I installed it on one server that I only ssh to JUST to use that ebook-convert so I can read anything (epub, mobi, pdf, etc) on the command line. It's so easy to use, detects to- and from-formats from filenames and works on anything.
You just said that someone is claiming that water and bleach are identical.
Let me put it to you this way, instead of saying "everything is a chemical": If you stand with the poster above worrying about "chemicals", perhaps state your question more clearly so we know exactly what we're getting ourselves into. I will even give you some examples. Do you perhaps mean chemicals known to cause cancer or other diseases? What about chemicals known to aggravate diseases or conditions? Or would it be enough to be simply suspected? Maybe your threshold of what is a sufficient amount of research should be mentioned. How many studies do you wait for before you eat a certain ingredient? Do all regulatory bodies need to agree?
That's certainly a lot of work going into asking a question, I suppose, almost as much as answering something like "are there [bad] chemicals in it?" What research is out there, is out there. Only you know what will make a "[bad] chemical" not just a "chemical".
Of course, if you know of a place that lists all the "[bad] chemicals" that you agree with, this [practically extreme] "lib" wouldn't mind seeing it.