As we were closing out poll this fall I noticed a 5 gallon bucket of tablets. They are a few years old as we have not used tablets in a awhile. I shook it and it had a few tablets left so I opened it and at some point water penetrated and the entire thing was full of what I can only describe as chlorine gas. I immediately shut I and left until the smell subsided. At this point my question is how do I properly dispose of it or neutralize it?