So this evening I made some chili the cans I bought were perfectly fine no dents or anything, I go to open the diced tomatoes and realize my can opener made a dent while opening the can I went ahead with making my chili but got concerned about botulism with dented cans. Should I be worried? Or was it okay that I went ahead with making the chili.

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    I've answered this question as best I can, but I'm interested in why you believe that botulism might be a risk here – what's your understanding of when to be worried about botulism?
    – dbmag9
    Jul 12, 2022 at 8:51
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    When people talk about dented cans+botulism it's usually buying a can already dented because you don't know for how long it has been like that, not denting immediately as you open.
    – Luciano
    Jul 12, 2022 at 9:51

2 Answers 2


Botulism is caused by spores (a kind of lifeform) growing in food. It is a danger when the way food is prepared and stored could allow those spores to grow.

Denting a can that contains safe food while you are opening it is not such a situation, and indeed any commercial producer selling cans knows that they will be opened using a can opener and possibly dented. If by 'dented' you mean that perhaps pieces of metal were cut off and entered the tomatoes, then that is a danger because your do not want to eat sharp metal shards, but that is nothing to do with botulism.


As already answered by dbmag9, this is not a problem at all.

But I think the question comes out of the very real concern about bulging cans. A bulging can is a sign of some fermentation or growth inside the can after processing. As canning is supposed to (essentially) kill everything so nothing will grow, that is a sign of a something wrong, and the something wrong could be benign but could easily be dangerous (e.g., botulism) and since canning is normally very effective the safe thing to do is throw it out.

But a dent is not the same thing. Most dents even in cans in the store are simply because somebody dropped a can on a hard surface (e.g., top shelf down to floor) and unless there is indication of penetration of the exterior (e.g., moisture, rust, etc.) even an actual dent is not in and of itself a problem. Though to play it safe I would avoid buying dented cans unless those are the only option and I really need that specific product at that time.

To take a step further, a dent in your own processing - e.g., while opening the can or a known drop at home shortly before opening the can - is not a problem at all.

Many people are careful to rinse off the top of cans shortly before opening them. That avoids the problem of any outside contaminants (dust, bugs, etc.) getting into the food during the opening process. But that is a separate concern, and even then the concern is not about botulism but about more "ordinary" types of contamination.

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    Supermarkets even put the dented cans in the 'flog off' pile just to get rid of them. They're generally safe. Just today I received my online shopping delivery; one 12-pack of beer had obviously been wet & cling-wrapped later, now dry. I accepted it anyway [knowing how this would work]. 11 of the cans were fine - I washed & dried them anyway - the last had been punctured & was ruined. Net result - 11 free beers.
    – Tetsujin
    Jul 12, 2022 at 16:04
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    @unlisted Agree re: dented cans on 1/2 off (or less) sale pile. The beer anecdote is an interesting one: in ye olde times (which were not that long ago) beer (and other deliberately alcoholic/fermented beverages) were the absolute safest thing because the ordinary water could not be trusted. Jul 12, 2022 at 16:08
  • You wouldn't have wanted to drink the punctured one ;) Somehow it had lost pressure so the can was squishy, yet squeezing it didn't allow anything to leak, so it must have re-sealed itself as it dried & congealed. The contents were considerably darker than one would expect of the brew. [No, I wasn't tempted to taste it, it went down the sink ;)
    – Tetsujin
    Jul 12, 2022 at 16:12
  • @unlisted Agreed. Though after drinking the first 11, the 12th would probably have tasted just fine... Jul 12, 2022 at 16:16
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    Let me hope I never get that drunk [… again] ;)
    – Tetsujin
    Jul 12, 2022 at 16:17

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