unsafe substrates

it is well known that certain woods are unsuitable to use as substrates due to toxicity - cedar would be a good example of this

I was wondering if anyone had any links to articles documenting this, or knows of papers on the subject?

I am particularly interested in what problems are observed in snakes on using a toxic substrate.

Thanks, Skye

My friend had a king snake that he kept on cedar (before everyone found out it was bad), and the snake started acting very strangely. He would try to bite your palm if you held him, and other behaviors that weren't normal. From what I understand, it is the oils in the cedar, and other strong scented trees like pine, that can cause the problem. The substrate that you get for reptiles is pretty dry, and has had the oils removed.