International Numbering System for Food Additives

The International Numbering System for Food Additives (INS) is a European-based naming system for food additives, aimed at providing a short designation of what may be a lengthy actual name. It is defined by Codex Alimentarius, the international food standards organisation of the World Health Organisation (WHO) and Food and Agriculture Organization (FAO) of the United Nations (UN). The information is published in the document Class Names and the International Numbering System for Food Additives, first published in 1989, with revisions in 2008 and 2011. The INS is an open list, "subject to the inclusion of additional additives or removal of existing ones on an ongoing basis".

INS numbers consist of three or four digits, optionally followed by an alphabetical suffix to further characterize individual additives. On packaging in the European Union (EU), approved food additives are written with a prefix of E. Australia and New Zealand do not use a prefix letter when listing additives in the ingredients. An additive that appears in the INS does not automatically have a corresponding E number.

INS numbers are assigned by the committee to identify each food additive. INS numbers generally correspond to E numbers for the same compound, e.g. INS 102, Tartrazine, is also E102. INS numbers are not unique and, in fact, one number may be assigned to a group of like compounds.

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