Off-gassing is the emission that happens while spray foam cures - and with a correct install, it's a short, managed window, after which properly cured foam is inert. The concern people read about almost always traces back to a bad install, not the product itself.
What's happening
Spray foam cures through a chemical reaction. During and shortly after application there's an emission window; the manufacturer specifies a re-occupancy time and ventilation requirements. A trained installer follows both.
Why installs go wrong
Prolonged off-gassing or lingering odour comes from off-ratio foam, incorrect substrate temperature, or spraying too thick in one pass - installer errors. Correctly mixed, correctly applied foam cures fully and stops.
How to avoid the problem
- Use a CUFCA-certified installer working to CAN/ULC-S705.
- Follow the manufacturer's ventilation and re-occupancy times.
- Don't rush the space back into use before the stated window.
The takeaway: off-gassing is real during curing and a non-issue once cured - if the install is done right. See is spray foam safe and certifications.
Thinking about spray foam? Get a free quote from a vetted Alberta installer.