I am looking to gather facts (although I am sure there will be a fair amount of opinions) about spray foam insulation and the health concerns associated with the install and everyday living. I mainly want to focus on closed cell but I will include the open cell as part of this topic.
The first thing that I have looked into are the different types of spray foam. So far I have come across Icynene and Polyurethane. It seems that Icynene is the open celled version and Polyurethane is the closed cell version.
Polyurethane
Polyurethane foam (commonly used in foam roofing and insulation) is
based on petroleum byproducts, although there are 'green' versions,
made partly from soy byproducts (instead of pure petroleum), which
contain less HCFC and CFC gases. All types of sprayed polyurethane
foam contain millions of tiny closed cells filled with HCFC or CFC
gases. A blowing agent agitates the plastics causing the bubbles to
form, and the material hardens within about one minute. Sprayed
polyurethane foam is inherently water resistant due to its closed cell
structure.
Icynene
Icynene foam is different because it is based on Castor oil (not
plastics, also known as petroleum by-products) and it does not trap
air in the cells. The resulting Icynene cells are open–which means no
gases are trapped in the cells, so air-infiltration is possible. Due
to air and vapor movement, Icynene foam does not insulate as well as
closed cell foam. In contrast, closed cell foam completely traps
vapors, completely blocking air migration–which enhances the
insulating capacity of polyurethane foam. Icynene foam is more ideal
for applications where some air or vapor must pass through the foam,
while polyurethane foam completely blocks air and vapor transmission.
Now, looking at the two. My research so far brings up the following as potential health concerns.
Polyurethane Risks Reference 1 Reference 2
Isocyanates, such as MDI (methylene diphenyl diisocyanate), are highly
reactive chemicals that can cause skin, eye, and lung irritation,
asthma, and chemical sensitization when absorbed through the skin or
inhaled.
Although this mainly focuses on application, a few 'claims' have been made that the chemicals keep getting released after the insulation and waiting periods of 36-72 hours. Reference 3
Icynene Risks Reference 4
Icynene brand, like similar brands of foam insulation, is composed of
almost 50% isocyanates
Again, like the other type, we encounter isocyanates which is where we get a lot of the issues like the first one.
This bring me to my main question.
Assuming that Isocyanate is the main issue and the stem of the health concerns(secondary question below in regards to that), is there an alternative spray foam product that has less health concerns? (ie. without Isocyanate or different application method) I am looking for a spray foam alternative, not just an alternative insulation. (so cellulose doesn't fit).
These are more secondary questions that don't necessarily need to be answered. Its just nice to include as much info as possible since they are all related.
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Most the articles I have seen have been a few years old. Not many current ones. Has the technology changed or any new advancements been made over the past couple years that make it safer or provide better insight? Any studies or expanded research would be helpful.
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Is there a way to test potential reactions ahead of time? Kind of like getting an allergy test? For instance, going to a week old insulation and just spending a couple hours in the room? or just touching the foam to skin to see if a reaction occurs?
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We have dogs and that is also a consideration. Has there been any research regarding the effects on pets that should be taken into account as well?
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My question assumes that Isocyanate is the main center issue with the spray foam insulation. Is it valid to assume that, or is the issue more related to a combo of chemicals or application method?
Best Answer
Spray foam insulation is a petrochemical product that is mixed on-site and blown with a blowing agent. The actual process is not great for anyone's health, which is why applicators wear protective suits. It is also exothermic, and if done incorrectly can cause a fire (rare). Additionally, if mixed incorrectly, or even in a small percentage of cases, the foam will offgas nasty stuff for a long time, rendering the house uninhabitable. I must stress that these cases are rare, but they do happen. Furthermore, fully-cured spray foam is flammable at elevated temperatures and will char and emit smoke at typical household fire temperatures.
Are there better insulations out there than spray foam? Absolutely. Spray foam is about the most expensive insulation you can get, and it is terribly mis-used most of the time, applied where its benefits are wasted. For insulating walls between stud cavities, wet-sprayed dense-packed cellulose, sprayed fiberglass (under the brand name "Spider") or mineral wool batts are better choices. For turning an attic into conditioned space, installing rigid foam boards above the roof sheathing is the preferred approach if already re-roofing. If that's not an option, then you can fill the spaces with the aforementioned choices of cellulose, fiberglass, or mineral wool batts, as long as you 1) create a ventilation channel of 2-4 inches in the rafter bays below the roof deck, 2) install a ridge vent and soffit vents that allow every rafter bay to be ventilated, 3) use an interior-side smart vapor retarder membrane such as Intello MemBrain (note: NOT a vapor barrier like polyethylene sheeting), and 4) you finish the assembly off with drywall, being careful to make the drywall layer as airtight as possible. Alternatively, you can detail the vapor retarder membrane as an air barrier and skip the drywall or use non-airtight finish materials like tongue-and-groove pine boards or something.