Any poisonous or deleterious substance, other than a pesticide, added to any food except when the substance is required in the production thereof or cannot be avoided by good manufacturing practice shall be deemed to be unsafe for purposes of the application of ORS § 616.235 (1)(b). When the substance is so required or cannot be so avoided, the State Department of Agriculture shall adopt rules limiting the quantity of the substance to the extent the department finds necessary for the protection of public health, and any quantity exceeding the limits so fixed shall also be deemed to be unsafe for purposes of the application of ORS § 616.235 (1)(b). While such a rule is in effect limiting the quantity of any such substance in the case of any food, the food is not, by reason of bearing or containing any added amount of such substance, considered to be adulterated within the meaning of ORS § 616.235 (1)(a). In determining the quantity of the added substance to be tolerated in or on different articles of food, the department shall take into account the extent to which the use of the substance is required or cannot be avoided in the production of each article and the other ways in which the consumer may be affected by the same or other poisonous or deleterious substances. [Amended by 1973 c.227 § 7; 2005 c.22 § 412]