A ‘Trojan Horse’ for Toxic Chemicals, Regulation of toxic substances has long exempted synthetic chemicals made of large molecules believed too big to escape products to cause harm. A new study shows how dangerous that assumption is. Inside Climate News Liza Gross  March 5, 2025 Five years ago, an international team of scientists compiled the first global inventory of commercially available chemicals with sobering results: they identified three times as many chemicals on the market than previously estimated, driven by the explosive growt h of petrochemical production over the past several decades.  Less than 5 percent of the 350,000 chemicals and mixtures registered for production and use has been tested for safety. And with scant information about the environmental behavior or toxicity of most compounds, it takes academic scientists years to identify their potential risks.  Now, a new peer-reviewed study adds to a growing body of evidence showing the failure of current regulatory approaches to protect environmental and human health.The researchers focused on polymers, very large molecules made of long chains of smaller molecules, which scientists considered too big to leach from products or enter the body’s cells and cause harm. Polymers are exempt from U.S. and European toxics regulations to encourage production of alternatives to chemicals shown to cause harm. In the new study, published Monday in the journal Nature Sustainability, the team found that polymers can not only break down in the environment but also become “substantially more toxic” when they do.

The team focused on polymeric brominated flame retardants, or polyBFRs, which are widely used in electronics to reduce fire risk. They have been marketed as safer alternatives to flame retardants found to pose environmental and health risks.. As one of the very few reports exploring the environmental impacts of polymeric BFRs, our work clearly shows that there are environmental risks associated with these polymers, and their use should be adequately assessed and regulated,” said Da Chen, an environmental chemist at Jinan University in China who led the study. Chen likened polymers to a Trojan horse carrying harmful chemicals inside a seemingly innocuous shell. 

More than 20 years ago, researchers raised concerns about “non-polymeric” brominated flame retardants, substances with simple chemical structures, which were widely used to reduce fire risk in numerous consumer and industrial products, from electronics and TVs to insulating foams and other building materials. At the time, there was little information about the toxicity of the scores of commercially available brominated flame retardants despite their increasing contamination of air, soil and waterways and buildup in people and wildlife species from bald eagles to endangered primates. Since then, independent scientists discovered the non-polymeric brominated flame retardants cause diverse health problems, including reproductivehormonal and neurodevelopmental damage, reduced IQ and increased risk of dying from cancer.  The polymeric versions emerged to replace brominated flame retardants that had been banned or phased out in the wake of a wealth of research on their ubiquity and toxicity.  Noting that production of polyBRFs will likely continue to expand as the simpler versions are regulated, Chen and his colleague sought to test the claim that they are unlikely to pose risks. The team collected environmental samples from electronic waste recycling facilities in South China, and from homes and outdoor environments within about a mile and at distances of more than 30 miles away. To determine whether the polyBFRs broke down into smaller molecules, they developed a new screening method to analyze the soil, dust and air samples they collected as well as what remained after they subjected the polymers to laboratory treatments designed to simulate real-world conditions that might cause them to degrade in the environment. 

In the new study, published Monday in the journal Nature Sustainability, the team found that polymers can not only break down in the environment but also become “substantially more toxic” when they do. The team focused on polymeric brominated flame retardants, or polyBFRs, which are widely used in electronics to reduce fire risk. They have been marketed as safer alternatives to flame retardants found to pose environmental and health risks. “As one of the very few reports exploring the environmental impacts of polymeric BFRs, our work clearly shows that there are environmental risks associated with these polymers, and their use should be adequately assessed and regulated,” said Da Chen, an environmental chemist at Jinan University in China who led the study. Chen likened polymers to a Trojan horse carrying harmful chemicals inside a seemingly innocuous shell.

More than 20 years ago, researchers raised concerns about “non-polymeric” brominated flame retardants, substances with simple chemical structures, which were widely used to reduce fire risk in numerous consumer and industrial products, from electronics and TVs to insulating foams and other building materials. At the time, there was little information about the toxicity of the scores of commercially available brominated flame retardants despite their increasing contamination of air, soil and waterways and buildup in people and wildlife species from bald eagles to endangered primates. Since then, independent scientists discovered the non-polymeric brominated flame retardants cause diverse health problems, including reproductivehormonal and neurodevelopmental damage, reduced IQ and increased risk of dying from cancer.The polymeric versions emerged to replace brominated flame retardants that had been banned or phased out in the wake of a wealth of research on their ubiquity and toxicity.  Noting that production of polyBRFs will likely continue to expand as the simpler versions are regulated, Chen and his colleague sought to test the claim that they are unlikely to pose risks.......read on              https://insideclimatenews.org/news/05032025/polymeric-brominated-flame-retardants-toxic-chemicals/