Benzoin gum
A natural tree resin from Styrax trees, historically used as a surface coating and flavouring. Not currently a permitted food additive in the UK or EU.
This is not a permitted food additive in the UK, so you will not normally find it on a UK label.
What is it?
Benzoin gum (also called benzoin resin) is a balsamic resin tapped from the bark of Styrax trees, principally Styrax benzoin (Siam benzoin) and Styrax paralleloneurum (Sumatra benzoin), grown in Southeast Asia. The bark is cut and the tree exudes a cream-to-amber resin that hardens on exposure to air. It has a warm, sweet, vanilla-like scent with hints of cinnamon and has been used for centuries in perfumery, incense, and traditional medicine as well as in food.
What does it do?
In food contexts, benzoin resin functions as a glazing and surface-treatment agent, forming a thin protective film on the surface of foods to reduce moisture loss and add sheen. It also has mild antioxidant and antimicrobial properties attributed to its benzoic acid and cinnamic acid ester content, which can slow oxidative rancidity and suppress surface mould growth. Its aromatic esters also contribute a sweet, balsamic flavour note.
Where you will see it
Because it is not a currently permitted food additive in the UK or EU, benzoin gum should not appear in food products sold in these markets. Historically, it was considered for use as a surface coating on confectionery and fresh produce, and as a flavouring in baked goods, beverages, and chewing gum. In third-country markets where it remains permitted, it may appear on labels as 'benzoin gum', 'benzoin resin', or 'E906'.
What the science says
Composition and functional chemistry
Benzoin resin contains a mixture of benzoic acid, cinnamic acid, and various esters including benzyl benzoate, benzyl cinnamate, and coniferin. These components underlie its antioxidant and antimicrobial activity in vitro. The benzoic acid content is particularly relevant because benzoic acid (E210) is itself a regulated preservative in the EU and UK, with maximum permitted levels in specific food categories.
Benzoin resins contain free benzoic acid and cinnamic acid alongside esters; in vitro studies show antimicrobial and antioxidant activity attributable to these components.
Allergen and sensitisation profile
Benzoin is a recognised contact sensitiser in dermatology and is listed in fragrance allergen panels. Balsam of Peru (a related resin mixture) cross-reacts with benzoin and is associated with contact dermatitis and oral allergy reactions in sensitised individuals. The EU Scientific Committee on Consumer Safety and dermatology literature have characterised benzoin as a significant skin sensitiser. Exposure via food is a different route from skin exposure, but individuals with fragrance sensitisation or Balsam of Peru allergy may experience oral reactions.
Benzoin is classified as a known contact allergen and a member of the fragrance mix II panel tested in patch testing for allergic contact dermatitis.
Cross-reactivity between benzoin and Balsam of Peru (Myroxylon pereirae) is documented; individuals sensitised to either resin may react to the other.
Where it stands with the regulators
Who should be careful
Because E906 is not permitted in UK or EU food, consumers in these markets are unlikely to encounter it in labelled products. Anyone with a known allergy to Balsam of Peru, fragrance mix II, or benzoin itself should be aware that the resin is a recognised cross-reactive allergen. Look for 'benzoin gum', 'benzoin resin', or 'E906' on labels of imported products from markets where it may still be authorised.
The honest read
E906 is an unusual entry because it carries an E-number but is not on the current UK or EU permitted list, meaning it cannot lawfully be added to food sold in these markets. The scientific attention benzoin has received relates mainly to its use in cosmetics and fragrances, where its sensitisation potential is well established. Its absence from the food-additive positive list means no formal EFSA safety opinion has been issued for food use under the current framework. There is no active regulatory concern about consumer exposure via food in the UK because the route of exposure is blocked by the lack of authorisation.
Related additives
Common questions
Is E906 banned in the UK?
E906 is not listed as a permitted food additive in the UK. It does not appear on the FSA's approved-additives list, meaning it cannot lawfully be added to food sold in Great Britain. It was never included in the EU's positive list under Regulation 1333/2008, which the UK retained after Brexit.
Can E906 trigger an allergic reaction?
Benzoin resin is a documented contact allergen in fragrance and cosmetic contexts, and cross-reacts with Balsam of Peru. Individuals with Balsam of Peru allergy or fragrance mix II sensitivity may react to benzoin. As it is not permitted in UK food, routine dietary exposure is not expected.
What foods contain E906?
No food legally sold in the UK or EU should contain E906, as it is not on the approved additives list. Historically, it was considered for use in confectionery coatings, baked goods, and beverages. It may appear in imported products from countries with different regulations.
Is E906 vegan?
Yes. Benzoin gum is a plant-derived resin tapped from Styrax trees, with no animal-derived ingredients.
Sources
- UK FSA Approved Additives and E Numbers
- EU Regulation 1333/2008 on Food Additives (Annex II positive list)
- EU Food Additives Database - European Commission
- Open Food Facts - E906 benzoin resin usage data
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