Food allergy is now recognised as an important food safety issue.

The greatest care must be taken by food manufacturers

• to formulate foods so as to avoid, wherever possible, inclusion of major allergens as ingredients;

• to organise raw material supplies, production, production schedules and cleaning procedures so as to prevent cross-contamination of products by "foreign" allergens;

• To train all personnel in an understanding of necessary measures and the reasons for them;

• To provide appropriate warning, to potential purchasers, of the presence or possible presence of a major allergen in a product;

• To have in place an appropriate system for recall of any product found to be contaminated but carrying no warning.

The problem of food allergens is part of a wider problem, that of all kinds of adverse reactions to foods, which can also result from microbial and chemical food poisoning, psychological aversions and specific non-allergenic responses. Dealing with at least the major serious food allergens is an essential part of Good Manufacturing Practice.

An allergy is an immune response, leading to the formation of immunoglobulin E (IgE) antibodies. These, through a series of biochemical reactions, result in the release of histamine, leucotrienes and other substances into the tissues from the body's mast cells, which reside in the eyes, skin, respiratory system, intestinal system and urinary system.

This photomicrograph demonstrates two mast cells. One cell is intact, the other damaged in preparation (demonstrating the individual granules).

Mast cells

These cells express, on their cell membranes, high affinity receptors for the Fc portion of IgE antibodies, thus most of the IgE antibodies produced by plasma cells are bound to the surface of mast cells. Reaction of the bound IgE with circulating (or in the case of mast cells, localized) antigens promotes degranulation of the mast cell. In addition, crosslinking of the bound IgE or interaction of the bound IgE with antibodies to IgE will also promote degranulation of the cell.

Let’s take a brief diversion to consider mast cells. For years they have been thought to do nothing but play this part in the mechanism of allergy. Then in July last year, researchers at Duke University Medical Center reported that mast cells also recognise pathogens such as Salmonella and dangerous strains of E.coli, and alert the immune system to destroy the bacteria (Abraham et al, 1999)¹. A protein molecule designated CD48, identified ten years ago on the surface of mast cells recognises a protein called FimH on the tips of hair-like projections on many infectious bacteria. This CD48-FimH connection triggers mast cells to alert the immune system by releasing a substance called tumor necrosis factor alpha (TNF-a), which is a type of early warning system of infection. The new research led to the conclusion that CD48 is a specific receptor on mast cells that recognises bacteria and triggers the release of TNF-a, which alerts the immune system to destroy the bacteria. Mast cells are alerted only when bacteria become invasive, burrowing into the gut lining, and are not activated by the beneficial gut-inhabiting bacteria that colonise only the surface of the intestinal lining.

Let’s return to allergy.

Allergy requires an initial sensitisation which may often occur in childhood. Once sensitised, repeat exposure causes full-blown allergic reaction. Repeat exposure is usually either because the person is unaware of being allergic to a particular substance or because of unawareness of the presence of a known allergic substance. An allergic reaction may be triggered by a minute amount of allergen. Allergic reactions may range from relatively short-lived discomfort to anaphylactic shock and death (and not only from the well-publicised peanut, see for example Nordlee²). A food allergy is an immune response to a food or a substance, normally a protein or glycoprotein, in a food naturally, or by contamination, or produced by processing, cooking or digestion. What distinguishes food allergy from food intolerance or aversion is that food allergy is an immune response rather than a gastrointestinal upset, that the reaction may be independent of the quantity consumed and that it may be life-threatening.

Many people perceive that they have food allergies; a survey of US households found that 13.9% perceive that one or more household members have food allergies. When specific cases are examined, the incidence is lower, with some 8% of children and 2% of adults exhibiting true allergy (Bush, 1997)³. This is accounted for by the fact that in some cases childhood allergies disappear as the individuals grow older.

Other adverse reactions to food occur which are not immune responses. These include microbial or chemical food poisoning, and intolerance of specific substances. The mechanisms of the latter adverse reactions are not fully understood but in the acute form tend to be essentially gastrointestinal upsets, usually dependent on the amount of the food consumed, and not normally life-threatening.

This is an extremely complex problem to which there are no cheap or easy solutions. There are few foods or food ingredients to which someone, somewhere, is not allergic, in some cases in very small (microgramme) quantities, but the risk should be treated seriously and safeguarded against by all food manufacturers, retailers and caterers.

No form of warning about the presence of an allergen in a food can be effective for an individual unless he or she is aware of the foods or food substances to which he/she is allergic. This information cannot be derived from any source except that individual and his/her medical adviser. People who think that they suffer from a food allergy owe it to themselves to undergo tests to determine if it is a true allergy, and if so, what is the substance that causes it. There are two methods of determining whether a person is allergic to a food or food substance. The first and simpler, is the skin test. The second, more elaborate, but more definitive, is the double-blind, placebo-controlled oral challenge test.

While not detracting from the responsibility of sufferers (and their medical advisers) to identify the particular foods or food substances to which they are allergic, there is need for due diligence by manufacturers in considering the use of major serious allergens as ingredients, in warning of the presence or potential presence of such allergens in products, and in preventing adventitious cross-contamination of products with allergens present in other manufactured products. This is not only a duty of care and a due diligence requirement, but an essential means of minimizing the risk of being subject to a product liability claim, and the risk of having to recall cross-contaminated products. Easy to advocate, but as companies now successfully operating such a policy have found, it is far from easy to introduce and implement. The new development of such a policy requires nothing less than a change in the company "culture", an allocation of very substantial funds and resources and a concentrated and sustained effort by everyone led by the Board; and its application and maintenance thereafter requires ongoing effort.

Led by the Board? The first task is to win the understanding and commitment of the Board itself.

and that needs both the dedicated effort of a sufficiently senior and sufficiently knowledgeable champion and the presentation and adoption of a plan.

Part of the work of implementing the plan, however, is the difficult and ongoing task of training all concerned – general managers, buyers, production managers, quality managers, engineers, supervisors, operators, cleaners, to understand the importance of the plan and the need to carry out conscientiously the measures that it contains.

I recall hearing a description of how, as just such a champion, Nancy Erdman secured, over a period of a few years, a complete change of company culture at Hershey and accounts could be given of similar changes leading to effective policies in companies like Kelloggs, General Mills, Nestlé and no doubt others. However, it has been done not only in large companies with huge resources, but in smaller companies too. An outstanding example was a relatively small UK company, Kinnerton, a manufacturer of many novelty confectionery products for kids – chocolate and biscuit products some containing nut and some nut-free, supplying both under its own name but also under major retailers’ own labels. In this case the champion was Clive Beecham, the owner of the company – and you can’t get much more senior than that! He was dissatisfied with measures to prevent cross-contamination, so last Easter, he shut down his factory for three weeks and reorganised the buildings and far-reaching changes to production methods to provide complete segregation of nut products from non-nut products.

Over 170 foods have been documented in the scientific literature as causing allergic reactions. Clearly it would be totally impossible to deal with all of these, and for practical purposes the food manufacturer should concentrate his attention on dealing effectively with a term which I originated back in 1997 and which is now widely used, "major serious allergens" (MSAs). What does the term signify?

It certainly includes the so-called "big eight", namely milk, eggs, soy, wheat, peanuts, shellfish, fruits, and tree nuts, which between them account for the great majority of food allergies (Taylor,1992)⁴.

It should also include the so-called "second eight", which includes sesame seeds, sunflower seeds, cottonseed, poppy seed, molluscs, beans other than green beans, peas, lentils.

For present purposes, tartrazine, sulphites and latex should be treated as MSAs.

There has been considerable confusion about whether the oils (e.g. of peanut, tree nuts, cottonseed) are allergenic. In the past there was an unsupported assumption that they must be; then an equally unsupported view that oil does not contain protein and therefore they cannot be. In 1997, papers on peanut oils by Hourihane et al⁵ and tree nut oils by Teuber et al⁶, showed that unrefined oils were allergenic but refined oils were not. However, a later paper by Olszewski et al⁷ (1998) reported the presence of protein allergens in refined peanut oil. The obvious explanation of the contradiction between the results of Hourihane et al and Olszewski et al is that they were using two different samples of "refined" peanut oil, which in turn suggests the conclusion that the unqualified term "refined peanut oil" cannot be assumed to mean non-allergenicity. This further suggests that unless the oil is an analytically-monitored highly refined and designated non-allergenic, peanut oil should be treated as allergenic.

"Dealing effectively" means taking due care to prevent or minimise the avoidable presence of MSAs, warning on the label of the presence of any MSA that is unavoidably present and preventing cross-contamination. The "due care" and the label warning are inseparable. So where does one start in exercising due care? We are talking about hazards that can give rise to serious and even life-threatening risks to consumers, so of course one starts with HACCP. No, not a HACCP separate from that which is already exercised to identify hazards and safeguard against risks of a food poisoning or toxicological nature, but a HACCP plan which, as it should, embraces all hazards and thus embraces allergens as well.

This means designing new food product formulations, or examining existing ones to eliminate or replace non-essential MSAs.

This means going all the way back to the sources and handling of ingredients, through all the stages all the way to distribution and retailing.

This means examining one’s suppliers for possibilities of cross-contamination in their operations and requiring them to take appropriate preventive measures.

It also means, if one is using a genetically-modified version of an ingredient that is not normally an MSA, that the manufacturer satisfies himself that his supplier (or his supplier’s supplier) has ensured that the genetic modification has not resulted in the acquisition of a allergenic gene.

Although there are no inherent grounds for assuming that genetically-modified or other novel foods are more – or less – allergenic than traditional foods, among other food safety aspects to which attention must be paid when introducing novel foods or developing genetically modified foods is the need to be careful that allergenicity is not introduced into the diet by a novel food, or transferred into a genetically modified food or ingredient. This requires assessment of the allergenicity of a new protein, by predictive methods, experimental testing and a post-marketing surveillance based on traceability.

During an experimental program to modify soya (not the highly-publicized "roundup-ready" modification), to improve its methionine content by the introduction of a brazil nut gene, scientists at University of Nebraska found, and subsequently published that the experimental modified soya contained a known proteinaceous allergen from brazil nuts (Nordlee et al, 1995b⁸; 1995c⁹). The seed company concerned (Pioneer Hi-Bred) reported these findings publicly and discontinued the brazil nut/soybean development program. A false version of this well documented piece of research has been widely used by anti-GM campaigners as "people were made ill by soya genetically modified with a brazil nut gene". In fact, it represented a straightforward case of preventing the introduction of a known allergen. It can be done by an IgE test with serum from sensitive individuals (Herian et al 1990)¹⁰.

However, there is also a need to test products where genes have been inserted from sources not known to be allergenic. Approaches to the more difficult matter of testing genetically modified products for unknown allergens are discussed by Wal and Pascal (1998)¹¹ and Metcalfe (1998)¹². Astwood et al (1996)¹³ have developed a method in which stability of a protein or protein fragments to digestion in simulated gastric fluid (SGF) may be used to assess the potential allergenicity of the protein.

Existing or proposed new product formulations should be carefully examined to see whether there is a possibility of excluding MSAs. Of course, in many cases an MSA is essential to characterise the food – if you are making peanut butter you cannot exclude peanuts, or if you are selling dairy products you can hardly exclude milk protein! In some cases, however, where MSAs are present as non-characterising ingredients, it may be possible to effect a substitution. Likewise, a similar approach should be made to MSAs in compound ingredients comprising less than 25% of the total weight (and thereby not at present required by UK or EU law to be individually named in the ingredients list). If it is necessary to include an MSA in such a compound ingredient, then the MSA should be named.

The adventitious presence of an MSA in a product may arise in three main ways; the second being accidental mis-formulation, and the third being cross-contamination by an MSA from a different product. But, as already indicated, the first, chronologically, is cross-contamination of an ingredient before you receive it.

Mis-formulation resulting in the inclusion of an MSA (or any other ingredient) not in the product formulation should be prevented by proper attention to the formulation development and control provisions to ensure that the product as prepared contains only the ingredients specified in the formulation.

Cross-contamination of an ingredient or a product by an MSA from a different ingredient or product may arise in storage and handling of raw materials, or during production due to residues in shared equipment, airborne dust, or the improper incorporation of re-work material without consideration of the allergen problem.

It should be emphasised that the importance of prevention of cross-contamination applies not only to a product nominally free from MSAs , but equally to a product containing one or more declared MSAs but not the MSA involved in the potential cross-contamination.

In companies producing on more than one site, or in different buildings on the same site, serious consideration should be given to segregation of materials storage and production. Where this is not possible, separate handling and production equipment should be used if possible.

Where shared production equipment between one or more MSA-free products and an MSA-containing product is unavoidable, the MSA-containing product should be run as the last production of the day, immediately before cleaning; for example, on a shared production line for mixed breakfast cereals, one of which contains nuts, the product containing nuts should be run last. An alternative approach might be to package the nut component separately elsewhere, in sealed pouches, which could then be put into the container, leaving it to the purchaser to mix them in or not, according to personal choice. However, it should be recognised that cleaning afterwards, especially in a plant producing dry products, will not necessarily guarantee against small quantities of trapped material waiting to be "carried over" into the first product to go through thereafter, and segregation may be the only acceptable solution. The same applies to small quantities of MSA in airborne dust.

The incorporation of re-work material in a product cannot in any event legally include any ingredient that is not in that product formulation; and compliance should therefore serve to exclude from any product re-work material that may contain an MSA not in the formulation of that product.

As I said earlier, it is vital that everyone involved, from the Chief Executive to the cleaner is fully trained to understand the requirements and importance of the plan and the need to carry out conscientiously the measures that it contains. Testing for the presence of Food Allergens

Because sampling can never be 100% and because adventitious cross-contamination in not necessarily homogeneously distributed, testing for presence of allergens cannot be regarded as a substitute for the precautions and preventive measures outlined. Systematic testing can, however, be a useful way of monitoring the effectiveness of those preventive measures. Diagnostic kits are available for testing raw materials and products, and for swab testing of plant and equipment, for peanut, egg, soya, casein and sesame protein allergens.

As regards the manufacturer’s responsibility, appropriate label warnings to the potential purchaser are necessary. Realistically, distinctive labelling cannot encompass every one of the 170+ foods documented as causing allergic reactions (or most food labels would have to carry numerous warnings and all impact would be lost). Nor, most importantly, should labelling be regarded as obviating the precautionary responsibilities of manufacturers already mentioned.

Labelling deficiencies resulting in allergic reactions may arise

• because an MSA may be present but not named when in a compound ingredient (in current European Union labelling legislation) used below 25%;

• because a known MSA is not recognised by its designation in an ingredients list, for example, declared "vegetable oil" may be unrefined peanut oil. Few, if any, consumers, knowing that they are allergic to milk protein would realise the significance of "calcium caseinate" in an ingredients list; and most people reading "gum base" would not realise that many gum base formulations contain latex; and

• because an MSA is unnoticed due to the smallness of print on many ingredients lists.

To minimise risk there is a clear need to provide some kind of label warning regarding the presence of any of the MSAs. In the first version of its Position Statement in September 1997 (repeated in the latest updating¹⁴, the Institute of Food Science & Technology (IFST) proposed that, pending any legislation to require this and the format in which warnings should be presented, manufacturers should voluntarily give warning, and suggested an appropriate way in which this should be done. Some weeks later the then UK Food Safety Minister (Mr Jeff Rooker, MP) urged manufacturers and retailers to give label warnings, and launched a campaign to raise awareness in the catering industry of severe food allergies.

IFST’s proposals were subsequently incorporated into its Good Manufacturing Practice Guide, 4^th Edition¹⁵. Many manufacturers and retailers are now giving such warnings.

Legislation on allergen warnings is likely to develop as a result of the current EU Review of Food Labelling and developments in Codex Alimentarius. The EU Commission has issued a Scientific Co-operation Report on Food Allergy¹⁶, and an initial draft proposal (III, 5907/97)¹⁷ for amending labelling Directive 79/112/EEC. Codex and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) have been considering the problem, and proposals were considered at the Codex Alimentarius Commission meeting in June/July 1999.

Pending legislation, the IFST recommendations regarding label warnings were, and remain, as follows:

Inclusion of the name of an MSA in an ingredients list should not be regarded as adequate warning. The presence or potential presence of an MSA should be separately stated, in a prominent and easily legible way, where it will clearly be seen by a potential purchaser under normal conditions of display.

Where a product contains one or more MSAs, whether as individual ingredient(s) or as component(s) in a compound ingredient, the presence of the MSA should be stated (for example "Contains PEANUT"). The terminology should be clearly understandable by the lay person. Thus where calcium caseinate is the MSA concerned, the warning should read "Contains MILK PROTEIN". It would be helpful to the purchaser to add to this category of warning the words "to which some people may be allergic".

Where a product nominally free from MSAs is produced on a production line shared with an MSA-containing product a suitable warning might be, for example, "May contain traces of PEANUT". Again the additional words "to which some people may be allergic" would be helpful. However, it cannot be emphasised too strongly – and both the FDA and the EU insist – that "may contain …." must not be used as a way of evading the responsibility to exercise "all reasonable precautions and all due diligence" to prevent cross-contamination. "May contain" moreover, is a two edged sword. Whereas when used responsibly, it is intended to warn those allergic to the substance referred to of a possible risk, some of the same sufferers tend to regard it as unfairly robbing them of choice.

Where a product nominally free from MSAs is unavoidably produced in the same factory building as an MSA-containing product, a suitable warning might be, for example, "Produced in a factory where PEANUT is also handled".

In making the foregoing recommendations, IFST was conscious, however, that under the EU Quantitative Declaration of Ingredients ("QUID") provisions that would apply to certain ingredients, from 14 February 2000, warnings of these kinds could be regarded as special emphasis of the named ingredients, and thereby trigger QUID; and we therefore sought to ensure that exemption from that provision was provided in the case of allergens named as warnings. The final official Guidance Notes on QUID, issued on 30 April 1999 provide that exemption

Despite the manufacturing precautions that I have outlined there have had to be numerous product recalls, in the USA and in Europe, of product batches containing an MSA, whether by mis-formulation of cross-contamination, of which there was no warning.

This has happened in the cases of major companies with well-established practices along the lines I have stated. This emphasises the importance of having not only a "belt" but "braces" in the form of a well-organised recall plan that can be quickly and efficiently put into operation should the need arise. It should, of course, go without saying that every manufacturer needs such a plan for any eventualities that require product recall.

In the present context, major retailers are manufacturers by proxy. The responsibilities of retailers in respect of own-label pre-packed products should be those as if they were themselves the manufacturer. In regard to pre-packed branded products, they need to satisfy themselves that appropriate label warnings are given. However, retailers have special responsibilities in regard to foods that are sold from open containers, e.g. on delicatessen counters. When such foods contain MSAs, the warnings should be clearly displayed by the foods in question. Moreover staff must be trained to take great care to avoid cross-contamination, e.g. that might occur by using the same ladle or other handling equipment for a food containing an MSA and one that does not contain it.

Reference has already been made to the responsibility of individuals with an allergy to find out to what substance(s) they are allergic. Only then can they make use of warning information. This also applies when eating food prepared by others.

For the purpose of this paper, foodservice may be viewed as a particular kind of manufacture with added complications. In general, the principles referred to for product formulation and avoidance of cross-contamination by manufacturers apply equally to caterers; and similar warnings should be given adjacent to appropriate items on menus or self-service display notices.

In some large restaurant chains, the expertise exist to do this, and their buying power enables them to lay down specifications and monitor performance of ingredient suppliers; but many small catering outlets have neither that expertise nor buying power. Label warnings on bulk packs supplied by manufacturers for foodservice use may be of some help.

An additional problem arises, however, in an establishment where a chef has a free hand in creating dishes. It is important, therefore, that chefs are given training in recognition of MSAs, the principles of minimising risk in respect of MSAs and the need to notify any use of allergens, including their use in ways that might go unnoticed by others, for example use of an egg glaze on pastry.

Throughout foodservice, the main cross-contamination problem is that of cross-contamination by the common use of equipment such as ladles, which inevitably happens in busy kitchens despite admonitions to the contrary.

In parts of the foodservice field, such as aircraft in-flight meals in economy class (where there is normally neither printed menu nor display) the problem of giving adequate warnings is far more difficult to solve. The same applies to the multiplicity of small cafes, where, in addition, many proprietors would not have sufficient knowledge to know what warnings to give.

With in-flight meals, the problem is compounded by having to deal with a tray containing several components (starter, main course, dessert, roll/bun and butter, cheese). Moreover, it is not like a situation where someone who is, for example, allergic to soya can look at the label of a food product before purchase, find a soya warning and decide not to purchase.

Aircraft meals are prepared in so-called "central kitchens" which are really factories manufacturing short-life high risk ready meals under stringent conditions of hygiene, and have technical managers with the expertise to deal with the minimisation of unnecessary MSAs in recipes, monitoring of their suppliers, prevention of cross-contamination and provision of warning information. One solution would be for the central kitchen to provide a menu (which could be just a sheet of paper), with each item carrying a warning of any MSAs present, and cabin staff distributing this to passengers in advance of meal selection. Another solution could depend on cabin staff being provided with such an annotated menu list and passengers being asked on the address system "If you have a food allergy, please tell the cabin staff what you are allergic to and they will be able tell you if that is present in any part of the meals available".

The situation is very different in small cafes (or in many larger restaurants), and street vendors. For the allergy sufferer to say "I am allergic to X. Is there any X in dish Y?" may or may not produce an accurate answer where the allergen is very obvious as a direct component of the dish, but is most unlikely to do so where X is a sub-component in, say, a sauce or a soup. Bear in mind too that the question may well be put to a transient low-paid employee whose first language may, anyway, not be the language in which the question is put.

From monitoring an allergy internet newsgroup, where this problem has been debated, I have heard of instances where asking has not produced an answer that the allergen is present and trouble (including anaphylactic shock) has ensued. Some sufferers conclude that the only solution for them is "never eat out". But that does not address the needs of those who do.

As you will see, I still lack a recommendable means of ensuring that allergic people receive reliable, accurate information in foodservice circumstances where there is no printed menu, or display alongside each self-service item. Maybe there is no solution, but if anyone here has one, please share it with us in the discussion.

In the UK, the Leatherhead Food Research Association maintains a Food Intolerance Databank, established some years ago, accessible by doctors and dietitians. This contains information, provided by some food manufacturers, of their products which do not contain specific substances, including some of the MSAs. Thus a person with an allergy may obtain, in those cases only, through his/her doctor or dietitian, a list of products which do not contain the substance to which he/she is allergic. Useful though this continues to be, it has limitations (of no help at all when eating out in catering establishments, or in the immediacy of encountering new food products when shopping). It does not obviate the need for manufacturers and caterers to pursue the measures outlined above. Indeed, the inclusion of a product in the database makes it all the more crucial for the manufacturer concerned to adopt stringent measures and procedures to prevent mis-formulation or cross-contamination of the food concerned.

The circumstances and raison d'étre of the Databank have changed since its inception in 1987. The current Databank is under review and proposals are awaited on how to improve it for the future.

The Center for Food Safety and Nutrition of the US Food & Drug Administration has issued a useful guide for consumers on food allergy¹⁸

In the UK, the Ministry of Agriculture, Fisheries and Food (MAFF) set up a Food Intolerance Research Programme in 1994 focussing on the causes and mechanisms of food intolerance and food allergy and including a variety of projects.

An expert sub-group of the UK Department of Heath Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) has been studying the problem and has issued some recommendations¹⁹ intended to reduce the incidence of peanut allergy.

One potential research area is to develop hypoallergenic versions of food substances that are allergenic, notably (for obvious reasons) in Japan to develop hypoallergenic rice (by enzymatic treatment, Watanabe et al, 1990)²⁰ and transgenic rice with a low allergen content (Matsuda and Nakamura, 1993)²¹.

Any measures to minimise the adverse effects of allergenicity can only alleviate matters in limited areas and in limited ways. Any prospect of overcoming allergenicity must lie in the direction of "switching off" or blocking the reaction by which the immune system mistakes the allergenic substance for an invader and reacts by generating the antibodies that cause the release of histamines.

One research programme in this direction is reported to be proceeding at Imperial College, London (Leake, 1997)²². Researchers have developed and are testing a "smart" vaccine, a single injection of which would provide permanent protection against the effect of numerous substances that make allergy victims ill. The vaccine is said to re-programme the immune system to block the biochemical processes that lead to release of histamines causing allergic reactions. The vaccine is reported to be composed of genetically-modified bacteria.

I end with a reminder of the key factors

Food allergy is now recognised as an important food safety issue. The greatest care must be taken by food manufacturers

• to formulate foods so as to avoid, wherever possible, inclusion of major allergens as ingredients;
• to organise raw material supplies, production, production schedules and cleaning procedures so as to prevent cross-contamination of products by "foreign" allergens;
• to train all personnel in an understanding of necessary measures and the reasons for them;
• to provide appropriate warning, to potential purchasers, of the presence or possible presence of a major allergen in a product;
• To have in place an appropriate system for recall of any product found to be contaminated but carrying no warning.

Key references