Our bodies do a great job of keeping us safe. From birth, most of us are able to metabolize and remove toxins from our bloodstream, thanks primarily to our liver and kidneys. However, the efficiency of these organs, and related metabolic processes, develops and matures over time. So when it comes to sun protection, children’s skin and bodies are still somewhat vulnerable.

Kids’ epidermis – the layer of the skin that provides the barrier function – is up to 30% thinner than in adult skin. That means sunscreen and skincare ingredients can penetrate children’s skin more easily.

And children’s detox systems — the liver and kidneys — are still developing. But before you panic, let’s dive deeper into our body’s detoxification systems.

Pre-birth

The process of detoxification begins while a baby is still in the womb. The placenta acts as the main filter, handling waste removal until the baby is born. A fetus’ kidneys start producing urine around the 9th to 12th week of pregnancy, and the liver begins to develop as early as the 7th week. 

Infancy and early childhood

After birth, a newborn's liver and kidneys begin to operate independently, but they are not yet at full capacity. 

• Liver: It may take several days for a newborn's liver to function efficiently, which is why jaundice is common. By about two weeks, the liver is more effective at processing bilirubin and other waste.

• Kidneys: A baby's kidneys undergo rapid maturation in the first weeks and months of life. While they are functional at birth, their capacity to concentrate or dilute urine and excrete certain substances is less developed than in adults. Kidney function generally reaches levels comparable to an adult's by 2 to 3 years of age. 

The efficiency of detoxification increases as a child ages, making them less vulnerable to potential harm from systemically absorbed chemicals.

What does this mean for your child?

• Under 6 months: Infants are the most vulnerable. Their thin skin and high surface area-to-body mass ratio increase the absorption of things like sunscreen and skincare products, while their immature liver and kidneys are less able to process and eliminate them. The American Academy of Pediatrics and Dermatologists advise avoiding sunscreen entirely for babies this young, emphasizing shade and protective clothing instead.
• 6 months to 1 year: This is a transitional phase. A child's organs and metabolic systems are maturing but are not yet fully developed. Many dermatologists still recommend mineral-based (zinc oxide or titanium dioxide) sunscreens as an alternative to chemical sunscreens during this period.
• Ages 1 to 2: By one year of age, most of a child's metabolic systems are reasonably mature, with function becoming nearly comparable to an adult's by age two.
• After age 2: While the body's detoxification systems are still developing, children over two are much less vulnerable.

You can rest easier.

Healthy school-age kids’ bodies are fully equipped to reduce their exposure to potential toxins. But no matter your child’s age (or yours!) if any doubt persists in your mind, there are alternatives.

Physical/mineral sunscreens containing only zinc oxide and/or titanium dioxide have been shown again and again to be safe and effective. These active ingredients sit on top of the skin, forming a protective layer that blocks UVA and UVB rays. No doubt, no worries, no burden on their bodies – just gentle, effective sun protection.