Updated: Aug 9, 2021
Sun, sun, sun...here it comes! With summer on the horizon many of us are spending more time outdoors with our little ones. As a responsible momma, you may be wondering: Should I use sunscreen to protect my baby's soft skin or are the active ingredients harmful? Short answer: Be careful of your sunscreen's ingredients! Some chemicals may be harmful for babies as well as pregnant or breastfeeding mothers. Also, don't use sunscreen on babies under 6 months old.
It's important to be vigilant about sun protection, not only to avoid painful sunburns but also because skin cancers are the most frequently diagnosed cancers in the United States (CDC Statistics). Harmful UV rays from the sun come in two flavors, UVA and UVB, which are divided based on wavelength. UVA waves are longer and penetrate deeper into the skin than UVB waves, but both can accelerate cellular damage and lead to skin cancer. It's therefore important to use sunscreen labeled as "Broad Spectrum", which protects against both types of UV rays (Julian et al., 2015).
When it comes to sunscreen, there are two types of active ingredients to consider: organic UV filters (also called chemical blockers or chemical sunscreen) and inorganic UV filters (physical blockers or mineral sunscreen). (In this instance, the terms “organic” and “inorganic” merely refer to the presence or absence of carbon atoms.) Organic filters act like a sponge in your skin, absorbing mostly UVB waves to stop them from penetrating further (Wang et al., 2010). Common examples of UVB organic filters are avobenzone, oxybenzone, octocrylene, homosalate, octisalate, octinoxate. Inorganic filters are thought to act like a shield on top of your skin, providing a physical barrier that absorbs and reflects UV waves. Metal oxides such as zinc oxide (protective against UVA and UVB) and titanium dioxide (protective against UVB) are common inorganic blockers (Schneider and Lim, 2018).
Let's delve into the safety data. It was recently discovered that even after a single application, all of the organic chemical filters listed above are absorbed into an adult's bloodstream at levels exceeding safety thresholds (Matta et al., 2020). Yikes! Use on babies is even more concerning because their skin barrier function is not fully developed and they have a higher surface-area-to-volume ratio than adults, both of which lead to higher chemical absorption through skin contact (Stamatas et al., 2011). Absorption of chemicals through the skin is also concerning for pregnant or breastfeeding mothers. A study demonstrated that when breastfeeding women apply sunscreen and/or makeup containing organic filters, the chemicals end up in their breastmilk (Schlumpf et al., 2008). Even more troubling, oxybenzone (which is found in 70% of sunscreen products) is a recognized endocrine disrupting chemical. This means that when oxybenzone is absorbed into a pregnant woman's blood and crosses the placenta to baby, it can disrupt migration of critical cells during embryonic development (DiNardo and Downs, 2019).
In contrast to organic chemical filters, inorganic mineral filters “do not permeate the skin to any significant degree” and consequently have “few to no health concerns in humans” (Schneider and Lim, 2018). Historically, however, these sunscreens were more difficult to apply and left a white, chalky residue on the skin. With the advancement of nanoparticle technology (making the particles smaller), these mineral sunscreens are becoming easier to apply smoothly and transparently.
For babies younger than 6 months old, skip the sunscreen and keep baby in the shade. "There is no compelling reason for infants less than 6 months to have sun exposure prolonged enough to require sunscreens. The best advice is to keep the infant out of the sun for the first 6 months of life" (Morelli and Weston, 1993).
In conclusion, it’s probably best to use to an inorganic mineral sunscreen instead of an organic chemical sunscreen, especially if you are pregnant, breastfeeding, or lathering up your offspring. And if baby is under 6 months, keep them in the shade!