Such information shall be provided at the time of initial assignment and at least annually thereafter. Copies of these instructions, printed in a language understood by the majority of the employees, shall be conspicuously posted at a place frequented by the drivers.
6. Do not permit others to ride.
Exception: to No. 6: The operation of agricultural tractor-mounted personnel transport carriers when used, operated and maintained in accordance with Section 3441(i) of these Orders.
EMPLOYEE OPERATING INSTRUCTIONS
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
1. Amendment and renumbering from Section 3669, and renumbering of former Section 3664 to Section 3337, filed 7-26-77; effective thirtieth day thereafter (Register 78, No. 30). For history of former section see Register 75, No. 49.
2. Amendment of subsection (a)(16) filed 8-9-79; effective thirtieth day thereafter (Register 79, No. 32).
3. New subsection (e) filed 12-26-80; effective thirtieth day thereafter (Register 80, No. 52).
4. Amendment of subsection (a)(22) filed 5-26-82; effective thirtieth day thereafter (Register 82, No. 22).
5. New subsection (a)(31) filed 12-12-84; effective thirtieth day thereafter (Register 84, No. 50).
6. Amendment filed 4-30-85; effective thirtieth day thereafter (Register 85, No. 18).
7. Amendment of subsections (a)(7), (a)(14)(A) and (a)(17) filed 9-25-96 as an emergency; operative 10-25-96 (Register 96, No. 39).
8. Amendment of subsection (a) and redesignation of former section 3664(a)(1)-(32) to section 3650(s)(1)-(32) filed 5-28-2002; operative 6-27-2002 (Register 2002, No. 22).
9. Change without regulatory effect amending subsection (a) filed 3-29-2007 pursuant to section 100, title 1, California Code of Regulations (Register 2007, No. 13).
10. New subsection (b)6. -- Exception filed 9-15-2015; operative 1-1-2016 (Register 2015, No. 38).