Aspartame (E951): What the Sources Found

Aspartame is the sweetener the food industry lists as E951. In our table it is moderate risk: it takes 15 of the 33 additive points off a product's score for a child.

In short

Moderate risk. 15 of the 33 additive points come off a product that carries it.
No child flag. Nothing below is written about children specifically, so the class is the same at every age.
3 citations from IARC, EFSA, FDA, each one below.

What Aspartame does to a score

A packaged food starts with 33 points for what is in its ingredient list. Aspartame takes 15 of the 33 additive 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.

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.

IARC Monographs Volume 134 (2023), aspartame; monographs.iarc.who.int/news-events/iarc-monographs-evaluation-of-the-carcinogenicity-of-aspartame-methyleugenol-and-isoeugenol/
A Working Group of 25 experts (Lyon, 6-13 June 2023) classified aspartame as Group 2B, possibly carcinogenic to humans, on limited evidence for an association with hepatocellular carcinoma in humans.
EFSA Journal 2013;11(12):3496, doi:10.2903/j.efsa.2013.3496
Full re-evaluation confirmed the ADI of 40 mg/kg bw/day and concluded aspartame was not of safety concern at current exposure estimates or at the ADI; intakes up to the ADI would not raise plasma phenylalanine above clinical guideline levels in normal subjects or PKU heterozygotes.
FDA High-Intensity Sweeteners / Aspartame and Other Sweeteners in Food (fda.gov/food/food-additives-petitions/high-intensity-sweeteners)
Aspartame remains an approved US food additive; FDA states it has no safety concerns at approved conditions of use, while people with phenylketonuria should avoid or restrict it.

Why this class

IARC Group 2B; or an EFSA re-evaluation that flagged genotoxicity data gaps, found safety could not be assessed on the available data, or cut the ADI citing child exposure; or an EU harmonised classification of the substance as a reproductive or developmental hazard; or an EU withdrawal of one authorised food use while others remain; or an OEHHA/Proposition 65 listing; or membership of the Southampton-six colourants.

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.