Okla. Admin. Code § 35:37-11-28
Equipment and utensils used for preparing and handling any product shall be of materials and construction as will make them susceptible to being readily and thoroughly cleaned and will insure strict cleanliness in the preparation and handling of all products. As practicable, equipment shall be made of rust resistant metal or other acceptable impervious material. Trucks and receptacles used for inedible material shall bear the word "inedible" in lettering that contrasts clearly and conspicuously with its background, so its intended purpose is clearly and concisely identified.
Added at 21 Ok Reg 1181, eff 5-27-04