In the report, we created a framework for evaluating what a truly sustainable plastic product would look like. These goals are lofty, and currently no existing plastic building materials meet these goals. However, they provide a pathway towards truly sustainable products.

To be considered a sustainable plastic, a product would have to enhance human and environmental health and safety across the entire product life cycle. It would have to be managed within a sustainable materials management system, and would have to meet the following goals: 

• Must be inherently low hazard. 
  • Hazardous substances are eliminated.
  • Transparency in terms of content and emissions exists at every step of the supply chain.
  • Full hazard assessments are available on all chemicals.
• Must have a confirmed commercial afterlife.
  • Products designed for durability, reclamation, reuse, and recycling.
  • Infrastructure exists to support reclamation, reuse, and recycling.
  • Materials can undergo multiple cycles of recycling.
• Must generate no waste.
  • Manufacturing scrap is eliminated at every step of the production process.
  • Scrap from installation is eliminated.
• Must use rapidly renewable resources or waste-derived materials.

The case study explores trade-offs that exist between different material choices.

For a flooring example, a product that is designed to use adhesive to install is typically thinner than one that uses a click tile system to install. These thinner products use less material per square foot and therefore have less chemical impacts associated with manufacturing and less waste at the end of life. However, adhesives may add hazardous substances to the product installation stage. By moving from a click tile product to a glue down product, chemical exposure burdens shift from manufacturing and end of life to the installation stage and use phase. 

For an insulation example, a product that is designed to chemically react at the build site, such as spray polyurethane foam (SPF), can allow the insulation to form an air-sealed custom fit. However, SPF is not recyclable, and adherence of that insulation to surrounding materials may also make those materials more difficult to reclaim or recycle. Moving from XPS, EPS or polyiso to SPF may reduce the ability of other surrounding materials to “have a commercial afterlife” in the pursuit of an added performance feature.

HABITABLE:
What got you interested in working in sustainable products and clean chemistry?

TERESA MCGRATH:
It all starts with my family. Specifically my father – who would never identify as an environmentalist – but through his actions taught me to care for those who are most vulnerable and to take care of our planet. For example, more than once I witnessed my dad giving CPR to an injured animal that one of our dogs had mangled. In grade school I disgusted my friends by pulling carrots out of a peanut butter and jelly coated baggie my father had reused (this was before reusable bags were a thing!).  

In college I did a research project on how to remove pesticides from drinking water using a biocatalytic filter method. It took me until the end of the project to ask myself “Wait, why is this pollution in our drinking water to begin with? Why are we using chemistry in such an inefficient, clumsy way?” After a little digging I stumbled on the Twelve Principles of Green Chemistry, authored by Dr. Paul Anastas and Dr. John Warner. These principles are centered around using chemistry to prevent pollution rather than create it, to make efficient use of resources down to every atom, to avoid waste. This was an inspiring moment for me.

Pharos is a comprehensive independent database of chemicals, polymers, metals, and materials.

It was originally developed by the Habitable research team to save time by consolidating data from hundreds of different sources into one place. This system is available via subscription and is used by manufacturers, retailers, designers, NGOs, government groups, and academics across many industry sectors.  

Pharos hosts hazard data for over 200,000 unique chemicals from more than 100 hazard lists. Pharos then maps these data to 25 different resulting types of human health and environmental hazards – such as reproductive toxicity or global warming potential – and assigns a hazard level (e.g high, moderate or low concern) for each endpoint. This translation and distillation of enormous amounts of complex data, to a searchable and practical set of bottom lines makes Pharos a powerful tool. Further, these data are constantly updated to ensure users get the most current information. Pharos helps companies save time finding hazard information, reducing risks by avoiding chemicals of highest concern, and leading the market with safer products. One specific way companies utilize Pharos in their chemicals management process is with RSLs. 

While 12,000 different chemicals are approved for use in the manufacture of food contact materials and articles, most of those chemicals have little to no chemical hazard data associated with them, and some are known to be toxic to humans and/or the environment. 1

Recently a global coalition of leading food service companies, environmental NGOs, and technical experts jointly developed a harmonized Food Contact Chemicals of Concern List (FCCoCL). Hosted on Pharos, FCCoCL provides users with a clear pathway to avoid the most concerning chemicals. 

The voluntary actions taken by companies to disclose and verify the absence of chemicals of concern will help them stay ahead of legislative and regulatory requirements and establish themselves as industry leaders.

Use RSLs to facilitate internal chemicals management.
Whether or not your company’s chemicals management policy is public, an RSL can reduce or eliminate restricted substances in your facilities and in your suppliers’ incoming materials. For example, the Zero Discharge of Hazardous Chemicals Manufacturing Restricted Substances list (ZDHC MRSL), available in Pharos, catalogs substances that are banned from intentional use in the apparel and footwear industries and their supply chains. By communicating these restrictions to the entire supply chain, manufacturers minimize the impact of banned hazardous chemicals on production workers, local communities, and the environment, while helping meet their corporate sustainability goals. 

Use RSLs to maximize your customers’ peace of mind.
Retailers, brands, and manufacturers have published Restricted Substances Lists (RSLs) to help their suppliers identify the top priority chemicals to remove or minimize in their products and processes. For example, Target has relied on an RSL to implement their Chemicals Policy since 2017. Their latest list, the Target Priority Chemical List, is intended to incentivize and support the design of beauty, baby care, personal care, and household cleaning products that are better for people and the planet.

RSLs are a great way to get started working towards eliminating chemicals of known concern, but they do have limitations. RSLs tell you what not to use, but they cannot tell you what chemicals to use. The best next step beyond RSLs is to prefer fully disclosed, fully assessed, safer alternatives. 

To identify safer alternatives, we recommend starting with full chemical hazard assessments, such as a GreenScreen for Safer Chemicals or those found in the ChemFORWARD shared repository of chemical hazard assessments. Hazard assessments enable informed decisions towards safer alternatives. 

With the building and construction industries anticipating growth over the next several years,7 commensurate growth is to be expected in their use of plastics. Indeed, market trends and projections show a steady increase in polyvinyl chloride (aka vinyl), polystyrene, polyethylene, polyurethanes, and other plastics used in building materials.8

It is, of course, unrealistic to avoid all plastic in building materials at this time, but there are steps we can take to reduce plastic waste, decrease toxic chemical use, and curb the demand for fossil fuels. 

Select Better: Avoid worst-in-class plastics where possible. 

• Where product performance and chemical hazards are similar or better, non-plastic products are preferred.
• Not all plastic products are the same when it comes to impacts. Where plastic products are needed, avoid halogenated plastics or plastics reliant on halogenated chemistry during production – such as polyvinyl chloride (PVC, also known as vinyl) and epoxy-based materials. 
• Where plastic products are needed, avoiding virgin plastic materials reduces demand for oil and gas extraction and ultimately mitigates harmful end of life scenarios for the plastic waste such as incineration or landfilling.

Prioritize Transparency: Prefer products that provide transparency 

• Disclosure of product content including the type of plastic used and any potential additives will allow for healthier materials choices and better material end-of-life planning.
• In the case of products containing recycled plastics, disclosure of where the recycled content originated and any additives that may be present is crucial in selecting healthier products.

Aim for Circularity: Select products designed for recycling.

• Where possible, incorporating recyclable building materials in ways that allow for end-of-life recycling is preferred.
• Prefer products with “take back” programs. Because true plastics recycling rates are abysmal, the most promising recycling programs are those in which manufacturers retain responsibility for their products and provide recycling options. 
• Prefer products that are made with high levels of recycled content that has been screened to avoid toxic tag-alongs and, equally as important, contact manufacturers to recycle any existing product.

With all of these plastic products, our buildings may seem increasingly like Barbie’s DreamHouse and a climate nightmare, but as specifiers, designers, architects, contractors, and owners we can do much to control what products end up in our projects. Starting with the recommendations above, we have the power to influence demand for better and safer materials. In the case of plastics, choosing better materials can lead to less reliance on fossil fuels, fewer greenhouse gas emissions, a decrease in toxic chemical use, and a win for our changing climate.