An E number is the classification number given to a food additive by the European Union — the coding system that identifies every approved additive, from E100 (curcumin) to E1520 (propylene glycol). The E marks an additive assessed as safe by European authorities and permitted for specified uses at specified levels; the number lets regulators, manufacturers, and shoppers identify it precisely across languages. Colours run E100–199, preservatives E200–299, antioxidants E300–399, and so on through emulsifiers, stabilisers, and sweeteners. The system brought order to additive law, but the numbers acquired a folk reputation as warnings — “no E numbers” became a marketing claim — even though many E-numbered substances are ordinary food components like vitamin C (E300) or lecithin (E322). The E number is information, not accusation: a regulated identity for a tested substance.