Did you know one additive can have many names?
The same colour or preservative can appear under a common name, an alternative name or an E-number, which is exactly how a trigger slips past you on a label. How to make sure it does not.
The fact, stated plainly
A single additive often hides behind several names. Sulphur dioxide is also “sulphites” and E220. Tartrazine is also E102 and, in some countries, FD&C Yellow 5. So you can scan a label, not see the exact word you were looking for, and still take home the very thing that flares your skin, because it was listed under a different name.
Why one additive has many names
There are a few reasons the same substance shows up under different labels. Additives have a common name, but they may also carry a chemical or trade name, and in the UK and EU they are given an E-number as an approved reference code. Rules also differ between countries, so a colour called tartrazine here may be printed as a “FD&C” colour on an imported product. Manufacturers can choose which permitted form to print, and they will not always pick the one you happen to have memorised.
It is worth saying plainly that an E-number is not a warning label. It simply means the additive has been assessed and given a reference number for use. The point here is not that E-numbers are bad, it is that the same additive can appear as a word on one pack and a number on another.
Who this affects most
This trips up the people who are trying hardest to avoid a trigger. If you have identified that sulphites or a particular colour set off your hives, you scan labels carefully, and it feels safe. But if you only know one form of your trigger, the label only has to use a different form to get past you. Parents shopping for a reactive child, and anyone managing several triggers at once, are the most exposed, because there is more to remember and more chance of a gap.
How to spot it on a label
The habit that protects you is knowing all the forms of each of your triggers before you shop, not working it out in the aisle. For each trigger, note:
- The common name (for example sulphites, tartrazine).
- Any alternative or chemical names (for example sulphur dioxide, or a “FD&C” or “CI” colour code).
- The E-number and its range where relevant (sulphites run E220 to E228).
On cosmetics, the equivalent is the standardised INCI name, which can look nothing like the everyday word, and colourants listed as CI numbers. Same rule: learn every version, not just one.
What to do
Keep a written guard list of every alias for each of your triggers and check labels against it, rather than trusting memory. Build the list once from a reliable source such as the Food Standards Agency or a food-information database, then reuse it. If you are cutting several additives out of your diet, do it with support rather than alone, so you are not restricting more than you need to.
When to see a professional
If additives seem to trigger reactions, a pharmacist is a good first stop for label-reading advice and simple soothing measures. See a GP if reactions are frequent or severe, if you ever get swelling of the lips, face or throat, or any breathing difficulty, which needs urgent care. A GP can arrange allergy testing or refer you on. If avoiding triggers means dropping whole food groups, ask to see a registered dietitian so your diet stays balanced and nutritionally complete. This page is educational and is not a substitute for personal medical advice.
A short video clip on this is coming soon.
Check it against your own list
A free database like Open Food Facts and Fig give broad ingredient information rather than a check against your own skin. A personal-list app like ClearaScan handles the aliases for you: save a trigger once and it recognises the various names and E-numbers when you scan any product, food, medication or cosmetic, flagging only yours. Its Reaction Journal lets you tie a flare back to the product, a shared Care Circle lets family scan for you, and a Trusted Products list keeps what you have cleared. It is currently in early access. (Disclosure: our editor co-founded ClearaScan, and we are not paid to mention the others.)
The Sensitive Skin Ingredient Decoder
A free one-page guide to reading a skincare label fast: the irritants to watch, the fragrance loopholes, and what "fragrance-free" and "hypoallergenic" really mean.
Common questions
Why does one additive have several names?
An additive can be listed by its common name, a chemical or trade name, or its E-number, and rules differ between countries. Sulphur dioxide, sulphites and E220 are the same thing. Tartrazine, E102 and FD&C Yellow 5 are also the same thing. Any of them can appear on a label.
What is an E-number?
An E-number is a code given to a food additive that has been assessed for use in the UK and EU. E does not mean unsafe, it simply means the additive has an approved reference number. Knowing the E-number of your trigger helps you spot it when the word is not written out.
How do I find every name for my trigger?
Look it up once and write down the common name, any alternative names and the E-number. Reliable starting points are the additive's entry on a food-information database or the Food Standards Agency. Keep the full list somewhere you can check while shopping.
Do cosmetics have the same problem?
Yes. Cosmetic ingredients use standardised INCI names that can look very different from everyday words, and colourants often appear as CI numbers. The same principle applies: learn every form of your trigger, not just one.
Who can help me work out my triggers?
A pharmacist can talk through label-reading, a GP can arrange allergy testing or referral, and a registered dietitian is the right person if you are cutting foods out, so that your diet stays balanced. Guessing from labels alone can miss things or lead to needless restriction.