The lotion you apply to your child’s skin might do more harm than good, according to new research. Children are especially vulnerable to harmful exposures through their skin because they have more skin surface area relative to their body size, better blood flow, and higher skin hydration than adults. A recent study found that using skincare lotions and oils significantly increased toxic phthalates in children’s urine.

Researchers surveyed parents of children aged 4 to 8 about their children’s use of skincare products and then tested the children’s urine for phthalates.

They discovered that children who used lotions had 1.17 times more mono-benzyl phthalate in their urine, and those exposed to oils had 2.86 times more monoethyl phthalate, 1.43 times more monobutyl phthalate, and 1.40 times more low-molecular-weight phthalates. Surprisingly, children who used products labeled “phthalate-free” didn’t have lower phthalate levels. The researchers speculated that phthalates used in packaging materials (such as bottles or tubes) migrated into the products.

These findings suggest that everyday skincare products, such as lotions or oils, expose children to high phthalate levels. Phthalates are known endocrine disruptors—compounds that can mimic or impair the activity of the body’s natural hormones and may harm children’s development and physiology.

Many skincare products also contain microplastics, which carry considerable health risks. Learn more about microplastics in our overview article.