How Does Contamination Happen in a Refrigerator?

Many of us don't think of the fridge as a high-risk area for contamination, but the risk is real. Find out why.
September 2, 2022

What is food contamination?

Food contamination occurs when a food is spoiled by another substance, rendering it unfit to consume. This may include physical contamination, which is spoilage due to the presence of an object; chemical contamination, which is spoilage due to the presence of a chemical agent like a cleaner or sanitiser; and biological contamination, which is spoilage due to the presence of a harmful bacteria, virus or organic matter, like salmonella. 

Additionally, food can be contaminated through cross-contamination, which is the transfer of harmful bacteria or substances from one source to another. For example, when food is contaminated with bacteria that cause food poisoning (consider raw poultry) and spreads it to other foods, surfaces, hands or equipment. Cross-contamination can occur from food to food, person to food, or equipment to food, rendering a food item unsafe to consume. 

Contaminated food is a serious health risk, as germs, food allergens, chemicals and physical objects can make customers sick or cause allergic reactions, injuries or choking hazards. It’s extremely easy for food contamination to occur, especially in a commercial kitchen, which has many moving parts and people. 

As a Food Handler or Food Supervisor, you may not think of the fridge as a likely source of food contamination. After all, there are multiple shelves and the food is all kept at a safe, cold temperature. However, if safe food storage procedures aren’t followed, it’s just as easy for contamination to occur in the fridge as anywhere else in the kitchen.

Examples of Contamination in the Fridge

  1. Peanut satay sauce in a cracked container leaks onto another food item in the fridge. That other food item is now contaminated with peanut allergens. As food allergens are not destroyed by the cooking process, if that food item is prepared and served to a customer with a peanut allergy, it could cause a life-threatening allergic reaction.
  2. An employee cleans the refrigerator using a chlorine bleach solution in a spray bottle. A box of fresh produce is uncovered on one of the shelves near where the employee is cleaning. The produce is now contaminated with an invisible layer of chemical solution that could cause a customer to get sick.
  3. An employee breaks a glass in the walk-in cooler. On the bottom shelves of the fridge, there are uncovered containers of pre-cut vegetables for salads and sandwich fillings. If even a tiny shard of glass has gotten into the pre-cut vegetables, and those vegetables are served to a customer, it could cause a serious injury.
  4. A tray of raw chicken breasts is stored above a container of chocolate mousse. Juices from the raw chicken drip onto the ready-to-eat dessert, contaminating it with harmful bacteria. Many types of bacteria and other harmful microorganisms can survive and even grow in the refrigerator (Listeria monocytogenes bacteria grows at temperatures as low as 0°C). If the contaminated mousse is served to a customer, they could get seriously ill with food poisoning.

The examples above demonstrate just how easy it is for contamination to occur in a refrigerator if safe food handling procedures are not followed.

How to Prevent Contamination in Your Refrigerator

To prevent contamination from happening in the refrigerator, follow the food safety rules and best practices below:

  • Place raw meat, poultry and seafood on the bottom shelf of the refrigerator in covered containers or sealed plastic bags that are food-grade to prevent meat juices from dripping onto and contaminating other food.
  • Keep ready-to-eat and cooked food above raw food in the refrigerator.
  • Ensure the fridge is emptied prior to cleaning and sanitising, and that spills are thoroughly cleaned when they occur.
  • Store foods in properly labelled containers with effective lids or seals, ensuring they are sanitised prior to use. 
  • Wash your hands thoroughly before handling and preparing food stored in the refrigerator.
  • Ensure you and your staff are trained in food safety policies and procedures, including the prevention of contamination.

The Australian Institute of Food Safety delivers high-quality, nationally recognised food safety training courses for Food Handlers and Food Safety Supervisors in all recognised food sectors in Australia. For more information about our food safety courses, contact our support team.

To learn more about the types of food contamination, visit our comprehensive blog post, which details the three main types of contamination and how to prevent them.