Spray Foam Off Gassing: Myths and Facts

Feb 3, 2026

Jamie Unruh

Spray foam as an insulation product is becoming a growing trend in the construction industry. It can be installed in large areas in a short amount of time, it’s quick to set, and it creates a permanent airtight insulation system that saves homeowners money on their energy bill. And as with most newfangled things, there are myths that abound, especially when it comes to off gassing of spray foam. It’s a topic that our clients bring up often, so we want to address some of those non-truths and give the straight scoop on where the dangers of spray foam really lie.

"there are myths that abound, especially when it comes to off gassing of spray foam."

Myth #1: Spray Foam is Toxic

It’s important to note that when spray foam is being installed there are two very different occurrences regarding the air that are happening: atomization and off gassing.

The toxicity of spray foam is often overexaggerated because there is confusion between the two different reactions. Off gassing does happen, but it’s minute, certainly less than other plastics that are in your home.

At Beyond, we're less concerned about off gassing and more concerned about the atomization that develops when the foam is being sprayed.

The atomization of the raw liquid product is actually the dangerous part.

Because it’s a pressurized system, the two liquids (isocyanate and polyol resin) being mixed will naturally atomize into the air as a mist. That mist becomes breathable and that’s not a good thing.

Isocyanate reacts with water and crystalizes, and humans being made of 60-70% water makes for a bad combination. That’s why our crews wear personal protective equipment (PPE) during the installation and why we ask homeowners to leave the premises during the project.

Off gassing occurs after the foam has been sprayed and while the foam is curing, it’s no more dangerous than the off gassing of plastics on a new toy. We encourage homeowners to vacate their homes for 24because we want to go above and beyond the standard safety measures that manufacturers require. More on that later.

When it comes to off gassing, our Technical Data Sheet (TDS) doesn’t provide the number because it’s so small the instruments used to detect any danger can’t measure it.

The finished foam product is inert. In fact, some employees joke that you can eat it! Obviously, we don’t recommend sneaking a taste, it is still plastic after all, but it goes to show that spray foam is really quite safe.

To summarize, the foam itself is not dangerous, the raw products that we use to create the foam are dangerous, which is why you want to make sure that you have a trained professional and a very experienced company doing the work.

Myth #2: Spray Foam is the New Asbestos

Due to the myth that spray foam is toxic, it has been said that foam is the new asbestos and that in due time spray foam will also be banned as a construction product.

Well, that’s simply not true. Spray foam has been around for decades. It’s been used in homes for the better part of 30 years. It’s been used in the automotive industry, in furniture, and even in space rocketry!

A NASA space shuttle’s external fuel tank was fully spray foamed(the orange colour came from the foam reacting to UV light) to insulate and maintain optimal low temperatures during launch.

The myth that spray foam could be the new asbestos might come from the fact that the foam used to contain formaldehyde. This type of foam was used in houses in the 1950s and 60s, so when crews come across old foam like this, which is not often, it is treated as asbestos, and they will call on our friends at Wise Abatement to remove it as a precaution.

Formaldehyde foam isn’t common. At Beyond we’ve seen it very few times and as such was in a very small area.

Myth #3: Spray Foam Causes Mold

The myth that spray foam causes mold has come about due to poor installation or using the wrong product, not the foam itself. The appearance of mold is usually due to any kind of insulation install gone awry whether it be foam or fiberglass or any other product.

Currently in the United Kingdom, there’s a lot of issues with mold in a spray foam environment.

Being a cool and humid climate, the UK is more susceptible to mold anyway, especially in very old, timber-framed homes that are not airtight as newer homes.

Many homes have seen the installation of the wrong product into those types of older homes, which have produced mold. In this instance, the use of open cell foam was the problem. Open cell foam doesn’t do well is colder climates, so a 2-pound closed cell foam (which we generally use here in Calgary) is what should have been used.

The use of the wrong type of foam has become such a problem in the UK that insurance companies won’t insure homes insulated with spray foam.

Foam is not an organic product so it can’t make mold appear, however, air leaks that cause condensation does create mold.

"it can’t make mold appear"

Beyond Goes Beyond

As mentioned above, we like to go above and beyond the standard safety measures for spray foam that manufacturers require.

We require homeowners to not be on site during the foam installation and for 24 hours afterwards to allow the air to vent out. The standard is that 30% of the air that's in the building needs to be replaced every hour for24 hours with fresh air.

In an attic installation, manufacturers usually don’t require people to vacate the house because it’s contained in one area outside the insulation enclosure.

But our standards are more strict. The reason we are spraying the attic is because it’s not 100% sealed, and we want everyone to be safe. Plus, the attic access is open during the installation, so we err on the side of super cautious for our peace of mind and our clients.

In situations such as spraying an apartment building attic where not everyone will need to leave, Beyond will take extra precautions to ventilate and seal off any doors or openings to limit exposure inside the building.

Where there’s a small area of floor being sprayed from the exterior and homeowners don’t want to leave the home for so long, sometimes just being away during the install is enough. Those judgement calls are made by management on a case-by-case basis.

There is a very small percentage of the population that is born desensitized to chemical isocyanate. A small whiff of this chemical can cause an allergic reaction including a sore throat, runny nose, watery eyes and soon. Because Beyond Group has grown as a company and are taking on more spray foam jobs, we are dealing with more and more clients which might increase the chances that someone will react in this way. So having homeowners leave the house is just another layer of safety we want to ensure just in case they are one of the very few who might react.

If you have any questions or concerns at all, please don't hesitate to reach out to us. We want to help as many people as we can be properly informed about insulation.

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