Allergenic hazards

Allergenic hazards

Food allergies are an increasing problem for the food industry including caterers. Food allergens cause the body’s immune system to react, often within minutes but sometimes within hours. In serious cases a person may have a anaphylactic shock which is life threatening. Even minute amounts of the allergen can result in serious problems. Peanut and other nut allergies are often very severe. The first exposure to a specific allergen does not produce symptoms; how ever, subsequent exposure results in an allergic response. Symptoms usually include some of the following:

  • generalised flushing of the skin,
  • nettle rash
  • swelling of the throat and mouth
  • difficulty in swallowing or speaking
  • severe asthma
  • abdominal pain, nausea and/ or vomiting
  • sudden feeling or weakness (fall in blood pressure) and
  • collapse and unconsciousness.

Food intolerance are usually less severe and do not involve the immune system. They may be due to a lack of enzymes or a response to an irritant.


Food which commonly contain allergens include,

  • Peanuts – also called groundnuts, are found in many foods, including sauces, cakes and desserts, Indonesian, Thai, Indian, Bangladeshi dishes and peanut flour and ground nut oil.
  •  Nuts – these include walnuts, hazelnuts, Brazil nuts, cashew, pecan, pistachio, macadamia, Queensland nuts and almonds. Found in sauces, desserts, crackers, bread, ice cream, oils and marzipan.
  • Milk – including lactose, in liquid or in powder form, in yogurt, cream, cheese and butter. Ready-made or glazed dishes may contain milk powder.
  • Eggs – found in mayonnaise, cakes, mousses, pasta, sauces and quiche. Sometimes used to bind meat in burgers, or to provide a glaze.#
  • Fish – e.g. anchovies used in salad dressings, sauces, relishes and on pizza.
  • Shellfish – including prawns, scampi, mussels, lobster and crab. Shrimp paste and oyster sauce are found in Chinese and Thai dishes.
  •  Soya – may be found as tofu, bean curd, soya flour and textured soya protein, Also found in ice cream, sauces, desserts, meat products and vegetarian products, e.g. veggie burgers.
  • Cereals containing gluten – Coeliacs need to avoid wheat, rye and barley, oats, spelt and kamut and foods made from these. Bread, pasta, cakes, pastry and meat products may contain wheat flour,. Soups and sauces, dusted, battered or bread crumbed foods may contain flour.
  • Sesame seeds – used in bread and bread sticks. Sesame paste (Tahiti) in Greek or Turkish dishes, including hummus. Sesame seed oil used in cooking or salad dressings.
  • Mustard
  • Celery and celeriac
  • Lupin flour.

Fruits such as strawberries and kiwi fruit can cause problems. Colourants, artificial flavourings and preservatives, such as sulphur dioxide and sulphates, also pose a risk to allergy sufferers.

Control of allergenic hazards

Manufactures must exercise particular care during food production to ensure allergens do not contaminate other products, for example, dust from nuts does not end up contaminating a product that does not normally contain nuts. Cleaning to remove all traces of contamination can be quite difficult and therefore many factories use completely separate production lines or even different factorises. Dust can be spread through ventilation systems or involve cross-contamination from cloths, cleaning equipment or personnel. 

Food businesses should implement an allergen control system based on HACCP and prerequisite programmes to reduce risk from allergens. This will involve using reputable suppliers and branded goods, with all ingredients and foods clearly labelled; satisfactory packing and segregated storage; using specific equipment for preparation, cooking, ect.; segregated displays; separate serving utensils and clear labelling. Ingredient information must be available for all products and staff should know how to check this. In the event of a product becoming contaminated with an allergen it must be discarded or dealt with as a contaminated product.


If there is any risk of a product containing an allergen, it must be clearly labelled. Requirements for labelling allergens are defined in the food labelling (Amendment) (England) (No.2) Regulations 2004. Foods which are identified as most likely to be allergens must always be clearly labelled.

In catering, effective communication and knowledge of all ingredients are essential to reduce the risk from allergens. Do not guess. Ensure that suppliers are aware of allergen controls and that they are required to notify the business if there are any changes in products. When food is delivered conduct checks to ensure that the food matches that which has been ordered and that different brands do not have different ingredients. Checks should also be made to ensure ingredient information is not obscured by other labels and that packaging is intact.


The risk of cross-contamination from allergens must be prevented throughout the process from storage to service and this will include ensuring allergen information is retained and that the food is suitably packaged to prevent cross-contamination. Products containing allergens should be stored away from other foods. Powders and liquids containing allergens should be stored below other foods to prevent cross-contamination should there be a spillage.

During preparation, food handlers should check the ingredient label before preparing food and should ensure they follow a recipe and avoid making substitutions with different ingredients where alternatives may contain allergens. Any changes made to recipe should be communicated to all other staff, including service personnel.

Products should be handled with care and hands wash controls are of utmust importance. It is particularly important to ensure preparation areas are free from allergens and the work surfaces and equipment are thoroughly cleaned before food which does not contain any allergen is prepared.

Clear menu descriptions identifying potential allergen ingredients should be provided, e.g. cooked in ground-nut oil. Always update the menu when ingredients or recipes are changed. Staff must be instructed and trained about allergens and the implementation of effective control measures. The risk of cross-contamination from allergens must be prevented.  Regular audits and effective supervision are important to ensure control measures are working.

When a customer confirms they are allergic to a particular food, the person taking the order must provide accurate information to the person preparing the food. It is not just the menu item that may contain the allergen, it could be sauce used to make a garnish, it may be the oil used to cook the food or the allergen may be introduced because of a failure to effectively wash the hands or clean preparation equipment, Allergens will not usually be destroyed by cooking.

All staff should be aware of the action to take in the event of a customer having an anaphylaxis (severe allergic reaction as a result of a susceptible person eating a food containing an allergen).

(The customer may have a pre-loaded adrenaline injection kit which they use as soon as a serious reaction is suspected).