These come from the FDA Food Code, which nearly every state adopts. A health inspector checks for them on plan review and at inspection — regardless of your state:
Also required in most kitchens: a mop/service sink (cleaning-water disposal), mechanical exhaust hood (Type I over grease/smoke), adequate hot water, indirect waste/air gaps on food & warewashing equipment, and a grease interceptor where local plumbing code requires it.
Licensing authority: County Environmental Health / Local Public Health Authority under OAR 333-162; Oregon Health Authority sets the rules. Regime: Local licensing under state rules, class-based.
CLASS SYSTEM DRIVES THE BUILD. Four mobile food unit classes assigned by MENU, and a unit may serve items within its class or below (OAR 333-162-0020(2)). Class I: intact packaged foods and non-hazardous drinks only, no preparation or assembly aboard, beverages from covered urns or dispenser heads, NO DISPENSED ICE. Class II: adds hot and cold holding display of unpackaged food but still no preparation, assembly or cooking, and no customer self-service. Classes III and IV allow progressively more. CRITICALLY: water and wastewater capacity requirements are set BY CLASS - so your menu determines your tank sizes before you buy anything. Units must operate from a licensed restaurant, commissary or warehouse; a warehouse qualifies only if selling prepackaged goods. Plan review happens locally and must be completed BEFORE CONSTRUCTION. Oregon health departments explicitly warn that commercially made carts often fail to meet the Oregon Food Code and advise calling before purchase. Licences are issued to one entity for one location; a change of owner requires a new licence. A Person In Charge must be present during all operating hours with authority to send staff home.
Mobile/food-truck reciprocity: Not established - licence is issued locally, confirm cross-county validity
New builds and remodels almost always require a plan review and a pre-opening inspection. Submit your equipment layout early — the sink count, hood, and hot-water sizing are the usual sticking points.
See restaurant-equipment dealers in Oregon → — many do design + fabrication and know local plan-review requirements.