A poisonous or deleterious substance added to food, except where the substance is required in the production of food or cannot be avoided by good manufacturing practice, is unsafe for purposes of the application of Alaska Stat. § 17.20.020(a)(2). When the substance is required or cannot be avoided, the department shall adopt regulations limiting the quantity of it to the extent necessary for the protection of public health. A quantity exceeding the limits fixed is unsafe for purposes of the application of Alaska Stat. § 17.20.020(a)(2). While a regulation limiting the quantity of a substance in the case of any food is in effect, the food is not, by reason of bearing or containing an added amount of the substance, adulterated within the meaning of Alaska Stat. § 17.20.020(a)(1). In determining the quantity of the added substance to be tolerated in or on food, the department shall consider 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 that or other poisonous or deleterious substances.