10 minutes read 

 

This is going to be a literal bird's eye view on the history of sunscreen to highlight a few milestones, though there many more scientific contributors to this area of research.

 

 

 

The Primordial Sunscreens

 

 

One of the oldest references to sun protection can be found in translated papyri scrolls and tomb walls of the Ancient Egyptian civilization. These records revealed the extent of their expertise in the making of potions with a selection of ingredients known for their sun protection.

Clearly they prized light, fair, untanned skin as a symbol of beauty.

Interestingly, scientific research of some of these ingredients has shown some
surprising sun protection properties, for example:

• Rice bran – contains an extract, gamma oryzanol, that is UV-absorbing.
• Jasmine – extracts repair damaged DNA.
• Lupine – extracts are mild skin lighteners.

 

Between 800 – 500 BC, there is evidence that the Ancient Greeks used olive oil to shield the skin from the harmful sun, as well as for care following sun exposure. This makes sense as we now know that olive oil and many other plant oils provide sun protection equivalent to SPF-8.

But the allure of keeping skin white increased from the early Medieval to the Renaissance periods (700 – 1600 AD), when women used lead powders to whiten skin or velvet masks to protect from the sun.

Discovery of What Causes Sunburn

 

Before the discovery of ultraviolet light in 1801 by the German scientist
Johann Wilhelm Ritter, it was believed that sunburn was caused by “sun heat” damage, and in 1789 the English physician Robert Willan, known as the father of dermatology,  described a condition of skin sensitivity to light named eczema solare.

Ritter’s work was based on previous work by Carl Wilhelm Scheele, who
demonstrated that strips of paper soaked in a silver chloride solution
darkened more rapidly and with greater intensity when exposed to blue light,
compared to red light. Because this blue light was below the visible range, Ritter called it “infra-violet”, what we now know as the ultra-violet spectrum.

 

Then, in 1820, the Englishman Everard Home conducted research that made
him conclude that the melanin in darker skin absorbed heat to protect the skin from sunburn. How did he arrive at this conclusion?

 

Home conducted a series of experiments by exposing his hands to sunlight.
So, he covered one of his hands with a black cloth, leaving the other hand
exposed. He found that although the hand covered with the cloth exhibited a
higher temperature it had no signs of sunburn, unlike the exposed hand.

 

 

Early Sunscreens

The discovery that light wavelengths cause sunburn led to the possibility of
using filters to screen the harmful rays.

One of the first attempts was made in 1878 by the Austrian Otto Veiel of Linz who published a report on the benefits of tannin to protect the skin from ultraviolet rays. However, this substance had limited practical use as it stained the skin and clothing.

But, in 1922 Karl Eilham Hausser and Wilhelm Vahle published that sunburn
in human skin is caused by a specific range of ultra-violet (UV) wavelength, between 280 and 315 nanometers.

This finding let to the development of filters that blocked this ultra-violet wavelength range, including the first commercially available sunscreen in the USA in 1928. This  filtering substance contained the now infamous PABA (p-amino benzoic acid) benzyl salicylate and benzyl cinnamate. Interestingly, although sunscreen agents were then made readily available they had no traction in the market.

Modern Sunscreens

 

Between the late 1920’s and early 1930’s the South Australian chemist, Milton Blake, formulated creams with substances that were used in the treatment of burns.  But, it was the chemist Eugene Schueller, who in 1936 developed a sunscreen using benzyl salicylate as ultra-violet ray absorber. Not only was Schueller the creator of the first modern sunscreen, but he was also the founder of L’Oreal.

Shortly after, in 1938, the Austrian Franz Greiter created the “Gletscher
Crème” (Glacier Cream) with an “SPF” equivalence of 2. However, the Sun
Protection Factor scale was developed by Greiter decades later, in 1962. This product was the genesis of the company Piz Buin, named after the location where Greiter was climbing when he got sunburn, and the inspiration for the product name – Glacier Crème.

 

 

 

By now there was wide interest in value of sunscreens and in the 1940’s in
the USA the pharmacist Benjamin Green created a “red colour jelly”, a
petroleum derived substance with a with some sunscreen protection. This was supplied to the US Forces in the Pacific during World War II. However, this substance had limited efficacy, and it staining clothing. Undeterred, Green went on to develop a commercially viable formula... and launched Coppertone.

Ironically, Coppertone’s success in encouraging sun exposure and sun
bathing also had negative consequences. Not understood at the time was the fact that the sun factor protection was insufficient to prevent the damaging effect of solar radiation and this resulted in an increased rate of skin cancer.

 

Some Notes on Active Sun Filters or Sunscreen Ingredients

 

UV rays comprise different type of wavelengths designated as UVA, UVB and UVC, all of which are damaging to the skin. There are several active ingredients used in modern sun protection against UVA and UVB that are damaging to the skin. Although PABA is still used, as it was in 1928, it does not provide sufficient protection against UVA, as it is more damaging to collagen than UVB. Besides, the PABA, Padimate A, has been removed from the FDA list of approved ingredients because it causes skin irritation when exposed to sunlight.

 

• Chemical sunscreens, also called chemical UV filters, such as the benzophenones, like oxybenzone, or the dibenzoyl methane group of agents, do absorb some types of UV radiation, but are problematic because they absorb the UV rays and convert these into heat on your skin. Since, this heat also leads to the breakdown of the filters, to get protection, you have to constantly re-apply the sunscreens.

 

• Other chemical sunscreen such as cinnamates, salicyclates, and anthranilates are used as UVB blockers, however cinnamates should not be used by individuals who are allergic to cinnamon. Also, the then popular ingredient, homomenthyl salicylate, was shown to have limited effectiveness for partial or complete sunburn protection.

 

• Mineral sunscreens such as zinc oxide and titanium dioxide, on the other hand, are the most common ingredients in sun blocks, which are often considered chemical free, as they are metals, and are less likely than sunscreens to cause allergic reactions.

 

• They are also very effective sunscreens or filters against UVA (titanium dioxide) and zinc oxide against all of UVA, UVB and UVC. However, these filters are also thicker than the more fluid chemical filters, can feel greasy to the touch and tend to leave a “white” residue on the skin, which is great acts as this acts as a mirror to reflect UV rays.

 

 

Zinc oxide Vs nano Zinc Oxide - Why You Must Avoid Nano Zinc Oxide? 

 

Although nano-zinc oxide, also called invisible zinc, is frequently used as a substitute for zinc oxide because it does not give the “white” appearance, you must avoid nano zinc oxide. 

 

Nano zinc oxide is a much smaller molecule than zinc oxide, (less than half), and it is easily absorbed through the skin. This makes this filter a useless one, as the “mirror on your skin” ceases to exist… so, no sun shielding.

 

Besides nano zinc oxide has been considered unsafe in the EU, as it has been associated with inflammation on the skin and even in the lungs.

 

Development of an SPF Rating

 

By the mid 1990s most common sunscreen products in the market ranged in SPF from 15 to 30, using a mixture of ingredients such as avobenzone (with octyl triazone as a photostability agent) for UVA protection, and octyl methoxycinnamate for UVB protection. 

 

However, in the early 2000s as evidence accumulated on the association of malignant melanoma with sun exposure and sunbed use concerns rose significantly on UV damage of the skin.  Public health authorities then linked with cancer associations to increase awareness on the need to avoid unprotected sun exposure in the peak periods of 12.00 pm – 3.00 pm, even in overcast weather.

 

This awareness is compounded by evidence that the chemical sunscreens were contributing to coral bleaching in areas of active human recreational activities. Major concern on the use of oxybenzone and octinoxate, led to the sate of Hawaii, USA, in 2018 to ban sunscreen brands with these ingredients. 

 

In 2019, a critical study published in the Journal of the American Medical Association provided evidence that the active sunscreen ingredients avobenzone, oxybenzone, octocrylene, and ecamsule accumulated in the bloodstream of users at rates that exceeded FDA approved levels. This risk had not previously been detected as the FDA permitted waiving of toxicology requirements for sunscreens.

 

 

 

Today, there is a far better understanding of the implications of an SPF rating, and that regardless of how high the rating is, application of sunscreens every 1 – 2 hours is a must. Besides, the regulatory authorities in New Zealand and worldwide are moving toward unified standards and to make a stand against unreliable claims.

 

But… What does Sun Protection Factor or SPF Really Mean?

 

SPF is a measure of how protective a sunscreen is against sunburn.

It reflects the time untanned skin with sunscreen will become red in comparison to untanned skin without sun protection.

 

But the protection value is not linear, so SPF 30 does not protect twice as much as SPF 15. In fact:

 

So, you can never get to 100 percent protection, and you still must re-apply the product every 1 – 2 hours, regardless of the SPF rating!

 

 

 

 

An outline of how to integrate sunscreens in your Daily Skincare Routine and how to manage their use depending on the SPF rating was previously discussed, so I won't elaborate here.

With much awareness on the damage UV rays cause the public is encouraged to avoid peak sun hours as well as wearing protective clothing... and as I regularly recommend, "wear a hat... and have fun in the sun!"

 

 

Light for thought?