Baby teethers may contain low levels of BPA, study finds

Next time you hand your baby a teething ring to soothe her aching gums, you may be unwittingly exposing her to endocrine-disrupting chemicals (EDCs) and potentially affecting her development, new research published Wednesday in the journal Environmental Science & Technology suggests.

In a first-of-its-kind study published by the American Chemical Society, researchers analyzed 59 baby teethers commonly sold in the United States, and found 100 percent of them contained Bisphenol A (BPA), Bisphenol S (BPS) or Bisephenol F (BPF), and most contained various parabens, as well as the antimicrobials triclosan and triclocarban.

BPA, a chemical found in plastic packaging, has been linked to obesity, cancer and childhood anxiety and hyperactivity and has been found to mimic estrogen. BPS, a chemical that replaced BPA because experts believed it wouldn’t leak into drinks as much as BPA did— which later was proven wrong— has been found to cause developmental issues in fish embryos. BPF is another replacement for BPA.

“These alternatives [to BPA] are equally toxic, or in some cases, more toxic,” study author Kurunthachalam Kannan, a research scientist at the New York State Department of Health, told

Parabens are commonly used as a preservative in teethers that are water- or gel-filled to prevent the likely growth of microorganisms. Triclosan and triclocarban are two of the most common ingredients found in antibacterial hand and body wash. In September, the FDA banned some of these antibacterial products because they could cause long-term harm, such as bacterial resistance or hormonal effects.

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Forty-eight of the studied teethers were labeled BPA-free or non-toxic.

The teethers, which were manufactured by 23 brands, also leached chemicals when exposed to water, which was used to mimic saliva. Study authors noted a German study previously measured paraben levels found in baby teethers, but the sample only included 10 products and did not analyze chemical leaching.

The plastics industry claims the amount of BPA used in baby and child care products does not present a health risk, but Kannan said recent studies have suggested that even at a nanogram or microgram level, the chemical can be harmful. Regulation is hazy, Kannan said, because the levels are still being debated and standards are not clearly described.

The team’s findings aren’t entirely surprising, said Dr. Josef George Thundiyil, a medical toxicologist and emergency medicine specialist at Orlando Health, who was not involved in the study.

“If you take urine samples, about 90 percent of Americans will have [BPA] in our bodies,” he told

In 2012, the Food and Drug Administration (FDA) announced that BPA could no longer be used in baby bottles and sippy cups. This change was not made for safety but because BPA was no longer deemed necessary as a food additive, according to the FDA.

There are many substances that could be toxic at the right dose— including water— but it’s unclear where that number lands for these chemicals, Thundiyil said.

“What the FDA has concluded is that at current doses, this doesn’t appear to be a danger. Where we get the most concerned is when we look at toxicity in those that are most vulnerable— young kids and unborn fetuses,” Thundiyil said. “The question is: Is there a safe dose for a developing child or fetus that might be exposed to this [chemical] that might affect development, hormonal changes, or ongoing developmental issues?”

One explanation for the lack of a recommended dosage for children may be that it is difficult to study this particular demographic, Thundiyil noted. Scientists have gained insight from animal studies— several show toxicity from BPA— but whether these data apply to humans has yet to be determined.

“There are studies that show the link between the chemical and different outcomes, but a link isn’t always clearly established as being the cause— that’s where the gray area lies,” he said.

Plus, since BPA was removed from baby bottles and cups, the FDA and other organizations have no longer been able to assess a child’s lifetime exposure because that part of the equation was removed, Thundiyil said, adding that the study’s finding of EDCs in teething rings may lead researchers to re-account for that exposure.

To simulate leaching of chemicals in saliva, the team immersed each teether in 200 mL of water for an hour to mimic a child’s daily use and measured for 26 potential EDCs.

They found that parabens were the most commonly leached, with a range of one-tenth to one-hundreth of a nanogram. The max value measured was 2,000 nanograms.

Based on estimates of the body weight of a 12-month-old baby, the team’s calculations suggest that levels of BPA and other regulated EDCs in teethers were lower than those of what European regulators consider safe. However, these thresholds are set for individual compounds,  and regulations don’t account for accumulation of multiple EDCs.

“If we’re looking at all different types of chemicals present— several hundreds of nanograms up to a microgram— many of these chemicals have been shown to be toxic, even at low levels of exposure,” Kannan said. “Putting this cocktail of chemicals, even in low amounts, during critical stages of development of many organs, can have an effect in many stages of life.”

He said research suggests multiple, environmentally mediated diseases, including neurodevelopmental issues, diabetes and obesity, that may result from EDC exposure.

“That’s why we’re concerned about it— the early-life exposure and epigenetic changes that results from the EDCs can contribute to some of the disease and development of some of these diseases later in life,” Kannan said, referring to the study of how genes can change their expression and may influence health outcomes.

“We should have policies limiting exposure,” he said.

Thundiyil also expressed skepticism.

“It’s always difficult proving what kind effect might occur in combination,” Thundiyil said. “[We’re] not being exposed to chemicals in a vacuum; we’re being exposed to chemicals along with other chemicals. It leaves a big unknown void about the potential interaction and interplay between that substance and another substance that child is being exposed to.”

But Thundiyil was most concerned by the fact that most of the products analyzed in the study were labeled as BPA-free or non-toxic.

“’Non-toxic’ can be a very broad designation to state something might have some toxin present, but not at a level that is toxic,” he said. “Applied to a single person, that’s OK. When you take the same device and apply it over a population, there will be those that use it infrequently, those that use it continuously, those that might use it in ways that are unanticipated, such as using heat to boil, which can enhance the release of [chemicals]. That’s what makes it a concern.”

“Usually when the FDA makes what we call risk assessments, they usually build those uncertainties in it … to account for different methods of use, ages, long-term exposure,” Thundiyil said.

Regardless of whether we realize it, we’re all exposed to a small amount of a variety of substances, Thundiyil said.  “They’re a part of life, what makes things function, what makes a lot of modern conveniences work the way they do.”

Kannan said he did not think EDCs posed an immediate threat to babies, but he suggested parents use frozen waffles as an alternative to plastic teethers, or rinsing the teether with water to possibly help leach possible chemicals.

Thundiyil said parents may consider limiting their children’s use of teething rings or to use alternatives, but to be mindful of other concrete areas of risk.

“In some ways it’s probably more important to make sure to have your child wear a helmet for bicycling and buckle in their seatbelt,” he said. “At the end of the day, those risks are probably higher while others exist, but are still theoretical. It’s important not to neglect the things we know cause injury and harm.”

The American Chemistry Council, an industry trade association, said the study "provides very little useful information for the parents of young children, as it focuses on the mere presence of chemicals, which parents should be reassured does not equate with harm." In a statement emailed to, a representative noted that the organization was not aware of any use for BPA or materials made from BPA being used in teethers.