Is it safe to drink from a rusty can? A comprehensive guide to food safety

December 19, 2025 •

4 min read

According to the USDA, heavily rusted cans should be discarded because the corrosion can create tiny holes, allowing dangerous bacteria to enter. This is why the question 'is it safe to drink from a rusty can?' is a critical consideration for your pantry's health and safety.

Quick Summary

The safety of drinking from a rusty can depends on the rust's severity and location. While light surface rust is often harmless, heavy rust can compromise a can's seal, introducing harmful bacteria like Clostridium botulinum. This guide details how to inspect cans and when to discard them to prevent foodborne illness.

Key Points

Surface Rust vs. Heavy Rust: Light, removable surface rust on the outside of a can is generally safe, but heavy, pitted rust that has damaged the can should be discarded immediately.
Check the Seams: Rust or damage on a can's end or side seams is a critical safety defect that indicates the seal is broken, making the contents unsafe.
Inside Rust is a 'No-Go': If you open a can and find rust on the inside, do not consume the contents, as it can cause health issues.
Beware of Botulism: A compromised can creates an ideal, low-oxygen environment for Clostridium botulinum bacteria, which causes deadly botulism food poisoning.
When in Doubt, Throw it Out: If there is any uncertainty about the can's integrity due to rust, dents, bulging, or leaks, discard it to avoid serious health risks.
Handle with Care: Heavily rusted or compromised cans should be double-bagged and disposed of carefully to prevent contamination.

Understanding the Risks of Rust on Canned Goods

Rust, or iron oxide, is the result of a chemical reaction where iron, oxygen, and water interact. While the rust itself is not acutely poisonous in small amounts, its presence on a can is a red flag for potential foodborne illness. The primary danger comes not from the rust, but from what the rust indicates about the can's integrity. When rust erodes the metal, it can weaken the seals and create pinhole leaks, providing a gateway for bacteria to enter the food or drink inside. The vacuum-sealed environment of a can, which is meant to preserve the contents, becomes an ideal breeding ground for anaerobic bacteria, including the extremely dangerous Clostridium botulinum.

The Severity of Rust: What to Look For

Not all rust is created equal, and knowing the difference is key to assessing safety. Your inspection should focus on the rust's depth and location.

Light Surface Rust: If the rust is just a light film that can be easily wiped away with a paper towel, the can's structural integrity is likely unaffected. The USDA advises that these cans are still safe to consume. The best practice is to clean the exterior thoroughly before opening.
Heavy, Pitted Rust: This is where the risk escalates. If the rust is deep, flaky, and has created pits or holes in the metal, the can's hermetic seal has likely been compromised. This provides a direct path for bacterial contamination. These cans should be immediately discarded.
Rust on Seams and Rims: The seams and rims are the can's most vulnerable points. Even minor rust in these areas can weaken the seal, and any rust that compromises the seam is considered a critical defect. Regardless of its depth, rust on a can's end seams, side seams, or rim means the contents are unsafe and should be thrown out.

What lurks inside a compromised can?

If rust has breached the can's defenses, the contamination can introduce significant health risks. This is why it is never recommended to taste test food from a compromised can. The risks include:

Botulism: The most serious concern is botulism, a rare but deadly form of food poisoning caused by the toxin produced by Clostridium botulinum bacteria. Symptoms include paralysis and trouble breathing. This bacteria thrives in the low-oxygen environment of damaged canned goods.
Other bacteria: A breached seal can also allow a host of other spoilage bacteria to enter, leading to less severe but still unpleasant foodborne illnesses.
Metallic Contamination: While iron toxicity from rust is unlikely in small amounts, prolonged exposure to acidic liquids, like canned tomatoes or sodas, in a rusty container can increase the heavy metal content of the food.

Comparison Table: Rust Scenarios and Safety Actions


Rust Condition	Description	Safety Assessment	Recommended Action
Light Surface Rust	A thin, powdery film that easily rubs off.	Generally Safe	Wipe clean with a damp cloth before opening.
Heavy or Pitted Rust	Deep, flaky rust that has eaten into the metal surface.	Unsafe	Discard immediately. Do not open or consume.
Rust on Seams/Rims	Any rust, regardless of depth, affecting the end or side seams.	Unsafe	Discard immediately. The seal is compromised.
Rust inside the can	Rust is visible on the interior of the can when opened.	Unsafe	Do not consume. Discard the contents and the can.
Bulging/Leaking Can	Can is swollen, leaking, or spurts liquid upon opening.	Unsafe	Discard immediately. Do not taste or handle suspected food.

How to discard a dangerous can safely

If you have a heavily rusted, leaking, or bulging can, handle it with extreme care to prevent the spread of harmful bacteria. Do not open the can to dispose of its contents. Instead, double-bag the sealed can in plastic bags and place it in a trash receptacle, ensuring it is out of reach of children and pets. This minimizes the risk of contamination in your kitchen and in public waste systems.

Proper Storage to Prevent Rust

The best way to avoid the dilemma of a rusty can is through proper storage. Canned goods should be stored in a cool, dry place away from heat and moisture. Avoid storing cans in humid areas like under the kitchen sink or in uninsulated garages, which can accelerate corrosion. Check canned goods regularly for signs of damage or rust, especially if you live in a humid climate. For more detailed guidance on food storage, consider consulting resources from the U.S. Department of Agriculture (USDA).

Conclusion: When in doubt, throw it out

The short answer to the question, 'Is it safe to drink from a rusty can?' is that it's often not worth the risk. While minor surface rust may not affect the contents, any deep rust or corrosion on the can's seams represents a serious risk of bacterial contamination, including deadly botulism. The best and safest course of action is to inspect all canned goods before consumption. If there is any uncertainty about the condition of a can, especially regarding rust that cannot be easily wiped away or affects a seam, it is always safest to discard it immediately. Prioritizing food safety ensures your health and peace of mind.

Frequently Asked Questions

No, rust does not cause tetanus. Tetanus is caused by a bacteria called Clostridium tetani. However, objects that accumulate rust, like rusty cans, are often found in environments where these bacteria might also exist.

If the rust is very light and only on the outer surface, and the can is not dented or bulging, it is likely safe after wiping it clean. However, if the rust is heavy, pitted, or located near the rim or a seam, the can's seal could be compromised and it should be discarded.

A metallic taste is a sign that the rust may have leached into the contents, especially if the liquid is acidic. While small amounts of iron are not immediately harmful, the metallic flavor indicates contamination. For safety, it's best to discard the drink.

The most visible signs are bulging or leaking cans, although not all cases have these indicators. Other signs include foul odors, foamy or murky liquid, or liquid that spurts out when opened. Never taste-test a suspicious can.

Do not open a bulging, leaking, or heavily rusted can. Double-bag the unopened can in plastic and seal it tightly. Place it in a secure outdoor trash receptacle to protect children and animals from potential contaminants.

No, if the can is heavily rusted or has rust on its interior or seams, the contents are already contaminated. Transferring the liquid will not remove the bacteria or toxins that may be present.

Cleaning the exterior can remove surface rust, but it cannot fix microscopic holes or compromised seals caused by heavy corrosion. If the can's integrity is in question, cleaning is not enough to make it safe.