The Pembroke, Va.–based materials designer NanoSonic is close to having ready a commercial version of Hybridsil, a 100% silicone-based foam insulation that the company’s chief chemist claims is significantly less toxic than widely used conventional spray polyurethane foam, or SPF.
Vince Baranauskas, NanoSonic’s vice president of polymer science and engineering, says NanoSonic has demonstrated that its concept—which it has been developing under an EPA Small Business Innovation Research grant—can meet thermal and sound performance standards comparable to existing foams. In September, Hybridsil was certified by MAS Certified Green, which through independent testing (in this case, its lab in Atlanta) trademarks low VOC-emitting products so purchasers and specifiers can earn credits in sustainability programs.
Hybridsil is a nanocomposite material produced without isocyanates, the raw materials that make up all polyurethane products. EPA and the Occupational Safety and Health Administration have identified isocyanates as possible causes of asthma and other adverse health effects. Baranauskas says most commercially available foams will ignite almost instantaneously in a fire, and are typically treated with halogenated fire retardants (that is, chemical compounds containing chlorine or bromine connected to carbon) that produce “highly corrosive and toxic smoke.” He believes manufacturers aren’t addressing this problem because “regulations aren’t demanding it.”
If fire-stop barriers to ignition get factored in, Hybrisil would cost 30% more than conventional spray foam insulation. But, Baranuskas points out, “our product doesn’t need a fire stop.”
In September, Branaukas told Builder that his company's next step was a "large-scale testing" that was contingent on getting new funding from EPA to pay for those tests. Ideally, NanoSonc would like Hybridsil to be US-approved, too. And it wants to optimize the spraying process so that the foam can be dispensed from a 55-gallon drum.
John Caulfield is senior editor for Builder magazine.