— By Dede Williams — 

Phthalates, a diverse category of plasticisers used in many plastics applications, in particular as additives for PVC, have been hard to banish, even if some of the allrounders appear periodically on the watchlists of regulators such as the European Chemicals Authority (ECHA, Helsinki; www.echa.europa.eu) or the US Environmental Protection Agency (EPA, Washington, DC; www.epa.gov).

This could be changing, though, with a growing number of studies showing that some of the health effects could be more devastating than previously thought.

Related: Nine PFAS added to TRI list; draft evaluations of phthalates published

One of the most recent studies, published in the journal eBioMedicine, part of The Lancet group, linked phthalates in plastics to more than 350,000 deaths from heart disease.

The research sees new evidence emerging that “plastic polymers and their chemical additives, particularly di-2-ethylhexylphthalate (DEHP), contribute to increased oxidative stress, metabolic dysfunction, and cardiovascular disease.”

Worldwide, the journal says, exposure to phthalates contributes to 13% of the 350,000 deaths from heart disease reported in people between ages 55 and 64 each year, 10% in the US. Some 75% of the deaths were in Asia, the Middle East, and the Pacific.

Along with epidemiological studies, the Lancet offshoot says phthalates have been linked to male fertility problems, heart disease, obesity, and ADHD. A small sample-size test found that the presence of microplastics could play a role as well, as their presence in the carotid artery increases the risks.

Related: New method for PVC product durability could reduce microplastics pollution

The study stresses that global estimates of phthalate-attributable cardiovascular mortality are needed to inform the ongoing negotiations on a Global Plastics Treaty, set to take place in August 2025 in Geneva, Switzerland. Due to a number factors, however, it doesn’t seem clear that the US will contribute to a global understanding of the issues any time soon.

Kevin Ott, executive director of the Flexible Vinyl Alliance, which represents PVC producers in the US, is sceptical of the findings. He told the newspaper Washington Post, which highlighted the study in a recent article, that “many studies on the health risks of phthalates do not meet the highest standards of evidence”.

According to Ott, the US Food and Drug Administration (Washington, DC; www.fda.gov) “confirmed as recently as 2018 that phthalates are not clearly linked with any health effects”.

The EPA said it is now seeking ad hoc reviewers to assist its new Science Advisory Committee on Chemicals (SACC) in the peer review of the agency’s data, methods, models, and approaches for evaluations of dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), and dicyclohexyl phthalate (DCHP).

Related:EPA reveals results of two phthalate assessments

Up to now the agency has had qualified scientists in-house, but plans by new administrator Lee Zeldin to downsize operations will leave a gap.

Another preliminary study, published in the American Chemical Society’s Journal of Agricultural and Food Chemistry, has found that starch-based biodegradable plastics are not as safe as initially believed.

The journal points to studies with mice exposed to microscopic particles from these plastics, showing that they experienced a number of health issues, including liver damage and disruptions to their gut microbiome.

According to the researchers, starch can break down and release microplastics, leading to health risks that include, for example, inflammatory bowel disease. Mice exposed to the starch-based plastic particles also had multiple damaged organs.