Whether it is running a large restaurant or local café, food safety is incredibly important for any business. Research has shown that each year, 600 million people around the world fall ill due to food contamination, resulting in $110 billion being lost in productivity and through medical expenses.
Food contamination can be very damaging to the reputation of any business. That is why ensuring all staff understand the four types of food contamination and how to prevent them is essential.
What is food contamination?
Before looking at the four types of food contamination, it is important to understand exactly what it is. Contamination is when any kind of substance comes into contact with food items, either physically, biologically, chemically, or through cross-contamination.
All foods are at risk of becoming contaminated, and contaminated foods can cause a range of symptoms, including:
- Nausea and sickness
- Vomiting
- Diarrhoea
- Abdominal pain
- Loss of appetite
- Muscular aches
- Fever
- Weakness
- Lack of energy
Food contamination is not always obvious, and the food may not taste or look any different. It can occur in one of two ways, accidentally or intentionally. Accidental contamination typically results from human error, such as improper handling of the food, or from machinery or equipment failure.
On the other hand, intentional contamination is caused by deliberate acts and can be caused by a stranger or an employee.
What is the impact of food contamination?
Thanks to social media and digitalisation, we live in a truly connected world, which means a bad experience from one customer can have far-reaching consequences for any business. However, there are also certain standards that organisations are expected to adhere to, and failure to maintain food hygiene standards can result in serious penalties.
While in the vast majority of cases, food poisoning caused by contamination will not have any long-term effects on an individual, this is not always the case. In the UK, thousands of people are hospitalised each year after eating contaminated food, while there are an estimated 180 deaths annually.
What are the four types of food contamination?
When it comes to types of food contamination, there are four core options that restaurants, cafes and businesses need to be aware of:

Chemical Contamination of Food
Chemical contamination is an example of direct food contamination caused by some kind of chemical substance. Cleaning items are amongst the most common causes of chemical contamination, often occurring when food comes into contact with a surface that still has some form of residue remaining on it.
However, that is not the only cause of chemical contamination. If food is incorrectly covered, then cleaning chemicals can be accidentally sprayed on them. Of course, sometimes it can occur outside of the kitchen too. When growing fruits and vegetables, many farmers utilise fertilisers and pesticides, which can be harmful to the human body.
To reduce the risk of chemical contamination, employees should:
- Ensure that all chemicals are stored away from food sources
- Follow all manufacturer-recommended instructions when using them.
- Utilise cleaning products that come from approved suppliers which guarantee food safety.

Microbial Contamination of Food
Another very common type of food contamination is microbial. This is when food items are contaminated through microorganisms such as viruses, bacteria, fungus, toxins, and mould. There are many ways that this contamination can occur, but some of the most common include:
- Not cooking chicken correctly, resulting in a bacteria called campylobacter occurring.
- Improper rearing and slaughtering of livestock, resulting in salmonella transferring onto food items.
- Improper storage of raw meat and vegetables.
- Pests interacting with food items.
- Out of date food.
When it comes to types of food contamination, biological is one of the most common causes of illness. That is why to reduce this risk businesses will need to:
- Ensure all employees are regularly washing their hands and are not around food items when ill.
- Following clear rules about the storage of raw meats and vegetables.
- Having a clear food handling process in place.
- Washing all raw fruit and vegetables before cooking with them.
- Maintaining a high pest control regime, ensuring your property remains free from rodents and insects.

Physical Contamination of Food
Physical food contamination is another very common cause of food poisoning and occurs when food ingredients come into contact with a harmful foreign object. This can happen during the growing stage, transport and preparation stages and can pose a significant risk of choking, broken teeth, and illness.
Some of the most common causes of physical contamination of food include:
- Lost jewellery finding its way into the food
- Stray hairs
- Animal bones remaining in the meat (particularly in fish)
- Pests remaining in the food
- Items of clothing
- Mechanical items such as screws
- Paint chippings
- Organic matter
Not only can these items cause physical harm to patrons, but they can also contain harmful bacteria that will make them ill. To reduce the risks of physical contamination, businesses should:
- Replace all faulty or damaged equipment immediately.
- Maintaining a comprehensive pest control programme
- Ensuring all staff follow strict protocols on food handling and preparation
- Having a clear dress code, which includes the use of hairnets and removing all jewellery

Allergenic Contamination of Food
The final type of food contamination is known as allergenic contamination. This is where food causes diners to suffer an allergic reaction after eating certain food and is typically caused by improper handling of food and tools by chefs. Some of the most common examples of direct food contamination include using the same knives or tools to cut multiple ingredients without washing in between or storing items alongside other food items (such as nuts).
There are countless different allergies out there, but the UK government requires businesses to declare 14 known allergens when preparing food. For individuals, consuming any of these allergens can result in serious reactions that, in some instances, could prove fatal.
To ensure customers remain safe, businesses should:
- Only utilise suppliers that follow strict allergenic contamination strategies
- Have clear preparation areas for certain foods
- Use set utensils for allergenic foods
- Separate all allergenic foods when storage
- Regularly clean all surfaces and food containers

Want to ensure your business is safe from contamination?
Food contamination is a major risk that every business needs to ensure they are working to minimise, and by law, all food businesses are required to ensure all food handlers have supervision and training.
Here at Shout Out Safety, we provide comprehensive health and safety training courses for businesses. Each of these courses has been devised by professionals with decades of experience within the sector, and they are thoroughly audited by recognised UK training bodies.
Our Food Safety Level 2 course has been designed to provide everyone who works in food preparation, no matter whether they are part-time or full-time. This online course is split into four key sections and covers everything that your employees will need to know to ensure safe handling and preparation. Want to find out more? Get in touch with our team today!