Monosodium glutamate (E621): What the Sources Found

Monosodium glutamate is the flavour enhancer the food industry lists as E621. In our table it is high risk: it takes 30 of the 33 additive points off a product's score for a child.

In short

High risk. 30 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.
3 citations from EFSA, FDA, each one below.

What Monosodium glutamate does to a score

A packaged food starts with 33 points for what is in its ingredient list. Monosodium glutamate takes 30 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 Journal 2017;15(7):4910, doi:10.2903/j.efsa.2017.4910 (PMC7009848)
Group ADI of 30 mg/kg bw/day expressed as glutamic acid for E 620-625, derived from a NOAEL of 3,200 mg MSG/kg bw/day in a neurodevelopmental toxicity study with a default 100-fold uncertainty factor — the first numerical ADI ever set for glutamates.
EFSA Journal 2017;15(7):4910, exposure assessment section (PMC7009848)
In the refined non-brand-loyal scenario the MEAN exposure in toddlers and children exceeded the dose associated with the MSG symptom complex (>42.9 mg/kg bw/day), i.e. well above the 30 mg/kg bw/day ADI; at the 95th percentile, exposure in infants, toddlers and children exceeded doses associated with adverse effects in humans (MSG symptom complex 42.9, headache 85.8, blood-pressure increase 150 mg/kg bw/day).
FDA Questions and Answers on Monosodium glutamate (MSG), fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg
FDA considers added MSG generally recognized as safe (GRAS) and requires it to be declared as 'monosodium glutamate' on the ingredient panel; US regulatory status is therefore clean — the child concern is EU exposure-based, not US-regulatory.

Why this class

IARC Group 1 or 2A with a dietary exposure route; or EFSA has withdrawn or negated a safety conclusion; or EFSA’s own exposure assessment finds a child age group exceeding the ADI at mean intake; or the substance is banned or formally being phased out for food use by the EU, by the US FDA, or under a US state law.

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.