Who Invented Sunscreen, and How Does it Even Work?
If you happened to read my previous article on the benefits of sunscreen (see below), then you probably already know that I am obsessed with sunscreen.
I’ve done a lot of research on sunscreen and tried dozens of different types to find the one that’s right for me. One night, I found myself wondering, how does sunscreen even work, and who even thought of it?
Since I can’t resist a good rabbit hole, I did an excessive amount of research on it. If you are also someone who enjoys wandering down niche rabbit holes, then let me take you back to a time before sunscreen.
The year is 1938, and Franz Greiter, a young Swiss chemistry student, is enjoying a beautiful climb in the mountains that border Switzerland and Austria. After a day spent climbing in the sun, he develops a painful sunburn, and is inspired to develop something that could protect his skin from the sun on future climbs.
He would go on to create what is one of the original commercially available sunscreens, under the brand Piz Buin. Greiter is also credited with establishing Sun Protection Factor (SPF) as a way to measure how long a sunscreen would protect skin from the sun’s harmless UVB rays. He called his original formula “Glacier Cream”, and it only had an SPF of 2.
In 1944, a World War II airman and pharmacist, Benjamin Green, was looking for a way to protect himself and other soldiers from UV rays and harsh conditions during the war, so he rubbed a greasy substance called “red vet pet” (red veterinary petrolatum) on his face, and found it to be heavy and unpleasant to wear, but effective as a physical barrier against the sun’s harmful rays.
After the war, Green added cocoa butter and coconut oil to the red vet pet, creating the product that eventually became Coppertone sunscreen. In the 1970s, Piz Buin, the brand that sold Franz Greiter’s Glacier Cream, introduced sunscreen with ultraviolet A and ultraviolet B filters.
In 1978, the FDA began to regulate sunscreens, and evaluating standards for effectiveness and safety, and 10 years later, in 1988, they approved a sunscreen containing avobenzone, a UVA-only filter. Before this, there were only sunscreens with UVB filters, which just provided some incidental protection from UVA rays as well.
There are two types of sunscreens: mineral (sometimes called physical) and chemical. Chemical sunscreens use chemicals like avobenzone to filter out UVB/UVA rays, while a mineral sunscreen, such as Benjamin Green’s early WWII version, provides a physical barrier to protect against the sun.
Mineral sunscreens physically block ultraviolet radiation using ingredients such as titanium dioxide or zinc oxide. They are made up of small particles that sit on the surface of the skin to block UV rays from penetrating the skin. These are often called sunblock.
Chemical sunscreen, on the other hand, allows the UV light into the skin, and once it’s absorbed, the chemicals found in the sunscreen such as oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate create a chemical reaction that converts UV light into heat, which dissipates off the skin.
A study published in 2018 in JAMA Dermatology found a strong association with regular sunscreen use in young adults and a reduced risk of melanoma. Melanoma is the most dangerous form of skin cancer, and according to the American Academy of Dermatology (AAD), skin cancer is the most common form of cancer in the United States. Fortunately, with the development of sunscreens, it’s very preventable.
Another long-term study published in the Journal of Clinical Oncology suggested that regular sunscreen use prevented melanoma in adults. Most dermatologists agree that wearing some form of protection from the sun’s rays is better than none, however, there are pros and cons to both chemical and mineral sunscreen.
The FDA has not labeled either type of sunscreen unsafe. However, as of February 2019, the FDA has proposed a rule to update regulations and requirements for sunscreen products sold in the US. As part of this, the FDA has called for additional safety information around the chemicals commonly used in chemical sunscreen.
A small, randomized clinical trial published in 2019 in the Journal of the American Medical Association found that four of these sunscreen chemicals, (avobenzone, oxybenzone, octocrylene, and ecamsule) are absorbed into the bloodstream at levels significantly higher than 0.5 nanograms per milliliter, which is far above the amount at which the FDA requires topical medications to undergo safety studies to determine if there are any possible toxic effects.
So, we may not know enough yet about the potential toxic effects of using chemical sunscreen. While the FDA has not officially declared either unsafe, mineral sunscreen may be the safer choice for this reason. Study authors say that these results show the need for more research, but don’t necessarily mean that chemical sunscreen is unsafe, the FDA is just requesting more research to be done on it.
However, the Environmental Working Group (EWG) recommends not using chemical sunscreens with oxybenzone, because of concerns that it may cause allergic reactions or disrupt hormones. Jennifer L. MacGregor, MD, a board-certified dermatologist at Union Square Laser Dermatology in New York City, also warns against using chemical sunscreens when going in the ocean, as chemical sunscreen ingredients such as oxybenzone have been found to bleach and damage coral reefs.
Therefore, chemical sunscreen may not be the best choice for health and environmental reasons. The pro of chemical sunscreens is that they are quick and easy to apply, and more comfortable and lightweight to wear than mineral sunscreen, which can be thick and uncomfortable, and leave a white film on the skin.
Chemical sunscreens do tend to perform better on tests that compare how long each of them last, so this would mean that a mineral sunscreen may need to be applied more frequently than a chemical sunscreen.
Mineral sunscreens are safer in terms of long-term exposure to the skin, since they do not expose the skin to chemical ingredients. Mineral sunscreens are ideal for children and people with sensitive skin. Mineral sunscreens also offer immediate protection, whereas chemical sunscreens typically take 20–30 minutes to absorb. Mineral sunscreen is also better for the ocean. However, it is thick and harder to apply, and could contribute to breakouts in individuals with acne prone skin.
There’s also the white tint that it leaves on skin, but mineral sunscreens have come a long way, with some options on the market that won’t leave the white cast. In conclusion, wearing some form of SPF is better than nothing, but mineral sunscreen has far more pros than chemical sunscreen does.
“I tell my patients that mineral sunscreens are like a healthy, home-cooked meal, [while] chemical sunscreens are like the fast food of sunscreens.” says Lauren Ploch, MD, a board-certified dermatologist in Augusta, Georgia.
Sunscreens have come a long way since the Glacier Cream of the 1930s or the thick, greasy, red vet pet from WWII, but those chemists and pharmacists that pioneered early versions of sunscreen paved the way to bring us a very valuable product, that can help prevent damage from the sun, and deadly skin cancer. As I mentioned in my previous article about sunscreen, the best sunscreen for you is the sunscreen you will wear everyday, and I highly recommend daily sunscreen use! (As do most dermatologists.)
