Ecologic Guides · Health & Safety
Is spray foam insulation safe?
Direct answer
Cured spray foam is safe to live with. The closed-cell foam Ecologic installs passed Canada's VOC emission test, CAN/ULC-S774, at 25 hours; the open-cell product passed at 24 hours and carries Greenguard Gold certification for low chemical emissions. The risk is concentrated in the installation window, when two liquid components (one an isocyanate) are reacting: installers wear supplied-air respirators and occupants stay out. For a ventilated retrofit, the CCMC listing sets re-entry at 25 hours, a regulatory number rather than a contractor's guess. The well-publicized Canadian failure cases involved foam sprayed off-ratio that never cured properly and kept releasing odour. That is a workmanship failure, and catching it is the purpose of the third-party quality program (SQAP, run by CUFCA) named on the CCMC listing. Once foam has cured, it has no meaningful off-gassing pathway.
Sources: CCMC 14133-L · CAN/ULC-S774 · CUSE TDS 2024/2021
01 The cured material
Is cured spray foam toxic?
No. Once the two components have reacted and the foam has cured, it is an inert solid plastic, chemically similar to the polyurethane in a mattress or a car seat, fixed in place inside a wall. The question that matters is how quickly emissions decay after installation, and Canada has a specific test for that: CAN/ULC-S774, which measures volatile organic compound emissions from installed foam over time.
The closed-cell foam we install passed S774 at 25 hours; the open-cell product passed at 24 hours. Those results are on the products' technical data sheets, and the 25-hour figure carries through to the CCMC listing as the time-to-occupancy for a ventilated retrofit. In other words, the re-entry time your contractor quotes should be a number from a listing, tied to a test, and for our foam it is.
The open-cell product goes one step further: it carries Greenguard Gold certification, an emissions standard strict enough that it is used for products in schools and healthcare settings.
| Item | Closed-cell (Grizzly Gold) | Open-cell (Grizzly 005) |
|---|---|---|
| VOC emission test | CAN/ULC-S774 · pass at 25 h | CAN/ULC-S774 · pass at 24 h |
| Emissions certification | CCMC-listed occupancy time | Greenguard Gold |
| Time-to-occupancy, ventilated retrofit | 25 h (CCMC 14133-L) | Per S705.2 ventilation plan |
| Fungal growth (ASTM C1338) | n/a | No growth |
The 25-hour occupancy figure applies to a retrofit where the work area is segregated and ventilated in accordance with CAN/ULC-S705.2. It is a listed condition, and meeting it is the installer's job.
02 The install window
What happens during installation, and why you leave
Spray foam arrives as two liquids that react in the spray gun. One side of that chemistry is an isocyanate (MDI), and airborne isocyanates during spraying are a real occupational hazard: they are respiratory sensitizers, meaning repeated exposure can cause a person to develop asthma-like reactions. This is settled occupational-health science, and it is why the precautions during installation look serious. They are.
Our installers spray in full protective gear with supplied-air respirators, meaning they breathe air fed from outside the work zone rather than filtered room air. Occupants, pets included, are out of the affected area for the duration of the spray and the ventilation period afterward. The work area is segregated and ventilated in accordance with the installation standard, CAN/ULC-S705.2.
None of this should alarm you, for the same reason a welder's mask shouldn't: the hazard is specific to the work, managed by the person trained for it, and gone when the reaction is complete. The chemistry finishes fast. Foam is tack-free in seconds to minutes, and the emission testing above measures what remains afterward.
What a proper install day looks like
Before spraying: work area sealed off from the rest of the house, ventilation set up, substrate temperatures checked and logged.
During: installers in supplied-air PPE. Occupants out of the affected area. Passes applied at documented thicknesses, batch numbers recorded in the daily work record required by S705.2.
After: ventilation continues; re-entry at the listed time, 25 hours for a ventilated closed-cell retrofit. You get the re-entry time in writing before work starts.
An installer who says you can stay in the house during spraying is telling you they either don't know the standard or don't follow it.
03 The failure cases
What actually went wrong in the documented cases
Canadian media, CBC prominently among them, have documented homes with persistent odour and health complaints after spray foam installation. Those cases are real, and they have a consistent anatomy.
Spray foam only becomes the safe, inert material described above if the two components meet at the right ratio, at the right temperatures, on a substrate that is warm and dry enough. When a rig sprays off-ratio, the chemistry is left incomplete: the foam may look normal but contains unreacted components that keep releasing odour, classically a fishy, ammonia-like smell from excess amine catalyst, for weeks or longer.
That is what the documented failure cases have in common. Off-ratio spraying, foam that never fully cured, odour that never cleared. In the worst cases the remedy was removing the foam, an expensive and miserable process for everyone involved.
Read those cases carefully and the lesson is specific: the failures were workmanship failures, produced at the gun on installation day. They were also detectable early. Persistent odour is not a subtle sign, and it appears within days, well inside any complaint window. This is precisely the failure mode the Canadian quality-assurance system was built to prevent, which brings us to who checks the work.
Anatomy of a bad install
Cause: components sprayed off-ratio, or onto cold or damp substrates, leaving the reaction incomplete.
Symptom: persistent fishy or ammonia-like odour that does not fade with ventilation. Sometimes foam that is soft, glassy or discoloured.
Timeline: apparent within days of installation. This is an installation-day defect, never a slow surprise years later.
Remedy: formal complaint to the installer and the quality program; in confirmed cases, removal of the affected foam.
Prevention lives in the process: ratio-monitored equipment, logged substrate temperatures, documented passes, certified installers, third-party audits.
04 The audit system
Who checks the installer's work?
For CCMC-listed foam, the answer is written on the listing itself. This is the part of the Canadian system most homeowners have never heard of, and the part most worth knowing.
The CCMC evaluation for the foam we install names a designated site quality assurance program (SQAP) provider: CUFCA, the Canadian Urethane Foam Contractors Association. CUFCA is accredited to ISO/IEC 17024 as a personnel certification body and ISO/IEC 17020 as an inspection body, which means the organization that certifies installers and inspects field work is itself audited against international standards.
In practice, the system gives you four concrete things:
- Certified installers with photo-ID licences. Every certified installer carries a valid photo-identification licence, and the listing requires that it be presentable on request. You can ask to see it. You should.
- Third-party site audits. Installations are subject to audits by the SQAP provider, independent of the contractor being audited.
- Building-official access. Your municipal building official can request a site audit, and the manufacturer's installation manual must be on site at all times for their review.
- A daily work record. The installation standard, CAN/ULC-S705.2, requires the installer to log substrate temperatures, pass thicknesses and material batch numbers. If something goes wrong, the batch and the conditions are traceable.
The system covers work performed by certified installers on listed products. Foam bought online and sprayed from disposable kits, and installs by uncertified operators, sit outside all of it. That gap is where most horror stories start, and it is the reason our hiring guide leads with the licence check.
05 The long term
Can foam cause problems years after installation?
Foam that cured properly gives no mechanism for it. The emission testing behind the occupancy listing measures the decay of emissions after installation, and the decay is fast: the products we install reach their pass condition within about a day. A cured polyurethane matrix is chemically stable across the temperature range a building assembly ever sees, and it does not re-liquefy, shed particles into living space, or resume off-gassing.
Some specific long-term questions come up often enough to answer directly. Electrical wiring embedded in foam is normal, accepted practice; installations follow the installation standard and the electrical code, and foaming over properly rated wiring is routine in Canadian construction. Foam in contact with concrete and wood is similarly uneventful; closed-cell foam is used against foundation walls precisely because it tolerates that environment.
The honest caveat repeats the last section: everything above assumes the foam cured properly. The long-term record of properly installed foam is quiet. The bad cases announced themselves early, through odour, and stayed bad because nobody made the installer fix it.
Emissions summary
During spraying: managed occupational hazard. Installers in supplied-air PPE, occupants out.
First 24–25 hours: emissions decaying; area ventilated per S705.2; re-entry at the listed time.
After cure: inert solid. VOC test passed; open-cell additionally Greenguard Gold certified.
Years later: no off-gassing pathway from properly cured foam. Persistent problems trace to installation-day defects.
Sources: CAN/ULC-S774 results and occupancy listing, CCMC 14133-L; manufacturer TDS 2024/2021.
06 Recourse
When to worry, and what recourse looks like
The signal worth acting on is simple: odour that persists weeks after installation. Fresh foam smells for a short time, and the smell fades with the ventilation period. A fishy or chemical odour still present two or three weeks later is outside normal and should be treated as a defect, and the response is procedural rather than dramatic:
- Document everything. Dates, symptoms, which rooms, photos of the foam. Ask the contractor for the daily work record, which S705.2 required them to keep, and for the batch numbers on it.
- Put the complaint to the contractor in writing and give them the chance to inspect. A reputable installer wants to see it.
- Escalate to the SQAP provider. For CUFCA-certified work, CUFCA operates the quality-assurance program and handles complaints about certified installers. This is the leverage the Canadian system gives you; use it.
- Involve your building official if needed. They can request a site audit under the listing.
Why the paper trail matters
Every step of recourse runs on documentation the installer was already obligated to create: the licence, the listing, the daily work record, the batch numbers. A homeowner whose contractor kept those records has a traceable case. A homeowner whose contractor kept none has a fight.
This is the practical reason to hire inside the certified system, and to check the paperwork before the rig arrives rather than after a problem appears. The hiring checklist covers exactly what to ask for.
07 Questions
Spray foam safety, answered
How long do we have to stay out of the house?
For the closed-cell foam we install, the CCMC listing sets time-to-occupancy at 25 hours for a retrofit where the work area is segregated and ventilated to CAN/ULC-S705.2. That is a listed regulatory number tied to the product's VOC testing, and it should appear on your quote in writing. Whole-house new-construction situations and unusual ventilation conditions can change the plan, so ask, and expect a specific answer rather than a shrug.
Source: CCMC 14133-L · CAN/ULC-S705.2
Is spray foam toxic?
The liquid components are hazardous and the reaction releases isocyanates, which is why installers wear supplied-air respirators and occupants stay out during the work. Cured foam is a different material: an inert solid plastic. The products we install passed Canada's VOC emission test, CAN/ULC-S774, at 25 hours (closed-cell) and 24 hours (open-cell), and the open-cell product carries Greenguard Gold certification for low chemical emissions.
Source: CUSE TDS 2024/2021 · CAN/ULC-S774
What is the fishy smell some people report?
A persistent fishy or ammonia-like odour is the signature of foam that was sprayed off-ratio and never fully cured, leaving unreacted amine catalyst in the material. Properly mixed foam has a mild odour that fades as it cures and clears within the listed occupancy window. A smell that persists for weeks is a workmanship failure and grounds for a formal complaint, and in bad cases the remedy is removal of the affected foam.
Can spray foam cause health problems years later?
Foam that cured properly is an inert solid with no meaningful off-gassing pathway; the emission testing behind the occupancy listing measures the decay of emissions after installation, and the documented long-term problem cases trace back to installation-day failures, usually off-ratio mixing, that were detectable early as persistent odour. If your foam has been odourless since the install, the evidence gives no reason to expect trouble years later. If odour never went away, address it now rather than living with it.
Is open-cell foam safer than closed-cell?
On emissions, no meaningful difference: both products pass CAN/ULC-S774, at 24 hours for the open-cell foam and 25 for the closed-cell, and the open-cell product additionally carries Greenguard Gold. Both use the same isocyanate chemistry during installation and call for the same precautions. The real differences between them are structural and moisture-related, which is a question of where each belongs in a building, and a safety-neutral one.
Source: CUSE TDS 2024/2021
Who checks the installer's work?
For CCMC-listed foam, a designated third-party quality assurance program named on the listing itself. For the foam we install that is CUFCA, accredited to ISO/IEC 17024 as a certification body and ISO/IEC 17020 as an inspection body. Installers carry photo-ID licences presentable on request, sites are subject to third-party audits, building officials can request a site audit, and the manufacturer's installation manual must be on site at all times.
Source: CCMC 14133-L
08 Sources
Primary documents
- CCMC evaluation listing 14133-L: time-to-occupancy, SQAP designation, audit and licence provisions.
- CAN/ULC-S774 (VOC emissions from installed foam) and CAN/ULC-S705.2 (installation standard, including ventilation and the daily work record).
- CUSE Grizzly Gold technical data sheet (2024) and Grizzly 005 technical data sheet (2021): S774 results, Greenguard Gold certification, fungal-resistance testing.
- CUFCA, the Canadian Urethane Foam Contractors Association: installer certification and the site quality assurance program.
- CBC News reporting on Canadian spray foam failure cases (off-ratio installations with persistent odour), which informed the failure-case section.
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