E-numbers / E560 Other

Potassium silicate

also: Potassium metasilicate
mineralVegan ✓Vegetarian ✓Halal - checkKosher - check
The short version

A potassium salt of silicic acid. Not a permitted food additive in the UK or EU, so it should not appear on food labels.

Why it's worth knowing

E560 is not authorised as a food additive in the UK or EU. If you see it on a food label, that product may not be compliant with UK food law.

What is it?

Potassium silicate is an inorganic salt formed from potassium oxide and silicon dioxide. It belongs to the silicate family, related to sodium silicate and silicon dioxide (E551), but carries its own E number from older classification systems. It is a glassy or crystalline solid, soluble in water, with strongly alkaline properties.

What does it do?

In industrial contexts potassium silicate acts as a binder, adhesive, or surface-hardening agent. In food contexts it was historically proposed as an anti-caking agent or surface treatment, but it was not included in the list of permitted food additives under current UK or EU law.

Where you will see it

Potassium silicate is used industrially in detergents, cements, fireproofing, and agriculture, not in food. It does not have approved food uses in the UK or EU, so it should not appear on food packaging. If it were labelled, it would appear as 'potassium silicate' or 'E560'.

What the science says

Regulatory non-inclusion

Potassium silicate received an 'ADI not specified' group opinion from the EU Scientific Committee on Food in 1991, alongside sodium silicate, silicon dioxide, calcium silicate and magnesium silicate. However, when EU Regulation 1333/2008 consolidated the list of authorised food additives, potassium silicate was not carried over into Annex II as a permitted additive. The UK FSA approved-additives register does not list E560, and the FSA data portal returns no record for it.

The EU Scientific Committee on Food established a group ADI of 'not specified' for several silicates including potassium silicate in 1991, but this opinion predates the current authorisation framework and was not converted into a permitted use under Regulation 1333/2008.

EU Scientific Committee on Food, Reports of the Scientific Committee for Food (26th series)1991regulatory review

The UK FSA approved-additives register and data portal contain no entry for E560 potassium silicate, confirming it is not a permitted food additive in Great Britain.

UK Food Standards Agency, Approved Additives and E Numbers register (food.gov.uk/business-guidance/approved-additives-and-e-numbers)regulatory

Silicate family context

Related silicates such as silicon dioxide (E551), calcium silicate (E552), magnesium silicates (E553a), and talc (E553b) are permitted anti-caking agents in UK and EU food law. EFSA re-evaluated these permitted silicates between 2018 and 2020 and set numerical ADIs or group ADIs for them. Potassium silicate was not part of those re-evaluations because it is not an authorised food additive. Its close chemical relatives show low acute toxicity and are largely insoluble, but potassium silicate itself has not been assessed in a food-additive context by EFSA.

EFSA's 2018 re-evaluation of silicon dioxide (E551) and calcium and magnesium silicates (E552, E553a, E553b) confirmed them as permitted food additives with group ADIs, but potassium silicate was outside the scope as it is not authorised.

EFSA ANS Panel, EFSA Journal 2018;16(1):5088 and 2018;16(8):53752018regulatory review

Where it stands with the regulators

Status
Not a permitted food additive in the UK or EU
Legal basis
EU Regulation 1333/2008 (Annex II, as assimilated into UK law) does not list E560. The UK FSA approved-additives register contains no entry for potassium silicate.
History
Potassium silicate received a group 'ADI not specified' from the EU Scientific Committee on Food in 1991 as part of a broad silicate opinion. It was assigned the E560 code in older EU numbering but was not included when Regulation 1333/2008 consolidated the authorised list. The related silicates E551-E553b remained on the permitted list; E560 did not. There is no record of it ever having been approved for use in food in Great Britain.

Who should be careful

Anyone buying food in the UK or EU should not encounter E560 on a label, as it has no authorised food use. If a product does carry 'E560' or 'potassium silicate' on its ingredient list, it may not be legally compliant and could be worth reporting to the FSA.

The honest read

Cutting through the noise

E560 sits in an unusual position: it has an E number from old classification work and was grouped with silicates that did receive safety clearances, but it was never authorised as a food additive under the law that governs UK and EU food. The silicate family it belongs to is well studied, but none of that study translates into a permitted use for E560 specifically. The absence from the register is the key fact here, not a contested finding.

Related additives

Common questions

Is E560 banned in the UK?

E560 is not listed as an approved food additive in the UK or EU. It was never included in the consolidated permitted list under EU Regulation 1333/2008, which was retained in UK law after Brexit. Using it as a food additive would not be lawful under current UK food regulations.

Why does E560 have an E number if it is not permitted?

E numbers were originally assigned to substances reviewed by the EU Scientific Committee on Food, even if they were not ultimately approved for use. E560 received a code during older classification work in the 1990s but was not carried into the current authorised list under Regulation 1333/2008.

What foods contain E560?

No foods in the UK or EU should lawfully contain E560, as it is not an authorised food additive. It is used in industrial and agricultural applications such as detergents, cements, and fertilisers.

Is E560 vegan?

Potassium silicate is an inorganic mineral compound with no animal-derived components. However, as it is not an authorised food additive, the question of vegan status is not practically relevant to food labelling.

Sources

Last reviewed: 20 June 2026

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