I wouldn't worry about it, maybe the preservatives in them, but still I would toss them in.

The only drawback I can think of is that they probably have some salt in them. It's probably not a lot in the overall scheme of things, though, so you should be fine.

If it's safe to eat, or was when it was fresh, there's no reason anything in there is not safe for the compost. And yes the salt will not be a problem once you mix in some dry brown materials to balance out the pile.

If it came from the soil, it can be returned to the soil.

I have done it for years. Personally, many of those foods I would have used in the kitchen. However,if anything is beyond its expiration date, even by just a wee bit of time, my wife won't use it. So in addition to canned goods, my compost piles regularly get dairy and other items not normally recommended and I never had any problems with them.

The BPA is in the material the container is made from, although some small quantities might leach into the food. BPA is supposed to be safe for human consumption in small quantities. No real reason to not compost those foods.

I guess the issue is that many people don't believe it's all safe to eat. I generally don't worry about BPA, but some people are extremely worried about it... refuse to use plastic water bottles, the old SIGG bottles, etc.. I'm aware it's in the can, not the food, but it does leach to some degree, supposedly particularly into acidic foods, like tomatoes. I was more wondering if there was anything which would interfere with the composting process (like the preservatives in the food) rather than "poisoning" it. But I guess that's a non-issue, considering how gross opened cans can get in the fridge....

Personally, I'd just eat the canned vegetables and fruit regardless of the expiration date if the can isn't swollen.....but that's just me.

On the other hand, I wouldn't worry for a second about the small amount of BPA or other chemicals in canned food contaminating a compost pile. There is a book titled The Humanure Handbook in which the author states that compost microbes "degrade toxic chemicals into simpler, benign, organic molecules." Here is a link to that chapter. It is an interesting book about composting in general, even if you aren't interested in using humanure (although you probably will be if you read the book..haha.) It is available online for free. http://weblife.org/humanure/chapter3_12.html Take a look. :)

Dilution and vigorous biodegradation are going to take care of that stuff. Aside from the fact that amount in any canned goods is going to be tiny, even after extended leaching, it does degrade aerobically in the environment, and should do so even faster in the compost bin.

A couple of weeks ago we ate some canned green beans from out late MIL's pantry. The pull date was 1988.

When should we start to worry about what these beans are doing to our health.

A good Friend of mine ran a canning factory, it was his families canning factory for years and years. (Sadly they are gone out of business now, purchased by a larger canning factory and shut down)

What he always told me, most canned goods are safe as long as the traditional lack of bulging of the container, and when opened if it still smells good (no strange odor),

He further explained for dated products as time passes beyond that, the product will still be safe and edible But, the taste can degrade over time.

He further added use common sense, there are a few products that just absorb all the liquids over time, you will open them and they will be dry or clumped together, and not necessarily unhealthy but for certain unappealing!

So it is often trust your nose and judgment the product will remain "safe" for a long time for the most part!

I looked at the nutritional info on a can of green beans once. I realized there is so little value in them that they might be bad for my health regardless of the age. :-]