I have seen a few cases where people using some commercial mulch products have developed allergies to that material over time. That indicates there is something in that commercial mulch that you might not want in your garden. This is kind of the same thing as medical personnel developing allergic reactions to latex from exposure to latex gloves over a long time. Since the occurrances are very small I am not aware of any studies being done in this area.

Can you post a link to this Cornell U. article? I am not certain what is meant by 'mulch toxin'. I get the impression there is a microorganism that can thrive in wood mulch under certain conditions, which produces some kind of toxin that causes an allergic reaction. I have not heard of this so I would like to learn more about it.

Here you go, tox.

This little article does not address the many problems associated with those who have developed skin or lung problems from mulch.

Here is a link that might be useful: Click here

OK, thanks. It sounds like they are mainly referring to anaerobic conditions and the attendant population of anaerobes and their foul secretions. Deffly something to be avoided.