DBfan187 5,000+ posts
Supa's mom was here!
Just for fact 1" MDF will get you really sick if you try to cut it. Thats why they only sell it at specialty lumber yards. Your best bet is to get either 2 -1/2" and glue/screw them together after cutting holes or get 2 3/4" MDF and do the same. Always make sure to wear eye protection as well, the particles that come from MDF when cut are about the smallest dust you can find it will penetrate most fabrics with no problem. Also make sure to have a good respirator.
Not familiar w/ that sick myth, but down here at the Home Depot that my mom works at and I shop at they sell 1" MDF! So I don't know of any "specialty lumberyards" that your talking about!