Did you know that just one blistering sunburn in childhood or adolescence more than doubles the chances of developing melanoma later in life? The same is true for a person who has had 5 or more sunburns at any age. Regardless of what type of sunscreen you use (chemical or mineral-based), the proven benefits of sunscreen outweigh potential risks. That being said, you can limit your child’s exposure to known chemicals by knowing which ingredients to avoid.
First, a few facts about sunscreen to get out of the way.
Chemical versus “Mineral” Sunscreens
Today’s sunscreen market is dominated by either “chemical” sunscreens or “mineral” sunscreens. Any liquid that you put on your child’s skin can penetrate her skin and get absorbed into her bloodstream, so it is very important to know the difference between the two types of sunscreen.
How Do I Know Whether My Sunscreen is “Chemical” or “Mineral” Based?
The best advice we can give you is to check the list of ingredients on your sunscreen bottle before you make a purchase. Mineral sunscreens contain either zinc oxide and/or titanium dioxide as the active ingredient. Chemical sunscreens usually contain one or more of the following ingredients:
- Benzophenones (dixoybenzone, oxybenzone) - linked to allergies, hormone disruption and cell damage. Also linked to low birth weight in baby girls whose mothers have been exposed to oxybenzone during pregnancy.
- PABA and PABA esters (ethyl dihydroxy propyl PAB, glyceryl PABA, p-aminobenzoic acid, padimate-O or octyl dimethyl PABA) – research shows this chemical releases free radicals, damages DNA, has estrogenic activity, and can cause allergic reactions.
- Ethylhexyl p-methoxycinnamate and Octyl methoxycinnamate – Estrogenic effects have been found in laboratory animals as well as disruption of thyroid hormone, and brain signaling.
- Octocrylene -may be used in combination with other UV absorbers for higher SPF formulas. Produces oxygen radicals when exposed to UV light.
- Ethylhexyl salicylate, Octyl salicylate – It is a penetration enhancer, which may increase the amount of other chemical ingredients passing through skin.
- Homosalate – Research indicates it is a weak hormone disruptor, and can enhance the penetration of a toxic herbicide.
- Menthyl Anthranilate – not permitted for use in Europe or Japan. 1 study found that it produces damaging reactive oxygen species when exposed to sunlight.
- Avobenzone – Sunlight causes this ingredient to break down into unknown chemicals, especially in the presence of another active ingredient, Octinoxate.
What’s Wrong With Chemical Sunscreens?
Chemical sunscreens are concerning for 3 reasons:
(1) They are powerful free radical generators.
This means that the chemicals used in chemical sunscreens increase cellular damage and changes to the skin, that can lead to cancer.
(2) They have strong estrogenic activity.
Several chemicals used in chemical sunscreens may disrupt the body’s hormone system. A human’s hormone system influences almost every cell, organ and function of our bodies, including the ability to have children.
(3) Synthetic chemicals used in chemical sunscreens tend to accumulate in the body.
No one truly knows how the new chemicals that have been introduced in sunscreens will affect our bodies over time. Many of these chemicals were created in laboratories and have not been tested, for generations, on humans.
Why Are Mineral Sunscreens Better?
The Environmental Working Group (EWG) has determined that Mineral sunscreens offer the best “safety profile” of today’s sunscreens. Mineral sunscreens are labeled as such because they contain zinc oxide and/or titanium dioxide minerals. Mineral sunscreens are often classified as having either micronized- or nano-scale particles of zinc oxide and/or titanium dioxide.
Zinc Oxide versus Titanium Dioxide
In case you were wondering, there is a difference between what both minerals offer in sunscreens.
Zinc Oxide offers broad spectrum protection against all UVA and UVB rays.
Titanium Dioxide, on the other hand, protects against both UVA and UVB rays, but does not cover the entire UVA spectrum. Also, recent research suggests that zinc oxide is superior to titanium dioxide at wavelengths between 340 and 380 nm.
Micronized versus Nanoparticle Sunscreens
This section caused me the most headaches while writing this article. Believe it or not, it is important to know whether your mineral sunscreen contains micronized or nanoparticles, and their sizes, because sunscreens with larger particle sizes (micronized) are less reactive than smaller particles (nanoparticles). As such, micronized sunscreens are usually classified as containing mineral particles greater than 100 nm in size.
What Is A Nanoparticle And Why Is It In Sunscreen?
According to the ASTM International Committee on Nanotechnology, a nanoparticle is defined as a particle between 1 to 100 nm and can be “composed of many different base materials (carbon, silicon, and metals such as gold, cadmium, and selenium)”. Many mineral sunscreens appear white or grayish when applied. So several mineral sunscreen companies have begun using nanoparticles in their sunscreens, in order to make the particle size small enough to get better absorbed into the skin and not create whitening.
However, according to Environment, Health & Safety at MIT:
“In the last year and a half, there have been a number of research articles on the toxicity of different types of nanomaterials. These studies have suggested effects at the cellular level and in short-term animal tests. The effects seen depend on the base material of the nanoparticle, its size and structure, and its substituents and coatings. Additional toxicology testing is being funded or planned by the National Science Foundation (NSF), the National Toxicology Program, and other research organizations in the US and in Europe. ”
So try to avoid nanoparticle mineral sunscreens and buy micronized mineral sunscreens.
What Does Uncoated/Coated Zinc Oxide Mean And Why Does It Matter?
Coated Zinc Oxide
Many sunscreen companies use zinc oxide whose particles have been coated with an inert substance. Coating minerals make small nanoparticles less reactive (less likely to generate free radicals) and easier to mix with base ingredients.
Uncoated Zinc Oxide
Uncoated zinc oxide is more photoreactive than coated zinc oxide, which means that when uncoated zinc oxide is exposed to UV light, it can generate free radicals, which can damage living cells.
Sunscreen companies, such as Badger, that use uncoated zinc oxide argue that uncoated zinc oxide is less reactive than even coated titanium dioxide, and that researchers have found that zinc oxide sits on the outer, dead, layer of skin. Therefore, any free radicals generated will not affect the living cells below the dead layer of skin.
Sun Protection Factor (SPF)
The SPF is a laboratory’s measure of the effectiveness of sunscreen. According to Wikipedia, “The SPF is the amount of UV radiation required to cause sunburn on skin with the sunscreen on, as a multiple of the amount required without the sunscreen.” In other words, if you normally get sunburned after 1 hour in the sun then a SPF 30 sunscreen would allow you to stay out in the sun for 30 hours before you get burned. However, we all know that, even with sunscreen on, several factors will determine whether or not someone will sunburn (i.e. time of day in sun, whether or not sunscreen is reapplied, exposure to water with sunscreen, etc.).
Typically, chemical sunscreens have protected users from UV-B (the ultraviolet radiation that causes sunburn) but have done little to protect users from UV-A (ultraviolet type a radiation) rays. UVA rays can cause invisible damage to the skin cells deep within the skin, and skin aging. In order to make sure that your sunscreen protects against both UVA and UVB rays, make sure that it is labeled as “Broad Spectrum.”
Do Sunscreens Higher Than SPF30 Really Work?
SPF30 blocks out 97% of the sun’s UVB rays. So anything above SPF30 will not offer any extraordinary amount of protection, just a marginal addition. It is safe to deduce that any sunscreens above SPF30 is purely marketing tactics. Also, the maximum amount of time that you have in the sun with any sunscreen is about 2 hours because after that the sunscreen’s ingredients begin to break down. That’s why most doctors will advise you to reapply every two hours, unless your child is sweating and/or playing in water, in which case you might need to reapply more often.
What Can I Do To Protect My Infant Under 6 Months Old?
The American Academy of Pediatrics (AAP) has historically recommended that sunscreen not be applied on infants under 6 months of age. The Australian Cancer Society has come out, though, and said that there is no evidence to suggest that sunscreen on small areas of a baby’s skin has any long-term effects, so the AAP now recommends that when you’re not able to fully protect an infant’s skin with clothing, sunscreen on areas such as the face, neck, and back of the hands is reasonable.
Recently, the EWG has recommended that people avoid sunscreens containing retinyl palmitate (vitamin A), as a recent FDA study indicated that vitamin A may speed the development of skin tumors and lesions when exposed to sunlight. 30% of sunscreens sold in the U.S. today contain vitamin A. So, try to avoid sunscreens that contain retinyl palmitate/vitamin A.
We will soon publish our 2011 sunscreen picks post after we finish our research, so stay tuned!
What other questions do you have about sunscreens?
Protecting Your Children’s Delicate Skin from the Sun
Is Your Sunscreen ‘Safe’? Vitamin A Added to Sunscreens May Do More Harm Than Good