Its almost officially summer, so what better time to discuss sunscreen! What is the difference between Chemical and Physical (“Mineral) Sunscreen? How do these things work? Which of the two is the least toxic? Which is most effective? Hopefully the following information will shed some light on the differences between two common types of sun protection.
Chemical sunscreens are what most of the outdoor-sport-loving/sun-worshipping population use. These are your Coppertones, Banana Boats, and so on. Chemical sunscreens work by absorbing (or sometimes diffusing) UV rays. These sunscreens are most effective protecting against the suns UVA rays. UVA rays are considered to be the UV rays associated most with aging.
These types of sunscreens contain chemicals such as Avobenzone, Octinoxate, Octisalate, Oxybenzone and Helioplex which are absorbed into the skin and in turn protect the skin by diffusing or absorbing harmful UV rays. These sunscreens need to be applied 20 min before sun exposure to be fully effective. Chemical sunscreens are sweat and water resistant so these are especially good for sports and swimming. One thing that many people don’t know about these sunscreens is that they actually break down in the sun after about 1 hour. So our moms were right, you really do need to re-apply!
Something to consider: Since these sunscreens are absorbed into the skin the active chemicals have been found elsewhere in the body. In fact, many of the most popular chemicals used in these products have been detected in mothers’ breast milk. There is some discussion in the health community that these chemicals may mimic and/or disrupt hormones. Also, it is not uncommon for these chemicals to cause allergic reactions on the skin. And finally, there is building concern that some of the chemicals used to block the UVA rays may actuallly be triggering hyperpigmentation as well as generating free radical damage. Sort of defeats the purpose right?
Of the chemicals that are used in these sunscreens, Oxybenzone is the one that is considered the most harmful. So perhaps when using these sunscreens look out for those brands that use Oxybenzone.
Physical, or “mineral” sunscreens reflect the UV rays and do not absorb into the skin at all. These sunscreens are comprised of Zinc Oxide and/or Titanium Dioxide. These sunscreens are most effective at protecting against UVB rays. UVB rays are the UV rays that cause our skin to burn.
Physical sunscreens protect us by blocking the UV rays from getting to the skin. The zinc oxide and titanium dioxide act as physical barriers. Now, to be clear…this is NOT the zinc from our childhoods. You remember…it was that greasy white stuff the lifeguards would wear on their nose at the pool. Or if you are a child of the 80’s like me…it was the greasy paint that came in a myriad of neon colors that we would put on our faces like war paint and that would inevitibly end up on EVERYTHING. The zinc of 2015 is actually “micronized zinc”. And, drumroll please…it goes on clear!
These sunscreens are normally non-irritating. If there is any irritation, it is most likely due to the titanium dioxide rather than the zinc oxide. Unlike the chemical sunscreens, these products begin to work immediately since they do not need time to soak into the skin. However, mineral sunscreens are not as water resistant as chemical sunscreens and thus need to be reapplied often. These are best for wearing on a day to day basis (put these on under other face products and/or make-up ). For the active types…these are still great, but may need to be reapplied more frequently than the chemical sunscreens due to their lower resistance to moisure.
Regardless of which type of sunscreen you choose to use, make sure you make a practice of wearing SOMETHING in order to protect your skin.
Happy Summer Everyone!