What is Accidental Food Additive

Identification of chemicals and additives

The identification numbers described here E number, CI number and CAS number mark ingredients in commercial products. In food technology, the E number is used, with the help of which permitted food additives are indicated on the packaging of food. Additives in cosmetics are labeled with INCI (International Nomenclature for Cosmetic Ingredients). I.International Nomenclature of Cosmetic Ingredients) or alternatively with a CI number (color index, engl. Color Index) specified. The CAS number C.hemical abstracts service, American initiative for the cataloging of chemical substances), chemical substances are uniquely registered.

E number

The E numbers describe the group of food additives. The leading letter E is derived from the EU as the approval location. They are divided into groups so that consecutive E numbers belong to the same group, e.g. antioxidants, thickeners, acidulants, emulsifiers, stabilizers, flavor enhancers or humectants. E numbers are usually three or four digits, e.g. E 300 for ascorbic acid (vitamin C). Some still have a letter at the end, e.g. E 160d for lycopene, the red pigment from tomatoes.

An E number does not necessarily have to hide just one chemical substance, because E 901 denotes beeswax, which is composed of a large number of natural components. If a food additive has an E number, it is approved for use in food throughout the EU. In some cases, the approval is valid up to a specified amount; more of this substance may then not be used in a product. Not all substances that are approved under food law have E numbers, e.g. aluminum oxide as an approved filler does not have an E number.

For more information on food additives, see the article Nanomaterials in Food.

In connection with the materials on the DaNa website, the following food additives are relevant:

It should be pointed out once again that dyeing with such inorganic dyes is based on microscale particles.

By the way: E 605, which plays a role in many crime novels and is also referred to as the “mother-in-law poison”, is, as you might already suspect, not a food additive, but a plant protection product called parathion. The designation E605 has nothing to do with the E numbers of the food additives, but can only be confused with them by chance; in fact it is a numbering from a laboratory journal [1].


CI number and INCI names

The CI of CI number stands for the Color Index, this term is used in cosmetics, among other things. CI numbers describe substances or mixtures of substances.

While the CI number describes substances or mixtures of substances that are intended to achieve certain colors, the INCI name (International nomenclature for cosmetic ingredients, engl. I.International Nomenclature of Cosmetic Ingredients) generally referred to as cosmetic additives. If a substance has a CI number or an INCI name, it is approved for use in cosmetics. On the packaging of traded cosmetics, the additives should be listed in such a way that the additive that makes up the largest (mass) proportion appears first in the list. This can be a substance with a CI number / INCI name, but does not have to be. Very often water is (lat. aqua) - with the INCI name AQUA - the predominant ingredient. CI numbers are usually six digits long, INCI names can consist of numbers, but also names [2].

By the way: If nanomaterials are used as cosmetic additives, this must be marked with the word "Nano" in brackets after the respective INCI name.


CAS number

The most comprehensive numbering of substances is carried out with the help of the so-called CAS number. CAS stands for Chemical Abstracts Service, an initiative of the American Chemical Society. The CAS initiative tries to catalog as many chemicals as possible. As of December 2017, more than 135 million chemical substances were registered in the CAS databases [3]. Every chemical that is placed on the global market has such a CAS number and when a chemist is looking for a substance, this will usually be done using the CAS number. Due to the almost infinite number of possible chemical compounds, the number of CAS numbers recorded is huge [4,5].


Overview of the identification numbers

The substances listed in the DaNa knowledge base are listed in the following table with their E, CI and CAS numbers. If no number is given for a substance in the respective category, the substance is also not approved for use in this category. E.g. there is no E number for tungsten because tungsten is not allowed to be used in food in the EU. Depending on the area of ​​application of a substance, it can be found either with an E number, CI number or CAS number, but it may be chemically the same substance.


  1. Wikipedia.de (DE): Parathion (last access: 09.12.2019)
  2. Commission Decision (EU) 2019/701 of 5 April 2019 establishing a glossary of common ingredient names for use in the labeling of cosmetic products (Text with EEA relevance), C / 2019/2541.
  3. Wikipedia (DE): Chemical Abstract Services (CAS), last accessed on 08/09/2018)
  4. Frankfurter Allgemeine Zeitung (DE). Who counts the fabrics ?, June 29th, 2003, Karl Huebner, www.faz.net
  5. Hübner, K. (2003), CAS provides an overview of published chemistry. Chemistry in Our Time, 37: 284-285.