Children’s phthalate exposure: Skin care products under scrutiny for racial and gender disparities

23 Sep 2024 --- A new study in Environmental Health Perspectives reveals a concerning link between children’s use of common skin care products and increased phthalate levels in their urine, with variations based on race, ethnicity and gender.

George Mason University’s study lead and professor of Global and Community Health, Dr. Michael S. Bloom, speaks to Personal Care Insights about his team’s discovery of how lotions, hair conditioners, sunscreen and oils may elevate exposure to endocrine-disrupting chemicals.

The US FDA says phthalates function as solvents and stabilizers in fragrances. They are found in nail polishes, hair sprays, aftershave lotions, cleansers and shampoos.

The paper adds to the growing evidence of the potential developmental risks associated with phthalates, a class of chemicals used in the ingredients and packaging of skin care products.

What are the key findings of your study?
Bloom: It is the first study to look at the breakdown products of different types of phthalates in children’s urine in association with using skin care products. Different types of phthalates tend to be used for different products. For example, low molecular weight phthalates, like diethyl phthalate (DEP), tend to be used as excipients (inactive ingredients) in skin care products, whereas high molecular weight phthalates, like bis(2-ethylhexyl) phthalate (DEHP), tend to be used in plastic packaging.

Dr. Michael S. Bloom (Image credit: College of Public Health).Based on the different types of phthalate breakdown products we found, we estimated whether the presence of phthalates in children’s urine was more likely to be related to the skin care products themselves or their packaging. We also studied whether these patterns were different based on race, ethnicity and gender.

The study’s key findings are:

• Associations between recent use of different skin care products, including lotions, oils and others, with higher urinary concentrations of phthalates typically used as excipients in personal care products. 
• Distinct patterns of using multiple skin care products were predictive of higher urinary concentrations of phthalates and phthalate replacement chemicals, which are typically used as plasticizers in packaging.
• There are different relationships between use of skin care products and urinary phthalates and phthalate replacement chemicals in children with different racial and ethnic identities and different sex-assigned births.

How do racial and ethnic identity, as well as sex assigned at birth, influence phthalate exposure?
Bloom: We found that the associations between using certain types of skin care products and specific phthalates in urine varied among children with different racial and ethnic identities. For example, using lotions was associated with higher levels of a breakdown product from butyl-benzyl phthalate (BzBP), a type of phthalate found in plastics, but only in non-Hispanic White children. However, using hair conditioner was linked to higher levels of Mono(3-carboxypropyl) phthalate (MCPP), a breakdown product of both high and low molecular weight phthalates, but only in non-Hispanic black children. Using oils, primarily for hair, was associated with higher levels of monoethyl phthalate (MEP), a low molecular weight phthalate, in all children, but the effect was strongest in Hispanic children and Asian and Pacific Islander children. High-molecular-weight phthalates tend to be used in plastics, while low-molecular-weight phthalates are often added to skin care products.

We also found that the associations between using certain skin care products and phthalate and phthalate-replacement chemicals in urine differed by gender. In females, using oils was associated with higher levels of low molecular weight phthalates, which may be added to skin care products as excipients, but we did not see this effect among males. On the other hand, males who used ointments had higher levels of di-2-ethylhexyl terephthalate (DEHTP) in their urine, a chemical used as a replacement for high molecular weight phthalates found in plastic packaging, but we did not see this effect among females.

What health risks are associated with early childhood exposure to phthalates and phthalate-replacement compounds?
Bloom: In this study, we didn’t look at health risks directly. However, experimental studies using animal models and cell cultures show that phthalates can affect endocrine function, cause inflammation and cause oxidative stress, biological pathways shared by humans that might lead to adverse human health effects. Yet, these studies were often conducted at very high doses of phthalates, greater than those typically experienced by human populations. Still, many observational studies in human populations worldwide have reported associations between exposure to some phthalates and neurocognitive problems, reproductive problems, changes in hormones, metabolic disease and other adverse health effects, suggesting that there are toxic effects. However, the results in human studies have been mixed, making it a controversial topic. 

Using certain types of skin care products and specific phthalates in urine varied among children with different racial and ethnic identities.It’s difficult to study phthalate exposure in people, especially in children. While the evidence is not definitive at present, the potential hazardous human health effects, coupled with growing evidence and widespread and ongoing exposure in sensitive populations, including young children, demand a precautionary approach now.

What implications do your findings have for consumer safety regulations?
Bloom: Our findings highlight that the packaging of skin care products could be a significant source of phthalate exposure for young children, separate from the products themselves. It’s also important to consider how using multiple skin care products together may increase exposure in a different way than just using individual products. Most importantly, our results suggest that the higher levels of phthalate exposure seen in minoritized populations compared to non-Hispanic White populations in the US may start in early childhood. This is reflected in the differences in urinary phthalate and phthalate replacement chemical levels we found between these groups in our study.

What further research is needed to confirm the study’s findings and address the risks of phthalate exposure in children?
Bloom: Future studies should track all personal care products used by children over several days, ideally as they are being used. This would also include collecting multiple urine samples from a larger group of children to better understand the link between using skin care products and the levels of phthalates or replacement chemicals in their bodies. Collecting the products themselves, along with their packaging, would let us test for phthalates and replacements directly, making a clearer connection with the chemicals found in the urine. However, we recognize the challenges of doing this kind of study, especially the financial support needed. For now, our next step is to take a closer look at our current data to see if specific products or brands are linked to phthalate levels in children’s urine and whether these patterns differ between groups.

By Venya Patel