Esters of colophonium
A glazing agent made from pine-resin derivatives. Its current permitted status in the UK and EU is unclear and it does not appear on the FSA's approved additives list.
Colophonium is one of the most common contact allergens in the European patch-test series. People with a known colophonium or rosin allergy may react to products containing its esters, including on skin contact with coated foods.
What is it?
Esters of colophonium are chemical derivatives of colophonium (also called rosin or colophony), a natural resin obtained by distilling the oleoresin of pine trees. The resin acids in colophonium are esterified, typically with alcohols such as glycerol or methyl alcohol, to produce a harder, more stable material suitable for surface coatings.
What does it do?
Acts as a glazing agent: applied to the surface of confectionery, fruit or other foods to provide a shiny finish, reduce moisture loss, and create a protective coating. The ester form improves heat stability and adhesion compared to crude rosin.
Where you will see it
Most commonly associated with hard-shell confectionery coatings, chewing gum, and glazed fruit in continental European markets. The closely related E445 (glycerol esters of wood rosins) is permitted in soft drinks; E915 is the glazing-agent variant. On a UK label it would appear as 'glazing agent (E915)' or 'esters of colophonium'.
What the science says
Colophonium as a contact allergen
Colophonium (rosin) is included in the European baseline patch-test series because it is one of the most frequently identified causes of allergic contact dermatitis. The sensitising fractions are abietic acid and related resin acids. Esters of colophonium retain some of these sensitising components, though esterification modifies the profile. Oral exposure from food coatings is generally at much lower levels than topical exposure, but individuals with confirmed colophonium allergy should be aware of its presence.
Colophonium is a recognised frequent contact allergen included in the European baseline patch-test series, with sensitisation rates typically reported at 1 to 3 percent of dermatitis patients tested.
Abietic acid and dehydroabietic acid, the main resin acids in colophonium, are the principal sensitising fractions identified in patch-test studies.
Regulatory data gap
E915 does not appear in the UK Food Standards Agency's publicly listed approved food additives, which skips from E914 to E920. The EU positive list under Regulation 1333/2008 and its annexes authorises food additives by a closed positive-list system: any additive not listed is not permitted. If E915 is absent from the current Annex II, its use in UK or EU food products is not authorised. This absence is itself the key regulatory finding.
The FSA approved-additives guidance page lists E914 (oxidised polyethylene wax) and then jumps to E920 (L-cysteine), with no entry for E915 esters of colophonium.
Where it stands with the regulators
Who should be careful
People with a diagnosed colophonium or rosin allergy should check ingredient lists for 'esters of colophonium', 'E915', or 'rosin esters'. Colophonium allergy is typically identified via patch testing for contact dermatitis; if you have this allergy, discuss food-label vigilance with your dermatologist.
The honest read
E915 sits in a genuinely uncertain regulatory space: it is not listed in the FSA's published approved-additives guidance, which is the primary UK reference. If it is not on the EU positive list either, its use in food sold in the UK is not permitted. The main established concern with colophonium compounds is contact allergy, which is well-documented in dermatology but primarily relates to skin exposure. The extent to which oral intake from food glazing could trigger reactions in sensitised individuals is not well-studied. This is not a case where the science is actively contested; it is a case where the regulatory status and the oral-exposure allergenicity data are both sparse.
Related additives
Common questions
Is E915 approved in the UK?
E915 does not appear on the UK Food Standards Agency's approved-additives guidance, which lists permitted E numbers. Additives not on the UK positive list are not authorised for use in food sold in the UK. If you see E915 on a UK food label, that would be worth querying with the manufacturer or reporting to the FSA.
Is E915 related to E445?
Yes. Both are esters of rosin (colophonium), but they differ in source and use. E445 is glycerol esters of wood rosins, permitted in soft drinks as a clouding agent and emulsifier. E915 is esters of colophonium (gum rosin), listed as a glazing agent. E445 is confirmed on the EU and UK positive lists; E915's current status is less clear.
What foods contain E915?
Hard-shell confectionery coatings and glazed products are the most commonly cited uses in older references. Given its uncertain current regulatory status in the UK and EU, it may not legally appear in food products sold here. Always check the ingredient list.
Is E915 vegan?
Colophonium (pine rosin) is plant-derived, so esters of colophonium are vegetarian and vegan. However, glazed confectionery products that use E915 may also contain other non-vegan ingredients, such as shellac (E904) or beeswax (E901), so the product label should always be checked in full.
Sources
- UK Food Standards Agency: Approved Additives and E Numbers
- European Society of Contact Dermatitis: patient information on colophonium
- EU Food Additives Regulation 1333/2008 (European Commission overview)
See this on every food you scan
NutraSafe reads the label and puts every additive into plain English, with the source, right in the app.
Get NutraSafe on the App Store