Before these drums can, legally, be recycled they must be cleaned of any residue of the product that was in them. A power washer is what is used to clean out these drums, at a drum recycling plant, and the employees wear full cover rubberized rain suits because of the spray from the process and the potential of getting some of what was in those drums on them. Start by finding out if where you obtained them did follow the law.

IF they were cleaned as required then a power wash using a chlorine bleach solution and several weeks of air drying/exposure should do the trick. Some folks burn out the barrel with a propane torch or a good fire in it. Never done it myself.

Dave

So how did you acquire these drums, were they a "sold" item and "some sort of chemical insulation"...that leaves a wide open thinking of what chemical is being discussed and how long has the drum been free of the chemical.

So when we discuss the word 'chemical', that takes in a whole lot of possibilities and many that are not harmful to anybody or anything.

"Water" is a chemical"....."air" is a chemical"...."nitrogen" a very good friend of gardeners is a chemical.
So what chemical was in the drum?

What use of said drum do you have in mind. Such drums make a fine furnace to burn refuse. They can be used as a compost bin if you cut a door in the bottom so that you can remove the contents.
What would a fire, made by adding kindling to the drum, do for what chemical was in it and be possibly hanging on to the interior walls.

Before going to extremes of washing, find out what chemical was in it and what possible affects it would have on what you have in mind for its use.

I would use Oxyclean or the cheaper version from Wal-Mart called Sun. Use HOT water to mix it and then dump it into the drum full of water.

If your drum is steel on the inside, either Oxyclean or chlorine bleach will attack the steel causing rust. So will the compost so keep that in mind. Rust is not bad for the compost, though.

Thank you for all of your responses. We got these drums from a guy who just had them laying around and he told us what was in them. After getting them and thinking about it, we realized that we may need to do some more researching before using them for composting since "the guy" probably didn't know much. We don't want to kill ourselves with poisoned compost but would like to make sure that they are clean. There's nothing visible but I know that doesn't mean they are "sanitary". If we can't get them sanitized, we'll just dispose of them (properly) and move on to another (more reliable) source for our drums. Thanks again, Patti