The UFFI confusion
Most fear around spray foam traces back to a bad product from a different era. Urea-formaldehyde foam insulation, or UFFI, was installed in Canadian homes through the 1970s and was banned from residential use by the federal government in 1980 after widespread complaints of formaldehyde off-gassing, headaches, and respiratory irritation. That history is real, and it made an entire generation of Canadian homeowners rightly cautious about foam insulation in general.
Modern spray polyurethane foam, both open-cell and closed-cell, is a different material built on different chemistry. It is a two-component system, an isocyanate (commonly MDI) reacted with a polyol resin, and it does not contain urea-formaldehyde. The name association with foam insulation is the only real link between the two products; the chemical reality is not the same, and the safety profile has to be evaluated on its own terms rather than inherited from a 46-year-old ban.
What is actually true during installation
During spraying
- Real hazard
- Isocyanates are present in aerosol and vapor form while the foam is being applied and are a well-documented respiratory sensitizer risk.
- How it is managed
- CUFCA-certified installers wear supplied-air respirators and full protective equipment, and the work area is ventilated and cleared of occupants and pets during application.
- Re-entry
- Manufacturers specify a re-entry period after spraying before the space should be reoccupied. This is followed as a fixed part of the job, not treated as optional.
After curing
- What changes
- The two-component chemical reaction finishes and the foam becomes a stable solid plastic. Off-gassing drops sharply from installation-day levels once curing is complete.
- What affects the result
- Correct mixing ratio, spray thickness per pass, and ambient temperature and humidity during application all affect how completely and quickly the reaction finishes. An under- or over-catalyzed installation can behave differently than a correctly installed one.
- Why installer training matters here
- This is precisely why CUFCA runs its Site Quality Assurance Program against the CAN/ULC-S705.2 installation standard: the material's long-term safety profile depends heavily on whether it was installed correctly, not just on the product data sheet.
Why this is a certification question as much as a chemistry question
Two crews using the identical product can produce different real-world outcomes if one follows correct ratios, lift thickness, and substrate temperature and the other does not. That is the reasoning behind asking any contractor for their CUFCA certification and installer training, not just the brand name of the foam being sprayed. Our team's certifications are public for exactly this reason.
Frequently asked questions
Is modern spray foam the same as the UFFI banned in Canada?
No. UFFI, urea-formaldehyde foam insulation, was banned from use in Canadian homes in 1980 after formaldehyde off-gassing complaints. Modern spray polyurethane foam is a completely different chemistry, a two-component polyurethane made from an isocyanate and a polyol resin, and does not contain urea-formaldehyde. The two products are frequently confused by name association but are not chemically related.
Is spray foam safe to be around during installation?
During spraying, isocyanates are present in aerosol form and are a real respiratory concern, which is why certified installers wear supplied-air respirators and full protective equipment, and why occupants and pets should not be present in the work area during application and for the manufacturer-specified re-entry period afterward. This is a real, well-understood, and manageable hazard during installation specifically, not an ongoing risk once the foam has cured.
Does cured spray foam continue to off-gas in a home?
Once the two-component reaction is complete, spray foam becomes a chemically stable solid plastic, and off-gassing drops sharply from installation-day levels. Correct mixing ratio, spray thickness per pass, and ambient temperature and humidity during application all affect how completely and quickly the reaction finishes, which is exactly what CUFCA's Site Quality Assurance Program and the CAN/ULC-S705.2 installation standard are designed to control.
Want to see our certifications before you decide?
Ask us for our CUFCA credentials and installation protocol. We'll show you both.
