If the data provided on chemical identity of a substance and the amount added to foods or the toxicological and metabolic studies on a substance or on closely related substances appear to be insufficient, further data may be requested. ... Toxicological and metabolic studies performed within a group of chemically related substances can be used to draw conclusions about possible toxicological effects of substances not studied or studied but not intensively. ... The first step in the establishment of the evaluation programme shall be the attribution of FL-numbers, as defined in the Flavis database system, to each flavouring substance of the register and subdivision of all substances into groups of related substances according to the list of groups as laid down in Annex I to this Regulation.
