Types of food contamination: Learn how food contamination occurs

If you are going to work in the food industry, food contamination is something you should have very good knowledge over. The safety of your food’s consumer will be at your hand. And since everyone eats food, food contamination can be a serious issue for anyone!
Now, the questions you need to ask as a beginner are – how does food contamination occur? What are the types of food contamination? Does it happen often?
To satisfy your quest, we have pinned down all the basic things you should know about food contamination. After going through this piece of writing, you won’t become an expert, but have a moderate idea over food contamination and its consequences.
So, let’s dive down!

Table of Contents

What is Food Contamination?

In simple words, food contamination is the contamination of the food we consume. It can happen in any possible way. Food contamination occurs when the food comes in touch with another corrupting substance, such as physical, biological, chemical etc.
Food contamination is a grave issue for anyone working in the food industry, for the consumers too. Therefore, even if you don’t work in the food industry, you should be well aware of the ins and outs of food contamination.
When manufacturers find a certain batch of their food contaminated, terror is what comes first to their minds, starting from the factory floor employees to the management of the company. Food that’s been corrupted by anything – from listeria or salmonella to a little broken piece of glass or metal – can cause serious harm to the health of the consumer, or even death!

Now, there are a few types of food contamination. The most common are physical contamination, biological contamination, chemical contamination, cross contamination and allergenic contamination. If your food gets contaminated, it has quite surely got contaminated by any of the mentioned means.
Now, let’s have a clear understanding of each of these types of contamination in the writing down below.

Physical Contamination

Physical contamination of food is one of the most common food contamination scenarios. This type of contamination refers to the food that has been corrupted by any physical object at some stage of the food preparation or production. These objects can cause serious harm to the consumer and make him or her ill.
This type of contamination has an endless list of objects; literally anything can get into the food and contaminate it. Here are a few examples and tips on how to avoid physical contamination in food:


Manufacturers must ensure that all the food floor workers wear heirnet. If the hairs are long, they should be neatly tied to the back.

Glass or metal

Broken glass from water glasses, cracked light bulbs, or smashed windows are serious substances that have a high risk of contaminating food. Sometimes the objects can be too little to be seen by bare eyes, and that’s when the problem occurs. To avoid this, be sure to wipe off every last fragment of glass and dispose of it. You should also halt the production line and wait until you are completely sure that the place is hundred percent clean of any glass object.
Metal objects can make its way into food as well. It happens mostly from broken machinery. What you can do to avoid this is implementing a strong Equipment Maintenance Plan to your production place. The best thing you can do is installing an x-ray detector, so that any such hazards can be identified and taken care of.


Everybody hates animal droppings in his or her food. Again, pests are one of the most disturbing sources of contamination. Insects like rats, mice, cockroaches often produce fur, saliva, urine or faeces that get mixed into the food. Even often, they themselves make their way into the food. So make sure to keep your production area thoroughly cleaned and take pest control measures.


Jewellery or any broken part of it can be a huge disturbance to the consumers. If consumers find such kind of objects in their food, they will lose trust in you and stop buying your products. To avoid this, you can rule out wearing jewellery in the production place – be it for religious purposes or decorative.


Detecting the dirt can be a challenge because the dirt particles are tiny and often unseeable by bare eyes. It can make its way into food if the equipment is unwashed. So make sure to wash every equipment before they enter the production lines.


Fingernails are dirty, and since they are little objects, they can come in touch with the food without being noticed. To avoid such instances, you can do spot-checks to make sure all the employees have their nails cut short and clean. Also, forbid the use of fake nails or nail varnish as they can fall off easily and get mixed with the food.

Biological Contamination

Biological contamination of food can occur in many different ways, and there are a number of elements that can make it happen. The bacteria and other harmful microorganisms can come in contact with food and cause food spoilage, food poisoning, or enormous wastage.
Such biological hazards are commonly microorganisms like viruses, moulds, yeasts, parasites, and bacteria (the most common one).

Some examples of such contaminating elements are

Such disease-causing elements can easily reach your food and make them contaminated, even to the point where the food may cause death.
The problem with such microorganisms is that they cannot be seen with your eyes, and thus, may go unnoticed. The viruses and bacterias can reach all over your food and may not even show any signs.
Therefore, the only way to prevent your food from being contaminated by biological hazards, is to enact a vigorous processing and storing strategy. You can have multiple steps of killing processes in place, for instance, pasteurisation or juices and milk or the use of vacuum sealing to eliminate the growth of bacteria.

Chemical Contamination

Chemical elements contaminate food and in most cases, the results are severe. Therefore, you have to be extra careful about whether or not any harmful chemical object is present within the area of your production and distribution.
Few of the common chemical contaminants are:

Chemical cleaning agent

Yes, your production line has to be regularly cleaned. Therefore, you certainly cannot avoid the use of cleaning chemicals (such as detergents, sanitizers) in your production area and to your machinery. However, you have to make sure that the chemicals don’t make their way into the food.
Rinse your machinery thoroughly after using chemical products on them in the cleaning process and make sure the equipment is maintained well enough. Never keep your food ingredients and cleaning products in the same place, or they might come in contact.

Unwashed vegetables and fruits

Fruits and vegetables are often susceptible to fungicides and pesticides. And when such poisoned food comes into contact with other food, it can contaminate the whole bunch of that as well.
Therefore, it is important to clean the vegetables and fruits on a regular basis. Also make sure to preserve them in a good place.

Pest control products

As mentioned before, pests are a big problem for food. So, you cannot avoid using pest control products; but that comes with another problem as well.
If the pest control products get mixed with your food by any chance, it may bring havoc. Pest controlling chemicals are heavily dangerous. They must be stored in a different place from the food or any of the equipment. Also, never use pest control chemicals inside or near your production line. Use them in the surrounding areas so that the pests cannot come in and the chemicals don’t affect the food as well.


According to the UK Food Standard Agency, there are 14 major allergens that can contaminate the food.

Here is a list of Allergens

There are a few ways you can follow to eliminate the risk of allergens contaminating your food.
Firstly, make sure that the suppliers of allergenic ingredients label the products correctly and separately store them. The units containing these allergens must be sealed tightly. Because even the slightest amount of allergen can cause havoc – from making the consumer ill to killing him.
On top of that, keep all the employees educated about the importance of avoiding cross-contact of these elements. Assign them in separate locations to minimize the risk of cross-contamination, especially in the time of staff changeovers.

What consequences can food contamination have?

Food contamination can have consequences in all different senses. When consumers of the food get ill or injured, or die from having it, the repercussions are potentially enormous for the companies that are involved.
In the worst case scenario, the company may go out of the business, having all of its employees losing their jobs. Even if the company manages to get through the conundrum, chances are people will lose trust in the company and quit buying their products. With the reputation gone, the company will face a financial crisis. And nobody wants that!
That is why, it is of paramount importance to make sure the food is being safely produced and distributed.

Does Contaminated Food Always Smell?

No, contaminated food doesn’t always smell. A food can smell and taste just as fine but still be contaminated. However, in many cases, contaminated food will smell bad and give you a direct hint that it’s not safe.

Foods like fish, red meat, milk, eggs, fruits and vegetables, chickens etc will most likely smell when they are out of date. Smelling and telling in such a case is useful but you cannot always tell if the food is contaminated by just sniffing on it.

Therefore, you better take useful methods to check if the food is contaminated.

Final Words

Food contamination is a serious issue for everyone, and it cannot be overlooked by a food manufacturer. If you are working in the food industry, it is your duty to ensure the ultimate safety in the food you are producing.

Take all the necessary precautions and measures to keep your food hundred percent clean, and your customers will keep loving it. The more you add value to your customers, the more value they provide to you!

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April 29, 2021

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