Whether or not you decide to read the article that my comment below is posted on (http://houseblog.ottopohl.com/2010/02/05/foaming-about-insulation/comment-page-1/#comment-41). I think you will find my information informative and revealing.

–Wow!!!

You did your research! I am very impressed that you were able to calculate all of those figures and actually obtain some of the “secret” information that you did.

I have to take you for your word on the calculations for the quantities of comparable Co2 inside the closed-cell products an credit you for being bold enough to point that out.

One point that you made which is valid but disconcerting to me  is the event of escape of the 245FA into the atmosphere. As you said, during a fire this would happen but the actual toxicity of many other building materials in the house will be far more harmful to the environment. Not to mention the harmful effects or borate, formaldehyde and other bonding agents and fire retardants in fiberglass and cellulose insulation. Closed-cell foam torn out during a renovation can and should be sent to a recycling plant, there are many available.

I also noticed that you strictly focused on a closed-cell product, which I can understand because it brings the most environmental concern regarding the 245FA. You could have opted to go with and open-cell foam that relies on a steam reaction and air to create the bubbles inside the foam which act as the insulator.  Most open-cell foam products do not rely on 245FA to increase the r-value. You mentioned that the product you decided to go with has a r-factor of 6.2/inch. You could have sought out a 1.0 Lb. open-cell foam offering an r-value of 4.5/inch and used that in all of your non-moisture related spaces. One example of a product is Demilec’s Agribalance which I have used hundreds of times in combination with a 2.0 Lb. closed-cell foam for the basement sill areas and areas that have moisture concerns and are hard or impossible to tackle with a vapor barrier.

As far as the foam guy that uses it for furniture, automotive, etc. The process is not the same. Spray foam used in homes needs to rise and typically have a volume of 1.8-2.2 Lb./Cu.Ft. This is not the case with much denser types of rigid foam. The reason that 245FA is used by most foam companies that sell foam to the construction market is that it allows for proper expansion while maintaining a high r-value. If one was to use a mix of materials such as this guy uses it would get sprayed on at 1/32nd of an inch and barely expand, if at all. It would go on very sloppy and not fill gaps through expansion.

My last note is regarding your quote, “The “soy-based” thing is a bit misleading, as it still contains a lot of petroleum-based chemicals.” I have to agree with you 100% that this is a misleading advertising scheme…however…I understand what it means to be qualified as a soy-based foam. As you said there are parts A and B and parts A are virtually the same across the board. In order for a foam product to be registered and accepted as a Soy-Based product it must contain 9+% soy/recycled/renewable materials. After you break it down it seems small but the fact is that spray foam insulation is the way of the future and will be used in 75% of all new construction in the next five years. Having 5% of the total materials being soy based, reused or renewable in a $100 billion industry is a step forward.