Toxic Insulation, Certified? Green Seal Needs to Hear From You

Tom Lent | March 29, 2016 | Policies

We have long counted Green Seal (GS) among the leaders in rewarding reduced toxic chemical content in building products. Green Seal did important early work to identify and certify leadership positions among wet applied products in reduced volatile organic compound (VOC) content and, importantly, also to go beyond VOCs to avoidance of other critical chemicals of concern. Their Paints and Coatings standard (GS-11), for example, offers an industry-best menu of prohibited substances.[1]

Unfortunately, a draft Green Seal insulation certification standard - the GS-54 Standard for Architectural Thermal Insulation Materials - open for comment until this Thursday, March 31, needs significant work to maintain this historical leadership position.[2] UPDATE: COMMENT PERIOD HAS BEEN EXTENDED THROUGH APRIL 7

In seeking to find products to certify in each insulation product category, the draft standard rewards insulation products that are loaded with toxic flame retardants, blowing agents with high global warming potential, and asthma causing isocyanates. Green Seal needs to hear from you about your concerns and priorities for this standard. Submit comments to Green Seal by COB Thursday.

The strength of the draft standard is uneven across product categories. It rewards products that show leadership in key toxics and environmental issues in some cases; in other cases, it does not go beyond industry norms or basic regulatory requirements. For example, the draft restricts blowing agents with very high global warming potentials in spray polyurethane foam (SPF) insulation, but allows extruded polystyrene insulation manufacturers to continue using blowing agents with even higher global warming potential, even when manufacturers have managed to replace them in other countries.[3] It prohibits the use of chemical compounds containing formaldehyde, but allows the continued use of halogenated flame retardants, despite the global availability of safer non halogenated alternatives.

In general, Green Seal takes a far more permissive approach to toxic content in this draft insulation standard than it applies to paints.   A commonly held misperception is that, because it is usually behind a wall, insulation presents less potential for exposure than interior finish products. In its rationale, the draft’s authors assert, “Once the insulation materials are installed, most of them are closed inside the building envelope and direct contact with occupants is limited.”[4]

But building material scientists say that is hardly the case.  “Both air and moisture move through a building fabric, regardless of how tightly they are constructed,” noted a team of scientists looking at halogenated flame retardants in insulation. “Substances within building cavities have the potential to migrate out of those cavities via movement driven by air, liquid and/or water vapour that occurs due to temperature, air and vapour pressure differentials. Chemicals may be present in dust from abraded materials or could volatilize and then settle in indoor dust to which building occupants could be exposed.”[5] Industry sponsored studies have also shown significant emissions through drywall, even exceeding the rate of emissions from bare insulation over time.[6]

The draft Green Seal standard allows the use of many high hazard chemicals that can be released from insulation during and long after installation, and can expose insulation installers and building occupants. It:

  • Does not categorically restrict chlorinated or brominated flame retardants, including the high hazard flame retardants, tris(1-chloro-2-propyl) phosphate (TCPP, commonly used in polyurethane foam insulation), and hexabromocyclododecane (HBCD, commonly used in polystyrene insulation).  Green Seal says it decided to exempt TCPP from restriction because it is “a common flame retardant that is not restricted by the health codes.”[7]  While technically true that “health codes” do not yet restrict TCPP regulation, these codes often lag behind the science. TCPP is found in household dust.  TCPP is structurally similar to other chlorinated flame retardants that are recognized carcinogens, mutagens, reproductive and developmental toxicants, neurotoxicants, and endocrine disruptors. HBCD is a persistent, bioaccumulative toxicant (PBT). It has been found worldwide, in human breast tissue, adipose tissue and blood. It is highly toxic to aquatic animals and biomagnifies in the environment. Over 90 percent of HBCD is produced for use in polystyrene insulation.[8] HBN recommends that Green Seal prohibit all halogenated substances in any product it certifies. (Section 3.7, Prohibited and Restricted Substances)
  • Exempts blowing agents with high global warming potential (GWP) in extruded polystyrene (XPS) insulation. In terms of global warming impact, these blowing agents offset energy savings from installing XPS insulation.  The Green Seal draft standard allows the use of agents with GWPs as high as 1,500 until the year 2021 when EPA regulatory enforcement will kick in, forcing manufacturers to use blowing agents with climate change impact potentials much closer to that of carbon dioxide, which has a GWP of 1.[9]  In so doing, this exemption supports several more years of use of HFC-134a, the most common blowing agent in XPS, which has a GWP of 1,430. HFC-134's GWP is 200 times higher than that of blowing agents used in European polystryene insulation.[10]  HBN recommends that Green Seal remove the high GWP exemption for XPS immediately. (Section 3.7)
  • Exempts and allows the use of methylene diphenyl diisocyanate (MDI) as a functional ingredient in spray polyurethane foam (SPF) and polyisocyanurate foam products.  Isocyanate vapors cause the onset of asthma disease and trigger asthma episodes. EPA warns that isocyanate vapors from SPF insulation “can migrate throughout the building if the area is not isolated and properly ventilated.  After application, vapors may linger in a building until ventilated and thoroughly cleaned.”  Even then, there is no time certain when SPF installed in a building stops off-gassing vapors. And, any cutting or trimming of SPF insulation may generate dust containing isocyanates that also may linger in a building. For these reasons, EPA warns anyone with sensitization history to beware and “consider safer alternatives.”[11]  The State of California has gone even further and targeted SPF systems containing unreacted MDI as a top priority for alternatives assessment to move inherently safer alternative materials into the marketplace.[12] Many safer alternatives are close to market ready, but progress may be stymied if Green Seal blesses MDI with a green certification. HBN recommends that Green Seal remove the MDI exemption for SPF and withhold certifying a product in the spray foam category until safer formulations are available. (Section 3.7)
  • Allows higher amounts of substances of concern than the GS-11 paint standard. The draft insulation standard allows products to contain targeted substances at up to a 0.1% proportion by weight (1,000 parts per million, ppm). Many heavy metals and biocides have toxic impacts at the 0.01% level (100 ppm, which the GS-11 uses), or even lower.  The draft insulation standard is ten times less protective than Green Seal’s paint standard. The insulation standard also uses a smaller set of hazard lists to screen substances.[13] HBN recommends that Green Seal use the same 0.01% threshold for restricted substances and the same carcinogen classifications that it has in its paint standard. (Section 3.7)
  • Does not clarify which scenario (classroom, office, or residential) would be used to determine compliance with its volatile organic compound emissions standard. The residential scenario is far more protective than the class or office scenarios. As many insulation products are used in both construction types it is important to assume a residential scenario unless the product is marketed only for non-residential applications.  HBN recommends that Green Seal require use of the residential scenario to determine compliance with the volatile organic compound emissions standard for any product marketed for residential settings and require labelling of other products that they are not certified on VOC emissions for residential use. (Section 3.4, Raw Material Sourcing)

The draft insulation standard also needs strengthening on two other pillars of green and clean production: recycled content and sustainable forest product sourcing.

Its recycled content requirement for fiberglass insulation (40%) is roughly the industry average for fiberglass insulation. HBN has identified many fiberglass batt and loosefill insulation products that substantially exceed 40% post-consumer glass content. The standard does not make the vital distinction between post-consumer and pre-consumer (manufacturing waste) content. It is also important to ensure that the recycled content does not introduce legacy contaminants. HBN recommends that Green Seal clarify whether its recycled content requirements are for post-consumer or pre-consumer sources; require recycled materials used in insulation to not contain heavy metals at levels higher than 100 parts per million as defined by state Toxics in Packaging laws; and, increase the required recovered content in fiberglass insulation to 50% post-consumer content for faced, and 60% post-consumer for loose-fill and blown fiberglass. (Section 3.1, Recycled Content)

The Standard also treats the Forest Stewardship Council’s (FSC) certification system as equivalent to three industry standards for sustainable sourcing of wood fibers.[14]  Our readers who have followed the timber wars in LEED, however, will know that there are vast differences between these certification systems. FSC is the only leadership standard of this group created by a diverse set of stakeholders. The other three standards named in the draft are industry creations, which are generally close to industry norms. The USGBC decisively determined, long ago, that only FSC represented a reliable leadership standard and rejected incorporation of the others. Green Seal staff have indicated to us that the Green Seal position is that, while FSC may be the best, fiber certified by any program is better than uncertified fiber. In fact, however, even that is not the case. There are gradations within the SFI/PEFC set of certifications, the lower tiers of which impose no meaningful restrictions and have not been demonstrated to be any better than uncertified fiber. HBN recommends that Green Seal only allow wood-based fiber that is sustainably derived, as certified by FSC (Forest Stewardship Council) (Section 3.5)

Green Seal staff welcomed our comments on the draft standard, and they will yours. They frankly acknowledge that they have been hearing from industry about their interpretations of the issues and need to hear more from users about their priorities.

HBN is concerned to see Green Seal taking a lower road than LEED on the forestry issues and providing generous exemptions for some of the most toxic substances used in insulation products today. While understanding their desire to have certifiable products in every category, we are concerned that in certain key areas, this draft standard will confuse the market by providing green certification cover for insulation that contains significant volumes of very toxic substances, even as scientists and regulators worldwide are recommending against using these products and seeking healthier alternatives.

We think that Green Seal can remain a bulwark against greenwash. This is sorely needed in the insulation market and we welcome their engagement. The draft standard, however, needs significant upgrading in order to keep it from being abused by actors in the industry who would use it to rationalize the hazardous status quo and to avoid moving any faster than required by law to invest in improved chemistries that are available now.

What You Can Do:

The Healthy Building Network urges our readers to take a look at the GS-54 draft standard website, consider our detailed comments, and submit your comments to Green Seal before its March 31 April 7 deadline. Or, if you are short on time but support our analysis, just drop us a line (email: and we’ll pass your message along to Green Seal. Thank you.

Missed the deadline? We still encourage you to contact Green Seal (email: with your thoughts and concerns.

HBN is submitting more extensive formal comments with more technical detail, which will be linked here when posted.

Extensive research, insights, analysis and editorial support for this article and our comments to Green Seal were provided by Jim Vallette and Rebecca Stamm.

[1] Unlike standards of the Master Painters Institute, Green Seal's paint standard (GS-11) prohibits the use of nonylphenol ethoxylates, suspected endocrine disruptors that are banned in Europe but rarely restricted in the United States. Green Seal Inc. “GS-11 Paints, Coatings, Stains, and Sealers (Edition 3.2).” Green Seal Inc., October 26, 2015.

[2] Green Seal Inc. “GS-54: Proposed Green Seal Standard For Architectural Thermal Insulation Materials Edition 1.0.” Green Seal Inc., February 3, 2016.,%20Edition%201.0%20-%20Green%20Seal.pdf

[3] HFC-245fa is the most common insulation blowing agent used in spray polyurethane foam insulation. It has a global warming potential (GWP) of 1030 (meaning it has 1,030 more global warming potential than carbon dioxide). HFC-245fa and three other common blowing agents -- HFC-227ea (GWP=3220), HFC-134a (GWP=1430), and HFC-365mfc -- exceed the draft standard’s GWP limit of 140. One less commonly used blowing agent, HFC-152a, with a GWP of 124, would comply with the draft standard. Also, while the draft standard in the case of SPF insulation is an improvement over the common, it could go further: hydrofluoroolefins (HFOs) -- blowing agents with GWPs as low as 1 (the equivalent of carbon dioxide) -- are now in use in SPF insulation. See: Ehrlich, Brent. “BuildingGreen Announces Top 10 Products for 2016.” Environmental Building News, December 2015. And, Lapolla Industries. “Lapolla Industries’ 4th Generation Foam Recognized in Green Builder® Media,” February 23, 2016.

[4] Green Seal Inc. “GS-54 Rationale For Proposed Green Seal(TM) Standard for Architectural Thermal Insulation Materials.” Green Seal Inc., February 2, 2016.,%20Proposed%20Insulation%20Standard%20-%20Green%20Seal.pdf

[5] Babrauskas, Vytenis, Donald Lucas, David Eisenberg, Veena Singla, Michel Dedeo, and Arlene Blum. “Flame Retardants in Building Insulation: A Case for Re-Evaluating Building Codes.” Building Research & Information 40, no. 6 (November 26, 2012): 738–55.

[6] Lent, Tom. “Formaldehyde Emissions from Fiberglass Insulation with Phenol Formaldehyde Binder.” Healthy Building Network, August 26, 2009. The surprisingly higher emissions at longer time periods may be due to slower initial offgassing immediately after installation

[7] Green Seal Inc. “Transcript. Webinar: Choosing Greener Insulation,” March 3, 2016.

[8] United Nations Environmental Programme. “Report of the Persistent Organic Pollutants Review Committee on the Work of Its Seventh Meeting. Addendum. Risk Management Evaluation on Hexabromocyclododecane.” Stockholm Convention on Persistent Organic Pollutants, November 8, 2011.

[9] US Environmental Protection Agency. “Protection of Stratospheric Ozone: Change of Listing Status for Certain Substitutes Under the Significant New Alternatives Policy Program.” Federal Register 80, no. 138 (July 20, 2015): 42807–959.

[10] According to a June 2015 Green Building Advisor article, hydrofluoroolefin (HFO) blowing agents have been used in XPS made in Europe “for some time” but not yet in North America. (Scott Gibson, “Friendlier Foam Insulation On the Way, Eventually,” Green Building Advisor, June 2, 2015,  The most commonly cited replacement, HFO-1234ze, used in XPS has a global warming potential of 6 (that is, its GWP is six times greater than carbon dioxide).

[11] US Environmental Protection Agency. “Health Concerns about Spray Polyurethane Foam.” October 14, 2015.

[12] California Department of Toxic Substances Control. “Initial Priority Product List.” What Is the Initial Priority Product List?, March 13, 2014.

[13] Unlike this draft insulation standard, GS-11 for paints also includes IARC Class 2B, and EPA IRIS Group C.

[14] “Products made from wood-based fiber that is sustainably derived, as certified by FSC (Forest Stewardship Council), SFI (Sustainable Forestry Initiative), ATFS (American Tree Farm System), other PEFC (Programme for the Endorsement of Forest Certification)-recognized labels, or equivalent,” the draft standard reads.