Positive lists are closed lists. It means that only ingredients mentioned on these lists are allowed and no other ones. Nevertheless, the fact that an ingredient is mentioned on a positive list does not give a 100% guarantee that the ingredient complies with the specifications, given that different processes (whose ones not allowed) are sometimes possible to achieve the same result.
In a short term, the positive lists will be integrated in a database.
Nevertheless, for the certification of any ingredient, the certification body will make the firm fill in a questionnaire in order to be sure that all the conditions mentioned in the specifications are met. To establish the positive lists (or Database), Probila-Unitrab based its decision on different criteria. Addition of new substances is evaluated case-by-case approach.