- Health Concerns Associated with Side A: Isocyanates
- Health Concerns Associated with Side B: Polyol Blend
- Isocyanates have been reported to be the leading attributable chemical cause of work-related asthma, a potentially life-threatening disease.
- Exposure to isocyanates can cause contact dermatitis, skin and respiratory tract irritation, sensitization, and asthma.
- Both skin and inhalation exposures can lead to respiratory responses.
- Isocyanates can cause “sensitization,” which means that some people may become allergic to isocyanates and could experience allergic reactions including: itching and watery eyes, skin rashes, asthma, and other breathing difficulties. Symptoms may also be delayed up to several hours after exposure. If you are allergic or become sensitized, even low concentrations of isocyanates can trigger a severe asthma attack or other lung effects, or a potentially fatal reaction. There is no recognized safe level of exposure to isocyanates for sensitized individuals.
- Some workers who become sensitized to isocyanates are subject to severe asthma attacks if they are exposed again. Death from severe asthma in some sensitized persons has been reported. NIOSH issued an earlier Alert in 1996, “Preventing Asthma and Death from Diisocyanate Exposure."
- Sensitization may result from either a single exposure to a relatively high concentration or repeated exposures to lower concentrations over time; this is an area where additional research is needed.
- Even if you do not become sensitized to isocyanates, they may still irritate your skin and lungs, and many years of exposure can lead to permanent lung damage and respiratory problems.
- All skin contact should be avoided since contact with skin may lead to respiratory sensitization or cause other allergic reactions. Appropriate personal protective equipment (PPE) should be used during all activities that may present exposure to any isocyanate compounds to avoid sensitization.
- Catalysts may be amine or metal catalysts
- Amine catalysts in SPF may be sensitizers and irritants that can cause blurry vision (halo effect)
- Flame retardants, such as halogenated compounds, may be persistent, bioaccumulative, and/or toxic chemicals (PBTs). Some examples include:
- TCPP -(Tris(2-chloroisopropyl)phosphate)
- TEP -(Triethyl phosphate)
- TDCP -(Tris (1,3-dichloroisopropyl) phosphate blend)
- Blowing agents may have adverse health effects
- Some surfactants may be linked to endocrine disruption
Losing their health and homes to spray polyurethane foam
When Keri Rimel's husband first came down with respiratory symptoms, he wasn't sure what caused them. He had a sore throat, congested sinuses, and runny eyes.
The day before, he has visited the construction site of their new home, where a contractor was installing spray polyurethane foam insulation. He and the architect were in the same room as the installer. "He didn't think anything of it," said Keri Rimel.
Their house in Austin, Texas was a new build. They had chosen Demilec's Sealection 500 spray foam as the only insulation and it filled every exterior wall cavity of the structure and the roof. Whenever he went back into the house, his symptoms would return.
"As soon as I went into the house, the smell would be overwhelming and my throat would clog up."Keri experienced symptoms herself when she visited the house. "As soon as I went into the house, the smell would be overwhelming and my throat would clog up," she said. "I would get chest pain on the left side of my chest. That always happened.”
Spray foam is often touted as a green building material because of its high insulation value and tight seal, which can make homes more energy efficient. The American Resource and Recovery Act of 2009 promoted spray foam as a source of green jobs that provides energy efficiency. According to the industry group Spray Foam Coalition, sales increased 29 percent from the first half of 2010 to the first half of 2012. Another industry report predicts spray foam sales to increase by 15 percent annually.
Yet as more homes and buildings are insulated with spray foam, a growing number of consumer advocates and green builders are concerned about the growing use of a product made from a number of toxic components. At the same time, homeowners around the U.S. are reporting serious health issues following the installation of spray foam or moving into a new home insulated with spray foam.
Spray foam insulation is produced during installation by mixing two liquid chemical components, referred to as "Side A" and "Side B." The liquid is then applied to the wall or ceiling with a spray gun, where it reacts and expands. Although there are toxicants in both Side A and Side B and installers are instructed to wear full body haz-mat suits, spray foam manufacturers say the final "cured" product is inert.
"The products are safe, There are no issues. The products become inert. There's no long term effect and we have over 25 plus years of history in this marketplace.""We do standard [Volatile Organic Compound] analysis on all of the products that go to market," said Robert Naini, the chief operating officer of Demilec, one of the largest manufactures of spray foam. "It's lab testing done as part of our procedures." Volatile Organic Compounds (VOCs) are chemicals with negative health effects that off-gas from a variety of solid or liquid products. Naini said that all of their products meet several established guidelines for low-emissions products, including LEED standards, standards set by the California Department of Public Health, and GreenGuard certification.
"The products are safe," said Naini. "There's no issues. The products become inert. There's no long term effect and we have over 25 plus years of history in this marketplace." Flickr/CC BY 2.0
According to the Environmental Protection Agency and the Centers for Disease Control, the issue of off-gassing is less clear-cut. The EPA recently launched a webpage dedicated to reducing the risk of chemical exposure from spray foam, which states, "The potential for off-gassing of volatile chemicals from spray polyurethane foam is not fully understood and is an area where more research is needed."
Another issue is reentry time, or in other words, when is it safe to be around spray foam without protective garments after installation? The Centers for Disease Control is currently researching this question, but some manufacturers estimate as little as seven hours while others say as many as 72 hours. There are many factors that can impact curing rates, included the type of spray foam, the humidity, the thickness of the foam, the ambient temperature, the temperature of the chemicals and the technique of the installer.
"The potential for off-gassing of volatile chemicals from spray polyurethane foam is not fully understood and is an area where more research is needed."Whatever the conditions might have been, it was unsafe for Keri Rimel's husband to be in the house at the time of installation without protective gear according to the majority of manufacturing guidelines. "No one told us to be out of the house," said Keri.
Rimel said the lingering chemical odor caused their building project to come to a halt. She and her husband delayed installing drywall to conduct air quality tests and attempted to ventilate their house. Eventually, they concluded that the foam had to be removed after testing indoor air quality tests found unacceptable levels of of VOCs, formaldehyde, acetaldehyde and hexanal. The written report from Argus Environmental, the company that conducted the testing, concluded that the Rimels should not occupy the home until the foam was removed.
But even after the spray foam had been removed, the chemical sensitization Keri and her husband suffer from made it impossible for them to stay in the house. "The fumes permeate everything," said Rimel. Even tiny amounts of chemicals can trigger their symptoms. After months of being unable to find a satisfactory solution, they sold the property.
"This new source of exposure potentially puts a large population at risk for adverse health effects."In the March 2012 edition of the Journal of Occupational and Environmental Medicine, Dr. Yuh-Chin T. Huang and Dr. Wayne Tsuang describe a case similar to the Rimels. A couple in their 30's returned to their home four hours after spray foam was installed in the attic. They almost immediately began experiencing difficult breathing, coughing, nausea, headaches and watery eyes.
The patients were diagnosed with asthma triggered by isocyanate, a chemical found in Side A and widely cited as the leading cause of occupational asthma. "The use of [spray polyurethane foam] in residential homes likely will continue to increase," they write. "This new source of exposure potentially puts a large population at risk for adverse health effects." The couple was eventually forced to leave their home after three months of trying to remediate both their symptoms and the lingering chemical odor.
Since publishing the article, Dr. Huang said he has been contacted by more than a dozen people who developed similar symptoms after being around spray foam. Although they call from around the country and he is not able to see them in person, he said most arrive at the same conclusion. "They cannot move back to their houses."
Chemicals in spray polyurethane foam: How can something so toxic be considered green?
Spray polyurethane foam is widely promoted as a green building material for its ability to improve energy efficiency. It insulates better per inch than fiberglass or cellulose, which can mean major energy saving on heating and cooling. However, energy efficiency isn't the only consideration when it comes to sustainable building. A closer look at spray foam's chemical makeup reveals a number of substances that are known to be hazardous.
Spray polyurethane foam consists of two liquid chemical components, referred to as "Side A" and "Side B," that are mixed at the site of installation. Side A is mostly made up of isocyanates, while Side B usually contains polyol, flame retardants and amine catalysts. These chemicals create hazardous fumes during the application, which is why installers and nearby workers should wear personal protective gear during this process. Once the foam has fully expanded and dried, manufacturers say it is inert. If the chemicals are not properly mixed, they may not react fully and can remain toxic. Flickr/CC BY 2.0
The risks associated with the isocyanate of Side A are relatively well-documented, but risks associated with Side B are less well understood. David Marlow at the Centers for Disease Control has been researching off-gassing associated with spray foam installation since 2010. Although Marlow was unavailable for interview, the Public Affairs office at the CDC was able to provide information about his ongoing research via email. These field studies aim to determine the extent of exposure to all the chemical components of spray foam, determine a better understanding of curing rates and establish safe reentry times, and develop engineering controls to reduce the risk of exposure.
In addition to the dangers associated with installation, these chemicals can potentially remain unreacted in the form of dust or shavings. The Environmental Protection Agency warns: "Cutting or trimming the foam as it hardens (tack-free phase) may generate dust that may contain unreacted isocyanates and other chemicals." This is also a concern during the process of removing foam.
IsocyanatesIsocyanates, such as methylene diphenyl diisocyanate (DMI), are found in the "Side A" of the spray foam mix. Isocyanates are also found in paints, varnishes and other types of foam. They are a known cause of occupational asthma. According to Dr. Yuh-Chin T. Huang, a professor at Duke University Medical Center, isocyanate-induced asthma is similar to other types of asthma, but instead of being triggered by exercise, it is triggered by exposure. Once someone has become sensitized, re-exposure can cause intense asthma attacks.
Homeowner Keri Rimel says she and her husband have both become extremely sensitive to isocyanates and other chemical smells following exposure during spray foam installation. "He still to this day can walk into any restaurant, home or office and he can immediately tell if there's spray foam in a building," said Rimel of her husband.
According to the CDC, direct contact with isocyanates can also cause a rash if it comes in contact with the skin.
PolyolAlso found in side B, polyols are alcohols that serve as catalysts. 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, an organization that advocates for building material transparency, the soy-based material makes up just 10 percent of the final insulation.
Ethylene glycol, a chemical used to produce polyol in some spray foam, can in cases of acute exposure (such as swallowing) cause vomiting, convulsions and affect the central nervous system. According to the EPA, exposure by inhalation can cause irritation in the upper respiratory system and studies in animals have shown kidney failure.
Flame retardantsFlame retardants are added to Side B to pass flammability tests in building codes. The main fire retardants used in spray foam are hexabromocyclododecane (HBCD or HBCDD) and tris(1-chloro-2-propyl) phosphate (TCPP).
According to the Centers for Disease Control, "flame retardants, such as halogenated compounds, are persistent bio accumulative and toxic chemicals." Bioaccumulation means that a chemical builds up in the body 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 enter the food chain.
A paper by Vytenis Babrauskas published in the journal Building Research & Information says that, “flame retardants whose primary use is in building insulation are found at increasing levels in household dust, human body fluids and in the environment.” The paper also cites several other studies that show these chemicals are associated with endocrine disruption and are potentially carcinogenic.
The chemical question markIn a post for the CDC, Marlow describes the components of Side B as "a chemical question mark." He described the need 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 secrets. This is particularly troubling for homeowners who want to have their air tested, because they won't know which tests to have done. "You have to tell the person testing what you're looking for," says Terry Pierson Curtis, an indoor air quality specialist. "The problem a lot of times is trying to figure out what you're looking for."
NEXT: Spray Polyurethane foam manufacturer may face class-action lawsuit
Weighing the Merits of Spray Foam Insulation
A homeowner gets conflicting advice on how to insulate a 90-year-old Cape Cod home
Mulling the benefits of foam
The house, located in Climate Zone 6, now has a 1/2-in. thick layer of rigid foam on the exterior walls. Jacobs’ plan is to insulate the house from the inside with spray polyurethane foam.
“This is my problem,” Jacobs writes in a Q&A post at GreenBuildingAdvisor. “Three companies have provided estimates now. Two say open-cell foam, 7 in. to 8 in., on the roof and 3.75 in. on the walls. One company just quoted 7 in. open-cell foam on the roof and 2 in. closed-cell foam on walls. Estimates vary between $4,500 and $5,500.”
First, Jacobs wonders, how do the 2 in. of closed-cell foam compare with 3 3/4 in. of open-cell foam? And second, for someone with not much money to spend, would installing rigid foam insulation in the rafter bays himself be a reasonable option?
That’s the topic for this month’s Q&A Spotlight.
Open-cell vs. closed-cell foamJean-Paul McGraw sums up some of the basic differences between these two types of insulation, including R-values and cost.
“The advantages of closed-cell foam compared to open-cell foam include its strength, higher R-value, and its greater resistance to the leakage of air or water vapor,” McGraw writes.
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Open-cell spray foam has an R-value of about 3.5 to 3.7 per inch and typically uses water as a blowing agent, while closed-cell foam has an R-value of about 6 per inch, he adds.
Costs, at least in McGraw’s area, average about 80 cents a square foot for open-cell foam and about $1.20 per square foot for closed-cell foam. With those R-values in mind, Jacobs will have trouble meeting energy code recommendations for his region if he goes with open-cell foam.
“A house in [Climate Zone] 6 requires R-49 insulation in the attic,” Armando Cobo says. “If your intention is to have a conditioned attic, 7.5 in. [of open-cell] foam is R-28, then you also need 3 in. minimum rigid insulation on top of the roof decking. If you want to install [closed-cell] foam, you would require 7.5 in., and it can only be installed in 2-in. applications.”
Cobo steers Jacobs toward a chart provided by Demilec, an insulation manufacturer, with more details.
“The companies that are proposing 7 inches of open-cell spray foam for your roof are only offering R-26,” adds GBA senior editor Martin Holladay. “That isn't much. In your climate zone, as Armando points out, you really want at least R-49. Don't let a spray-foam contractor talk you into accepting insulation that is less than the minimum code requirements.”
Energy codes aren’t everythingEnergy codes may call for R-49 in the roof, but that doesn’t mean it’s absolutely necessary, some commenters argue.
Among them is A.J. Builder in upstate New York, who writes that “code R-values do not factor in how well spray foam works compared to fiberglass of the same R value. Most times spray foam is not installed to code R values and yet it performs much better than fiberglass.”
Others go even further. Meeting the R-49 requirements is a “waste of money,” Eric Price writes.
“Eric is right,” adds John Pfeiffer. “IMHO the law of diminishing returns really takes a bite out of using more than 2 to 3 in. of closed-cell (depending on your location, I'm in southern N.Y., zone 4a). Don't trust the codes for telling you what is the most cost-effective way to insulate a house. They are written by people wearing suits and working in offices, not contractors.”
An R-40 roof may leak half the amount of heat as an R-20 roof, he says, but savings may amount to only pennies per square foot at the expense of adding twice the amount of insulation at double the cost.
“Also, consider what happens if your roof has a leak,” he adds. “Open-cell is a sponge and will need to be taken out and replaced; closed-cell won't show the leak and will soak the plywood until something gives.”
Our expert’s opinionGBA technical director Peter Yost added this:
Scott, it sure sounds as though you would like to optimize energy performance, taking advantage of the framing cavities being open, and do it as economically as possible, including DIY. Given all that, here are my recommendations:
- Get a sense of where to spend your money – the best two ways to do this, in my opinion, are to get a whole-house performance assessment done by a BPI-certified technician, and to use the LBNL Home Energy Saver Pro Energy Assessment Tool. I have used this on more than one project, and using the detailed assessment path, I have come within $100 of total household annual utility bills, and their recommendations are useful.
- Seriously consider the DIY rigid-foam approach to cavity fill. Yes, this is labor-intensive, but it is relatively easy to do, and you often can employ scraps of rigid foam or salvaged rigid foam insulation. The key is to not be too fussy about how your cuts fit, because you can’t cut it tight or well enough to be your air barrier anyway, so save the air sealing for later, when you spray foam all your joints and perimeters.
- Others have given solid guidance on choosing open-cell or closed-cell foam. On this, let me add that if you do choose a spray foam approach to cavity fill, be sure to use a certified installer.
- Evaluate your investment options. Martin and I just both wrote useful blogs on the topic of payback analysis – give those a look.