Definitions and standards of identity, quality and fill of container and their amendments, now or hereafter adopted under authority of the federal Food, Drug and Cosmetic Act, shall be the definitions of standards of identity, quality and fill of containers in this state. Whenever the commissioner and director agree that such action will promote honesty and fair dealing in the interest of consumers, they, acting jointly may promulgate regulations establishing definitions and standards of identity, quality and fill of container for foods where no federal regulations exist. Temporary permits granted by federal authority for interstate shipment of experimental packs of food varying from the requirements of federal definitions and standards of identity shall be effective in this state under the conditions provided in such permits. In prescribing a definition and standard of identity for any food or class of food in which optional ingredients are permitted, the commissioner and director, acting jointly, shall, for the purpose of promoting honesty and fair dealing in the interest of consumers, designate the optional ingredients which shall be named on the label. The definitions and standards so promulgated shall conform, so far as practicable, to the definitions and standards promulgated under authority of the federal act, the federal Meat Inspection Act or the federal Poultry Inspection Act.