There was no chemical attack, or at least not one that worked. We would have had confirmation by now from civilians or foreign reporters.
You can't suppress the news like this in a free society.
How would Israel confirm anything? If it blew up then the evidence could have gone with it. It would take time to confirm this type of information. There are a lot of explosions going on over there right now. I can't see Israel being able to confirm anything at this point. Hard to say but that seems logical.