Beyond SPF: Rethinking Sun Protection in a Changing Market - Part 2

Kristin Köhler, Head of Care Ingredients at Berg + Schmidt Solutions GmbH & Co. KG, Brian Ecclefield, CEO/Founder at Validated Claim Support
Panel Interview

SPF 30 is often perceived as only slightly less protective than SPF 50 because both block a high percentage of UV radiation. Given that SPF 30 allows roughly 3% of UV through while SPF 50 allows about 2% – a 50% difference in transmitted radiation – how should we explain the non-linear relationship between SPF values and their biological impact, and should the industry reconsider communicating SPF in terms of UV transmitted rather than UV blocked?

Brian Ecclefield, Validated Claim Support:

People generally think of the acute, short-term implications of sun protection as it pertains to sunburning, and this is a function of both SPF testing and marketing. In reality, the label claim is derived from a function of erythemal grading and responsivity, however the real danger of UV exposure is not the short-term sunburn, it’s the long-term risk of skin cancer and DNA damage.

I think consumers can often look at the very commonly utilized language denominating that SPF 30 allows 3% of radiation through and SPF 50 allows 2% through and really miss the important take aways. With radiation the risk factor is in cumulative life-long dosing.

I’m going to simplify UV dosing for the purposes of discussion and just describe it in Arbitrary Units – this is for conversational purposes only. The reason for this is that I don’t want to describe dosing in “time units” since the number of seconds in the sun versus delivered UV radiation varies so much around the world and throughout the year. We’ll describe radiation as a function of how much has actually gotten to the skin from here on out as “arbitrary units.”

To begin with, someone who receives significantly more radiation over their lifetime than another person, with other variables remaining constant, is more likely to develop skin cancer. It is not an exact science – a person receiving 3 million units is not 1.5x more likely to get cancer than a person that got 2 million units. . . But I doubt there are experts anywhere who would disagree that the person with the higher dosing is not at least more likely to experience detrimental effects in the long term. You’ll find that individuals who work around nuclear radiation use personal dosimeters that are meant to track their lifelong exposure, and they can lose their right to work in certain fields once the dosing gets beyond a certain point because we know how dangerous it is with the cumulative exposures. There is no way to step back and reduce the damage done by lifelong exposure, and in this manner nuclear and UV radiation are similar.

With suncare, this concept is generally lost – people think that once their sunburn fades they are good to go and things have reset back to normal, but in reality, that lifelong personal dose has gone up.

If you are someone who enjoys going to the beach – let’s say you can get 1,000,000 arbitrary units of radiation throughout your summer leisure unprotected. Utilizing an SPF 30, your body would only get 30,000 units, and using an SPF 50 your body would only get 20,000 units.

Over the course of 20 years, using an SPF 30 your body would receive 20 x 30,000 units = 600,000 units. Using an SPF 50 your body would receive 20 x 20,000 units = 400,000 units. Over 40 years of exposure we can double that – SPF 30 = 1.2m and SPF 50 = 800,000. Meanwhile the unprotected alternative would be at 40,000,000 units of radiation.

What this means is that for arguments sake, an SPF lets you spend roughly 35 more summers in the sun before you would have the same amount of radiation as someone who wears no sunscreen for one full summer. An SPF 50 would give you 50 summers to hit the same relative dose. It’s a function of time, and how you want to spend it. . . If you are a sun bum – you want to get as many summers as you can doing what you love. . . So protect yourself. The unprotected doses add up really quickly in comparison.

For people that get normal UV exposure on an occasional walk or their daily commute – an SPF 30 is way better than unprotected. . . On those random beach days, step it up to high protection SPF 50+.

Regarding the shifting of messaging – the entire concept of SPF as it stands in the US is still based on the sunburn or erythemal responses, with only a pass fail for UVA Critical Wavelength. I think the rest of the world does a much better job in converting UVA protection into scales, as UVA is not something that should be treated lightly. From a messaging perspective I think its really important not to just let the SPF numbers become an arms race – we saw that a decade ago as sunscreens came out with label claims as high as SPF 100 and SPF 120.

In the real world, there is definitely a diminishing return on the final protection factor – and tying everything together it is important to consider the UVA protection as well as the overall ease/likelihood of wearing a product daily and reapplying it.

How do you balance high SPF performance with texture and user experience, especially in daily-use products?

Brian Ecclefield, Validated Claim Support:

Equally important to protection in many ways for heavy outdoorsmen and women is the concept of application, ease of use, and wearability. If you don’t like the texture and feel of your sunscreen, you’re not going to want to reapply as often.

Let’s face it – people have really different lifestyles, skin types, and environments that they live in. Being different is part of what makes us all so special. A product that works for me may not be a product that works for you – some of that is tactile and some of it is visual/tonal, but either way the sensory responses to suncare products must be considered by consumers and manufacturers alike.

It’s important to find a product which doesn’t gross you out to put on. . . If the first thing you do is cringe because it feels “slimy” to you, or look in the mirror as your eyes pop out of your head because you think you’re all of a sudden wearing circus makeup, its very likely that there is a better alternative for you out there.

Personally I really like the convenience of sprays and I shy away from thick oily creams. . . That’s my preference. You want something that is easy to wear, doesn’t leave you cringing, and looks/sits naturally on your specific skin tone. It may take a lot of trial and error to find the perfect sunscreen, but with thousands of products out there. . . Most likely it does exist.

Reapplication and good application are just as important as the actual SPF factor on the label of your chosen product. The reasons that all labels ask you to reapply every 2 hours are mainly 2 fold: product will wear off through contact and friction with other surfaces, and sunscreen is actually known to break down over time through continuous UV exposure. If you’re at the beach you have towels, sweat, sand, salt water, and the sun all beating down on the protective film you’ve coated on your body. Every so often you need to reapply to account for the external stressors.

This is one of those areas where not everyone will agree with what I say next. . . But if you find an SPF 30 that you love, and you can wear it daily, you’re way better off than someone who puts 50 on sparingly and cringes at the thought of the feeling of it coming into contact with their skin. You are more likely to apply daily, and reapply after a few hours simply because you have a good relationship with your product. Accordingly its not all a numbers game and an arms race, and there is an element of subjectivity.

How reliable are current in vivo and in vitro SPF testing methods, and where do they fall short in predicting real-world efficacy?

Brian Ecclefield, Validated Claim Support:

There is a lot to say about the current models, and how in many cases, they often fall short. In the US market, the fact that UVA is still treated only as a “pass fail” critical wavelength is a big problem when there are levels to protection.

In vivo testing models also still rely on high intensity, short term doses of radiation where real world exposure is more of a “low and slow” input. People don’t understand how important it is to reapply sunscreens, as they really do degrade differently in the sun then they do in the lab.

Water resistant testing models are still built with fresh water exposure, whereas the majority of people in the world are swimming in salt and chlorinated water. . . Ocean salt and chlorine are similar in that they can both be extremely chemically reactive, and they present variables that impact film formation that do not come into play with fresh water alone.

Because the “front and center” label on most sunscreens is still SPF – which is tested only on Fitzpatrick I-III or lighter skin types, the real-world protection for people with darker complexions is often lost in the mix. It is particularly important that the concept of UVA protection becomes an earthly consideration for people’s health, longevity, and quality of life.

I would love to see water resistance factor in additional assays that look at different types of water which better mimic a day at the pool or the beach. The concept of hybridizing in vivo and in vitro models is also important, as while there is no perfect replacement for human skin, measuring transmittance and absorption is much better achieved in the analytical lab than the clinical lab.

Despite all of this – I will still double down that being protected in any capacity is multitudes better than unprotected, especially in high exposure lifestyles. Wear your sunscreen daily, and scale up your protection if you’re going to be outside for extended periods of time, all other things constant.

As consumers demand multifunctional products, how does combining UV protection with skincare benefits impact the robustness and credibility of SPF claims?