Trailer found, cork testing in process

We're building a small scale model to help us understand the design and building process and to test the feasibility of our found/collected/donated materials. Haas found 5x8 perfectly dumpy trailer to begin building a small scale model. We will soon be searching for a building guide/s for this phase. And we are currently looking for someone with a vehicle that has a hitch or a long bed pick-up truck to help us collect the trailer--it is located one hour from Champaign-Urbana.

Testing: we are looking into ways to replace foam floor insulation because it's expensive and toxic. We gathered wine corks (synthetic and natural cork), and burned both. Natural cork burns like a mother-*&%!. Synthetic doesn't burn. Hallie thought that was great! The question is: is it toxic? If it is, is it more toxic than foam-floor insulation. If not, we may use it. Another question regarding the natural cork: is it possible to coat it in wax (wax is flame-resistant), how heavy would that be, how long would that take, etc.