I would think that the question is whether or not the chlorine can be liberated from where it’s bound to. Some compounds of chlorine are more stable than others and it’s difficult to get ions to pop off and thus make free radicals that can turn into acids that would damage your machine.
As for toxicity almost everything you laser is going to be toxic to some degree, just make sure your ventilation is set up properly. You really after is something called an MSDS, it’s a data sheet that tells you what happens when you abuse the material. You can find out more in number four here: