Bacteria are not the only danger. Food can also be made unsafe by physical objects, harmful chemicals, and allergens.

In this module, you will learn about physical, chemical and allergenic hazards, how to control them, the 14 named allergens, and the law on allergen information.

Physical hazards are objects in food that should not be there. They may not cause food poisoning, but they can cause choking, cuts to the mouth or broken teeth, and they can carry bacteria. They are also very distressing for customers.

Physical contamination comes from six main sources, known as the six Ps: people, packaging, product, pests, premises, and plant, which means machinery and equipment.

• People: hair, jewellery, buttons, false nails, nail varnish and plasters can fall into food. Careless repair work can leave screws or wire, and occasionally items are added deliberately.
• Packaging: glass, string, cardboard, plastic, staples, wood splinters and film from deliveries and wrapping.
• Product: things that come with the raw food itself, such as stones, soil, vegetable stalks, feathers, shell and bones.

Most physical contamination is accidental, but not all of it. Food handlers, engineers and visitors can all introduce foreign objects. Some fall into food by accident, such as hair, buttons, plasters or stones from jewellery, and nail varnish can flake off into food during preparation. Occasionally, objects such as needles or glass are deliberately added to food as an act of sabotage, which is one reason why staff should report anything suspicious, including damaged or tampered packaging.

Maintenance work brings its own risks. A repair carried out carelessly near open food can leave screws, wire or fibres behind, so maintenance should be planned for times when food is covered or removed, and the area checked afterwards. Packaging also deserves attention. Materials from food deliveries, cleaning chemicals and maintenance equipment, such as string, cardboard, staples, splinters and polythene, can all find their way into food if they are opened or stored close to it.

• Pests: bodies, droppings, eggs, fur and feathers. Pests also carry harmful bacteria.
• Premises: broken glass, flaking paint, rust, loose plaster and wood splinters, and drawing pins or paper clips from notice boards.
• Plant: nuts, bolts and screws from machinery, metal from worn slicers and mincers, and bristles, threads or paper from cleaning equipment.

To prevent physical contamination:

• Wear clean protective clothing with no outside pockets, tie hair back and cover it.
• Remove jewellery, and cover cuts with blue, detectable plasters.
• Keep food covered, and remove outer packaging away from open food.
• Check equipment for damage, use it correctly, and report wear or breakages.
• Follow the glass breakage policy, and keep glass away from open food.
• Report any signs of pests at once.

Chemical hazards are harmful substances in food. They can get into food at any stage, for example through:

• Cleaning chemical left on surfaces and equipment.
• Sprays used near open food.
• Chemicals kept in food areas, or in unlabelled containers.
• Food stored in old chemical containers.
• Delivery vehicles that have carried chemicals.
• The misuse of pesticides, fertilisers or veterinary medicines on farms.

To prevent chemical contamination:

• Buy food from reputable suppliers, and keep food and chemical deliveries apart.
• Store chemicals away from food, ideally in a locked store, in their original, labelled containers.
• Never decant chemicals into unmarked containers, or store food in chemical containers.
• Follow the manufacturer’s instructions, dilution and contact times, and rinse where required.
• Cover or remove food while cleaning, and use only food-grade packaging.

A food allergy is a reaction by the body’s immune system to a particular food. Symptoms include an itchy mouth and throat, a rash, swelling of the face, difficulty swallowing, and difficulty breathing. For some people, even a tiny trace of an allergen can be life-threatening.

Other people have a food intolerance, for example to milk, or have coeliac disease and cannot eat gluten. These are not allergic reactions, but they can still cause serious illness or discomfort.

Allergies affect people in very different ways. Some find their food allergy easy to manage, because their reactions are mild and can be kept under control by making careful food choices. For others, a food allergy is life-threatening, and they have to think seriously about everything they eat every day. These customers rely completely on the information a shop gives them. Other people are intolerant to certain foods, such as dairy, caffeine or wheat, and people with coeliac disease cannot eat gluten.

They do not suffer an allergic reaction, but they can still experience severe discomfort after eating the wrong product. Almost any food can cause an allergic reaction, but the law names fourteen allergens that you must know and must declare to customers whenever they are used in any of your products. Tree nuts, for example, include walnuts, hazelnuts, almonds, cashews, pecans, Brazil nuts and pistachios, and each must be identified correctly.

Almost any food can cause an allergy, but the law names 14 allergens that must be declared:

• Celery, cereals containing gluten, crustaceans such as prawns and crab, eggs, fish, lupin, and milk.
• Molluscs such as mussels and squid, mustard, tree nuts such as almonds, hazelnuts and walnuts, peanuts, sesame, soya, and sulphur dioxide and sulphites above 10 milligrams per kilogram or per litre.

Anaphylaxis is a severe, life-threatening allergic reaction. It can develop within minutes. Signs include:

• Difficulty breathing, wheezing, or swelling of the throat or tongue.
• Problems swallowing or speaking.
• Dizziness, confusion, collapse, or loss of consciousness.

It is a medical emergency. Call an ambulance straight away. People at risk often carry an adrenaline auto-injector, which can be used if you are trained or they ask for help.

Anaphylaxis happens when the body's reaction to an allergen causes blood pressure to drop significantly. Breathing often becomes fast and shallow, the heart beats rapidly, and the person may wheeze, feel dizzy, light-headed or faint, and become confused, anxious and severely distressed. It can develop within minutes. What makes allergen control so demanding is the tiny amount involved. Even trace amounts of an allergen can affect the body severely and can cause death within minutes.

For someone with a severe peanut allergy, a trace far smaller than you could see on a knife, a glove or a slicer blade can be fatal. This is why cleaning between products, separating allergen-free food and never guessing about ingredients matter so much. If someone shows signs of anaphylaxis, call for emergency help immediately. People at risk often carry an adrenaline auto-injector, which can be used if it is available and you are trained.

To keep allergic customers safe:

• Keep allergen-free food separate, from delivery to sale, to prevent cross contact.
• Use separate or thoroughly cleaned equipment, utensils and cloths.
• Keep ingredient labels and recipe information for every product you sell.
• Tell all staff when a recipe or supplier changes.
• Watch for hidden allergens, such as egg in mayonnaise, or sesame in hummus.
• Never guess. Check the information, and make sure someone on every shift knows the allergens in each product.

Under Regulation (EU) 1169/2011, on food information to consumers, all prepacked food must list its ingredients, with any of the 14 allergens emphasised, for example in bold.

In Ireland, allergen information must also be given for non-prepacked food, such as food sold loose, served at a counter, or packed in the shop for sale. This information must be in writing, for example on a label, a menu or a notice, and it must be accurate.

Many shops make and pack food on the premises, then sell it from the same premises. Examples include sandwiches, baguettes, salads, cakes, muffins, and soups or smoothies made and bottled on site.

For these foods, customers must be able to find out, in writing, which of the 14 allergens they contain. A clear label listing the ingredients, with allergens emphasised, is the simplest way to do this. Keep recipes and labels up to date.