The skinny on "organic" spray foam insulation

This morning I had just enough quiet time as my young daughters ate breakfast to catch "Living With Ed", a really great and entertaining show on the Planet Green network.  I'll save you the entire recap but Ed (Ed Begley Jr., the movie star and avid green technologist) had visited some friends in their mountain cabin and the couple were having some energy efficient upgrades done to their home, including having some (apparently) open cell spray foam applied to the underside of the roof deck in the attic.  Ed got excited about the product and went to speak with the installers who noted that the foam they were applying was "...a soybean based polyurethane foam as opposed to a petroleum based product."  Naturally this impressed Ed - I mean, gosh, all organic insulating foam - how good is that?  Here's the thing - either this installer was egregiously misinformed or he was being deliberately misleading on national TV.

By DEFINITION, all polyurethanes are petroleum derivatives obtained by combining a polyisocyanate (iso) group with a polyalcohol (polyol) group.  A great chemistry write-up on polyurethane foam can be found here.  While polyurethane foam can take many forms, from car seats and mattresses to spray foam insulation, the isocyanates are relatively few while the "secret sauce" of the polyol can vary wildly from manufacturer to manufacturer and product to product.  To cover up its petroleum heritage some companies call these components the harmless sounding "Part A" and "Part B", and even give the finished foam product hokey descriptions like "...having anglefood cake like consistency", but they're all coming from pretty much the same or very similar chemistry.

Most people know that by fermenting fruits or vegetables you can derive an alcoholic beverage (think corn->moonshine, grapes->wine, etc).  This can exactly be the alcohol needed for the reaction required to make polyurethane foam!  In fact, the preferred alcohol in most of the polyurethane foam industry FOR THE PAST 50+ YEARS has been acquired from post-process sugar beets - the same sugar beets used to make table sugar.  This happens to be the desired alcohol because it simply gives the best overall performance of characteristics that are important to the people that use foam.  Flow (in application), adhesion, strength, insulation, etc., are just a few of the characteristics looked at.

Back to my trouble with the comment made to Ed on his show.  Again, all polyurethane spray foams (open cell or closed cell) are petroleum based.  Many companies experiment with their polyol (remember this is the "secret sauce") to chase different desirable properties, and sometimes, as in the case of soybeans, the greatest property achieved is MARKETING.  I've spoken with many large foam manufacturers and they've all tried soy-based foams but admit that quite frankly it does not insulate as well, or flow as well, or adhere as well as the sugar based foams.  Sugar beets are natural and organic, and so are soy beans, so why all of the hype for soy?

For the record, the foam used in our structural insulated panels is a closed cell polyurethane foam.  We're not going to try and fool anyone on this, though we are proud to say one of its components comes from post-process sugar beets and has far superior insulating, adhesion, flow and strength properties to other "de jour" foams on the market such as the soy type.  We also firmly believe and support the use of petroleum products in insulation.  Mind you this is not an "active use" of a fossil fuel such as in your car.  Our use is very long term - in fact if you could go back to the refinery and choose which process the raw materials would go towards, the petroleum you use in the course of driving for less than a month could have been refined to insulate your house for the rest of your life, saving tens of thousands of pounds of fossil fuels through reduced energy costs.