What is E555? Potassium Aluminium Silicate Explained
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E555 is Potassium Aluminium Silicate — a anti caking agent (mineral) used in table salt, icing sugar.
What is E555 (Potassium Aluminium Silicate)?
E555 is Potassium Aluminium Silicate, a food additive classified as a anti-caking agent that prevent powders and granules clumping. A anti caking agent (mineral) used in table salt, icing sugar. You'll find it in table salt, icing sugar, dried soups and many other packaged foods. Like every E-number, E555 has been authorised for use in food following an EFSA safety evaluation — though authorisation doesn't mean concern-free, as the safety section below explains.
Where is E555 found?
E555 (Potassium Aluminium Silicate) is found in table salt, icing sugar, dried soups, baking powder, powdered drinks, seasoning mixes.
- table salt
- icing sugar
- dried soups
- baking powder
- powdered drinks
- seasoning mixes
Is E555 safe?
E555 is authorised in the EU and UK but carries genuine concerns. EFSA's 2020 re-evaluation of E555 concluded that its safety could not be fully assessed, due to limited toxicological data — and calculated that realistic exposure to aluminium from some of its uses could exceed the Tolerable Weekly Intake (TWI) of 1mg aluminium per kg body weight set for aluminium-containing additives as a group. For most people consuming Potassium Aluminium Silicate in typical quantities, health effects are unlikely — but the caution flag reflects either active scientific debate, mandatory warning labels, allergen status, or conditions attached to its authorisation.
EFSA opinion: Potassium Aluminium Silicate — status Some concerns.
Check the calorie content of foods containing E555. If you’re pregnant, see our pregnancy food safety guide.
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E555 FAQs
What is E555 in food?
E555 is Potassium Aluminium Silicate — a anti caking agent (mineral) used in table salt, icing sugar.
Is E555 safe to eat?
E555 is authorised in the EU and UK but carries genuine concerns. EFSA's 2020 re-evaluation of E555 concluded that its safety could not be fully assessed, due to limited toxicological data — and calcu
Is E555 vegan?
E555 (Potassium Aluminium Silicate) is vegan. It is derived from mineral, with no animal involvement in standard food production.
Is E555 halal?
E555 (Potassium Aluminium Silicate) is halal. It is derived from mineral, which involves no haram sources.
Why this page's verdict changed from a plain 'safe'
E555 (and its close relative E554, sodium aluminium silicate) is one of a small number of additives where EFSA's own most recent scientific opinion did not conclude the additive is safe — it concluded the opposite of a clean bill of health. In a 2020 re-evaluation, EFSA's Food Additives and Flavourings Panel stated plainly that the safety of E554 and E555 ‘could not be assessed’, because too little toxicological data and physicochemical characterisation had ever been submitted for either additive. That is a data gap rather than a finding of harm, but it is a meaningfully different situation to the hundreds of additives EFSA has actively reviewed and confirmed safe, so this page reflects that distinction with a caution rating rather than a plain safe one.
The aluminium exposure calculation behind the concern
Aluminium is the specific concern. Potassium aluminium silicate is roughly 20% aluminium by molecular weight, and EFSA has set a Tolerable Weekly Intake (TWI) for aluminium from all food-additive sources combined of 1mg per kg of body weight per week, reflecting evidence that aluminium can accumulate in the body and has been linked to effects on the nervous system and reproduction at high exposure levels in animal studies. EFSA calculated that realistic exposure to aluminium from E555's actual permitted uses — principally as an anti-caking agent in powdered and granular foods such as dried soup mixes, spice blends and icing sugar — could theoretically exceed that weekly limit on its own, before counting any other aluminium-containing additive a person might also consume.
What this does and doesn't mean for you
It doesn't mean E555 has been found to cause harm — EFSA's conclusion was explicitly that there wasn't enough data to assess safety either way, not that unsafe levels had been proven. It also doesn't mean E555 is banned; it remains legally permitted in both the EU and UK at its existing authorised levels while regulators wait for manufacturers to submit the missing data. For most people, exposure to E555 specifically is occasional and small, since it appears in a limited range of powdered products rather than everyday staples. The practical takeaway is the same one EFSA itself draws: this is an additive worth being aware of if you consume a lot of powdered or instant food products regularly, rather than one to panic about from occasional use.
Common myths about E555, checked against the evidence
“EFSA found E555 to be dangerous or banned it”
Not accurate. EFSA's 2020 opinion said the safety of E555 could not be assessed due to insufficient data — a data gap, not a finding of harm. E555 remains a legally authorised food additive in the EU and UK, and no ban or mandatory withdrawal has followed from this opinion.
“If an additive is legally authorised, EFSA has confirmed it's safe”
Usually true, but E554 and E555 are a specific exception worth knowing about. EU food law allows additives authorised under older rules to remain in use while EFSA works through its re-evaluation programme, even where a re-evaluation — as happened here — concludes that safety couldn't be fully assessed with the data available.
Further reading
Related Anti-Caking Agents additives
Also check: safe for cats? · safe for dogs? · calorie checker · medication interactions
Data: Open Food Facts (ODbL) · EFSA