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Is It Safe to Heat Food in a Can? | What You Need to Know

One of the several ways to reduce the load of heavy pans and pots and still have delicious food is to heat food, such as soup, in a can. Food and beverage cans can be especially useful on a camping trip or when you need to heat small amounts of food or leftovers. However, there is a lot of concern about the safety of food heated in these containers.

Heating food in a can is not recommended and should be done only if you need to. Metals from which the can is made and chemicals from the can’s lining can leach into your food as you heat it. Large amounts of these chemicals may cause health problems such as cancer and nervous system disorders.

The rest of this article will explain in detail everything you need to know about the physical and health risks associated with heating food in a can. Keep reading to learn all these important details and more.

Soup in a Can on the Stove with Flame Underneath

Why It May Be Unsafe to Heat Food in A Can

The primary use of a can is to store, preserve, and distribute food. Food and beverage can manufacturers don’t recommend using these containers for cooking or reheating food as they are not designed for these purposes and such levels of heat. Here are some reasons why you may want to avoid heating your food in a can.

Leaching of Metals into Food

The material from which a can is made makes a huge difference if you’re heating your food in it. Cans are usually made of either aluminum or steel. In the United States, most food cans are made of steel, while beverage cans are manufactured using aluminum.

Steel cans are mostly tin-coated or chromium coated. When a steel can is heated, it may release tiny amounts of chromium and nickel into your food. An increased amount of these metals in the human body can cause health problems such as dermatitis.

Aluminum, on the other hand, leaches more easily and in larger amounts into food when heated. Ingesting aluminum in large amounts is considered dangerous and has been linked to Alzheimer’s disease. While heating foods in aluminum cans is not scientifically proven to cause nervous system disorders, it is still a potential problem.

Related What’s the Best Way To Prepare Food in a Survival Situation?

Can Linings May Contain Harmful Chemicals

Food and beverage cans can store and preserve food for several years. Such lengthy storage times require adequate protection of the food from its packaging material. To prevent the metals from reacting with the contents of the can, manufacturers coat the inside of cans with food-grade epoxy.

Without this coating or lining, the metals break down when exposed to oxygen and migrate into the food or beverages. However, these coatings may contain potentially harmful chemicals such as Bisphenol-A (BPA). BPA is a compound that is commonly used in the manufacture of water bottles, dental sealants, CDs, DVDs, as well as can linings.

When a can of food is heated, BPA from its linings can leach into the food. This chemical has a structure similar to that of the hormone estrogen, and some studies have linked it to infertility, cancer, heart problems, brain problems, and diabetes.

A troubling fact is that many of the food cans manufactured in the US contain BPA in their linings. In fact, a study carried out in the US analyzed 78 canned food samples and detected BPA in 71 of them. Also, some of the coatings in cans may contain different additives such as lubricants, adhesives, anti-foaming agents, and abrasion and scratch-resistance agents.

According to the FDA (Food and Drug Administration), BPA is still safe when consumed at very low levels. So, heating food in cans may not be the best idea as the increased temperature can release large amounts of this chemical into your food.

Risk of Food Poisoning and Botulism

During the canning process, food is processed, sealed, and heated to high enough temperatures to kill harmful bacteria. This heating of canned food is usually done in a controlled and monitored environment at the factory.

In contrast, if you’re heating your food in a can, you may not be able to accurately control the cooking times and heating temperature. Inadequate heating temperatures create the perfect environment for the growth of harmful bacteria such as campylobacter, salmonella, and botulism bacteria.

How to Safely Heat Food in A Can

While heating food in a can is not recommended, there are times when you may have no other option. If you find yourself needing to cook or reheat your food in a can, here’s what you should know before getting started.

Use an Open Can

If you’re on a camping trip or you need to just heat your food in a can over an open fire, the first thing you should do is take off the lid of the can. Opening the top of the can allows the pressure in the container to escape.

When pressure is allowed to build up in the can, it will be forcefully released through a point where the can is weakest, exploding, and spraying the food everywhere. Not only will this create a mess and waste your food, but it could also injure you, cause serious burns, or start a fire.

If you’re concerned about ashes from the fire getting into your food, you may poke holes in the top of the can instead. However, this method requires you to be careful as it can be very challenging to remove the lid of the can after it has been heated to a high temperature.

In case you want to skip cooking over an open flame, I wrote an article on how to make a simple stove called What Is a Hobo Stove? (And How To Make One). Be sure to check it out.

Get Rid of the Can After Using It

After using a food can to heat food once, throw it in the trash, or take it out for recycling. Heating a can in boiling water or over an open fire damages and weakens the can. Reusing or reheating a food or beverage can further weaken it and increases the chances of metals and chemicals leaching into your food.

In addition to food contamination, folds and corners in cans can make them difficult to clean, and you may cut yourself when scraping off food particles. So, just get rid of it.

Other important safety precautions to remember are:

  • Remove the paper labels. If the can has an outer paper label, tear it off and scrub off the remaining glue before using it to heat your food.
  • Consume your food immediately after heating it. Leaving hot food in a can for longer may allow metals or chemicals from the can’s lining to migrate into the food.
  • Avoid heating a can in the microwave . Instead, put the contents of the can in a microwave-safe container and place it in the microwave. Keep any leftovers in a safe storage container, like this one found on Amazon.


In summary, cans are meant for food storage and are not recommended for heating food. Depending on the type of can and acidity of the food, can metals may react with your food, and chemicals from its lining may leach into the food. For this reason, you should only use them if you have no other option.

If you must heat your food in a can, the following safety precautions are very important:

  • Completely remove the top of the can or punch holes in it.
  • Don’t reuse a can after heating it. Get rid of it by recycling it.
  • Remove the paper label on the can and scrub off the remaining glue.
  • Don’t leave your food in the can after cooking or heating it.

For more, check out Can You Use a Regular Pan Over a Fire?