The Top 9 Food Safety Risks in Supermarkets

Food safety in supermarkets

Food is so easily available in our developed, industrialised country that we take it for granted. We just expect that the food we buy in supermarkets and corner shops is safe to eat and nutritious.  It is displayed on clean brightly lit shelves and cabinets and presented in attractive packaging, all looking perfectly fine.

This masks the complexity of factors involved in ensuring the food we buy is safe. The retail food industry, in fact, is at the forefront of consumer protection.

An increasing amount of our food products is supplied through complex supply chains that can link to producers all over the world. Every item has multiple risks associated with it on the journey from farm or producer to you the consumer.

Many factors along the food supply chains can affect the health of consumers:

  • From pesticides, herbicides and GM crops on the farm, to contamination from pests;
  • From handling practices at every point along the chain, to the ingredients of processed foods and the methods used to make them;
  • From storage conditions and food packaging to labelling adequately informing the consumer of safety and dietary considerations;
  • And lastly, of course, the hygienic handling of products in the store.

Many types of technology, processes and materials as well as the food ingredients go into producing the food products that end up in your shopping trolley.

Even a small supermarket can have tens of thousands of products, with up to 90,000 in a large superstore, all having to be sourced and handled safely to protect the consumer.

In the stores there is also a myriad of ways in which food is presented to you the buyer. Fruit and vegetables come loose, bagged, chopped, peeled and packaged. Fridge displays and fresh food counters offer raw meats, seafood, multiple types of dairy products, cooked products and other prepared foods, then there is the bakery, frozen food, bottled, canned, bagged and boxed products.

These give a multitude of opportunities where the safety of you the consumer can be compromised.

Here are 9 main categories of food safety risk in supermarkets and grocery stores.

1. Hygiene of employees

hand hygiene

Across all businesses preparing or processing food one of the most common causes of food contamination is poor personal hygiene practices by staff.

Hands, which can easily transfer bacteria from a contaminated surface to fresh food.

Personal habits that are not acceptable around food preparation include:

  • smoking;
  • spitting;
  • touching the hair, face or parts of the body or clothing;
  • eating;
  • working while ill with diarrhoea, vomiting or any infectious diseases
  • working with open wounds or skin infections;
  • wearing watches or jewellery, as they can fall in the food;

Adequate hand washing with soap is essential:

  • after handling: raw meat and equipment used to cut it; food waste and containers; cash, phones or door handles;
  • after using the toilet;
  • after  blowing your nose, coughing or sneezing;
  • before and after wearing gloves;
  • after using cleaning products, such as cloths, sponges, mops, cleaning and sterilising chemicals, pesticides, etc.

2. Bacteria on shopping trolleys and baskets

Shopping trolly

Shopping trolleys and baskets are supposed to be handled by customers.

When you are wandering round a store picking up your shopping you can also pick up the hygiene history of hundreds of people from the handles.

While trolleys are parked outside the store, birds can add to this unwelcome record.

After holding the trolley handle you can then contaminate everything you put in your basket, including fresh fruit and vegetables that you eat raw, including a baby or small child.

Shopping trolleys have far higher levels of bacteria than surfaces in public toilets and other public places, according to a study by the University of Arizona.

Coliform and E. coli bacteria (a sign of contamination from faeces) were found on 72% of trolley handles but only 7% of samples from nappy/diaper changing tables, chair arm rests, playground equipment, ATM buttons, restaurant table tops, escalators, and restaurant condiment containers.

Other studies have found Salmonella and Campylobacter on trolleys carrying raw meat, and pathogenic Staphylococcus aureus.

Small children are more susceptible to infections, with their natural reaction to put their hands and anything they can get hold of in their mouths — and they often don’t have the best of hygiene themselves.

3. Raw foods

raw food

Raw foods can pick up bacteria and other contaminants along the path from farm to shelf.

  • Raw meat, poultry, fish and shellfish can carry infectious diseases and pose a risk to shoppers if not handled or packaged properly.
  • Products prepared and packaged in store, such as cooked meats, cheeses or bakery products, need the same food safety practices required of a food processing factory or restaurant to prevent shoppers getting food-borne infections.
  • We may all handle lose apples, tomatoes, sweet peppers, etc to choose the best ones and contaminate those not selected.
  • Products that are eaten raw and grow near the ground, such as celery, lettuce and strawberries can easily pick up soil particles.
  • You should wash fresh fruit and vegetables before eating to ensure any contamination from farm to store and in store, from fellow shoppers’ hands or coughs and sneezes, is safely removed.

4. Rats & mice


Rodents not only gnaw packaging and eat food, they also leave a trail of contaminated surfaces along their runs from urine, droppings and greasy smudge marks from their fur, or dirt from their feet.

  • Rats and mice are primarily attracted by accessible food and water and will then seek shelter nearby as they do not like to travel far in their daily foraging for food.
  • Loading bays where food may be temporarily stored, or spilled, and garbage storage areas can attract rodents and provide points of entry into a building.
  • There are many potential points of entry to a building, especially a large supermarket, which can be exacerbated due to poor construction and maintenance, such as cracks around doors and windows or in walls, vents, pipes, cabling, drains, doorways, windows, screens. Rodents, especially mice, only need a tiny gap to squeeze through and can gnaw away at the edges to enlarge them.
  • If rats and mice can access a building they will be attracted by food in storage and on display, as well as food spills and waste left or stored inappropriately.

The multiple diseases that rodents can carry include Salmonellosis, Leptospirosis, Toxoplasmosis, Lyme disease, rat-bite fever and they can also introduce parasites, including ticks, fleas, lice and mites and the diseases that these carry.

5. Flies


A number of different types of fly can contaminate food in supermarkets.

House flies, drain flies, flesh flies and even fruit flies carry dangerous bacteria and other disease causing microorganisms.

Over 100 pathogens have been recorded from flies, including Salmonella, cholera, Shigella, Campylobacter, E. coli, Cryptosporidium, and also parasitic worms and fungi.

  • They feed on faecal matter, garbage and rotting materials, while doing that they also pick up contaminated materials on their feet and bodies.
  • They then transfer it to clean areas and fresh foods that they feed on.
  • House flies regurgitate digestive juices and defecate while feeding and resting, transferring more pathogens.

Electric fly catchers kill flies that land on their high voltage wires, but the resulting sparks can spatter fly parts onto foods nearby, spreading diseases themselves, rather than ensuring food safety.

6. Cockroaches


Cockroaches are another group of insects that can spread many types of disease, including Salmonella, Staphylococcus, Listeria, E. coli, and also fungi, viruses and parasitic worms.

  • They are attracted by even small residues of food left around food preparation areas or from spills, garbage and drains — they even eat cardboard.
  • Cockroaches can also be brought into premises in deliveries due to poor practices by suppliers or transporters.

They feed on decaying matter, mould, faecal matter in sewers, from rodents and birds, and animal carcasses, which can then be transmitted onto food production, preparation, storage and display areas.

They shelter in shelving in food stores, dark places such as cracks and crevices in walls and floors, drains, sewers, inside equipment and machinery.

How cockroaches damage food and spread disease:

  • defecate as they crawl around;
  • frequently expel saliva on surfaces to ‘taste’ their environment;
  • droppings and bodily secretions stain and leave a foul odour on food, packaging and surfaces;
  • cast skins and egg cases contaminate products and packaging;
  • droppings and cast skins contain allergens that can induce asthma.

Good hygiene practices and building maintenance will prevent infestations of cockroaches.

7. Building design and maintenance

Poor building design and maintenance allows pests access through windows, doorways, drains and sewers, spaces around pipes and cable ways, vents, screens and holes in roofs.

Once pests have access, they present a major threat to food safety.

Poor maintenance of grounds around buildings gives rodents harbourage, and poor management of garbage — the containers and the areas where they are stored — attracts rodents, flies, cockroaches, birds and ants.

Inside buildings, rats, mice and cockroaches will look for small hidden places to shelter undisturbed, and birds can access poorly maintained roof spaces.

8. Ingredients and labelling

food label

The choice of food that you eat is one of the biggest risks to your health. Diabetes, obesity and certain allergies are all affected by what you choose to eat.

Buying fresh meat, fruit and vegetables is an easier dietary choice, but they still require safe handling to reduce the risk of infection.

Campylobacter and Salmonella are the most commonly reported food-borne diseases across the EU and are mainly caught from raw chicken meat.

Processed foods

In processed foods, however, there is a minefield of ingredients to navigate.

Knowing the amount of sugars, refined carbohydrates, types of fat, salt, vitamins, minerals or fibre that are in the products requires reading tiny characters on a label and working out the portions you are going to eat.

Then knowing what the other ingredients are may require a degree in chemistry and a reference manual to look up the E numbers.

From polyphosphates to glutamates and calcium propionate, you trust the scientists and regulators to ensure that what is allowed and actually goes into your food is safe and that the labels tell you what you need to know.

9. Food fraud

The risk of food fraud is low in products found in the stores of the main retail food suppliers. However, occasionally the safety barriers are breached.

Remember the horse meat scandal? Several meat and processed food suppliers were found to have put both registered and unregistered horsemeat into products where it was labelled as beef. Wrongly labelled products were found in Ireland, the UK, the Netherlands, France, Lithuania, Latvia, Belgium, Spain and Luxembourg.

Some of the horse meat was originally exported from Rumania legally and correctly labelled, while other sources were race horses in the UK and research horses in France illegally put in the human food chain.

It was seen as a breakdown in the food supply chain safety measures as retailers had trusted their suppliers and did not have full traceability of ingredients. One commentator put the blame on the lack of food inspectors available to inspect food processors and retail food stores.

However, recently 10,000 litres of fake and adulterated wine, whisky and vodka were found in the UK, peanuts repackaged as pinenuts were found in Australia, 85 tonnes of olives coloured with the toxic chemical copper sulphate were found in Italy, among many other case of food fraud worldwide.

Find out how supermarkets can ensure food safety and protect the health of consumers