Why UFFI Insulation Was Banned?

Just the name–urea formaldehyde foam insulation (UFFI)–is scary in North America. Yes, it does off-gas formaldehyde–especially when mixed and installed improperly. It was banned in North America; but never in Europe. Does it really deserve its reputation?

UFFI Insulation

History of UFFI Insulation

Urea-formaldehyde foam insulation was originally developed in Europe in the 1950s. It was injected into walls and cavities in buildings to completely seal and insulate them. It is still regularly used across Europe.

Urea-formaldehyde foam insulation (UFFI) was used in the late 1970s and early 1980s in North America to insulate hundreds of thousands of houses in response to the 1973 energy crisis. Complaints of health problems led to it being banned in Canada in 1980 and in the United States in 1982. The US ban was rescinded a year later but it remains in Canada. It has been declared a “known carcinogen”.

UFFI Formaldehyde Off-Gassing

The UFFI scare was based on studies that were questionable. Later studies suggested the problems were overstated. The amount of off-gassing was not consistent and largely dependent on how the product was mixed onsite.

UFFI is an open cell foam that off-gasses quickly–a matter of days. Tests done months after installation show zero amounts of formaldehyde off-gassing.

What is UFFI Used For Today?

UFFI is used in very limited applications in North America.


In Canada

UFFI is still completely banned in Canada. The last urea formaldehyde foam called Retro Foam used in Canada ended with a 13 million dollar lawsuit that the company lost.


In the United States

The number of UFFI manufacturers has gone from 39 to four or five. They all avoid using the term urea formaldehyde foam insulation; preferring the term amino foam instead.

UFFI foam is used to fill hollow concrete blocks. It provides a whole wall R-value of about R-11. The foam is fully expanded when installed and is very flowable. It flows around masonry protrusions and fills all voids. Concrete block cavities are small–making shrinkage a virtual non-issue.

Changes in chemistry have reduced the amount of off-gassing so it can be used in walls but there is almost no market for it.


In Europe

UFFI was never banned in Europe. It has been used to insulate homes since its development there. Europe and Britain never became part of the UFFI scare.

UFFI Insulation Value

Despite all of the concerns about formaldehyde off-gassing, the real problem with UFFI as an insulation product is shrinkage. The R-value of UFFI is about 4.6 per inch–better than fiberglass batts and cellulose insulation. Typical shrinkage is 0.05% but can be as much as 4%. Some cavity installations have pulled away from the studs by an inch.

Courtesy: activerain.com – UFFI installed in wall cavities. Note the amount of shrinkage.

UFFI Insulation and Moisture

Moisture causes the bond between urea and formaldehyde to break down. The breakdown reduces insulation value and allows fungus to grow in the material. Fungus spores inside the house cause symptoms similar to exposure to formaldehyde.

Should UFFI Be Removed?

The cost of removing urea formaldehyde foam insulation from a home could reach $50.000.00. Getting UFFI out involves removing all of the drywall to get at it; then re-insulating, drywalling, and painting. Sealing all of the wall and ceiling gaps and cracks and installing heat recovery ventilators (air-to-air heat exchangers) is less costly and may provide the same benefits.