A bread additive with animal, human-hair and fermentation sources, and scholars who differ
E920 (L-cysteine) is doubtful (mushbooh). It is an amino acid used mainly as a dough improver in bread. Most of it is made by breaking down animal material such as poultry feathers or hog hair, but a fermentation method also exists. The label does not say which was used.
Scholars are not unanimous. One mosque-based answer we read says foods containing L-cysteine are permissible whatever its source, because the substance is transformed into another substance. A UK Hanafi food guide, in contrast, lists E920 among the additives to be careful about and says it is "manufactured from animal hair and chicken feathers".
Cysteine is one of the amino acids that make up proteins. As the food additive E920, L-cysteine is used as a dough conditioner: it makes dough easier to handle and shortens mixing time. The general reference on cysteine says it is also used as a processing aid for baking. You will find it mainly in industrial bread, buns, pizza bases, bagels, tortilla wraps and some flavourings.
Because it is a processing aid at low levels, it sometimes does not appear on the label at all, depending on local labelling rules. If it does, you will see "L-cysteine", "E920" or "cysteine hydrochloride".
The reference entry on cysteine says that most L-cysteine is made by breaking down animal materials, such as poultry feathers or hog hair, through hydrolysis. It states that human hair is rarely used and cites an EU rule that "human hair may not be used as a source for this substance". It also describes a synthetic route that uses fermentation with an engineered bacterium, which is available at a higher price and suits kosher and halal requirements.
So there are three possible routes behind the single label "E920": animal feathers or hair, a fermentation process, and, in some countries and historically, human hair. The ruling can differ for each, which is why scholars treat this one separately from the plant-based additives.
An answer published by Green Lane Masjid says that eating foods containing L-cysteine (E920) is permissible "no matter what its source is", because the substance is transformed into another substance and becomes pure and lawful. It adds that if harm from it were proven, its use would not be allowed, and that if a substance came from an impure source without transformation, small amounts absorbed into other ingredients are permissible, citing the Ninth Medical Fiqh Council, which lists L-cysteine as an example of such absorption. The answer also says that excessive enquiry is not required.
The MuftiSays answer, published through IslamQA and dated July 2012, lists E920 among a small group of exceptions to its rule that other E-numbers were considered halal at the time of publication. It describes E920 as "manufactured from animal hair and chicken feathers". The answer does not argue the point in detail, but its placement of E920 on the exception list shows that it advises caution.
Many readers ask about human hair because of news stories. The reference we read says it is rarely used and that EU rules do not allow it as a source for this additive. In Islamic law the use of parts of the human body raises its own question of respect for the human being. We do not have a ruling to cite on that point, so we say only that it is a reason many people prefer a confirmed source. If a manufacturer states that its L-cysteine is made by fermentation, this concern does not arise.
| Product | Comment |
|---|---|
| Industrial bread, buns and burger rolls | Most common use; a halal logo or a "no L-cysteine" claim helps |
| Pizza bases, bagels, wraps | Used to keep dough extensible |
| Biscuits and crackers | Occasional |
| Savoury flavourings | Occasional; look at the whole list |
Artisan or small-bakery bread is often made with flour, water, yeast and salt only. Asking the baker is easy and usually gets a clear answer.
Feather- or hair-derived L-cysteine is not vegan or vegetarian. Fermentation-derived L-cysteine can be. Kosher treatment depends on the certifier and the source. In every case, the label alone is not enough, and the simplest guide is a certification mark that fits your needs.
A short, polite email usually gets a useful reply. You can copy and adapt this:
Keep the reply. If the answer is vague, treat the product as doubtful and choose a certified alternative.
Islamic teaching on doubtful matters is the basis for how we label these ingredients. A well-known hadith, recorded in the collections of al-Bukhari and Muslim, says that the halal is clear and the haram is clear, and between them are doubtful matters that many people do not know about. Scholars generally draw two practical points from it. First, you are encouraged to avoid what you have real reason to doubt, as far as you reasonably can. Second, this is not a call to be anxious about every additive: where there is no real reason to doubt, most scholars do not ask you to investigate beyond what is reasonable.
That is why our "doubtful" label means check if you can, not assume it is forbidden. A halal logo, a clear source on the label, or a short email to the maker will usually settle the matter. If you follow a particular madhab or scholar, their guidance comes first.
| E-Code | Name | Status | Notes |
|---|---|---|---|
| E920 | L-cysteine | Doubtful | Commonly made from animal feathers or hair, or by fermentation. Some scholars permit it whatever the source because it is transformed; others avoid animal or human-hair sources. Labels rarely say which. Full guide → |
| E481 | Sodium stearoyl lactylate | Doubtful | Stearic acid source is not stated. Contains no milk, despite the name. Full guide → |
| E491 | Sorbitan monostearate | Doubtful | Stearic acid source varies. Full guide → |
| E322 | Lecithin | Doubtful | Usually soy or sunflower and therefore halal. Classed as doubtful because the source is not always stated. Full guide → |
| E471 | Mono- and diglycerides of fatty acids | Doubtful | Source is not disclosed on labels and can be plant or animal. Full guide → |
| E631 | Disodium inosinate | Doubtful | Source is not always stated. Full guide → |
It is doubtful. Sources differ: one scholarly answer permits L-cysteine whatever its source because it is transformed, while a UK Hanafi food guide lists it as an additive to be careful about because it can be made from animal hair and chicken feathers.
The reference we read says human hair is rarely used and that EU rules do not allow it as a source for this additive. Most L-cysteine comes from poultry feathers or hog hair, or from fermentation.
It depends on the source and on your scholar. A halal logo or confirmation of a fermentation source removes the doubt.
Not if it comes from feathers or hair. Fermentation-derived L-cysteine can be vegan, but the label usually does not say.
Not always. As a processing aid it may be exempt from labelling in some countries, which is a reason to ask the baker or choose certified bread.
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✦ Open Free Halal CheckerThese are the pages we read for this guide. We summarise what each says; we do not claim these bodies endorse Afiya AI.