CMC (E466): What the Sources Found

Sodium carboxymethyl cellulose (CMC) is the thickener the food industry lists as E466. In our table it is low risk: it takes 6 of the 33 additive points off a product's score for a child.

In short

Low risk. 6 of the 33 additive points come off a product that carries it.
Flagged for young children. Set only where EFSA’s own exposure assessment shows toddlers or children exceeding or approaching the ADI, or where a regulator used explicitly child-specific language. For a child under 6 it moves one class up.
4 citations from EFSA, Peer-reviewed, each one below.

What CMC does to a score

A packaged food starts with 33 points for what is in its ingredient list. CMC takes 6 of the 33 additive points off a product's score, and a child under 6 sees it one class higher again. 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.

What the sources found

Every classification in our table comes from the citations below, and nothing else. They are quoted as the source wrote them.

EFSA 10.2903/j.efsa.2018.5047 (PMC7009359)
Re-evaluation of celluloses E 460(i)/(ii), E 461-E 466, E 468, E 469: no need for a numerical ADI, no safety concern at reported uses for the general population, no genotoxicity concern.
EFSA PMC9732683 (2022 opinion on E 466 in foods for infants below 16 weeks and follow-up)
Available data still did not allow an adequate assessment of E 466 in foods for special medical purposes for infants and young children (FC 13.1.5.2); toddler exposure in that category up to 911 mg/kg bw per day at the mean; microbiota effects flagged as requiring further investigation over longer exposure periods.
Peer-reviewed PMID 34774538 - Chassaing B et al., Gastroenterology 2022;162(3):743-756
Double-blind randomised controlled-feeding trial (15 g/day CMC, 11 days, healthy adults): reduced gut microbiota diversity, reduced faecal short-chain fatty acids and free amino acids, increased postprandial abdominal discomfort, and microbiota encroachment into the normally sterile inner mucus layer in 2 of 7 CMC subjects.
Peer-reviewed PMID 25731162 - Chassaing B et al., Nature 2015;519:92-96
CMC and polysorbate-80 at relatively low concentrations induced low-grade intestinal inflammation and metabolic syndrome in wild-type mice and robust colitis in colitis-prone mice, with reduced mucus thickness and bacterial encroachment.

Why this class

A credible adverse or precautionary signal that stops short of every Moderate and High criterion: peer-reviewed adverse findings not yet reflected in regulatory status, an exposure exceedance confined to high-percentile or single-event estimates, or a precautionary regulatory step short of those criteria — a reduced ADI, a data limitation noted without an adverse conclusion, a narrowed or conditioned authorisation, or a child-focused assessment or school-food law that covers the additive as part of a class.

Our confidence in this row's classification is high. 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.