Is Spray Foam Insulation Safe? What You Need To Know
August 4th, 2023
5 min read
When you first heard about spray foam insulation, you thought it was a good idea. After some research, you're not so sure anymore. You came across stories of spray foam gone wrong. Terms like off-gassing and toxic chemicals popped up.
If spray foam is made of chemicals, why would I want to put that into my house? What if something goes wrong? Am I going to regret investing in spray foam to insulate my home? Could the worst happen to me?
These are valid concerns. It can be sad and scary to read personal stories of people who were confident in a product that failed them. As contractors, we don't want any customer to regret their decision.
South Central Services has performed hundreds of spray foam installations throughout Greencastle and other areas of southern Pennsylvania. We have made minor repairs on less than 1% of our jobs, and have never had a complete installation failure. We work with homeowners and builders every day to create the best insulation solutions for their projects.
By the end of this article, you'll understand:
- What spray foam is made of
- How spray foam insulation is made
- What off-gassing is
- How long off-gassing will occur
- Why spray foam insulation must be installed by trained professionals
Don't have time to read right now? Check out everything you need to know at a glance.
Spray Foam Insulation Is Safe When Installed Correctly.
It is possible for spray foam insulation to be unsafe. Spray foam is created through a chemical reaction. For the chemical reaction to have the right results, several variables have to be controlled.
A qualified professional contractor has the equipment and expertise to ensure that chemical reaction is successful. However, not every advertised spray foam installer is qualified for the job. One of the biggest problems with the spray foam industry is the lack of training.
Spray foam insulation should only be installed by trained professionals to ensure that the finished product is safe and effective.
Let's examine the spray foam chemical reaction in greater detail, so you can understand where spray foam installations could go wrong.
What Is Spray Foam Insulation Made Of?
Spray polyurethane foam insulation (SPF) is created by two chemical components: the A-side and the B-side. Contractors receive these components from spray foam manufacturers, usually in 55-gallon drums. There is a drum for the A-side and a drum for the B-side.
The A-side is isocyanate, and the B-side is a polyol blend. Those are both big words, so let's break down what these chemicals are.
Isocyanate is a byproduct of refining petroleum. When we make things like gasoline and diesel oil, we also generate byproducts that can create isocyanate. It exists in many products we use every day. A few examples of everyday products with isocyanate include the seats inside cars, memory foam mattresses, and the soles of shoes.
Polyol is an organic compound that is used as a resin component. At the molecular level, polyol is made of up hydroxyl groups, which are an oxygen atom covalently bonded to a hydrogen atom.
When the A- and B-sides mix, their chemical reaction forms them into a polyurethane, which is a type of plastic.
How Do A-Side And B-Side Make Spray Foam Insulation?
How do two giant buckets of liquid chemicals turn into foam? It's a chemical reaction.
The A-side and B-side are pressurized and heated to a specific temperature. The heat, combined with high pressure, atomizes these chemicals as they leave the spray gun. Atomizing means that the liquids turn into tiny uniform particles, allowing them to mix effectively. The liquids react to create plastic foam, which expands and sticks in place.
After the chemical reaction has occurred and the foam has cured, spray foam insulation is safe and stable. Properly installed foam insulation is safe to touch, breathe near, and even to cut pieces from.
You could compare spray foam insulation to table salt. Table salt is made of two elements from the periodic table: chlorine and sodium. These two elements are poisonous and not something we would eat. But when they combine to form sodium chloride, they create something safe to sprinkle on our food.
Similar to the elements of table salt, the individual chemicals that make up spray polyurethane foam are not safe to touch or breathe. When combined on ratio and installed properly, spray foam is an inert product and safe to live with.
What Is Off-Gassing?
A byproduct of the chemical reaction that creates spray foam is off-gassing. Off-gassing is a common phenomenon. Remember the car seats, memory foam mattresses, and shoe soles we mentioned earlier? New car smell and new shoe smell are both examples of off-gassing. Manufacturers recommend that memory foam mattresses should air out in a garage for a day before anyone sleeps on them.
We should not inhale off-gassing fumes. To protect themselves, foam insulation contractors wear suits and respirators while they spray. Building occupants, including pets, are required to vacate. To protect any belongings inside the home, contractors set up ventilation to direct off-gassing fumes outside the home.
Twelve to twenty-four hours later, after the foam has cured, there is no more chemical reaction. There is no more A-side or B-side, just polyurethane foam.
If there's no more chemical reaction or chemicals, there is no more off-gassing.
Continuous Off-Gassing
One of the warnings you may see online about spray foam insulation is the possibility of continuous off-gassing. There are devastating stories of families abandoning their homes due to health concerns from fumes. How could this happen?
Continuous off-gassing means that the spray foam insulation was not installed correctly. Specifically, spray foam insulation that continues off-gassing was not installed in a 1:1 ratio.
There is still some chemical left that did not react to create foam because there was not enough of the other chemical to react with.
So, Is Spray Foam Insulation Safe?
The finished product of spray foam insulation is safe if it was installed correctly. The only hazards or risks it can pose are during the application process when the chemical reaction happens. The residents are not there during that process, and the contractors wear personal protective equipment for safety.
Twelve to twenty-four hours after application, the chemical reaction is done. There are no chemicals left to react. Any off-gassing has been ventilated, just like airing out a new mattress.
However, that finished product can only be safe through correct installation by professionals. Spray foam insulation is not a product that is safe for the average person to install. It is not unsafe because the finished product is harmful but because the application process requires training and precision.
To be set up for success, the process should start in a professional rig that can control and monitor the ratio of the foam. DIY spray foam kits cannot provide this control and result in an inferior product.
Creating insulation from spray foam is more complex than pointing and spraying. Contractors spray at the right thickness and density for the foam to be effective insulation. Contractors must also consider other factors like climate, humidity, and the surface they are spraying.
The Bottom Line About The Safety Of Spray Foam Insulation
The stories of failed spray foam insulation can be frightening. You can't help but feel empathy. As spray foam professionals, we are confident in diagnosing those instances as the wrong foam, in the wrong place, installed the wrong way.
For the right application, the right spray foam installed the right way is an excellent and safe insulation option. But even if you learn all there is to know about spray foam, it still needs to be applied by a professional contractor.
Now that you know spray foam insulation is safe when installed correctly, your next step is to:
- Learn how to find a qualified spray foam installer
- Decide if spray foam insulation is worth the cost
- Discover how long spray foam insulation will last
Alexis has been fascinated by spray foam insulation since 2018. When she isn’t thinking about insulation, Alexis is geeking out over storytelling and spreadsheets.
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