I thought the Hydrohut problem was taken care of?

Anyway, my first makeshift growroom was a tent that at first was lined with aluminum foil (giant disaster), but later was lined with a reflective material like mylar and it worked really well. I think the biggest factor when using any kind of tarp is going to be making sure that the light/lights aren't allowed to be close enough to the synthetic plastic to cause it to melt or burn. If you have a buffer of at least a few inches, and good ventilation, you should be fine with most of the stuff you'll find at Home Depot.