Mind & Matter

 

Material Chemistry: Part 2

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[This is the second part of an interview with Michael Werner of McDonough Braungart Design Chemistry about green materials. Go here for the first part]

So, the challenges are great. Suppose you are able to track down the necessary material chemistry information—what then?
 
Assuming you obtain the level of chemical information you need, there is still an overall lack of robust toxicity, chemical-chemical interaction, and degradation data on the chemical ingredients used in products. I don't know what the latest statistic is, but I've heard that of the 80,000 to 110,000 ingredients used in commerce every day, less than one-third have been fully vetted from a toxicity perspective. The issue here is that companies have—for the most part—not been required to fully evaluate the toxicity of their chemicals and products. The Toxic Substances Control Act (TSCA) was supposed to have allowed the U.S. Environmental Protection Agency (EPA) to require manufacturers to prove the safety of their ingredients before going to market. But more than 62,000 ingredients used in commerce at the time the regulation passed were then grandfathered in, allowing their use continuously without full toxicity studies. In 2008, those grandfathered chemicals made up about 90% of the chemicals used in commerce. Then, there are companies that have done their due diligence around toxicity screening, but consider the data to be confidential business information so they withhold it from the public. The bottom line is that we need better, more publicly available ingredient and toxicity data on the chemicals we are exposed to everyday, and I'm hoping that TSCA reform will help address this problem with Lisa Jackson's tenure at EPA. I am very encouraged by those companies that are proactively creating change in the marketplace with responsible material chemistry choices rather than waiting for politicians to vote on law.
 
Yes, this country’s habitual consideration of untested materials as “innocent until proven guilty” will likely change. However, won’t it be necessary to develop a more comprehensive evaluation methodology?
 
Presently, there is no unified, robust, scholarly reviewed, and publicly available evaluation process for selecting which chemicals and materials are appropriate for use in every day products. The Global Harmonization System (GHS) has done a tremendous job establishing toxicity thresholds and labeling categories for chemicals. National and International laws also make an attempt at regulating some of bad actors. However, we need to reach the point where we can evaluate the hazard a chemical poses based on several criteria and endpoints and make a decision on whether or not it should be used in a building materials or consumer products.

What about an open-source tool?
 
This tool is in the works as MBDC is moving quickly to publish the chemical and material evaluation protocol it has been using for the Cradle to Cradle® Certification program. We’re seeing other players step up, too. For example, the Clean Production Action (CPA) has built off of our position in the marketplace around chemical hazard assessments and developed a very similar chemical assessment methodology. EPA’s Design for Environment (DfE) program is also a chemical screening tool and they’ve been doing great things to help industry evaluate the health hazards posed by chemicals in their products. However, even with these chemical evaluation processes, there is a general disagreement between two camps of people: those that believe in reducing risk and those that believe in reducing hazard. If Risk = (Hazard) x (Exposure), then I believe we really ought to be focusing our energy on utilizing low hazard ingredients in products as a way of reducing risks rather than quibbling over limited exposure scenarios for the use of high hazard ingredients in products.
 
Right. The complete life cycle of these products may not be fully controllable.
 
Exactly. If you live in an industrialized society, you have little control over the myriad of chemicals you are exposed to everyday—in your car, at work, in your home, walking down a busy street, at a restaurant, everywhere…  

Some companies are being proactive in doing the right thing, but there are too many looking to continue using the same highly hazardous ingredients and justifying that use with limited exposure scenarios and risk analyses. That being said, there is no such thing as perfect science, so you will need to make some value judgments with elements of risk analysis at the end of the day. I just don't like those situations where companies insist on using toxic chemistry because their weak risk model says that it's not a problem in a limited set of use and “end of life” scenarios.
 
What about cases when nontoxic materials are not an option for particular established uses?
 
You raise a very interesting question. Certain fire codes can actually mandate the use of toxic chemicals today where nontoxic versions may not exist. Most of the great performing flame retardants are incredibly hazardous to humans and the environment. While I believe fire safety is important, I wonder if we are going too far? The advocates would say we're not doing enough, but there are ample opportunities to allow more room for performance-based fire codes to offset the essentially prescriptive approach for what flame retardants must be used in certain materials and applications. For example, if design features of a building—such as water sprinklers—reduce fire risk scenarios, then we ought to be able to eliminate the use of highly hazardous flame retardants as a result. We know that persistent, bioaccumulative, and toxic brominated flame retardants (BFR) are used in seat cushions on commercial aircraft. There are some alarming studies showing extraordinarily high concentrations of BFRs in aircraft cabin dust. The BFRs are in the foam to meet fire safety codes that are, in part, a holdover from the days when passengers were allowed to smoke on planes. Now that smoking in commercial aircraft is a felony in the United States, the codes haven’t been adjusted to account for the change in risk scenarios. I flew more than 80,000 miles in 2010. I wonder how exposure to these chemicals could be affecting my health when they might not need to be there anymore.
   
That certainly makes me think differently about air travel. Also, the increased inclusion of post-industrial and post-consumer content further complicates matters.
 
Indeed it does. I see a tug-and-pull between the use of recycled content and the creation of healthy products. You just can’t be certain what chemicals are used in most post-consumer recycled materials. I think it’s fair to say that many people believe that a product with high recycled content must mean that it’s great for the planet, humans, and our health. What if that product is 100% recycled PVC with lead stabilizers and hormone system disrupting plasticizers?  Not so healthy, but people see it as a trade-off for managing waste. Just be careful what you ask for…

So, the dilemma here is that it if you want to use healthy ingredients and a post-consumer recycled material, it can be quite difficult to identify all chemical constituents of some materials from this feedstock with a high level of certainty, especially if you don’t know what you’re starting with. This isn't so much a problem with metals or glass, because you can reasonably perform analytical tests to identify chemical composition much more easily than plastics. Paper and plastics are a different beast because the polymer types vary tremendously and the additive packages that make plastics special are all over the map. Manufacturers add their versions of stabilizers, modifiers, flow additives, strengthening agents, colorants, cross-linkers, antioxidants, and so on. The additive packages can easily make or break a healthy plastic. So, creating a healthy recyclate requires manufacturers to use nontoxic ingredients to start with. If all manufacturers are using healthy ingredients, then consumers will not need to choose a tradeoff between post-consumer recycled content and healthy products. Underlying this, of course, is the need for a system that can effectively pool and process individual classes of polymers and other materials in an economic way so that we can continue using those healthy materials.  
 
Doesn’t this imply a kind of biomimetic transformation of the technical nutrient cycle?
 
Yes—it would be pretty revolutionary if there were a digester of some kind that could take any post-consumer recycled plastic and upcycle all the chemicals much in the same way nature biodegrades and digests plant or animal matter and upcycles those nutrients. This is easier said than done, of course, but it could be the future.

 

 
 

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About the Blogger

Blaine Brownell

thumbnail image Minnesota-based architect and author Blaine Brownell, AIA, is a self-defined materials researcher and sustainable building adviser. His "Product of the Week" emails and three volumes of Transmaterial (2006, 2008, 2010) provide designers with a steady flow of inspiration—a 21st-century Grammar of Ornament. Blaine has practiced architecture in Japan and the U.S. and has been published in more than 40 design, business, and science publications. The recipient of a Fulbright fellowship for 2006–07, he researched contemporary Japanese material innovations at the Tokyo University of Science. He currently teaches architecture and co-directs the M.S. in Sustainable Design program at the University of Minnesota. His book Matter in the Floating World was published by Princeton Architectural Press in 2011.