Plastic Packaging Chemical DINCH Linked to Lower Birth Weight

By Olivia Hart

Each tenfold increase in exposure to DINCH, a plasticizer marketed as a "high safety" alternative to phthalates, cut newborn birth weight by 27 grams in a new peer-reviewed study of more than 6,600 US pregnancies. The average newborn weighs about 3,400 grams, or roughly 7.5 pounds — so the loss is small per child, but the exposure is anything but rare.

Up to 70% of the women in the study showed DINCH in their urine. The analysis, conducted by New York University Langone Health using federal US health data collected under the National Institutes of Health Environmental influences on Child Health Outcomes (Echo) Program, is the first to link the chemical to lower birth weights and birth lengths.

The formal name is 1,2-cyclohexane dicarboxylic acid diisononyl ester. It makes plastic more flexible and durable, and it sits in ordinary kitchen products: cling film, plastic wine corks, soft plastic food packaging across the United States and European Union. It also appears in children's toys, medical devices, some textiles and flooring.

What does the study actually show?

Higher urinary DINCH levels increased the risk of a child being classified as "small for gestational age" — below the 10th percentile for babies born at the same stage of pregnancy. That classification matters, because fetal growth problems can raise the risk of heart disease, learning difficulties and obesity later in life, the authors wrote.

The burden did not fall evenly. Hispanic mothers and women with lower education levels were more likely to have children affected by DINCH, the study found.

The mechanism remains partly an inference. Previous research on animals and human cells found that DINCH by-products can interfere with the hormones that guide fetal development, and may trigger inflammation affecting how nutrients and oxygen reach the baby, according to the NYU authors. Direct human evidence on DINCH remains thin — a caveat the industry's "safe" label never carried.

"Chemicals should be properly tested for their safety before they become a widespread exposure for unwitting people in the general public," said Leonardo Trasande, a lead author on the NYU paper.

How big is the market?

Large, and growing fast. After US and EU regulators moved in the aughts against toxic phthalates such as DEHP, industry shifted to DINCH. Global production jumped from 25,000 tons in 2002 to 400,000 tons in 2024 — a sixteenfold increase. German chemical giant BASF is among the major producers.

Researchers at the Switzerland-based Food Packaging Forum say they are concerned about DINCH and the scarcity of health information around it. Evidence shows the chemical migrates from packaging into food, and levels in the EU population have risen across recent decades. The Forum is now conducting its own health research on DINCH.

The takeaway: a chemical marketed as the safe option has reached industrial scale before anyone tested its effect on pregnancies.

Is this another 'regrettable substitution'?

The pattern is familiar. The paper exposes what the researchers describe as a classic case of industry replacing one dangerous chemical with a compound that has similar health effects — resetting the regulatory and research clock even though the substitute is structurally similar.

Researchers call this "regrettable substitution," and it has precedent. Chemical companies replaced the most dangerous PFAS "forever chemicals," such as PFOA, with GenX compounds; years of research later found GenX to be more toxic.

The NYU findings "raise pretty serious concerns about regrettable substitution," Trasande said.

"These results underscore the need for stronger oversight of chemicals used in food packaging and other household products by requiring they be tested before they are introduced to the market, instead of after they are connected to health concerns," he said. He pointed to the plastics treaty under negotiation at the United Nations as an opportunity to establish those policies.

The takeaway: the study's real target is not one chemical but a testing regime that lets exposure precede evidence.

What can consumers do in the meantime?

Trasande and the researchers suggest practical steps: buy plastic-free products, including clothing and toys, where possible; choose food sold in glass packaging; and use glass or wood storage containers and utensils in the kitchen.

None of that is verifiable protection at scale. What is verifiable is the exposure — in up to seven in ten pregnancies studied — and a birth-weight link that now sits in the peer-reviewed record.