Cal. Health & Safety Code § 114301

(a) Except to the extent that an alternative construction standard is explicitly prescribed by this section, construction standards for mobile food facilities that are subject to Part 2 (commencing with Section 18000) of Division 13 shall be governed by that part.
(b) Mobile food facility equipment, including, but not limited to, cooking equipment, the interior of cabinet units, and compartments, shall be designed and made of materials that result in smooth, readily accessible, and easily cleanable surfaces.
1. (1) Unfinished wooden surfaces are prohibited.
2. (2) Construction joints and seams shall be tightly fitted and sealed so as to be easily cleanable. Silicone sealant or equivalent waterproof compounds shall be acceptable, provided that the gap is smaller than one-quarter inch and applied smooth so as to prevent the entrance of liquid waste or vermin.
3. (3) Except as specified in Section 114314, nonportable equipment shall be an integral part of the primary unit.
(c) Mobile food facilities that handle potentially hazardous foods, except for prepackaged frozen ready-to-eat foods, whole fish, and whole aquatic invertebrates, shall be equipped with refrigeration units as defined in Section 113885.
(d) All new and replacement gas-fired appliances shall meet applicable ANSI standards. All new and replacement electrical appliances shall meet applicable Underwriters Laboratory standards. However, for units subject to Part 2 (commencing with Section 18000) of Division 13, these appliances shall comply with standards prescribed by Sections 18028, 18029.3, and 18029.5.
(e) Space around pipes, conduits, or hoses that extend through cabinets, floors, or outer walls shall be sealed. The closure shall be smooth and easily cleanable.
(f) Equipment in which spillage is likely to occur shall have a drip tray fitted so that spillage drains into a waste tank.
(g) All equipment shall be installed so as to be easily cleanable, prevent vermin harborage, and provide adequate access for service and maintenance.
1. (1) Equipment shall be spaced apart or sealed together for easy cleaning. There shall be a minimum of four inches of unobstructed space provided for sanitary maintenance beneath counter mounted equipment or between the sides of adjacent equipment.
2. (2) Portable equipment or machinery need not comply with the minimum leg height requirement.
3. (3) Threads, nuts, or rivets shall not be exposed where they interfere with cleaning. Threads, nuts, or rivets that interfere with cleaning shall be sealed or capped.
4. (4) All floor mounted equipment shall be sealed to the floor to prevent moisture from getting under the equipment, or it shall be raised at least six inches off the floor by means of an easily cleanable leg and foot.
(h) Floors, walls, and ceilings of all enclosed food preparation areas shall be constructed so that the surfaces are impervious, smooth, and easily cleanable. Floor surfaces shall provide employee safety from slipping. The juncture of the floor and wall shall be coved with a 3/8 inch minimum radius coving, with the floor surface extending up the wall at least four inches.
(i) Notwithstanding Section 114143, ground or floor surfaces where cooking processes are conducted from a grill, barbecue, or other unenclosed cooking unit on a mobile food facility shall be impervious, smooth, easily cleanable, and shall provide employee safety from slipping. Ground or floor surfaces in compliance with this section shall extend a minimum of five feet on all open sides of where cooking processes are conducted.