How Much Do You Really Know About Sunscreen?

Chemical or physical sunscreen? What about nanoparticles? Here’s what you should know to choose the best sunscreen for you.


Spending time outdoors in the sun can be nourishing on many levels, yet at the same time, we know that the sun is a source of UV radiation that has been linked to skin cancer, cataracts and visible signs of aging. These can build up from continued exposure to the sun, with the severity of the effects dependent upon the timing and pattern of sun exposure, which is especially critical during childhood. UVB and UVA radiation are the two kinds of concern. UVB consists of shorter waves and is responsible for sunburn, while UVA is comprised of longer waves that can pass through glass windows and clouds to penetrate deep within the connective tissue causing skin damage and wrinkles.

UVA is of equal intensity throughout the year and the day, so is of particular concern. Exposure to both UVA and UVB has been linked to skin cancer. The deeply ingrained advice from public health officials is to generously use sunscreens as an antidote to the sun’s UV radiation. The irony here is that the evidence showing that sunscreen prevents skin cancer is incomplete, and some studies have even shown an increased risk with sunscreen use — possibly because people are not applying sunscreens correctly or because they spend more time in the sun believing that they are fully protected from the radiation.

Other considerations include that sunscreens block the skin’s own production of beneficial vitamin D, and sunscreens can frequently contain active and inactive ingredients of questionable safety.

Chemical or physical: How does your sunscreen work?

There are two general types of sunscreens available — chemical and physical — each working by a different mechanism to block UV rays. Chemical sunscreens, including oxybenzone and octyl methoxycinnamate, protect skin by absorbing the sun’s rays. They do this by actually seeping within the skin. This is why chemical sunscreens apply smoothly, without leaving a thick film. What is most alarming here is that some of the chemical sunscreen active ingredients have been shown to have endocrine disruption activity — especially concerning since we know that they are getting into the body.

There are also environmental consequences, as these active ingredients, frequently used at beaches and waterfronts, are thought to be toxic to aquatic life. Finally, most chemical sunscreens do not provide broad-spectrum protection against UVA and UVB. Given all that, it seems wise to avoid chemical sunscreens if there are effective alternatives available. The second type of sunscreen is a physical sunscreen, which utilizes zinc oxide and titanium dioxide as active ingredients.

Physical sunscreens sit on top of the skin and physically block the sun’s rays, like a mirror. Benefits include the facts that they work immediately and they do not seep into the skin. In addition, zinc oxide is protective against UVA and UVB rays, unlike most chemical sunscreens, which are only effective against one or the other. But the key drawback to physical sunscreens has been functionality — they often apply with a chalky, white film.

Concerns for nanoparticles

Recently, nano-sized physical sunscreens have been developed, which apply smoothly on the skin. There could be concerns with this new technology as well. Nanoparticles are basically very, very small particles of a particular substance, defined as less than 100 nanometers. For comparison’s sake, the head of a pin is about 1 million nanometers, while a red blood cell is 2,500 nanometers. Nanotechnology is an emerging technology with useful preliminary applications, but what is potentially concerning is that molecules at the nano size seem to behave differently from a chemical and biological standpoint than molecules at the non-nano size.

This could be of concern if these nanoparticles were to cross the skin barrier and get into the tissues of the body, as the use of these ingredients is relatively new and long-term effects are unknown. Furthermore, labeling is not required, so the only way to know for sure whether or not a particular mineral-based ingredient is nano-sized is to ask the manufacturer.

What to choose? 

Given the complexity of these issues, how do Whole Foods Market Quality Standards address the matter of sunscreens? Because sunscreens are over-the-counter (OTC) drug products tightly regulated by the FDA, only a limited number of active ingredients are allowed in sunscreens in the United States, therefore both chemical and physical sunscreens are allowed in our baseline Quality Standards for Body Care. What’s different about the products that Whole Foods Market provides is that our standards ensure that the base ingredients in the sunscreens are as clean as possible and that botanicals are used wherever possible, both of which may benefit skin health. And we go further to help you choose.

If the issues surrounding either chemical sunscreens or nanotechnology are of concern to you, the easiest solution is to choose our top tier Premium Body Care™ sunscreens, which are comprised of only non-nano, physical sunscreens.

Premium Body Care opens in a new tab prohibits chemical sunscreen active ingredients, and all Premium Body Care products are carefully screened for particle size: we require manufacturers to submit test results showing the absence of nanoparticles in these products. So even though these non-nano, physical sunscreens may apply with a slightly white film, you will be assured that these products do not contain chemical sunscreens or nanoparticles. Note that store-specific Premium Body Care product lists can be found on your store’s webpage. Find a store here opens in a new tab.

Other tools for sun protection

Remember that while sunscreens can allow us to enjoy our time outdoors, they are not the only tool available for sun protection. Wearing protective clothing and hats are helpful, and what rarely gets mentioned is the nutritional component to skin protection. It’s been shown that adequate antioxidant and omega-3 fatty acid intake in the diet can be protective to the skin.

We also know that nourishing topicals — such as green tea, vitamin E, carotenoids and shea butter — can offer protection from the effects of the sun. Choosing the highest quality sunscreens available — made easy with our Premium Body Care program — in combination with these other strategies can help us nourish our skin and revel in the summer sun at the same time.

What’s in your summer sun-protection tool bag?

Originally published June 2012. Updated June 2016.

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