Substances with or without nutritional value which are normally neither consumed as food nor used as a characteristic ingredient of a food and which are added to a food for other than technological reasons during production or treatment, as a result of which they themselves or their degradation or reaction products become or may become directly or indirectly a constituent of the food, shall be deemed to be equivalent to food additives; except substances of natural origin or chemically similar to natural substances which are generally accepted as being predominantly used for their nutritional, olfactory or gustatory value or as stimulants, minerals and trace elements and their compounds other than common salt, amino acids and their derivatives, vitamins A and D and their derivatives.