E-Mail The use of the polymeric flame retardant PolyFR in "eco-friendly" foam plastic building insulation may be harmful to human health and the environment, according to a new commentary in Environmental Science & Technology. The authors' analysis identifies several points during the lifecycle of foam insulation that may expose workers, communities, and ecosystems to PolyFR and its potentially toxic breakdown products. With the climate crisis fueling demand for energy-efficient insulation, the production of PolyFR is increasing rapidly. That's because this flame retardant is added to all foam plastic building insulation in North America to comply with flammability codes, replacing the flame retardant hexabromocyclododecane that has been globally phased out due to its toxicity and persistence. PolyFR is commonly assumed to be safe. However, the authors question that assumption.