Home › Ingredients › Carboxymethylcellulose (E466)
Is carboxymethylcellulose (E466) safe?
- EFSA, FDA, FSSAI, WHO: all permit E466 — no ban or restriction anywhere
- 2022 human trial: adding CMC to an additive-free diet caused stomach discomfort after meals and changed gut bacteria
- 2023 BMJ study: people who ate more of it had a higher rate of heart disease — an association, not proof of cause
- EFSA: found the data too limited to assess infant foods and has issued a call for new safety data
- LabelCop: flags E466 as high-risk — based on the human evidence, with the sources shown
What is carboxymethylcellulose?
- A synthetic thickener and stabiliser made by chemically modifying cellulose — plant fibre
- Jobs in food: thickening, stopping ice crystals in ice cream, keeping mixtures from separating
- Label names: carboxymethylcellulose, CMC, cellulose gum, E466, INS 466
- US labels usually print the friendlier name — "cellulose gum" — for the same additive
Which foods contain it?
- Ice cream and frozen desserts (its single biggest use)
- Flavoured milk, milkshakes and protein shakes
- Low-fat dairy, sauces, dressings and packaged desserts
- Gluten-free breads and bakery, where it stands in for gluten's texture
- Instant drink mixes and some tablets and toothpastes
- In India: most common in ice creams, frozen desserts, flavoured milk and instant mixes — look for INS 466 or "carboxymethyl cellulose" on the label
What the regulators actually say
| Regulator | Status | Reasoning |
|---|---|---|
| EFSA / European Union | Permitted — new data requested | EFSA's 2018 re-evaluation found no safety concern at reported uses for the general population and saw no need for a numerical daily limit. In 2022 it concluded the available data were not sufficient to assess safety in foods for infants under 16 weeks, and it has issued a call for new technical and toxicological data covering all population groups. A data call is a re-examination, not a restriction. |
| FDA (United States) | GRAS — permitted | Sodium carboxymethylcellulose is generally recognised as safe (21 CFR 182.1745) when used under good manufacturing practice. No FDA review of that status is currently announced. |
| FSSAI (India) | Permitted | Allowed as a thickener and stabiliser (INS 466) in specified product categories under FSSAI's additive regulations. |
| WHO / JECFA | ADI "not specified" | The joint FAO/WHO expert committee grouped CMC with other modified celluloses and set an acceptable daily intake of "not specified" — its category for additives judged to pose no hazard at expected intakes. |
So why is it on our high-risk list?
- The approvals came first; the human trials came later. The key evidence post-dates every listing above
- Gastroenterology, 2022: in a controlled human feeding trial, adding CMC to an otherwise additive-free diet caused stomach discomfort after meals and changed participants' gut bacteria
- BMJ, 2023: a large French cohort study found people who ate more cellulose-type emulsifiers, including E466, had a higher rate of heart disease — an association, not proof of cause
- EFSA's own follow-up flagged data gaps for the youngest infants and asked industry for new toxicological data
- None of this is a ban. It is a gap between the age of the approvals and the age of the evidence — we show you the gap instead of hiding it
- E466 is a high-risk flag in LabelCop
- Why: a controlled human trial (Gastroenterology, 2022) linked it to stomach discomfort and changed gut bacteria, and a large BMJ study (2023) associated higher intake with a higher rate of heart disease
- This flag rests on human evidence, not a regulator's ban — there isn't one, and we say so
- The product's score takes a penalty — and you see the flag, the reason and the sources. No black box
Frequently asked questions
Is carboxymethylcellulose banned anywhere?
No. It is permitted by EFSA, GRAS with the FDA, permitted by FSSAI and cleared by the WHO's expert committee with an ADI of "not specified". The debate is about human research published after those approvals — not about legality.
Is cellulose gum the same thing?
Yes. "Cellulose gum" on a US label is the same additive as carboxymethylcellulose, CMC, E466 or INS 466 elsewhere.
Does it cause gut problems?
No regulator has concluded that it does. A 2022 controlled feeding trial in Gastroenterology reported post-meal stomach discomfort and gut-bacteria changes in healthy adults eating CMC — a small, short study, but a direct human test rather than a mouse one.
Isn't it just plant fibre?
It starts as cellulose from plants, but it is chemically modified to behave differently — it is a synthetic derivative, not intact fibre. That modification is what makes it useful in food, and it is also what the gut research examines.
How do I avoid it?
Check ingredient lists for carboxymethylcellulose, CMC, cellulose gum, E466 or INS 466 — especially on ice cream, flavoured milk and gluten-free bakery. Or scan the label with LabelCop and it's flagged automatically, with the sources shown.
LabelCop reads any food label you photograph and flags additives like E466 instantly — no barcode needed.
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EFSA (2018): re-evaluation of celluloses including E466 as food additives · EFSA (2022): follow-up opinion on E466 — infant foods and all population groups · EFSA: call for technical and toxicological data on E466 · FDA — 21 CFR 182.1745: sodium carboxymethylcellulose (GRAS) · WHO/JECFA database: sodium carboxymethyl cellulose · Chassaing et al., Gastroenterology (2022): randomised controlled-feeding trial of carboxymethylcellulose · Sellem et al., BMJ (2023): food additive emulsifiers and risk of cardiovascular disease · FSSAI: Food Safety and Standards regulations — permitted additives
Related ingredients: Emulsifiers overview (E471, E466, E433) · Carrageenan (E407) · Xanthan gum (E415)
This article explains regulatory status and published scientific assessments in plain English. It is not medical advice.