Question about chemical reactions in chlorine?

Without reading up on it…

The moisture is changing the composition of the tablets by reacting with them, meaning they are not the original compound they’re supposed to be. This could effect their effectiveness, but honestly I dunno without reading further. I mean you’re supposed to mix them with water (and a much higher volume of it at that), so one would assume a small amount of water wouldn’t severely hamper their effectiveness.

You are correct on the fumes, do not breath in chlorine gas fumes. They are very toxic.

As far as drying them out, you could try taking the lid off during the day and letting it “air out” in a sense. Some of the moisture would go away, plus you would air out the fumes. If it really bothers you you could take a hair dryer to it, but I’d be cautious in that as heat tends to start a variety of reactions.

The most common reaction with chlorine tablets that causes this type of fume is an interaction with ammonia. It actually creates a very dangerous chlorine gas (like, chemical warfare status). So be very very careful.

Not sure how that could have happened, but it’s unlikely that a bit of moisture caused it. Ammonia comes from fertilizers, plant decay, animal waste, etc. That stuff can build up in places like a backyard shed and such.

Air out the container, possibly move the tablets to another bucket or container with a good seal. It’s doubtful that any of the tablets would lose potency unless they were partially dissolved in the process.

I’d call the manufacturer or ask for an MSDS (Material Safety Data Sheet), which they will surely have on file. It’s a Federal requirement. (In fact, I’m surprised that you don’t have very explicit instructions / warnings on hazards, handling caveats and instructions for disposal, should that be necessary – including instruction on when that is or may be necessary.)

Thanks to all, I actually did as @tedd suggested and aired them out after I did what @gambitking suggested and put them in another container after having ACTUALLY read the bucket warnings, etc. as mentioned by @CWOTUS.
It seems to have have helped. I also had to leave the lid open for a while on the storage container that all the pool stuff is stored in. I assume chlorine is heavier than air. I appeared to have accumulated in the bin that the bucket was in.