You pull out a can and notice a bit of rust on the rim. It is safe to eat? Do you have to throw it out? Here are the rules for deciding.

Are Rusty Cans Safe to Eat From?

Ever reach for a can and notice a bit of rust on it?  Most likely, on the rim? It’s happened to us several times, generally with something that sat around a bit longer than I expected it to (okay, a couple of years longer), that got “lost” in the bottom of a locker or that fell into an inaccessible place and I didn’t find for a while.

Hmm, is it safe to eat?

You pull out a can and notice a bit of rust on the rim. It is safe to eat? Do you have to throw it out? Here are the rules for deciding.This article was triggered by an e-mail from Margaret McGovern.  She and her husband Phil  had returned to their boat after 6 months in the US and discovered a bunch of cans with rust around the rims.  Margaret wondered if they were okay to use or if she had to throw them all away.

The good news for Margaret:  those cans are probably fine to use.

According to the FDA:  “Discard heavily rusted cans. Cans that are heavily rusted can have tiny holes in them, allowing bacteria to enter. Surface rust that you can remove by rubbing with your finger or a paper towel is not serious. You can keep these canned foods. If you open the cans and there is any rust inside, do not eat the food. Rust (oxidized iron) is not safe to eat.”

The Canned Food Alliance (a trade group for manufacturers of canned goods) says: “Rust or dents do not affect the contents of the can as long as the can does not leak. If the can is leaking, however, or if the ends are bulged, the food should not be used.”

I’d add that you should probably wipe away as much rust as possible from the lid, so that when you cut the lid off, loose “rust dust” doesn’t fall into the can (I don’t have any source for that, just my own comment).

As with anything else when you’re away from prompt medical care, use common sense and don’t push it too far.  If you have any suspicion that a can is unsafe (rusted or dented so that bacteria could enter), don’t eat the food in it.  Food poisoning is never fun, but it can be extremely serious when medical care is a day or more away.

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  • Candy Ann Williams on Facebook
    Posted at 14 December 2011 Reply

    My husband and I always argue about that!! LOL

  • The Boat Galley on Facebook
    Posted at 14 December 2011 Reply

    I hope you were right!

  • Margaret McGovern
    Posted at 07 May 2012 Reply

    I used all those cans and there were no ill effects. Thanks for researching that for us.

    s/v Sunshine

  • Laura Zechin on Facebook
    Posted at 04 November 2012 Reply

    Timely article.

  • Donna Tourt Cantwell on Facebook
    Posted at 04 November 2012 Reply

    Donating our safe can and boxed goods to those in our area devastated by Sandy. We are in Freeport Long Island. Our marina took a big hit, but our Gulfstar trawler weathered the storm and kept us safe. On to the cleanup.

  • The Boat Galley on Facebook
    Posted at 04 November 2012 Reply

    Donna — so sorry to hear about the marina but very glad you’re safe. We’re too far away to give “things” but donated $$ to the Red Cross. I feel for you with the cleanup — we’ve helped with several after Marty and after chubascos hit, and it’s a big job.

  • Billy Forde
    Posted at 15 November 2013 Reply

    Lets be realistic. Canned food is very cheap. Hospitals are not. Any signs of rust means the airtightness of the container could be breached allowing bacteria to develop. Dont risk it – Dump it

  • Dani
    Posted at 26 February 2014 Reply

    Hi hope you don’t mind if I add something I learned from my brother, who worked in a grocery store.

    He told me that the way canned goods are handled, it is inevitable that some cans will be exposed to things like rat and cockroach urine. He said for this reason, one should always wash off the outside of any can before opening it. (Same for canned beverages!)

    When I thought about it, I wondered why that had never occurred to me before. Considering that when people are boating, they might be picking up groceries from places with even more such risks, I think it’s a good idea (and you should wash your hands after handling cans too).

    • Carolyn Shearlock
      Posted at 27 February 2014 Reply

      Funny but I heard the same thing from a local friend yesterday. I’m going to cross post your comment on Why Wash Cans? as well!

  • Ken Arnold
    Posted at 17 May 2014 Reply

    I usually put 2-3 regular sized Cans in a Gal. Ziplock, then squeeze as much Air out and they seem to hold up well.

    I also reuse them for more Cans since they’re still Clean inside.

  • nathan johnson
    Posted at 15 October 2016 Reply

    What if you eat food from a can that you didn’t no had rust on the inside of the can until it was 2 late. I didnt find the rust in the can until I threw it away. We had allready eaten it an of all things it was kraut. I thaught in the back of my mind {don’t eat this something is wrong with it}. Kraut is an odd food an I havnt eaten it in years an when I do I find rust in the bottom of the can after we eat.their wasn’t any rust on the out side of the can an that is what threw me for a loop.

    • Carolyn Shearlock
      Posted at 16 October 2016 Reply

      Never heard of something like that before. If you start feeling sick, see a doctor.

  • Terry Bogart
    Posted at 02 August 2017 Reply

    I’ve opened non-rusty cans of tomatoe paste and had the contents explode. Always a fun mess…

    • The Boat Galley
      Posted at 02 August 2017 Reply

      And doubly nasty since it was probably the last can you had, so now what are you having for dinner??

  • Susan Kam
    Posted at 02 August 2017 Reply

    When we were long term cruising most cans did not have dates on them. I wrote on the top the month and year I purchased them with an indelible pen so at least we knew which ones to use first! We never had a rust issue.

  • Terry Peake
    Posted at 02 August 2017 Reply

    Unless you have hemochromatosis, rust ingestion is not a problem. Most of the caution is related to the bacteria within the rust. In emergency, we would give you a booster shot, not because of the rust, because of the bacteria. I have eaten out of rusty cans myself. I bleached the can. When i could open the other end, i did not worry. I did check inside the can though, in order to make sure the rust did not delaminate and let bacteria in. Some iron is good for you.

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