Reducing intrinsic chemical hazard, GreenBuild interview, February 11 Flame Retardant Dilemma
I recently met with Paul Anastas who heads EPA's Office of Research and Development and is considered the "Father of Green Chemistry" to suggest research ideas on the impacts of halogenated flame retardants in buildings.
Paul suggested instead reading his new paper authored by by Voutchkova, Osimitz, and Anastas, Toward a Comprehensive Molecular Design Framework for Reduced Hazard (Chemical Reviews2010, 110, 5845–5882) Paul said that reducing exposure to persistent molecules was a simpler and more effective strategy than complex toxicological analyses. This important new paper reviews how to reduce the intrinsic hazards of chemicals and design rules for safer chemicals. The authors call for a dialogue between toxicologists and chemists.
They discuss the reduction of hazard or intrinsic toxicity of chemicals as opposed to the traditional risk assessment paradigm. Risk assessment, which seeks to characterize the probability that a specific exposure scenario will result in toxicity, requires knowledge of the potential toxicity and an estimate of the exposure that an organism will receive. In contrast, we can design less toxic chemicals via incorporation of specific design features that, for example, block their access into organisms (bioavailability), thereby reducing or eliminating exposure to a chemical.
Further, the authors question the traditional dose-response paradigm used for toxicology studies because endocrine disrupting and other chemicals are reported to exhibit complex, non-monotonic dose-response curves . Evidence also exists that some estrogenic chemicals are active at concentrations far below those currently being tested in toxicological studies. Given these emerging complexities in toxicology, a sole reliance on assessing risk by controlling exposure (reducing the external dose) may not be prudent.
The move to an emphasis on the intentional design of molecules that have reduced intrinsic toxicity can be facilitated by several tools. Toxicologists have generated a large amount of experimental toxicity data on diverse chemicals, which is a basis for chemists to extrapolate design rules for reducing toxicity. Since the publication of the sequence of the human genome, there have been many investigations on the complex interactions between the structure and activity of the genome and adverse biological effects caused by chemicals. With this knowledge, guidelines have begun to be deduced for designing molecules that are: not easily absorbed, distributed, or bioaccumulated; do not interfere with regulation pathways; or do not induce carcinogenic activity.
SAVE THE DATE: Friday, February 11, 2011
The Green Science Policy Institute Flame Retardant Dilemma
8:30am - 3:30pm, 150 University Hall, UC Berkeley,
To attend, RSVP with your contact information: FRDilemma@gmail.com or 510 644 3164
How can we achieve fire safety as well as protect public health? This series brings together contributors from academia, industry, government, and citizen groups to share information on the science and policy of organohalogen chemicals. New information on adverse health effects and lack of fire safety benefit of flame retardants in furniture, insulation, and other products will be presented.
Here's my interview at http://www.healthybuilding.net/, about my upcoming talk at Greenbuild, "On the Toxicity of Flame Retardants in Buildings and What to Do About It" at 8:30 on Thursday morning.
Please share with your colleagues who might be attending Greenbuild.
Igniting the Debate on Flame Retardants: Q&A with Arlene Blum
By Bill Walsh, Executive Director, Healthy Building Network
November 10, 2010
Arlene Blum is a biophysical chemist, author and mountaineer. She is the founder and executive director of the Green Science Policy Institute which works with scientists, government, industry, and non-profits to facilitate more informed decision-making about flame retardants and other chemicals used in consumer and building products. Blum is a master speaker at Greenbuild this year and will present a talk entitled "On the Toxicity of Flame Retardants in Buildings and What to Do About It" at 8:30 on Thursday morning.
HBN Executive Director Bill Walsh caught up with her on her way to prepare for her TEDx lecture last Friday.
Bill Walsh: How did you get started working on flame retardants?
Arlene Blum: Thirty years ago, as a researcher at the University of California, Berkeley, I published a paper in Science magazine showing that "Tris" flame retardants in children's sleepwear caused mutations, were possible cancer hazards, and migrated from pajamas into children. The flame retardants were removed from children’s sleepwear in 1977, but chlorinated tris is now back in use in foam in furniture and other products.
BW: Why are you so concerned about flame retardants in building materials?
AB: If a building contains halogenated flame retardants in the insulation, they can filter into the building throughout its life and also form toxic dioxins if the building burns.
I know it's a real dilemma for people when they learn that plastic insulation materials, such as polystyrene, polyisocyanurate, and polyurethane, that can help reduce climate change, often contain flame retardants which can cause serious health and environmental harm. But the good news is that this is a problem that can be solved.
Once green building professionals understand the issue, they can move to safer substitutes and strategies that don't have potential adverse health impacts. In fact of the various groups with which I've worked on reducing toxics in products, the green building community has been the most responsive. So I am very happy to have the opportunity to share the message about moving away from the use of halogenated flame retardants at Greenbuild.
The new LEED Pilot Credit on Chemical Avoidance for not using phthalates and halogenated flame retardants inside buildings should accelerate our progress towards healthier buildings.
BW: You mentioned that this is also a chemical contamination problem that could have negative impacts on our health and well-being at a global level? How?
AB: Many halogenated flame retardant chemicals are persistent and bioaccumulate especially in humans and animals high on the food chain. It is almost impossible to clean them up once they are out in the world. For example, PCBs, chlorinated chemicals that were also used as flame retardants, were banned in 1977, but very high concentrations can still be found in wildlife and some human populations today. Studies show that human breast milk contains flame retardants, and toddlers have three to four times higher body levels than their mothers.
When tested in animals, many halogenated flame retardants have been found to cause health problems like cancer, reduced fertility and IQ, thyroid disorders, and developmental impairment. Many halogenated flame retardants are also endocrine disrupting chemicals that can harm us at very low concentrations.
BW: How do you weigh the known benefits today against long term unproven risks?
AB: In furniture there is no proven benefit. It makes more sense to reduce the sources of ignition with fire-safe cigarettes and candles than to put potentially toxic chemicals in all the possibly flammable materials in our homes. Today the risk of home fires is diminishing due to a 50% decrease in cigarette consumption since 1980, enforcement of improved building, fire, and electrical codes, increased use of sprinklers and smoke detectors. These strategies provide measurable improvements in fire safety without toxicity.
Smoke and toxic gases kill people in fires, more than flames. Research on furniture fires show that while halogenated flame retardants can reduce the time for ignition by seconds, they greatly increase the carbon monoxide, smoke, and soot. The chemicals also release dioxin and related compounds when burned at relatively low temperatures. So the benefits of retarding the fire with toxic chemicals is greatly reduced by the increased fire toxicity and dioxins at the fire scene.
Given the lack of proven benefit in some cases, the risk-benefit calculation on chemical flame retardants can be tenuous even before you start to consider the widespread exposure to these chemicals on a daily basis.
Better methods of reducing fire risks include careful material selection and alternative fire suppression strategies that can be designed into products and buildings.
BW: What will people take with them from your speech at Greenbuild?
AB: I hope they will leave with the confidence that the toxic flame retardant problem can be solved, and that they can contribute. When people know about the hazards of the flame retardants that are commonly used in many plastic foam insulations, furnishings and other building materials, they can choose alternative products or push for less toxic flame retardants. I will give them the information they need to get started avoiding halogenated flame retardants. When green building professionals make these choices, this will increase the availability and decrease the cost of the alternatives.
We will also have a discussion of the new Chemical Pilot Credit - how to get it and how to improve it. The credit currently targets interior finish materials and furniture but can be even more beneficial if it includes insulation - one of the largest sources of halogenated flame retardants in the building.
Moving the market demand for flame retardants in the huge building sector can also help with policy changes. We have been providing scientific support to change a California furniture flammability standard to provide similar or greater fire safety without flame retardant chemicals.
We also need national chemical policy reform. Because of weaknesses in the Toxic Substances Control Act, which has not been updated since 1976, chemicals are innocent until proven guilty and that proof is almost impossible to obtain. Even asbestos could not be banned. And manufacturers are not required to perform any toxicity tests before putting chemicals into products! Green buildings need to be both energy-efficient and healthy. Reducing the use of halogenated flame retardants will help achieve this and help create a healthier world for us all.
What you can do to avoid toxic flame retardants and support the new LEED Pilot Credit on Chemical Avoidance ):
1. Learn more about where halogenated flame retardants (HFRs) are used in insulation and other building materials from Arlene's Green Science Policy Institute
2. Join the LEED Pilot program and use the new credit for innovative points on your current projects. Find out more at LEEDuser
3. The new Pilot Credit currently targets interior finish materials and furniture. Foam insulation (such as XPS, EPS, polyisocyanurate and polyurethane) is also a major source of HFRs in buildings. The USGBC wants to know if you are interested in exploring use of the Pilot Credit to get these toxic chemicals out of the insulation in your building in addition to, or instead of furniture. Contact the USGBC on this by commenting at the LEEDuser Pilot Credit 11 website or by writing to Leedinfo@usgbc.org
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