Allergy is a major health challenge. Estimates suggest that 30–40% of the global population has one or more allergies. In the UK, a recent report found that over 30% of adults reported an adverse reaction after consuming food, while an estimated 6% of adults, or 2.4 million people, have a clinically confirmed food allergy. Allergy is a response by the body to something that is generally harmless but that the immune system mistakenly recognises as a potential hazard. Consequently, the list of allergens is virtually endless. However, some common substances are known to elicit allergic reactions in susceptible or sensitised individuals, including pollen, pet hair, insect stings, house dust mites, foods, drugs, latex, heavy metals and other chemicals. The societal cost of food allergy alone in the USA has been estimated to be over $370 billion per annum.
What is allergy?
The human body has evolved a powerful array of tools to identify and respond to substances that it considers hazardous. These tools are grouped under the general heading of the immune response, although several different mechanisms may be involved depending on the specific threat. In most cases, this immune response neutralises or destroys the hazard. For example, white blood cells can phagocytise pathogenic microorganisms. The immune response may also involve the production of antibodies that target the hazard, either neutralising it directly or enhancing its subsequent destruction by specialised white blood cells. The final destruction of the hazard involves cells producing a cocktail of chemicals. These chemicals help white blood cells access the hazard, stimulate enhanced activity and disrupt the metabolism or cellular integrity of invading organisms. Repeated exposure to the same hazard primes the immune system, as an increasing population of white blood cells that recognise the specific hazard remains after each exposure. Consequently, exposure to new hazards can result in a somewhat delayed immune response, whereas pre-exposed hazards provoke a rapid and enhanced response. There are some excellent videos and texts on the immune response (Immune video; Immune text).
Allergy is simply this same natural immune response but to a substance that does not present a threat to the body. The hazard in these cases is referred to as an allergen and exposure to these in allergic individuals results in the typical symptoms of allergy. The symptoms generally occur at the site of exposure to the allergen. With consumer products, this may appear as skin reactions, such as contact dermatitis, rashes or hives, following the application of topical formulated products such as perfume, body creams and shampoo. Reactions may also occur through contact with compounds in fabricated products, such as heavy metals in jewellery or latex in gloves. Contact dermatitis can present in two main forms: irritant contact dermatitis, caused by repeated exposure to substances such as cleaning products, laundry products and everyday chemicals; and allergic contact dermatitis, which invokes a true allergic response. For foods, because the allergen progressively passes through the gastrointestinal tract, the reaction can be both local and systemic, meaning it can affect the whole body. Reactions include vomiting, stomach or intestinal pain, diarrhoea, itchy skin and rashes or hives. Some individuals experience an enhanced immune response to allergens, particularly certain food allergens, where the immediate release of chemicals from the immune system provokes a life-threatening condition referred to as anaphylaxis. The symptoms of anaphylaxis can occur within minutes and include swelling in the throat, tongue or upper airways, sudden onset of wheezing, and difficult or noisy breathing. Systemic symptoms include dizziness, feeling faint, sudden sleepiness, confusion, pale clammy skin, loss of consciousness or collapse.
History of allergy
The scientist Clemens von Pirquet first proposed the term ‘allergy’ in 1906 for the altered reactivity induced by what he termed an ‘allergen’ - a foreign substance. This came from studies on ‘serum sickness’ in children who had been administered animal antiserum that resulted in both protection against an infection but also sensitisation with occasional serious or fatal consequences because of the immune response. Allergy might feel like a modern phenomenon but records indicate that it goes back a long way with Chinese Emperors as early as 2735 BC advising the public on foods to avoid due to allergy and Hippocrates (460 - 377 BC) noting adverse impacts (‘hostile humors’) after eating cheese. King Richard III (1478 - 1535) was the first individual with recorded food allergy (to strawberry) although this is somewhat disputed.
Allergy-related skin diseases, food allergy and anaphylaxis (including food specific anaphylaxis) have been increasing in recent decades due to increased awareness, diagnosis and what appears to be a sustained underlying occurrence. To respond to increasing allergy amongst the public, products have been formulated to remove allergenic substances or ingredients e.g. fragrance-free and specific products have been developed to cater for individuals avoiding specific allergens e.g. hypoallergenic, Free-from, etc.
Legislation and Industry Guidance
Regulation for allergen management including labelling differs markedly between food and non-food products.
Food: In general, foods must be labelled with an ingredients list that includes specific allergens. In some countries, such as the UK and EU member states, these allergens must also be highlighted or emboldened so that they are clear to the consumer. The allergens that must be listed differ between countries, reflecting the allergies experienced in different nations. In the USA, the major food allergens, often referred to as the “Big 9”, must be declared. These include milk, egg, fish, shellfish (crustacea), peanut, tree nuts, wheat (Triticum species including common wheat, durum wheat, club wheat, spelt, semolina, Einkorn, emmer, Khorasan and triticale), soya and sesame. Sulphites are not included in USA allergen regulations, but they must be listed on a label due to similar respiratory reactions in some individuals. In the EU and the UK, these allergens are extended to include other gluten-containing cereals (rye, barley and oats), molluscan shellfish, celery (and celeriac), mustard and lupin, with sulphites (including sulphur dioxide) also mandated as part of allergen regulations. Technically, pure oats do not contain gluten but are included due to contamination in the harvesting and processing supply chains. There are also differences in the tree nuts that must be declared, with the EU and UK requiring almonds, hazelnuts, walnuts, cashews, pecan nuts, Brazil nuts, pistachio nuts and Macadamia or Queensland nuts to be on a food label. In Australia, New Zealand and the USA, this list is further extended to include pine nuts. An excellent reference source of allergens that must be declared on pack across the world is available from the Food Allergy Research and Resource Program (FARRP).
The position on the labelling of allergens that may be unintentionally present due to cross contamination, known as precautionary allergen labelling (PAL) or ‘may contain’ labelling, is covered in legislation although it is not mandatory. In the USA, “an allergen advisory statement, such as ‘may contain’” is not a substitute for adherence to current good manufacturing practices or food allergen preventive control, and it must be truthful and not misleading (section 403(a)(1) of the FD&C Act). In the EU and UK, “Precautionary allergen labelling statements should make specific reference to one or more of the 14 regulated allergens, that may be unintentionally present in the food, so that consumer food choice is not unnecessarily limited”. In general, PAL should not be applied to foods described as free from a particular allergen. A key challenge associated with PAL has been determining the levels of allergens that would merit a warning such as ‘may contain’. This has often led to overuse of such labelling on products where the risk would be exceptionally low. CODEX has recently agreed to progress the revision to the General Standard for the Labelling of Pre-packaged Foods (CXS 1-1985) to include the Annex: guidelines on the use of precautionary allergen labelling to CAC49. This will provide the framework for businesses to implement risk-based precautionary allergen labelling of foods with reference to specific threshold levels of allergens set at the ED05 level (eliciting dose 5%). This level relates to the reference dose of allergen protein expected to elicit a mild or moderate allergic reaction in 5% of the allergic population.
Although most legislation is directed at pre-packaged foods, the provision of allergen information is also applicable in many countries to foods sold loose and purchased in restaurants. In the UK, this has also been extended to foods prepared and packaged on the premises for direct sale (prepackaged foods for direct sale). In addition, the increasing prevalence of allergy in young children and the associated risk of anaphylaxis has led to some country-specific legislation on the provision of adrenaline auto-injectors and associated allergy training in schools.
As noted above, there has been a significant increase in foods that are produced for special dietary needs including those specifically designed to be “Free-from” a particular allergen e.g. peanuts and nuts, milk, eggs and wheat. Such foods are targeted at those with a specific allergy to the ‘Free-from’ ingredient/allergen but there are also many individuals who choose to avoid certain allergens for general dietary and/or lifestyle reasons. A recent BRCGS article on Special Diets has covered this in some detail. It is worth noting that the term ‘free-from’ is not legislated for in any country, but it is generally interpreted as meaning that the allergen is not present at the lowest current reliable level of quantification in the product. The only exception to this is ‘Gluten-Free’ where a specific legislative limit of 20 mg per kg (parts per million) of gluten is applied.
There are a number of excellent reference sources produced by CODEX, national regulators and industry on allergen management and labelling requirements (Regulators: USA, EU, UK, Australia/New Zealand, Ireland) (Industry: Allergens Knowledge Hub, Allergen Risk Assessment, Allergen labelling, Free-from, Allergen recall prevention, Allergen-free and Vegan Claims). An excellent online training tool has also been made available by the UK FSA.
Consumer products: Regulations for the management and labelling of allergens in consumer products are restricted to a subset of products, and the labelling itself is far less prescriptive than for food. The main sectors where allergen labelling, in the form of ingredient declarations, is required include cosmetics and medicines. In the case of cosmetics, regulations generally require ingredient labelling on-pack or in an accompanying leaflet. This must include a defined list of fragrance allergens if they exceed a certain concentration. In the EU, Regulation 1223/2009 defines a cosmetic product as “any substance or mixture intended to be placed in contact with the external parts of the human body (epidermis, hair system, nails, lips and external genital organs) or with the teeth and the mucous membranes of the oral cavity with a view exclusively or mainly to cleaning them, perfuming them, changing their appearance, protecting them, keeping them in good condition or correcting body odours.” This includes a wide range of products, such as creams, emulsions, lotions, gels and oils for the skin, soaps, bath preparations and shampoos, deodorants and antiperspirants, perfumes, toilet waters and Eau de Cologne, hair care products, hair tints and bleaches, cleansing and conditioning products, shaving products, dental care products, sun protection products, self-tanning products and anti-wrinkle products. Fragrance allergens must be listed on these products if they exceed 0.001% in leave-on products and 0.01% in rinse-off products. The list of fragrance allergens that must be listed has recently been updated in EU Regulation 2023/1545. This now includes 82 substances, with new products having to meet the requirement by the end of July 2026 and existing products having to be sold through by the end of July 2028. In the USA, there is no specific legislation on allergens in cosmetics, but ingredient labelling is required.
Despite the detailed legislation on cosmetics in relation to fragrances, legislation does not address commonly used terms such as ‘hypoallergenic’. This term, commonly used on consumer products and especially cosmetics, is entirely defined by the manufacturer and therefore may simply relate to the removal of an ingredient that is recognised as causing irritation or allergy or by the addition of ingredients that are believed to reduce irritation such as aloe vera.
Fabricated consumer products are not subject to specific allergen labelling requirements although several substances known to cause allergic reactions such as heavy metals may be regulated in commodity specific legislation, primarily for safety reasons.
There are some useful guides on allergen risks associated with consumer goods products produced by allergy associations (Allergy UK, Anaphylaxis Campaign).
Assurance
The management of allergens in foods and consumer products is critical to their safety. Allergens are now widely recognised as significant potential hazards that must be considered as part of the hazard analysis a business undertakes. In foods, this is addressed through the systematic identification of hazards and implementation of controls using HACCP (hazard analysis critical control point). This is often supported with third-party certificated audits to verify the effective operation of the food safety management system. Standards such as the BRCGS Food Safety standard provide substantial detail on the allergen risk assessment and management requirements expected of a business to receive certification. Similarly, voluntary third-party certification (vTPA) standards exist for the manufacture of products making specific allergen-free claims, such as the BRCGS Gluten Free standard, and also for the Hospitality and Catering Sector. Similar assurance approaches have been adopted for consumer products, particularly through vTPA standards such as the BRCGS Consumer Products standard. In this standard, the risk associated with the handling of allergenic or sensitising materials must be assessed, and policies or procedures developed for their effective management and labelling where necessary. It is important to recognise that many allergen incidents are caused by failures in the systems of control at raw material suppliers. An effective supplier assurance programme that includes consideration of allergen management is therefore key.
An additional element of assurance, particularly relevant to allergens, is analytical testing. Testing for allergens can support effective risk assessment and management in raw material, in-process and finished products. It can also help establish effective cleaning and control programmes to prevent cross contact during manufacture. Allergen testing requires careful consideration of the sample to be tested, the method being used and the interpretation of the result, to avoid false positive or false negative results. False positive results can occur when substances in the sample cross-react with the allergen. False negative results can occur if chemicals inactivate or mask the test method or signal. Alternatively, test methods may be applied that are not sufficiently sensitive for the required product specification, or the wrong target allergen may have been selected. For example, testing for the allergen referred to as ‘milk’ can utilise technology to detect beta lactoglobulin, casein, lactose or bovine DNA. Each approach has its merits but can also give false assurance if used in the wrong circumstances. A number of useful articles have been published on considerations regarding allergen testing (Allergen Bureau, Campden BRI, IFT, RSSL), but it is recommended that accredited laboratories are consulted to support any analytical testing needs.
In conclusion, allergens present a complex and evolving challenge across both food and consumer products. Effective management depends on clear labelling, robust risk assessment, strong supplier assurance and appropriate testing, supported by reliable guidance and recognised standards. By taking a systematic approach, businesses can better protect consumers and build confidence in the safety of the products they provide.
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AuthorAlec Kyriakides Independent Food Safety Consultant
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