spray foam insulation, roof, wooden

Non-Toxic Spray Foam Insulation

Many products used in the construction of home have a potential of being dangerous to our health. This is unintentional on the part of the manufacturers, but the risk exists even so. While the wood and other major components themselves aren’t dangerous, some of the chemicals they are treated with can be toxic. One striking example of this is the formaldehyde-based adhesives used in the manufacture of plywood products.

The most common of these toxic chemicals are chemical retardants, volatile organic compounds (VOCs) and the aforementioned formaldehyde. Foam insulation is mostly going to cause problems due to VOCs, as they are dispensed as a liquid, which then dries into a solid after expanding to fill the available space. A large amount of VOCs outgas during this period of time, which is the time of greatest danger.

Few of these chemicals are openly listed as being potential health problems in product literature or on product labels, mostly because they are used in what’s known as “trace amounts.” Even those amounts are not normally an issue for the homeowner, as they flash off before the home is occupied.

Spray Foam Insulation

One of the more toxic chemicals used in home construction is spray home insulation. While the majority of the insulation in most homes is fiberglass batts, spray foam is used to fill odd areas where batts cannot be used. It can also be used for the underside of decks, attic roofs, crawlspaces, basements and even inside walls.

According to the EPA, inhaling spray foam insulation, which is polyurethane, can be very dangerous, causing potential lung damage, asthma, and other respiratory problems, in addition to skin and eye irritation. However, this risk only happens while the insulation is in its liquid state and while it is curing. Once it has cured, the insulation stops outgassing, eliminating the risk. Again according to the EPA, a window of 24 hours after spraying is sufficient to ensure that there is no risk from breathing in harmful VOCs from the insulation. Additional information from the EPA recommends a maximum period of 72 hours for safety. During this time, the site needs to be well ventilated, so that the VOCs can leave.

As an alternative to polyurethane spray insulation, there is also ultralight magnesium oxide cement insulating foam. This material, which is sold as a “green product” releases no toxic fumes while it is curing. It is perfectly safe for people and animals to be inside the home while this insulation is being applied. This is also a totally fireproof product.

Fiberglass Batts

But chemicals aren’t the only risk with insulation products. Fiberglass batts not only are made with chemicals which can be toxic, but the fiberglass fiber itself can be. Even though fiberglass batts were originally developed as a replacement for asbestos, a fibrous mineral which is a known carcinogen, there has been a lingering suspicion that spun fiberglass could also cause cancer. But in 2001, the International Agency for Research on Cancer pretty much quashed this concern by removing the materials which fiberglass batts are made of from their list of potential carcinogens.

The problem with fiberglass batts, which are used in 90 percent or more of new home construction, is that the spun fiberglass can break. This is what causes so much itching and skin irritation when it is handled. The theory is that those same tiny pieces of broken fibers can be breathed in, causing the same sort of irritation to the lining of the lungs, that it causes to the skin.

The solution to this risk is to wear a dust mask while working with fiberglass batts. Once the batts are installed and covered by drywall, there is no risk of broken fibers being in the air where they can be breathed in. There is some risk in an attic, if the batts are disturbed, but this is not a common problem, as few people spend much time in the attic with uncovered fiberglass batts.

Alternative Insulation Products

Although the fiberglass batts and polyurethane foam mentioned above are the most common insulation products used in homes today, there are quite a few other options available. In many cases, these options are less toxic or totally non-toxic. Some are even more environmentally friendly options.

The downside of most of these alternatives is that they are more expensive than fiberglass batts or foam insulation, which is why those two are the most commonly used. But if you are concerned about your health or about protecting the environment, then you may want to consider the extra cost involved in using these products.

Non-Fiberglass Batts

While fiberglass batts are the most popular insulation, due to their low cost, manufacturers provide insulation batts made from other materials, specifically:

  • Mineral wood – This is a recycled product which is naturally fire-resistant. 
  • Cotton – Cotton batts are actually made from recycled denim, making it eco-friendly.  It may be treated to repel insects, which technically means that it doesn’t qualify as being non-toxic, but that’s a manageable risk.
  • Sheep’s wool – Another recycled material with an interesting advantage. Due to the characteristics of the wool fibers, this insulation draws harmful substances out of the air, absorbing them. It also absorbs moisture out of the air, without getting damp itself. That makes it ideal for areas where humidity and moisture are issues. 
spray foam insulation, roof, wooden
Spray foam insulation, Adrian Sheils

Spray Insulation

There are also a number of other spray insulation materials to be considered, which are not polyurethane foam. While these are all sprayed, they are not all liquids that expand once applied.

  • Icynene – This is actually made of castor oil. It works similar to spray foam insulation, but does not have the toxic characteristics. It is also great for sealing leaks and drafts, as well as having excellent sound insulation characteristics. 
  • Soy – Soy foam insulation works similar to polyurethane spray foam, but without the risk of toxic outgassing. It is moisture, mold and fire-resistant. 
  • Cellulose – The most environmentally friendly option there is, cellulose insulation is a blown-in insulation made of recycled paper, mostly newspapers. Due to the way that the paper is shredded, the fibrous material can fit into small spaces. This is an especially good insulation option for attic insulation, either in new construction or when adding additional insulation to the attic. 
  • Polystyrene – Another plastic option, polystyrene is similar to polyurethane, but without the high VOC toxicity. It comes in both spray-in options as well as rigid foam boards, which have no problem with outgassing. 

Other Solid Insulation Options

If you want an environmentally friendly option in a solid insulation product, there are a few more unusual options to consider.

  • ThermaCork – Made from the outer bark of the oak trees, cork insulation is a 100% natural product, which can be installed on the inside or outside of your home. It is also a great sound absorber, which has the ability to dry out when wet. It is also naturally fire retardant. 
  • Hemp – Not yet available in the US market, look for hemp insulation to be coming soon. It is a semi-rigid insulation product, with similar R-values to fiberglass and mineral wool. If it gets wet, it can dry out naturally, unlike fiberglass which is ruined when wet.
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