Spray polyurethane foam is widely promoted as a green structure product for its capability to enhance energy performance. It insulates much better per inch than fiberglass or cellulose, which can mean major energy saving on heating & cooling. However, energy performance isn’t the only consideration when it comes to sustainable building. A closer look at spray foam’s chemical makeup exposes a number of substances that are known to be hazardous.
Spray polyurethane foam includes two liquid chemical parts, described as “Side A” and “Side B,” that are mixed at the website of installation. Side A is mostly made up of isocyanates, while Side B normally consists of polyol, flame retardants and amine drivers. These chemicals develop dangerous fumes during the application, which is why installers and close-by employees ought to wear individual protective equipment throughout this procedure. When the foam has totally expanded and dried, manufacturers say it is inert. If the chemicals are not effectively combined, they may not react fully and can stay hazardous.
The threats associated with the isocyanate of Side A are reasonably well-documented, however threats associated with Side B are less well comprehended. David Marlow at the Centers for Disease Control has been researching off-gassing connected with spray foam installation considering that 2010. Marlow was unavailable for an interview, the Public Affairs workplace at the CDC was able to offer details about his ongoing research study by means of email. These field studies intend to determine the level of exposure to all the chemical parts of spray foam, figure out a much better understanding of curing rates and establish safe reentry times, and establish engineering controls to lower the threat of direct exposure. In addition to the risks associated with setup, these chemicals can possibly stay unreacted in the form of dust or shavings. The Environmental Protection Agency warns: “Cutting or trimming the foam as it solidifies (tack-free phase) may generate dust that may contain other chemicals and unreacted isocyanates.” 1 This is likewise an issue throughout the procedure of getting rid of foam.
Isocyanates, such as methylene diphenyl diisocyanate (DMI), are discovered in the “Side A” of the spray foam mix.2 Isocyanates are also found in paints, varnishes and other types of foam. They are a known cause of occupational asthma.3 According to Dr. Yuh-Chin T. Huang, a professor at Duke University Medical Center, isocyanate-induced asthma is similar to other types of asthma, however instead of being activated by exercise, it is triggered by exposure. Re-exposure can trigger intense asthma attacks.2 as soon as somebody has ended up being sensitized.
Property owner Keri Rimel states she and her husband have both end up being exceptionally conscious isocyanates and other chemical smells following exposure during spray foam installation. “He still to this day can stroll into any dining establishment, office or home and he can right away inform if there’s spray foam in a structure,” said Rimel of her husband.
According to the CDC, direct contact with isocyanates can also trigger a rash if it can be found in contact with the skin.
Amine drivers are among the Side B chemicals that the CDC is looking into, in an effort to comprehend the levels of exposure during installation. “Amine catalysts in [spray polyurethane foam] may be sensitizers and irritants that can trigger fuzzy vision (halo effect),” they write.4.
According to a report released by the Consumer Product Safety Commission, amine drivers can also irritate the eyes, skin, and breathing system and if consumed “may likewise cause a reversible result referred to as glaucopsia, blue haze, or halovision in the eyes.” 5.
Also discovered in side B, polyols are alcohols that work as drivers. Polyols are usually made from adipic acid and ethylene glycol or propylene oxide. Some polyols are made from soy, but according to the Pharos Project, a company that advocates for constructing material transparency, the soy-based product makes up simply 10 percent of the final insulation.6.
Ethylene glycol, a chemical used to produce polyol in some spray foam, can in cases of intense direct exposure (such as swallowing) cause vomiting, convulsions and affect the central nervous system.7 According to the EPA, exposure by inhalation can trigger inflammation in the upper breathing system.
Flame retardants are contributed to Side B to pass flammability tests in building regulations. The main fire retardants utilized in spray foam are hexabromocyclododecane (HBCD or HBCDD) and tris (1-chloro-2-propyl) phosphate (TCPP).
Bioaccumulation means that a chemical constructs up in the body much faster than it can be flushed out, so there can be a risk of chronic poisoning even if the level of exposure is low. The chemicals also build up in the ecosystem, where they go into the food chain.A paper by Vytenis Babrauskas published in the journal Building Research & Information states that, “flame retardants whose primary usage is in constructing insulation are discovered at increasing levels in household dust, human body fluids and in the environment.
The Chemical Question Mark.
In a post for the CDC, Marlow explains the components of Side B as “a chemical question mark.” 10 He described the requirement for “real-world sampling.”.
In addition to those listed above, there may be other chemicals used in spray foam that are undisclosed and are protected trade tricks. “You have to tell the individual testing what you’re looking for,” says Terry Pierson Curtis, an indoor air quality expert.