Within the context of food ingredients with technological properties under EU legislation, the very first and natural thought is their classification as “food additives”. However, some of these substances result being classified as “simple” food ingredients as for instance the colouring extract of spirulina, or in the other way around, substances apparently not fitting as “food additives” end up being approved as such, like the Extracts of Rosemary (E392), or the enzymes Invertase (E1103) an d Lysozyme (E1105). To understand this phenomenon, the food additive’s regulation (EC) No 1333/2008 is analysed in detail and a research is performed on pertinent academic literature, sources of law and policy documents allowing the elaboration of four rules for the classification of food ingredients with technological properties.