From wartime zinc paste to modern broad-spectrum SPF: the history of sunscreen

Sunscreen has the strange status of being both the most-recommended product in skincare and the one with the messiest history. The science is straightforward enough. The story of how that science arrived on shelves is a different matter, and it involves war, mountaineering, a Florida pharmacist, and several rounds of regulatory disagreement that are still not settled.

I think the history matters because it explains why the modern sunscreen landscape is so geographically uneven. The same product is illegal in one country and standard in another. The reasons are not chemistry. They are regulatory history.

The pre-sunscreen era

Before any product called sunscreen existed, people used what was around. Ancient Egyptian records mention rice bran and jasmine for sun protection. Greek and Roman writers describe olive oil as a sun barrier. Burmese thanaka paste has been used for centuries with documented mild UV-blocking properties. None of these were measured products. They were cultural practices with incidental protection.

The first scientific recognition that sun exposure caused skin damage beyond simple burns came in the late nineteenth century. Erythema (sunburn redness) was identified as a specific UV-driven inflammatory response in the 1890s, and the connection between cumulative sun exposure and skin cancer was established in the 1920s through observational data on outdoor workers. The pharmaceutical question (how do you block this) lagged the observation by decades.

The wartime breakthrough

The first widely used sunscreen products came out of two parallel WWII contexts. In the Pacific theater, downed American pilots were spending days on rafts in equatorial sun, and the Army Air Forces needed a barrier product. Benjamin Green, a Miami Beach pharmacist who later founded Coppertone, formulated red veterinary petrolatum (a thick, viscous compound used on horses) as a pilot survival ointment. It was unpleasant to wear and stained everything, but it worked.

In Europe, an Austrian chemistry student named Franz Greiter had his own sun problem. He suffered a severe sunburn climbing the Piz Buin glacier in 1938 and spent the next decade working on a topical solution. The product he released in 1946 (Piz Buin Gletscher Creme) is widely credited as the first consumer sunscreen marketed as such. Greiter later went on to develop the SPF concept itself.

SPF arrives in 1962

Sun Protection Factor, the number on every modern sunscreen bottle, was invented by Franz Greiter in 1962. The method was straightforward. Apply the product to a patch of skin at a defined thickness (2 mg per square centimeter), expose it to a standard UV source, and measure how much longer it takes to produce the same minimal erythema dose as unprotected skin. The ratio is the SPF.

The 1962 introduction of SPF gave consumers a measurable spec for the first time. It also baked in a specific test condition (the 2 mg per square centimeter application thickness) that almost nobody actually uses in real life. Most studies of consumer application show real-world application around 0.5 to 1.0 mg per square centimeter, which means most people are getting roughly a third to a half of the protection their bottle advertises. That gap has been known for decades and has never been resolved on the label.

UVA and the long broad-spectrum delay

SPF measures UVB protection. The longer-wavelength UVA radiation (which penetrates more deeply, drives photoaging, and contributes to skin cancer) was a separate problem that took decades to address. The first dedicated UVA filters (avobenzone, the original chemical UVA absorber) became available in Europe in 1981. The FDA did not approve avobenzone in the United States until 1988.

Even with UVA filters available, there was no standardized way to measure UVA protection on a label until the 2000s. The European PPD (Persistent Pigment Darkening) method and the broad-spectrum certification adopted by the FDA in 2011 were the first widely used UVA standards. The Boots Star rating in the UK and the PA+ system in Asia developed in parallel. The result is that a sunscreen that meets one region’s broad-spectrum standard may not meet another’s, even with the same active ingredients.

The contrarian H2: SPF is not the most important number on the bottle

I have been thinking about this for a while. The skincare internet has trained consumers to chase the highest SPF available, as if SPF 100 is meaningfully better than SPF 50. The math says otherwise.

SPF 30 blocks roughly 97 percent of UVB. SPF 50 blocks roughly 98 percent. SPF 100 blocks roughly 99 percent. The differences between high SPF values are smaller than the differences caused by under-application, missed spots, sweat, and reapplication frequency. A perfectly applied SPF 30 will out-protect a sparsely applied SPF 100 every time.

The more important numbers on the bottle are the UVA protection rating (broad-spectrum, PPD, PA+++ or higher), the water resistance claim, and the texture spec that determines whether you will actually wear it daily. SPF is the headline because it is the only number consumers learned to read. The protection is in the other specs.

The real numbers

The CDC’s 1985 to 2014 surveillance data on melanoma incidence in the United States shows roughly a tripling of cases over that period, despite sunscreen availability throughout. The interpretation in the literature (summarized in a 2018 JAAD review by Lim and colleagues) is that sunscreen alone has not been sufficient to offset rising recreational sun exposure, and that under-application is a major driver of the gap.

A 2013 randomized controlled trial in Australia, published in the Annals of Internal Medicine by Hughes and colleagues, followed 903 adults using daily SPF 16 sunscreen versus discretionary use over 4.5 years. The daily group showed a 24 percent reduction in basal cell carcinoma and a 38 percent reduction in squamous cell carcinoma, with a smaller and not statistically significant signal for melanoma. The protection is real; the realistic effect size at daily-use SPF 16 is meaningful but not total.

What this means for your routine

The history gives a few practical anchors. Daily SPF 30 or higher, applied at a reasonable thickness, reapplied through significant sun exposure, with broad-spectrum certification or PA+++ equivalent. The SPF arms race past 50 is mostly marketing; the UVA spec underneath matters more.

Mineral filters (zinc oxide, titanium dioxide) have been in continuous use since the wartime era and have the longest safety record. Newer chemical filters (Tinosorb S, Tinosorb M, Mexoryl SX and XL, Uvinul A Plus) are available in Europe and Asia but most are still not FDA-approved in the United States. That regulatory gap is the practical reason European and Korean sunscreen reviewers consistently rate their local options as more elegant than the American shelf.

For the broader thinking, see the mineral versus chemical sunscreen primer, the sunscreen application guide, and the SPF myths explainer.

FAQ

Who actually invented sunscreen? Benjamin Green’s red veterinary petrolatum (1944) and Franz Greiter’s Piz Buin Gletscher Creme (1946) are the two foundational consumer products. Greiter later invented SPF as a measurement in 1962.

Why are European sunscreens better than American ones? Regulatory history. The FDA classifies sunscreens as over-the-counter drugs, which makes new filter approval slow. The EU classifies them as cosmetics, which permits faster filter approval. The result is a wider modern filter palette in Europe.

Did SPF mean the same thing in 1962 as it does now? The core method is the same. The test conditions have been refined and the global standards diverged in the 1990s and 2000s, but Greiter’s original ratio definition is still recognizable in the modern ISO 24444 standard.

How long has zinc oxide been used in sunscreen? Continuously since the WWII era. The micronized and nano forms came later, but the underlying ingredient has the longest unbroken safety record on the market.

Is SPF 100 worth it over SPF 50? Marginally, in laboratory conditions. In real-world use, the gap is dominated by application thickness and reapplication, not the bottle number.

Tag hub: More on SPF, sunscreen filters, and daily protection

Sources

Hughes MCB et al. Sunscreen and prevention of skin aging. Annals of Internal Medicine 2013. Lim HW et al. Photoprotection. JAAD 2018. CDC United States Cancer Statistics 1985 to 2014. FDA Sunscreen Drug Products for Over-the-Counter Human Use Final Monograph. ISO 24444 in vivo sun protection factor standard.