Feb. 4, 2008 -- New research suggests a link between the use of baby lotions, powders, and shampoos and higher levels of potentially harmful manmade chemicals known as phthalates in infants.
Researchers reported that babies exposed to all three products had levels of three different phthalate metabolites that were five times higher than babies whose mothers reported using none of the products.
All the infants in the study had evidence of at least one phthalate metabolite in their urine, even if they had no exposure to baby lotions, powders, or shampoos.
And the baby products were not tested, so it was not clear if they actually contained phthalates or if their use contributed to the phthalate levels seen in the babies.
But researcher Sheela Sathyanarayana, MD, MPH, of the University of Washington, Seattle tells WebMD that the strong association between use of the baby products and higher phthalate levels suggests that the products may be an important source of exposure.
"We don't know the long-term health effects of (phthalate) exposure, but if parents are concerned they need to decrease their exposure to these products," she says. "You really don't need to use them on newborn babies."
A spokesman for the cosmetic industry called the new study methodologically flawed, adding that there is no evidence that baby lotions, powders, and shampoos pose even the slightest risk to babies.
"Their recommendation that parents not use these products is simply not supported by the science," Personal Care Products Council chief scientist John Bailey, PhD, tells WebMD. "It just doesn't make any sense."
What Are Phthalates?
Phthalates are commonly added to plastics to soften them, but several are also widely used in cosmetic products to stabilize fragrances.
They are rarely listed as ingredients on cosmetic labels, however, because the FDA does not require the listing of the individual components of fragrances.
Choosing unscented beauty products is no guarantee that they will be phthalate-free, though, because these products often contain masking fragrances that may contain the chemical.
Animal studies have linked some, but not all, phthalates to reproductive development and endocrine problems, and several recent studies in babies suggest that the same thing may be true in humans.
To examine whether the use of baby personal care products might be a source of phthalate exposure in babies, Sathyanarayana and colleagues measured urine samples from 163 babies between the ages of 2 months and 28 months for exposure to nine metabolites from seven different phthalates.
The babies' mothers also filled out questionnaires asking about their use of baby personal care products within the past 24 hours.
The researchers concluded that use of baby powders, lotions, and shampoos was strongly associated with higher phthalate levels, while use of baby wipes and diaper creams was not.
Every baby in the study had detectable levels of at least one phthalate in their urine, and four out of five had detectable levels of seven or more phthalates.
Sathyanarayana tells WebMD that the use of baby lotion was associated with the strongest increase in phthalate concentrations in babies 8 months and younger, and the use of lotions, shampoos, and powders was associated with a roughly fivefold increase in concentrations.
The observed association between use of the baby care products and phthalate exposure was strongest in younger babies -- those who were eight months old and younger at the time of the study.
The study is published in the February issue of the journal Pediatrics.
Other Experts Weigh In on Phthalates
In a news release, Bailey noted that only one of the seven phthalates included in the new study is actually in baby care products.
That is what a 2006 FDA study of phthalates in cosmetics found.
"For this reason, we question the validity of the alleged link between the use of baby personal care products and the presence of phthalates in infants," he notes.
In an interview with WebMD, Bailey adds that this phthalate -- diethyl phthalate (DEP) -- is used in very low levels, as a component of fragrance, and has not been linked to reproductive or endocrine disturbances in animal studies or any health issues in humans.
Phthalates researcher Kim Boekelheide, MD, PhD, agrees that the available research does not implicate the DEP metabolite monoethyl phthalate (MEP) in endocrine disruption.
Boekelheide is a professor of medical sciences at Brown University. He was not involved with the University of Washington study.
"It is important to point out that not all metabolites of phthalates are of similar concern," he tells WebMD.
In a separate news release, a spokeswoman for the American Chemistry Council says the new study adds little to the debate about phthalate safety, failing "to provide meaningful or useful data."
Marian Stanley of the ACC notes that the study's recommendation to limit the use of infant care products is not justified by the findings.
"We believe that there is potential value in the study of metabolized phthalates. But we take great exception to any effort to draw unfounded conclusions that suggest human health risks are associated with the mere presence of very low levels of metabolized phthalates in urine," she says, adding that, "In 50 or more years of use, no reliable evidence has ever been found that phthalates, either alone or in combination, cause negative health effects in humans."