Is Foam Board Insulation Safe To Breathe? | Plumbing Appliances (2022)

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Foam board insulation is an excellent solution for homes that are looking to reduce their energy bills. You can install this type of insulation in both walls and ceilings.

However, it requires a professional installer, so you don’t have to worry about mess or safety issues.

Foam board insulation comes in two types – open-cell foam and closed-cell foam. Closed-cell foam is much more effective at reducing noise levels.

This makes it perfect for bedrooms or other rooms where silence is essential.

Open-cell foams are usually used as fillers when building high-performance walls that need strong thermal resistance.

A foam board is building insulation made from rigid foam, which can be open or closed cells. The two types of foam boards are often called “blueboard” and “yellowboard.”

Foam board insulation uses an adhesive to attach the boards directly to the structural elements of a home.

This reduces heat loss by creating a continuous barrier across interior walls and ceilings.

Once installed, you cannot remove a foam board without damaging the wall or ceiling it’s attached to.

A typical foam board has a top layer that resists moisture and an aggressive bottom layer that makes installation quick and easy for contractors.

These panels comprise polystyrene or polyurethane, but they may also include specific features such as a vapor barrier, antimicrobial additives, or a fire-resistant coating.

These panels are especially popular in colder climates because they can help reduce heat loss by 25 percent or more at home.

Is Foam Board Insulation Safe To Breathe?

No. Foam board insulation boasts toxic flame retardants in its formula to meet safety guidelines.

These flame retardants are polybrominated diphenyl ethers or PBDEs, and they can be harmful in several ways.

They have created foam board insulation by compressing closed-cell foam in a press until it hardens into a rigid sheet.

According to Energy Star, it’s often found as blue boards in homes and schools because it resists moisture and has an R-value of 5 per inch.

However, this type of insulation comes with a risk: PBDE exposure can cause problems from skin irritation to reproductive issues for both men and women.

And if the flame retardant chemicals leach from this type of building material, there could also be health effects from breathing the fumes.

Is Foam Board Insulation Safe To Breathe? | Plumbing Appliances (1)

PBDE is a flame retardant that you can find in insulation. PBDEs cause reproductive and thyroid problems, as well as skin irritation.

There’s also evidence of PBDEs causing cancer, but there is no confirmation yet. With one compressing the foam board insulation to create it, there is an increased risk of leaching.

Thus, if you have any concerns with your insulation.

Try to find out if it contains these chemicals and considers changing it or leaving your home for a bit before entering until the fumes disperse.

If you’re ventilating your space and not inhaling too much of the toxic fumes.

Then foam board insulation should be safe to breathe, but there’s no guarantee, so it’s best to err on the side of caution.

Does Foam Board Off-Gas?

Yes. Foam board off-gases very bad, worse than pressurized cans.

Therefore the manufacturers of most spray paint ban it for sale on Amazon and eBay (and elsewhere on the internet).

They will sell you a can that says “airbrushing only” or similar to it; this is to allow them to say there was no VOCs in their product because they only used compressed air.

But if you use pressurized gas as you would in a CAFÉ or PAC unit, which always uses nitro and co2 (carbon dioxide).

Then be aware hydrogen cyanide gas will most definitely come out of your foamboard while it is drying.

Which is better, EPS or XPS?

EPS is better than XPS . EPS stands for expanded polystyrene, and this stuff is one of the most popular forms of plastic available.

It has been in use in a wide range of industries since it became commercially viable.

If you need something that will be lightweight, strong, and puncture-resistant, then EPS is a great option. It also offers good insulation.

Thus if used to provide warmth in the winter or coolness in the summer, it can have an impressive impact on performance.

EPS foam has become more common as a building material in recent years, with architects recognizing how versatile it can be.

The bad news is that while EPS is great, there are still some negative aspects associated with its use.

For instance, if it’s exposed to humidity, it absorbs the moisture and becomes weighed down.

It’s also not strong in low temperatures, which can make it unsuitable for outdoor use.But there are different ways around these problems.

Such as painting or spraying EPS foam surfaces with water-resistant paint or using them inside where they’re less likely to be exposed to humid conditions.

Another option is to cover plastics in an exterior grade laminate coating which will protect against all kinds of weather and environmental conditions.

Because of its application’s wide-ranging benefits and simplicity.

EPS has established itself as one of the most popular choices for packaging and insulation among global manufacturers.

Can I Leave Foam Board Exposed?

No, it would be best if you always covered exposed foam board with either wallpaper or paint.

This is because exposed foam board can absorb any moisture in the air, which will cause it to expand and warp.

Additionally, if exposed for an extended period, the unexposed areas may discolor from being close to the foam board while absorbing moisture.

Sometimes, if there is a minimal amount of exposed foam board with flat black color, it might be okay aesthetically.

However, this would have to be carefully determined on a case-by-case basis. Test out the particular paint mixture on a small area if it’s covered with paint before attempting this.

Inside areas are fine to leave foam board exposed unless the unexposed sections are absorbing moisture.

Specifically, if they are in contact with humid air near or around windows or stairwells, you should cover it if you want to minimize warping because of humidity levels.

The lower the humidity, the better (i.e., don’t put your house near swamps).

Sometimes attics can get very hot during summer, so it’s best not to use them for storage until winter when they cool off because heat can cause expansion/warping problems.

Is Foam Board Toxic?

Yes.A foam board is a core made of polystyrene sandwiched between two sheets of paper.

It can be simply glued or stapled together but not hammered or nailed because it would cause the core to crumble and break apart.

Styrofoam is a brand of foam board that is also made from polystyrene.

However, unlike other brands, which are white on one side and pink on the other, Styrofoam is blue on both sides.

There have been multiple studies on the toxicity of styrene [3], an ingredient in polystyrene.

Some studies suggest that exposure to styrene causes urethra and epididymal cancers in rats.

It also increases the number of nose and lung tumors in rats exposed to Zyklon B (a type of cyanide gas).

Other studies, however, show no cancerous effects on male or female rats exposed to styrene;

Nor do they cause cancer in mice, hamsters, guinea pigs, rabbits, primates (rhesus monkeys), dogs, or other animals.

The “US Department of Health and Human Services” has determined that human exposure to styrene is low enough not to be a health hazard.

Therefore, it’s still legal to use polystyrene as an insulating material for food packaging.

Does Foam Board Need A Vapor Barrier?

No, often not. Foam board is simply made of expanded polystyrene (EPS). It has a high resistance to moisture transfer.

Thus there is no need for a vapor barrier unless it’s needed to control the temperature of the interior space.

Styrofoam® is another type of foam used in insulation boards with somewhat unique properties.

But most commonly with an aluminum foil facer that forms a vapor barrier on one side.

Styrofoam® may have an interior paper facing as an air retarder and can sometimes act as a vapor barrier.

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However, styrofoam® insulations are more often used with the foil facing exposed or faced on both sides with kraft paper or another similar product having low perm rates.

Is Pink Foam Board Flammable?

Yes, the pink foam board is flammable. The dark pink (and black) ones burn even faster than the white.

For safety precautions, always use proper fire extinguishers and smoke detectors in burning or an emergency.

You should never take fire lightly; you must stay on guard with all fires near your home or at work. Dont leave a fire unattended for any reason.

Does Styrofoam Catch On Fire In A Microwave?

No, Styrofoam does not catch fire in the microwave. The material is highly flame resistant and doesn’t burn easily.

The material is not combustible, and so it does not catch on fire.What can happen, however, is the Styrofoam melts.

When microwaving food in plastic containers, it’s best to be sure that the plastic isn’t made of polystyrene.

If it melts, there could be a potential for leaching chemicals into your food.So unless you are using microwave-safe plastic containers.

Avoid putting any plastics in the microwave when trying to heat something or use an alternative heating method like stovetop or oven.

Styrofoam is widely used thermoplastics available today.

It has been around since about 1941 – as disposable packaging – but now it is also used for applications like insulation and home construction.

The “Styrofoam,” which you can buy at Home Depot or other paint stores, is simply extruded polystyrene foam (XPS),

Not expanded polystyrene (EPS) like what’s found in disposable cups, plates, bowls, and cutlery.

XPS is the rigid type of EPS, where EPS offers a range of densities from about 1.5 pounds per cubic foot to over 5 pounds per cubic foot.

Are There Dangers Associated With Rigid Foam Insulation?

Yes, there are some significant dangers that rigid foam insulation can cause. One of the most common problems is when the rigid foam insulation comes in contact with a flame.

When this happens, it can cause a fire to start or make an existing fire burn faster and hotter.

The rigid foam insulation burns so easily that sometimes even a fireplace log, lit at one end with a match.

This will quickly burn all the way across because it melts right through the material.

The problem exists because these types of insulation use many dangerous chemicals to create their fire resistance properties

— including vinyl ester resin and Penta-fame equation [PFAs]. Vinyl ester resins release hydrochloric acid when burned, while PFA emits hydrogen fluoride gas when burned.

Once a piece of the rigid foam insulation is on fire, it will keep going until someone with a fire extinguisher extinguishes it or the fire burns itself out.

It’s also important to note that even water from a garden hose won’t put out a piece of this type of insulation.

Once it burns like the hot gases inside cause water to steam before even reaching the actual material.

Additionally, these types of insulation release carcinogens and hazardous pollutants into the air for many years after installation.

Which can pose additional hazards to people living in those homes.

Rigid foam insulation needs to be carefully installed because it poses dangers if improperly handled during its application process.

Rigid foam can burn away at an alarmingly fast rate, which is why it’s essential to research any contractor before allowing them to use this type of insulation for a home project.


If you’re a homeowner trying to decide if EPS or XPS insulation is suitable for your needs, it’s essential to understand the differences between the two.

To be clear, both are safe and effective at insulating homes from heat loss in cold climates and cooling costs in hot weather zones.

However, some key differences may affect which one would work best for your situation: durability of foam board (EPS can last up to 15 years while XPS lasts about 10).

Fire safety (XPS has less chance of catching on fire due date because it doesn’t use petroleum products as EPS does) and cost (about $1 more per square foot).

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