To create a truly sustainable circular economy, we must know what’s in the materials and products we choose, and those choices should focus on optimized chemistry for human and environmental health. Only then will we have the building blocks for a circular economy.

A circular economy is fueled by the creation and retention of value. By keeping material streams as pure as possible from the beginning and through the entire use cycle, the full value of a material is retained. Value retention is key to activating the systems that make the circular economy function, including the incentive for manufacturers to take back products because they have value and the motivation for entrepreneurs to create robust secondary markets.

Not all materials are fit for a circular economy, however. When they contain chemicals that are hazardous for humans or the environment, they provide little to no value in supporting  circularity. Fortunately there are ways to choose materials that are safe AND circular so you can build a better offering for your users and introduce valuable inputs for a sustainable economy.

To help designers, entrepreneurs, and innovators make positive materials choices and integrate better chemistry into the design process from the very start, the Ellen MacArthur Foundation and the Cradle to Cradle Products Innovation Institute (C2C PII) have released a new series of advanced learning modules as part of the foundation’s Circular Design Guide, which was co-created with IDEO.

You’ll find them in the Methods section of the guide (scroll to the “Advanced” section), which aims to fuel design thinking for the circular economy by challenging traditional design methods, delivering new approaches, and introducing users to circular economy concepts as well as techniques updated for this new economic framework.

Our study found, among other things, that the Gulf Coast region (which includes Mossville) is home to nine facilities that use outmoded asbestos technology, and home also to some of the industry’s worst polluters: Five of the six largest emitters of dioxins––a long lasting, extremely toxic family of hazardous waste that causes cancer and many other health impacts, are located there. The Bennets reminded the EPA that according to studies by a division of the Centers for Disease Control, Mossville residents have three times higher levels of dioxin in their blood than average Americans, and the dioxin levels found in their yards and attic dust exceed regulatory standards typically used for toxic waste remediations of industrial sites. Even the vegetables in their gardens tested positive for dioxin.

When I think about why we fight so hard to exclude PVC from any palette of green, healthy, or sustainable building materials, I think first of people like Delma and Christine. I then think about the many non-profits, government agencies, and private enterprises dedicated to recycling. Way back in the 1990’s, the industry Association of Plastic Recyclers declared PVC a contaminant to the recycling stream. A generation later, a 2016 study by the Circular Economy evangelist Ellen MacArthur Foundation called out PVC packaging for global phase-out, citing low recycling rates and chemical hazard concerns. Much of the concern about PVC packaging is driven by worries about ocean pollution.  HBN’s study found that at least one U.S. PVC manufacturer is routinely dumping tons of PVC pellets into local waterways and refusing to stop even after being ordered to do so by the state of Texas.

The list goes on. Our report documents the types of industrial pollution in addition to dioxin that could be reduced or avoided by a switch to more recyclable plastics that are not made with the chlorine that is an essential ingredient of PVC, including ozone depleting and potent global warming gasses. HBN’s earlier studies have documented the hazards posed by legacy pollutants that are returning to our consumer products in recycled PVC content––heavy metals such as lead, and endocrine-disrupting plasticizers known as phthalates.

As the report reminds us, it’s important to consider not only the use-phase impacts of building products, but the entire life cycle, including primary chemical production that’s several steps back from final product manufacture. 

Blowing agents are used in plastic foam insulation to create the foam structure and also contribute to the insulative properties. Over the years, manufacturers have cycled through a range of fluorocarbons as each prior class is phased out due to environmental concerns – from ozone depleting chlorofluorocarbons (CFCs) to less ozone depleting hydrochlorofluorocarbons (HCFCs) to the non-ozone depleting but high global warming potential hydrofluorocarbons (HFCs) currently common in many types of foam insulation. Manufacturers have now begun the latest shift to next generation, low global warming potential hydrofluoroolefins (HFOs). For extruded polystyrene (XPS), this translates to a shift from commonly used HFC-134a with a global warming potential (GWP) of 1,430 to HFO-1234ze with a GWP of six.2

The summary of these chemical transitions only tells part of the story. While HFOs do not directly deplete the ozone layer or significantly contribute to global warming, many HFOs use carbon tetrachloride (CCl4) as a chemical feedstock. This includes HFO-1234ze, the replacement for HFC-134a (which does not use CCl4) in many applications.3

How is it that this ozone depleting substance is still in use? Many uses of carbon tetrachloride were phased out in 1995, under the terms of the Montreal Protocol to protect the ozone layer. But the Montreal Protocol phase-outs exempted the use of CCl4 as a chemical feedstock, under the assumption that emissions would be minor.4 However, carbon tetrachloride “is not decreasing in the atmosphere as rapidly as expected” based on its known lifetime and emissions, according to a 2016 report on the Mystery of Carbon Tetrachloride. The authors of this report concluded that emissions of carbon tetrachloride during its production, and fugitive emissions from its use as a chemical feedstock, have been significantly unreported and underestimated.5

Production of carbon tetrachloride is likely to increase as industry replaces HFC blowing agents (and refrigerants), most of which aren’t produced with carbon tetrachloride, with HFOs that do use CCl4 as a feedstock.[6] With increased production and use of carbon tetrachloride, increased emissions are expected – and that’s bad news for the earth’s recovering ozone layer.

We recommend against the use of plastic foam insulation whenever possible, but if you do use it, some products are available that use other, less impactful, blowing agents, including hydrocarbons and water. For more recommendations about preferable insulation from a health hazard perspective, review our product guidance at informed.habitablefuture.org.

By applying its chemical strategy to all products in target categories, Home Depot makes important strides toward equity in the green building movement. It tracks many of the recommendations HBN provides to the affordable housing community in our HomeFree initiative. Because it impacts products at all price points, not just premium products and not just those that qualify for the retailer’s Eco-Options program, the policy ensures that all contractors and do-it-yourself customers get healthier products regardless of the brand purchased, and regardless of whether or not the product has been certified “green.” One of the qualifying products, a flat sheen paint, is the first “zero VOC” paint priced under $20 per gallon.[1] “We’re not just sourcing new healthier products, we are striving to improve our current assortment of the products we already sell,” Ron Jarvis, Home Depot Vice President of Merchandising and Sustainability, told HBN.

The vinyl/asbestos connection stems from the fact that PVC production is the largest single use for industrial chlorine, and chlorine production is the largest single consumer of asbestos in the US. [1] More than 70% of PVC is used in building and construction applications – pipes, flooring, window frames, siding, wall coverings and membrane roofing. [2] This makes the building and construction industry the single largest product sector consuming chlorine, bearing sizeable responsibility for the ongoing demand for asbestos. [3]

Despite the existence of asbestos (and mercury) free chlorine production methods, the PVC industry has positioned itself at the vanguard of industry efforts to frustrate stronger asbestos regulation. According to Mike Belliveau, the Executive Director of the Environmental Health Strategy Center and a senior advisor to Safer Chemicals Healthy Families coalition, “The PVC market has spurred chemical industry lobbyists to urge the Trump Administration to exempt their use of deadly asbestos from future restrictions.” The last time the vinyl industry positioned themselves so publicly on the other side of common sense, they were defending the use of lead in children’s vinyl lunch boxes.