A few weeks ago the EPA held a webinar on the safe use of spray foam insulations titled “What You
Need to Know About the Safe Use of Spray Polyurethane Foam (SPF)”. We at Eco Brooklyn are not crazy about spray foam so we watched what the EPA had to say closely.

Their view in a nutshell is: more information is needed and it isn’t as safe as people make it out to be.

Their presentation was a good non biased overview of spray foam and what is needed to make it safer. They have some good info (although not exhaustive). You can view the full report and slide show online (links below).

Key points from the presentation:

  • SPF is one of the fastest growing products in building and construction
  • Companies make misleading marketing claims: “No off-gassing”, “non-toxic”, “safe”, “green” and “environmentally friendly”, “is plant-based”, “made from soy beans”
  • The ingredients of spray foam and their side effects:
  1. Amines (catalysts) – sensitizers; irritants; can cause blurry vision (halo effect).
  2. Flame retardants – some are persistent, bioaccumulative, and toxic
  3. Blowing agents – global warming potential and other considerations
  4. Isocyanates – cause asthma and are the leading attributable cause of work-related asthma. Isocyanates are potent lung and skin sensitizers (allergens) and irritants. Isocyanates can trigger severe or fatal asthma
    attacks in sensitized persons at low levels.
  5. MDI – a hazardous air pollutant – Clean Air Act. NIOSH issued an Alert in 2006 to prevent MDI exposures for a similar spray application. The European Union has issued new regulations for consumer products containing MDI.
  • Long term stability of polyurethane foam:
  1. Fully cured polyurethane foam is not considered a problem unless disturbed.
  2. Heating, welding, or grinding generates free isocyanates and other hazards.
  3. Fires and thermal degradation can generate and release hydrogen cyanide, carbon monoxide, amines, and isocyanates.
  • Alternative Technologies are:
  1. Fiberglass, cotton, and mineral wool batts.
  2. Fiberglass and cellulose mixed with an adhesive can be wet sprayed into wall cavities and have an R-value per inch similar to low density SPF.
  3. Polyisocyanurate rigid foam boards can have similar R-values per inch as high density (2 lb) SPF.
  4. Cementitious and tripolymer foam products can be poured into walls or behind special netting.
  5. A new class of hybrid non-isocyanate polyurethanes (HNIPU) in development

The “112” page presentation is available on EPA’s Design for the Environment site:

Or, here is the direct link to review or download the pdf of the slides:

At Eco Brooklyn our own experimentation on green brownstone renovation shows the same thing the EPA says. We actually find Polyisocyanurate rigid foam boards (PolyISO) to be a BETTER alternative than spray foam. They can be sealed at the seams to create an effective insulating and air barrier.

We use salvaged PolyISO that is in good shape and otherwise would go to the landfill. This means that not only are we not using up new resources but we are making energy efficient brownstones that literally REMOVE garbage from the landfill.

Space is a big issue in brownstones and that is why the high R value per inch of PolyISO is so great for walls. In the floors and ceilings where there is more space we like to use cellulose insulation. Again it is a recycled product without the off gassing and petrochemical issues of spray foam.

The dust is a problem with cellulose, and we don’t know much about the dyes in the paper although we suspect current newspapers don’t use heavy metal dyes like they used to, but we like to think that is only an issue during the day of installation since we try to make sure the cellulose is contained behind the walls. The benefits of cellulose outweigh these comparatively minor considerations when you compare them to the health and ecological impact of spray foam.