I would not be overly worried about mold growing on coconut fiber, though that may be a concern. It is chemicals that are sprayed on plants or that they are dunked in that I worry about. The Chameleon is not going to ingest the fiber, but crickets crawl on it they can sometimes be affected by crawling on some chemicals. But that is being overly cautious. Some states require that plants are dunked, some do not.