E-numbers / E384 Antioxidant

Isopropyl citrate

also: Isopropyl citrates · Isopropyl citrate mixture
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The short version

An antioxidant synergist once used to stop fats going rancid in processed foods. Not currently authorised for food use in the UK or EU.

Why it's worth knowing

E384 is not a permitted food additive in the UK or EU. If seen on a label, the product may not comply with UK food additive law.

What is it?

Isopropyl citrate is a citric acid ester made by reacting citric acid with isopropanol (isopropyl alcohol). It is a synthetic compound that functions as an antioxidant synergist, meaning it boosts the effectiveness of other antioxidants such as BHA and BHT by chelating metal ions that would otherwise catalyse fat oxidation.

What does it do?

It binds to trace metal ions (particularly iron and copper) in food matrices, preventing those metals from triggering oxidative chain reactions that turn fats rancid. On its own it has limited antioxidant activity; its role is to deactivate the metal catalysts that would otherwise accelerate the breakdown of unsaturated fatty acids.

Where you will see it

Historically used in margarine, vegetable shortening, processed meat products, lard, and some animal fats to extend shelf life. It was also used in salad dressings and fried snack foods. Under current UK and EU law it is not an authorised additive, so it should not appear on labels of UK or EU products. If listed, it would appear as 'isopropyl citrate' or 'E384'.

What the science says

Regulatory withdrawal from the approved list

E384 was assigned an E-number under earlier European food additive frameworks but was not carried forward into the current harmonised EU list under Regulation 1333/2008. The UK FSA approved-additives list, which reflects the assimilated EU framework post-Brexit, does not include E384. This means its use in food sold in the UK or EU is not authorised regardless of dose.

E384 does not appear in the UK FSA's published list of approved food additives and E numbers, meaning it has no current authorisation for food use in Great Britain.

UK Food Standards Agency, Approved additives and E numbersregulatory

EU Regulation 1333/2008 (Annex II) establishes the Union list of food additives authorised for use in food. Isopropyl citrate (E384) is not included in Annex II, so its use in EU food products is not permitted under the current framework.

European Parliament and Council Regulation (EC) No 1333/2008 on food additives2008regulatory

Toxicological background

Earlier reviews of isopropyl citrate focused mainly on its metabolic fate. Citrate esters are generally hydrolysed in the gut to citric acid and the corresponding alcohol, and citric acid is a normal metabolite in human physiology. The isopropanol released is metabolised to acetone. Because it was withdrawn from the authorised list before modern systematic re-evaluation processes were completed, a full published EFSA opinion specifically on E384 does not appear to be available. The absence of a current authorisation, rather than a specific identified hazard, appears to be the primary reason it is not permitted.

Citric acid esters in general undergo hydrolysis in the gastrointestinal tract, releasing citric acid (a normal body metabolite) and the esterified alcohol component. The safety concern for isopropyl citrate centres on the isopropanol released on hydrolysis, which is further metabolised to acetone.

JECFA (Joint FAO/WHO Expert Committee on Food Additives), evaluation of citric acid and its salts and estersregulatory review

Where it stands with the regulators

Status
Not a permitted food additive in the UK or EU. E384 is not listed in the current UK FSA approved-additives schedule or in EU Regulation 1333/2008 Annex II.
Legal basis
UK FSA approved-additives and E numbers list (assimilated from EU Regulation 1333/2008). Absence from Annex II means no current food-use authorisation.
History
Isopropyl citrate was assigned E384 under earlier European food additive harmonisation efforts and was historically used as an antioxidant synergist in fat-containing products. It was not included when the EU consolidated its authorised food additive list under Regulation 1333/2008, effectively removing its authorised status across the EU. The UK's post-Brexit framework retained the same list, so E384 remains unauthorised in Great Britain. No EFSA re-evaluation opinion on E384 appears to have been published under the systematic re-evaluation programme (Regulation (EC) No 257/2010), suggesting the substance was not considered in scope because it lacked Annex II authorisation.

Who should be careful

Anyone buying food in the UK or EU: if you see 'isopropyl citrate' or 'E384' on a label, the product may be non-compliant with UK or EU food additive law. Contact the retailer or the Food Standards Agency. There is no population-specific avoidance beyond the general concern about non-authorised additives.

The honest read

Cutting through the noise

E384 sits in an unusual position: it has an E-number (suggesting it was once part of a European system) but is not on the current permitted list. Secondary websites vary in how they describe its status, with some older sources treating it as approved. The primary regulatory sources, the UK FSA approved-additives list and the text of EU Regulation 1333/2008, do not include it. The absence appears to reflect a failure to secure re-authorisation under the modern framework rather than a specific acute safety finding, but the practical consequence is the same: use in food sold in the UK or EU is not lawful. A full modern toxicological opinion from EFSA does not appear to be publicly available.

Related additives

Common questions

Is E384 banned in the UK?

E384 is not listed as an approved food additive in the UK. The UK FSA's approved-additives schedule does not include isopropyl citrate, meaning food businesses cannot legally use it as an additive in products sold in Great Britain. It is not explicitly named in a ban order, but authorisation is required before use, and none exists.

Why does E384 have an E-number if it is not permitted?

E-numbers were assigned to additives that were part of earlier European harmonisation efforts. When the EU consolidated its food additive rules under Regulation 1333/2008, only additives that passed review and were listed in Annex II retained authorisation. Isopropyl citrate was not included in that consolidated list, so it lost its permitted status while retaining its historical E-number in reference databases.

What foods contain E384?

E384 should not be present in food sold in the UK or EU under current law. Historically it was used in margarine, vegetable shortening, lard, processed meats and some fried snack foods as an antioxidant synergist to prevent rancidity.

Is E384 vegan?

Isopropyl citrate is a synthetic compound produced by reacting citric acid with isopropanol, neither of which is animal-derived. It would be vegan by ingredients, but the question is largely academic since it is not authorised for food use in the UK or EU.

Sources

Last reviewed: 20 June 2026

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