Food Safety and Hygiene

What are the 4 Types of Food Contamination?

Ricky Kambray
Ricky Kambray

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The food we eat has to go through many processes before it is finally lent to our plates. Throughout the process, the food gets handled in many ways. If not handled properly, it may get contaminated.

For example, Health Protection Scotland says, “A newly published scientific review by the Food Standards Agency (FSA) has estimated that around 2.4 million cases of foodborne illness occur every year in the UK.”

There are 4 types of food contaminations, and you may not be able to tell if your food is infected just by looking at it. However, there are different symptoms for different types of food contamination.

But, before you want to treat yourself from food contamination, you need to know about the 4 types of food contamination. This blog will teach you about the types and symptoms of food contamination and how to stay safe from them.

What is Food Contamination?

When foods get corrupted and intoxicated by another substance, it can make one sick, known as food contamination. However, contamination can occur any place that food is touched and at any point during the manufacturing process. The most common symptoms of food poisoning are- nausea, diarrhoea, stomach cramps and vomiting.

The 4 Types of Food Contamination

Food contamination is divided into 4 types depending on the nature of contamination. The 4 types are- Chemical, Microbial, Physical, and Allergenic contamination. Among these 4 types, Microbial contamination is the most common in the world.

Chemical Contamination of Food

Man with tank reservoir on his back spraying disinfectant

Chemical contamination happens when chemicals infect food. Cleaning products, fertilisers, and insecticides from unwashed fruits and vegetables are some of the most common sources of chemical contamination of food. Some of the chemicals contaminants are- toxic metals, industrial chemicals, agricultural chemicals and preservatives.

Foodborne illness caused by chemical contamination can cause anything from mild gastroenteritis to deadly hepatic, renal, and neurological disorders.

Microbial Contamination of Food

A doctor is checking coronavirus and there are foods in a plate

During processing involving sick people and animals and faeces from infectious agents, poor hygienic conditions can induce harmful Microbial contamination in humans. Microbiological contamination can introduce contagious material such as bacteria, yeast, mould, fungi, viruses, prions, parasites, toxins, and by-products unintentionally or accidentally.

Contaminated foods may not seem, taste, or smell different from items safe to eat. However, there are no specific symptoms of Microbial food contamination.

Physical Contamination of Food

When a physical object enters food during the production or preparation process, it is referred to as physical contamination. Food with physical objects can cause choking and often introduce biological contamination.

Glass, metal, rubber, bone, wood, stone, and plastic are the most frequent physical contaminants. These objects carry hazardous biological pollutants, resulting in sickness.

Allergenic Contamination of Food

A man is having food allergy and other people are trying to figure out from which food


Allergenic contamination in food happens when a trace amount of a food allergy is accidentally introduced into another food during the manufacturing or preparation process. Saliva can also transmit it after touching utensils, surfaces, or items.

An allergic reaction is triggered by even a tiny amount of an allergen. Allergenic contamination is also known as Cross-contamination.

According to Quality Assurance and Food Safety, “The U.S. has declared eight food allergens (Big 8) to be of most concern, including milk, wheat, peanuts, tree nuts, fish, shellfish, soy, and eggs. These foods were identified because they cause about 90% of food allergenic reactions in the U.S.”

Some of the symptoms of allergenic contamination include-

  • Eczema, hives
  • Tingling or itching
  • Wheezing, nasal congestion, or breathing difficulties.
  • Lips, cheeks, tongue, and throat swelling and swelling in other areas of the body
  • Pain in the abdomen, diarrhoea, nausea, or vomiting.
  • Dizziness, lightheadedness, or fainting.

Besides, “What is Food Poisoning? Types, Causes, Symptoms & Treatment” sheds light on the diverse aspects of food poisoning, from its various types and causes to the symptoms one might experience and how it can be treated.

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How to treat Food Contamination?

Food contamination symptoms include- vomiting, diarrhoea, headaches, fever and chills. The symptoms commonly appear 8 to 48 hours after exposure. For example, a bacterial foodborne disease might take anywhere from 24 hours to 7 days to recover from.

To recover, you need to replace the minerals you lose during vomiting and diarrhoea with water, broth, or an electrolyte solution. Start with tiny portions of bland, nonfat items like toast, rice, and crackers when you’re ready. Make sure you get enough sleep.

Most infections will resolve in one week, whether or not they are treated. If you see any of these following symptoms, see a doctor or get medical help right away.

  1. More than 102°F (38.9°C) of temperature
  2. Diarrhoea that lasts more than 3 days
  3. Dry mouth, passing little to no urine,
  4. And difficulty keeping fluids down are all signs of severe dehydration, as are difficulty seeing or speaking.

As these different types of contamination can lead to foodborne diseases, it’s essential to learn about the role of microorganisms and contamination in causing such illnesses. The Chill: You should keep your refrigerator below 40 degrees Fahrenheit and refrigerate food as soon as possible. Germs can grow in many foods in as little as two hours if they are not refrigerated. (Reduce the time to 1 hour in the summer heat.) Learn how to store foods and beverages properly, how to keep them fresh, and when to discard them by visiting the FoodKeeper website or app. provides valuable insights into these aspects, helping you understand the causes of foodborne illnesses and the preventive measures necessary to ensure food safety.

If you’re handling food, it’s a smart move to check out the Food Safety Diploma. This course gets you up to speed on all things food safety. You’ll learn the ins and outs, from principles to practical skills, so you can handle food like a pro. Whether you’re a catering manager or just someone who loves cooking, this course sets you up with the know-how to keep things safe and sound in the kitchen.

Food Safety In Catering

Equip yourself with the skills required to become a certified food Safety supervisor

How do you stay safe from food contamination?

It is said that prevention is better than cure. However, if you can prevent food contamination, you do not have to worry about the treatment. Instead, you should follow the ways discussed below to keep yourself safe from food contamination.

  • Clean: Wash your hands before and after preparing, serving and eating food. Make sure you follow the proper hand washing method.
  • Separate: Even if you’ve entirely cleansed your hands and surfaces, raw meat, poultry, shellfish, and eggs can spread germs to ready-to-eat meals unless they’re kept separate. Ensure that you do not cross-contaminate.
  • Cook: Make sure you cook thoroughly and at the right temperature. Preheat the oven to the correct temperature. To check the internal temperature of food to ensure it is safe, use a food thermometer.
    • 145°F for whole beef, calf, and lamb, as well as fresh pork and ham (wait 3 minutes for the meat to cool before cutting or eating), and fin fish.
    • It would be best to cook ground beef, veal, hog, lamb and egg dishes at 160°F.
    • All kinds of poultry, including ground chicken and ground turkey, stuffing, leftovers, and casseroles, should be cooked to 165°F.
  • Chill: You should keep your refrigerator below 40 degrees Fahrenheit and refrigerate food as soon as possible. Germs can grow in many foods in as little as two hours if they are not refrigerated. (Reduce the time to 1 hour in the summer heat.) Learn how to store foods and beverages properly, how to keep them fresh, and when to discard them by visiting the Food Keeper website or app.


If you are involved in handling food, being aware of the types of food contamination and taking proper steps to maintain food safety should be your ultimate priority.

Food contaminations spread rapidly. So, it would help if you keep certain things in mind while you prepare, eat or handle food in any way.

This blog has discussed the types, symptoms and treatment of food contamination. Hope you learned what you were looking for and helped yourself and others keep safe from the contamination of food.

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Ricky Kambray

Hey this is Ricky Kambray an award-winning first-aid trainer with over 20 years of healthcare and teaching expertise. Highly certified general nurse regularly appears in the press discussing accident prevention and first aid advice.