Potassium aluminium silicate (E555): What the Sources Found

Potassium aluminium silicate is the additive the food industry lists as E555. 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.
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, Law, FDA, each one below.

What Potassium aluminium silicate does to a score

A packaged food starts with 33 points for what is in its ingredient list. Potassium aluminium silicate takes 15 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 2020;18(6):6152 — doi:10.2903/j.efsa.2020.6152, Re-evaluation of sodium aluminium silicate (E 554) and potassium aluminium silicate (E 555) as food additives
'Considering that only very limited toxicological data and insufficient information on the physicochemical characterisation of both food additives were available, the Panel concluded that the safety of sodium aluminium silicate (E 554) and potassium aluminium silicate (E 555) could not be assessed.' For E 555 specifically the Panel considered it 'is not being used as a carrier, but as an inseparable component of potassium aluminium silicate-based pearlescent pigments', and calculated a theoretical regulatory maximum exposure as carrier for E 171 and E 172 that 'could theoretically far exceed the TWI' — no age-group-specific exposure estimate was produced for E 555.
EFSA Journal 2008;6(7):754 — Safety of aluminium from dietary intake
TWI of 1 mg aluminium/kg bw per week; dietary exposure exceeds the TWI in a significant part of the European population, children in particular.
Law Commission Regulation (EU) No 380/2012, EUR-Lex CELEX:32012R0380
Cut permitted levels for aluminium-containing additives for consumer protection, citing EFSA's finding that the aluminium TWI 'is generally exceeded for high consumers, especially children'.
FDA 21 CFR Part 182 Subpart C enumerated in full (six anticaking sections, none of them potassium aluminum silicate); 21 CFR §73.350 (mica-based pearlescent pigments), incorporating the identity spec at §73.1496(a)(1)
No US anticaking authorisation located for potassium aluminum silicate. It appears in US food law only as the mica substrate of a titanium-dioxide-coated pearlescent colour additive permitted under §73.350 at ≤1.25% in cereals, confections and frostings, gelatin desserts, candies, supplement tablets and chewing gum.

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 medium. 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.