What i have done in the past is to wear a cheap dust mask and open old jars out side. I dump the contents into 5gl buckets and pour it on the compost pile. I also have an old wash tub that i add water and bleach to to soak the jars in. Sometimes you will open a jar that will have mold in it, that is the reason i wear the mask. Some others may have other ideas.

Agree. I'd do it outside with great care, a mask of some type, and rubber gloves. Clean all jars and utensils used with strong bleach solution soak.

The official USDA policy is to dispose of them without opening, especially if they have a broken seal, as they could contain botulism spores as well as molds and fungi.

So it is up to you how much risk you wish to take.

Dave

Personally, I am very leary of opening jars of foods. If you get any on a cut or splash in you eye, you can still get botulism. At least that is the last information I was given. It should never be dumped in the garbage disposer. It can splash up on you or the sink, counter, etc.
It only takes the amount of botulism on the head of a pin to kill an entire city of 60,000 people. It is that deadly.
So, you do as you wish, but this is the info on it :
How Dispose of Spoiled Canned Food
Never taste food from a jar with an unsealed lid or food that shows signs of spoilage. As you use jars of food, examine the lid for tightness and vacuum; lids with concave centers have good seals.

Before opening the jar, examine the contents for rising gas bubbles, and unnatural color. While opening the jar, smell for unnatural odors and look for spurting liquid and mold growth (white, blue, or green) on the top food surface and underside of lid.

Spoiled acidic food should be discarded in a place where it will not be eaten by humans or pets.

Treat all jars and cans of spoiled low-acid foods, including tomatoes, as though they contain botulinum toxin and handle in one of two ways:

If suspect glass jars are still sealed, place them in a heavy garbage bag. Close the bag, and place it in a regular trash container or bury it in a landfill.

If the suspect glass jars are unsealed, open, or leaking, detoxify (destroy the bacteria) as follows before disposal:

Carefully place the containers and lids on their sides in an eight-quart or larger pan. Wash your hands thoroughly. Carefully add water to the pan until it is at least one inch above the containers. Avoid splashing the water. Place a lid on the pan, and heat the water to boiling. Boil 30 minutes to ensure that you have destroyed all toxins. Cool and discard the lids and food in the trash, or bury in soil. Sanitize all counters, containers, and equipment that may have touched the food or containers--don't forget the can opener, your clothing, and hands. Place any sponges or washcloths used in the cleanup in a plastic bag and discard.

I live in the real world and have limited income so I so the following with an old jar - the last 150-180 I got were canned in the 1970's and some still had liquid content and others (because of roof leaks) had the lids completely rusted out with dried up contents inside.
Made two piles - dried up contents
- liquid contents
Getting the band off sometimes a real problem when very rusted. Easiest thing was to take a small metal cutter and nick the metal ring and turn it off just sardine can with a needle nose pliar.
Hold dug in garden and all liquid contents poured into bottom of hole for soil organisms to break down. These jars were placed in a large tub of warm water with bleach and strong soap.
Dried up contents were put into a different tub with warm soapy water for a week or so to let the contents soften.
Removal of rust stains on the exterior of bottles done with industrial toilet cleaner intended for removal of rust from toilet interiors. It worked very well.
When done, threw away the rubber gloves and covered the jar content hole with 12 inches of soil and a board.
In groups, turned on my outside propane burner and cooked all the jars for 30 to 60 minutes. Removed groups of jars and stood upside down to drain and put next batch in.
After cool enough to handle, checked all bottles for cracks and rim chips. I had missed a couple during the initial "dirty" inspection and discarded these.
Used all the bottles up a week later to can tomato products - BWB and Pressure Can. None broke.
Got some neat old jars. Spent a good 8 hours time on cleaning the 150 to 180 jars.
I live in a urban area in So. Calif. and canning jars here at pretty rare. There are no basements at "Aunties" house full of jars (there are no basements anywhere). Finding 150 to 180 in one place 35 miles away was a real find.
I know Linda Lou would have thrown them all out. That would have been the cautious thing to do. I also should not have replaced the missing shingles on the roof of my house and I should not have picked up the rattle snake in the yard and moved it to the edge of the forest. I now treasure my old bottles and I don't kill snakes.
Jim in So. Calif.

LOL, Jim, I don't think I'd have moved the rattlesnake, I'd have let it move itself, but I do stop and move turtles out of the road, even the big honkin' snappers that could take a finger off.

I konw the official and safest way is to discard jars and contents, but I also know I wouldn't do it. I'd empty the jars, probably into a hole and not into my compost that I use in the garden, then I'd clean the jars in hot soapy water with bleach. Given the age of the food, I'd probably boil the suckers too!

Annie

Annie,
Boiling after soaking was also the quickest way to soften the remaining food that had dried and re-hydrated in our hot climate for 30 plus years. Jars that you never thought would clean came out visibley "clear as new". The rust from the bands was a great deal more work to eliminate.
You have a great Christmas. Annie's Salsa by volume is still the largest single item I have canned at one time - 85 or so jars. They are ALWAYS labeled with your name and I tell your story as well as I know it.
Jim in So. Calif.