Brooklyn brownstone owners are becoming aware of the positive effects of spray foam insulation, also known as Spray-applied polyurethane foam or SPF, to get a nice tight building envelope that does not let heat out in the winter and in during the summer. Examples of SPF are Icynene, Heatlok, Tiger Foam and SUPERGREEN FOAM.

Despite the effectiveness of spray foam to create a tight building envelope, however, most people are not aware of the health issues the spray foam can bring.

Yes current spray foam applications are sort of green because they do not off gas harmful ozone depleting chemicals like the earlier spray foams. And yes they give a very good envelope seal so that the house consumes less energy to heat or cool it.

But SPF are all made from petrochemicals and they all have huge embodied energy (i.e. a lot of energy is needed to manufacture them). On a side note don’t believe the hype around soy based spray foams. It is a bunch of lies. Yes they contain soy but the amounts are miniscule, hovering around 5% of the entire mixture.

Green builders and architects are increasingly specifying SPF for green brownstone renovations, reasoning that the energy saved in a well sealed house makes it worth the energy consumed to turn petrochemicals into spray foam. I disagree but that is another argument.

What is important in this post is that off gassing issue is only now becoming more evident. Up until now it has not been part of the equation because nobody really knew about it.

All manufacturers had claimed their particular SPF did not off gas harmful chemicals. Apparently this is not true. The common knowledge has mostly been the party line very similar to this statement here by Foam Tech. They say:

Urethanes are non-toxic and only require protection for our operators during installations, but the finished product is completely safe and has no formaldehydes.

No formaldehyde yes true. And no nuclear waste or explosives. It is an empty statement because formaldehyde is not the problem with SPF. They throw that in to make the product look greener since everyone knows formaldehyde is bad. It is like olive oil producers saying their product has no cholesterol. Duh. Olive oil never had cholesterol. But it contains fat and lots of it.

Here is the truth about spray foams: SPF foam contains diisocyanates, and dermal (vapors through the skin) or inhalation exposure to these chemicals can cause significant health risks, such as asthma and lung damage, if specific workplace precautions are not followed during product application and clean-up.

Risks also may apply to building occupants who may remain on-site during or re-enter shortly after application.

That is one thing; workers being exposed. But I have found cases where homeowners even experienced negative effects from the spray foam long after it was installed. This is when it gets serious for me. Workers can be trained to be safe by using masks, ventilators and body suits (notice all publicity pictures of people applying SPF have white body suits).

But homeowners have no way of protecting themselves in this way. This applies to children especially who have much more porous bodies than grown ups and absorb chemicals much faster and with much greater effect.

Here is a statement by William Swietlik on the issue, clipped from his much longer comment (No. 11) on the Green Building Advisor site:

I am a member of the Federal Interagency Spray Polyurethane Foam (SPF) Workgroup and Co-Chair of the EPA SPF Workgroup. The mission of these federal groups is to ensure the knowledgable and safe use of SPF, a valuable insulating material.

Spray polyurethane foam (SPF) insulation, both open cell and closed cell, is made from diisocyanates (50% of the formulation), polyol oils, amine catalysts, flame retardants and blowing agents (the other half of the formulation). Dissocyanates are the leading cause of work place asthma and are a well-known sensitizing toxicant to humans.

Once an individual becomes sensitized to diisocyanates there may be no safe exposure level. Sensitization can occur from excessive and/or chronic respiratory and dermal exposures. Diisocyanates are odorless. The amine catalysts (which have an odor) and the blowing agents, can also have health impacts, but these are used in smaller quantities in the formulations.

When installing SPF using high pressure and temperature spraying, unsafe levels of these chemicals are released into the air in the building or home.


Or how about this long list of comments from giving all sorts of damning evidence, both from studies and personal experiences. A couple of them:

Dan in Atlanta says:

June 30, 2009 at 11:02 am

We installed Icynene under our attic roof on June 11, 2009. It’s now June 30, and we haven’t been able to live in our house since because the fumes were so intense they give use headaches. We’ve be ventilating the house 24/7 since then, and the intensity of the fumes has decreased, but not our headaches.
Our next door neighbor is a PhD research chemist, and he says the ingredients of Icynene are very toxic. If the chemical reaction were 100% completed that would not be a problem. However, he says that a 100% complete chemical reaction is rarely, perhaps never, achieved. That means outgassing of toxic fumes.
We are now sensitized to the chemical, so we may have to replace our whole roof. The company claims you can inhabit your house after 24 hours, but don’t believe it. That’s a problem when your Icynene installation is a retrofit rather than a new build when the outgassing might occur before you inhabit the house.

Heather says:

I had Icynene MD-R-200 sprayed on 2 walls in my basement a month ago and have been having problems with the smell ever since. The dealer has been very supportive and blames the smell on the lack of ventilation in the area. They have installed fans in both of the windows in an effort to increase the air exchange but this has not helped so far.


Bottom line, as a green builder in Brooklyn I have never recomended spray foam insulation to seal the entire house. We use it in small quantities to seal small cracks around pipes or between wood boards. But for the insulation we only install cellulose insulation.

The embodied energy of cellulose is next to nothing compared to spray foam (off the top of my head 600 vs 14,000). It is recycle NY Times newspapers I’m told.

It is true that it is hard to match the airtight quality of spray foam, but if done correctly you can do it with small amounts of foam, tape, caulking and cellulose. The green qualities of doing it this way are much larger.

We also use fiberglass insulation once in a while when we find it being thrown out as overstock from a job. We don’t buy it or use it if it is used, but we will use it if it is new and being thrown out. It has low levels of formaldehyde and also huge embodied energy (12,000 if I remember), but using it is better than sending it to the landfill in our opinion.