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.

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.