Mushrooms to provide eco-friendly insulation

27-Jun-07

"Greensulate" - an organic, fire-retardant board made of water, flour, oyster mushroom spores and perlite, a mineral blend found in potting soil - will soon be part of the growing market for eco-friendly products. Unlike many green building products, Greensulate isn't made from pre-existing materials. It offers the advantage of being sustainable, and enviro-friendly, and is not based on petrochemicals. It requires little energy or expense to produce because it's grown from organic material. Bringing the insulation to market will require much more research and work, more sophisticated equipment and a better work space. A mixture of water, mineral particles, starch and hydrogen peroxide are poured into 7-by-7-inch molds and then injected with living mushroom cells. The hydrogen peroxide is used to prevent the growth of other specimens within the material. Placed in a dark environment, the cells start to grow, digesting the starch as food and sprouting thousands of root-like cellular strands. A week to two weeks later, a 1-inch-thick panel of insulation is fully grown. It's then dried to prevent fungal growth, making it unlikely to trigger mold and fungus allergies. The finished product resembles a giant cracker in texture. The two say recent tests at the National Institute of Standards and Technology have shown it to be competitive with most insulation brands on the market. A 1-inch-thick sample of the perlite-mushroom composite had a 2.9 R-value, the measure of a substance's ability to resist heat flow. Commercially produced fiberglass insulation typically has an R-value between 2.7 and 3.7 per inch of thickness, according to the Oak Ridge National Laboratory in Tennessee. With a rapidly increasing global population, a limited supply of natural resources, and rising energy prices, eco-friendly housing products are selling fast. Numerous companies have carved out their niche selling "green" building supplies such as recycled fiber board and plant-based paints.