Researchers Urge Caution About the Use of Plastic “Waste” in Construction Materials

Construction materials made from used and discarded plastic are linked to negative ecological, economic, health, and social impacts that are commonly overlooked and understudied, and they problematically create new markets that drive demand for more plastic production, according to new research.

In a review published this month in Frontiers in Built Environment, researchers analyzed 100 studies primarily from the last 10 years, and assessed the costs and benefits of incorporating used and discarded plastic into composites, roads, synthetic turf, lumber, soil stabilizers, adhesives, insulation, and rammed earth. Based on their findings, the researchers urge caution—and more research—before these materials are created and widely adopted for use. 

Industries and businesses have typically categorized discarded plastic as plastic “waste” to justify its suitability for lucrative secondary markets. As the plastic pollution crisis—and a search for solutions—intensifies, production of construction materials made from plastic waste as a means of sequestering and making use of plastic pollution is growing rapidly.

Downcycling Plastic “Waste”: Oversold Benefits and Serious Hazards

The researchers set out to determine what is known and to evaluate the hypothesized effects of incorporating plastic waste in construction materials. They found that studies commonly portrayed construction materials made from plastic waste as “recycled,” though in reality, the wastes were downcycled or applied to downgraded uses. Studies overwhelmingly portrayed creation of these materials as beneficial, even when negative impacts were clearly identified.

Studies overwhelmingly failed to fully assess—and in some cases, omitted—certain serious effects of producing construction materials from plastic waste. Notably absent were investigations into the effects of producing plastic particles (microplastics and nanoplastics), a step inherently necessary in creating many of the materials reviewed. The production and pollution of microplastics and nanoplastics is known to be hazardous to human cells, wildlife, and Earth systems. Also missing from reviewed studies were vital discussions of environmental injustices and occupational exposures to pollutants caused by producing the construction materials, and the health impacts of housing people in constructions made of plastic waste.

The majority of studies skewed toward favorable despite evidence of serious costs and hazards. Downcycling plastic waste is not circular and represents an ongoing effort at greenwashing, which perpetuates plastic pollution and its related injustices—delaying urgently needed real solutions.

– Erica Cirino, lead author of the review, Communications Manager at Plastic Pollution Coalition, author of Thicker Than Water: The Quest for Solutions to the Plastic Crisis

Researchers Urge a Focus on Upstream Solutions to Plastic Pollution

The researchers emphasized the need to prioritize effective upstream solutions to plastic pollution, principally through curbing wasteful plastics production. In the immediate term, they recommended that safeguards be implemented to promote better health and labor conditions for people working in the informal waste sector, mandatory material end-of-life plans, and standardized material toxicity tests (preferably audited by a third party).