L-cysteine is the additive the food industry lists as E920. In our table it is no risk identified: it takes no points off a product's score.
- The key finding, from EU law: E 920 L-cysteine authorised in the EU as a flour treatment agent (Regulation (EC) No 1333/2008 Annex II)
- No child flag. The class, and the points it costs, are the same for a child of any age.
- Where you meet it. It turns up in 24 of the 10,000 packaged foods scanned most on Open Food Facts, most often in bread. Nine in ten of those foods are sold in Europe (counted 26 Sep 2026).
- 2 citations from EU law and the FDA, each one below.
What L-cysteine does to a score
A packaged food's additive subscore starts at 100 and loses points for each additive on the label; that subscore is a third of the final score. L-cysteine takes no points off a product's score. Scan the pack in Sito and the score you get is the one for your own child's age, with this additive named in the reasons. How we score has the whole method.
See what is in your own cupboard
Scan a packaged food and Sito names the additives in it, then scores the product out of 100 for your child's age.
What the sources found
Every classification in our table comes from the citations below, and nothing else. Each finding is our one-line summary of what the source concluded, with the source and reference beside it.
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EU law
Regulation (EC) No 1333/2008 Annex II
E 920 L-cysteine authorised in the EU as a flour treatment agent. -
FDA
Substances Added to Food inventory — L-cysteine / L-cysteine monohydrochloride
GRAS direct food substance (dough strengthener, nutrient).
Why this class
Clean current EFSA and FDA status. These rows exist so that an unfamiliar additive is never treated as a bad one: a missing row costs a product nothing, and a clean row says so with citations.
Our confidence in this row's classification is medium. Medium or low does not mean the evidence is weak; it means something about the row is still being pinned down, usually a regulatory status confirmed from one source rather than two.
Questions parents ask
Is L-cysteine (E920) safe for kids?
No risk identified. No regulator finding we score, so a product keeps its full additive subscore in Sito. The current status is clean: GRAS direct food substance (dough strengthener, nutrient) (FDA Substances Added to Food inventory, L-cysteine / L-cysteine monohydrochloride).
What is E920?
E920 is the E number for L-cysteine, an additive. Open Food Facts tags it en:e920.
Next to it on the label
The E numbers either side of E920 in our table, then the closest additives of the same kind by number.
- Oxidised polyethylene wax (E914), no risk identified
- Potassium bromate (E924a), high risk
- Chlorine dioxide (E926), no risk identified
- Azodicarbonamide and carbamide (E927), low risk, flagged for young children
- Azodicarbonamide (E927a), low risk, flagged for young children
- urea (E927b), no risk identified