Product Review

BioBase 501 Foam Insulation

Low-density, open-cell polyurethane foam insulation made from soybeans may soon replace the non-renewable version.

Over the past year, three companies have begun marketing a low-density, open-cell polyurethane foam insulation made, in part, from soybeans. By far the best organized and established of these is BioBased Systems of Spring Valley, Illinois. Experienced users tell EBN that BioBase 501 works just as well as its petrochemical-based competitors, and they are even more excited about the fact that it costs less.

Until about 1990, sprayed-in-place polyurethane foam was always a closed-cell product, blown with ozone-depleting CFCs, that hardened to leave a durable surface once it cured. During the 1990s, installers of standard polyurethane switched from using CFC-11 to using the much less damaging HCFC-141b as a blowing agent. Meanwhile, a company called Icynene in Ontario, Canada pioneered a low-density (0.5 lb/ft3 or 8 kg/m3), open-cell polyurethane foam insulation that used water as its blowing agent (see EBN Vol. 4, No. 5). This low-density foam doesn’t cure with as hard a surface as standard polyurethane, and, because it doesn’t have the low-conductivity HCFC gas in its cells, it has a lower R-value—R-3.7 per inch (RSI-0.7) as opposed to about R-6.2 per inch (RSI-1.1) for the high-density foam. But it seals against air infiltration just as well, and it can be installed in thicker layers to make up for the lower R-value. Over time, Icynene and a similar product, Sealection 500 from Demilec (see EBN Vol. 6, No. 5), have slowly been making inroads in the North American insulation industry. But now there’s BioBase 501.

Published September 1, 2003

Malin, N. (2003, September 1). BioBase 501 Foam Insulation. Retrieved from