The Purito Sunscreen Controversy: what does it mean for the state of sunscreens and what do consumers need to know?
by: Sara A. Dudley, MA, MBA
Disclosure: I am the CEO of The Sunscreen Company™. All opinions are my own and shared in the interest of promoting discussion and understanding.
Update: April 13, 2021 Additional sunscreen brands have had their sunscreens pulled due to issues with SPF claims, including a product by Krave Beauty. The article below still applies and provides a possible explanation as to the ongoing issue.
A long overdue scandal is brewing in the world of beauty insiders, influencers and consumers alike. Is the SPF 100 that you have been using on you and your kids really a SPF 10? Has your favourite skincare expert been wrong about their cult K-Beauty pick and has it left you unprotected? If you are not an avid Reddit Skincare Addict fan then the Purito Sunscreen controversy may not have even been a blip on your radar. However, here is why it’s not really that shocking for those in the industry and why it could impact the beauty and skincare industry going forward.
I am the CEO of a sunscreen company, aptly called The Sunscreen Company ™ and as always, I was late in hearing about this perceived SPF scandal. I have young kids and I can get mired in the latest Baby Shark and other parenting trends and traps. It was only when a journalist that I know at Beauty Independent reached out about a story she was putting together and asked for my opinion did I see all the other internet commentary and discussion that has ensued. There are a lot of opinions going around- some of them are very informed but I still felt like the situation could be further clarified. It’s something that we as a company have been talking about in our 13 years, figuratively shouting it into the void, and it’s now come to light. We as a company formulate all of our own sunscreens and skincare products in-house and we do no use third part formulators to develop our products. Our co-founders include a dermatologist, a retired OB-GYN with a specialty in reproductive endocrinology, a cosmetic chemist and myself, an MBA type. I’ve been able to learn from some of the heavy weights in the academic and technical world of sunscreens. I’ve also had to immerse myself in the complex regulatory world of making and selling sunscreens in one of the most restrictive areas- much love and respect to Health Canada!
As a quick summary for those who have not heard:
-A popular blog called the INCI Decoder sent one of their favourite sunscreens called Purito Centella Unscented Sun SPF 50+ to an independent lab for SPF testing after being skeptical about its labelled SPF claim.
-After sending the product for in-vitro SPF testing and then to two other independent labs for in-vivo SPF testing, they received a range of results that showed the SPF to be closer to 15–19 rather than what the brand claimed to be an SPF 84.5 or as labelled as an SPF 50+.
-Consumers and beauty enthusiasts are now wondering how to explain these different results and whether this could be a problem for other sunscreens in Korea, the United States and globally. Spoiler alert- it has nothing to do with the product being Korean and is not an indictment of K-Beauty. It is part of a more widespread issue, one that can happen in any part of the world.
Who is right?
Most people’s first question is whether these several new results showing a much lower SPF than what is labelled are accurate. The short answer is-probably. Cosmetic chemists use a basic arithmetic to calculate what an expected SPF should be based on a concentration of filters. It’s the rough, back-of-envelope type of calculation that probably made the INCI Decoder’s chemist suspicious of the Purito SPF. It’s the same arithmetic that informs the algorithms for on-line SPF simulators like the BASF Solar Simulator and the DSM Sunscreen Optimizer. For example, for every 1% concentration of zinc oxide, you can expect to achieve 1.6 SPF points. If you have 2% zinc oxide in your formula then you can expect it to contribute roughly 3 SPF points to your formula. Inorganic/mineral filters like zinc oxide can be relatively inefficient in terms of SPF protection so you therefore need a lot of it to get reasonable SPF’s and protective UVA Protection Factors. Organic ‘chemical’ filters like Tinosorb S are more efficient in contributing to an SPF so every 1% concentration can contribute something like 3+ SPF points.
These on-line solar simulators are conservative tools in that they underestimate the potential SPF and the UVA Protection efficiencies of filters. They are meant to be industry tools for providing benchmarks. Can formulators improve on the metrics provided? Absolutely. Within the formulators tool kit, things like dispersion techniques, particle size and distribution, coatings etc. can improve the performance of the filter. Your 1% concentration of zinc oxide starts contributing 2 SPF points to your overall formula. Congrats! Can your innovations in formulation technology improve your efficiency by a magnitude of 20x. No! As a small aside- we recently patented as a company the use of a certified organic (Ecocert) raw material derived from sugar cane to improve the SPF and UVA Protection Factor efficiency of mineral filters by up to 50%. In terms of SPF, we might see an expected SPF go from a SPF 30 to an SPF 37.5. Pretty exciting gains! We did not see our SPF 30 become an SPF 75 and that is the crux of the issue. So why are some companies seeing these types of gains?
Performance Enhancement versus Performance Duping
I know, duping is not a real word. But it’s the best one to describe the type of SPF gaming that can happen as a result of the current methods for testing.
Most regulatory authorities require that the SPF of a sunscreen be tested according to one of two in-vivo methods. In other words, it involves irradiating humans and measuring their body’s response via erythema of the skin (skin redness). A sunscreen is tested against a standardized benchmark and analysts compare the level of skin redness that is produced. Why is this important? Many sunscreens contain anti-oxidants and anti-inflammatories that reduce skin redness. Some of our most beloved ingredients like Niacinamide or Centella Asiatica Extract (both are contained in the Purito product) are designed to remove skin redness. Less commonly known are ones like Bisabolol (derived from Chamomile) and Butyloctyl Salicylate (chemically similar to Aspirin). INCI Decoder and other skincare blogs label Butyloctyl Salicylate as a common UV filter solvent, an ingredient used to stabilize unstable filters like Avobenzone. However, these anti-inflammatories and anti-oxidants when used in sunscreens do not enhance the performance of the UV filters. They do not make them more efficient or effective. Rather they simply mask the biological end point that is used to determine their effectiveness. Duping. The best analogy that I’ve heard for this to put it in easy terms comes from another skincare blog called The Triple Helixian (Editor’s note: this is a blog post from 2013 and while I like the analogy, I do not agree with everything). If you can imagine a scenario where the sun is like a gun and UV light is like a bullet. UV filters are the equivalent of a bullet proof vest. They may not stop all harm from being inflicted but they do actually protect to a certain degree. Anti-oxidants would not prevent any harm so the person in question would still get shot. They do repair some of the damage though so it would be like having a medic on hand to come and bandage the wound. Anti-inflammatories do not prevent harm nor do they really repair damage. They mask the body’s immune response. They would be the equivalent of leaving the wound gaping but providing a gag for the victim, muffling the outcry but not much else. I admit it’s a little dramatic but it’s a nice and easy visualization. I personally love anti-inflammatories in skincare but have found their use in sunscreens that do not contain enough UV filters to be problematic.
This has been an ongoing concern in the industry- the Environmental Working Group has shared their concerns about artificially high SPF’s. I know that some recent studies have attempted to disprove the possible effect of anti-inflammatories on SPF in-vivo results as in here. This study did use benchmark samples that contained filters containing salicylates like homosalate and ethylhexl salicylate. These filters have also been questioned for potentially having erythema reducing properties and also inflating SPF in-vivo results. I would question their use within a control that is attempting to parse out the effect of anti-inflammatories. I would also note that the use of anti-inflammatories is problematic when there are insufficient UV filters being used. If sufficient filters are being used then, the impact of anti-inflammatories will be less obvious as the filters themselves are doing their purported job of reducing erythema. This study does not mention that concentration of the filters used in the samples so it’s difficult to say. I would love to see more studies being done on this. As a final note, one of the most tell-tale pieces of evidence that this SPF gaming is a known phenomenon is that there are raw materials that are commercially available and publicized as being SPF boosters.
Beyond Red Flags
I know that a lot of industry insiders might be critical of my assessment of the role of SPF gaming using anti-inflammatories. I’m sure many will criticize it as simplistic. I would argue though it provides an important tool that consumers can use to red flag their formulas. Customers do not have easy access to what type of testing was done on any given formula. The ingredient listing of the actives and in-actives are an important source of information for them as the accuracy of the claims on the front of the bottle are called into question. If their given formula seems to include a low amount of filters but has a high SPF and does include ingredients like Niacinamide, Centella Asiatic Extract, Bisabolol, and Butyloctyl Salicylate, then it’s something reasonable for them to question. If you are a consumer reading this, then I encourage you to go-forth and read the back side of all of your sunscreens. I would love to hear about your findings in the comments. If you are looking for a more comprehensive analysis of the Purito example and whether it could be widespread within the industry (maybe you are a brand and are worried about an SPF within your line) then continue on for other contributing factors to this question of questionable SPF. A Part Two if you will on SPF testing, the impact of Good Manufacturing Practices on batch-to-batch consistency and other sunscreen nerdery.
Sunscreen Testing Methodology
I remember in my early days of attending many conferences on sunscreens how contentious discussions among academics were on the subject of sunscreen testing methodology. Debates were pretty heated; you would have thought people were discussing politics not SPF. I’ll share the secret that there is not a lot of consensus when it comes to the standardization of testing methodologies, the role of UVA vs. UVB in skin cancer and photo-aging, the importance of safety concerns of certain filters from an endocrine disruption and ecological point of view.
The current ‘gold’ standard for testing sunscreens SPF involves testing on human subjects (in-vivo). There are two variations of this method- the FDA method and the recently updated ISO 24444. The ISO 24444 method was updated in 2019 and seems in practice to result in lower or more conservative results than its counterpart, the FDA method. The INCI Decoder blog does use this newer method as part of its investigations. There is a fairly long list of criticism against both methods, including:
-Both involve irradiating human subjects and have ethical implications.
-Both are subject to a considerable amount of variability in terms of results in terms of inter-labs and even intra-labs. Factors like the application of the spreading technique of the sunscreen, the range of Fitzpatrick Skin types used as test subjects, the variability in the observation of the Minimal Erythema Dose all can impact consistency of results. The reproducibility of results is an important standard for validating a scientific method and is at question for both methods. The 2019 update for the ISO method did look to improve on this.
-Both use solar lamps as stand ins for natural sunlight and there have been multiple studies questioning if they are suitable replacements due to the limits on their spectral output that are not present in natural sunlight.
There are other methods that are available and are in contention for being validated as a global standard. It should be noted though that these are not currently accepted by most regulatory governments to register a sunscreen. Therefore, these methods would need to be done in addition to either of the in-vivo SPF ones. Uli Osterwalder, who is now working with the ISO committee on sunscreen methodology validation, provides a nice summary of the various methods that are in contention with their pros and cons. As a company in 2019, under the behest of our co-founder and my father Dr. Denis Dudley, we paid for multiple samples of commercially available and one non-commercially available sunscreens to be tested using a hybrid method called HDRS (Hybrid Diffuse Reflectance Spectroscopy) that while in-vivo does not irradiate human subjects. It uses a test to measure the UVA Protection Factor in-vivo and then uses an in-silico extrapolation to calculate the SPF. Since the purpose of this series of testing was to investigate the use of the HDRS method and our focus was more on the UVA Protection Factor of the tested sunscreens, no brand names are listed. All testing was done at the Institute Dr. Schrader. There are a couple of outlier results but for the most part there is a general observable trend. You can see a nice correlation between what can be expected in terms of SPF, UVA Protection Factor and the concentration of the active ingredients. Formulation techniques, innovations and constraints can be a factor but generally speaking the more of an active that is used (within its allowable limits from a regulatory and formulation perspective) that the more protective it will be in both the UVB (SPF) and UVA (UVA PF) range.
There has been a lot of talk with respect to the Purito example of whether brands should be taking on the additional expense of testing their products using multiple methods or using multiple labs. I will say that sunscreens are very expensive to develop in comparison to other skincare products. The marketer in me looked at the expense we undertook to test our formulas for this non-recognized method, something we did in the name of advancing the science of sunscreen forward, and thought it would have nicely contributed to a Facebook ad campaign instead. As a company, it’s incredibly challenging to balance short term priorities against longer term ones of establishing credibility, confidence and improving the industry for the common good. This is not meant to be a dig at any other brand. It’s genuinely hard to do. You need a balance of voices at the table, marketing working hand in hand with technical formulations and product development.
A Note on the Impact of Good Manufacturing Practices on SPF’s and Sunscreens in Production
I’ve seen it mentioned in a couple of blogs the fear that this SPF inconsistency could be something that is happening after a product has been launched, commercialized and once in production, i.e., inconsistencies showing up from batch-to-batch. In other words, consumers might not be able to trust that the product they are buying off the shelf can be trusted. Maybe the INCI Decoder sent off a bad bottle to be tested and this is why it had a lower SPF?
In most jurisdictions, there are considerable regulations in place to ensure that sunscreens are not being made in someone’s bath tub. There are typically licensing requirements for manufacturers that mean they are subject to inspections and enforcement actions. There are operational practices called Good Manufacturing Practices that are in place as well. We sell what is considered Natural Health Products as sunscreens. These are considered drug products by Health Canada.
This means on a practical level:
-We need to validate our suppliers of our Active Pharmaceutical Ingredients and make sure they are supplying materials that meet prescribed specifications. We have a supplier validation program in place that involves a considerable amount of testing on our part to certify we are working with good suppliers.
-We actually test our raw materials before use at an independent third-party lab and then test our finished product again to make sure that it includes the correct concentration. A sunscreen that has a Drug Identification Number (DIN) requires it contains the labelled concentration of a declared active within 10%. A Natural Health Product (NHP) has a wider limit theoretical limit of 20% but in actuality you should not see this type of variability in production. Even if you did, it would not account for the type of wide SPF swings that are being discussed.
-We also test our Finished Products for microbial limits, heavy metals and more on every single batch.
All to say, there are fail-safes put in place to ensure that customers should not be doubting the potency of their product in terms how they are manufactured.
Who is to blame? Brands, labs, contract manufacturers or even consumers?
My feeling ultimately that a lot of SPF mis-steps are ultimately derived at the formulation level. They just do not contain enough actives to provide enough broad-spectrum protection. A robust sunscreen formula is therefore essential. We are approached by 3–4 other brands a week to see whether we would consider making them a sunscreen for their line in a private label capacity. These calls have given me a lot of insight into the predicament that brands face. Many feel pressure from their current customer base to include a sunscreen in their line. While these founders and management teams are very knowledgeable about other skincare products, they find the world of sunscreens overwhelming and they feel that they have few options in terms of providers. A lot of them could talk passionately about the sourcing of their Manuka honey for twenty minutes but are limited in what they know they want in terms of a sunscreen formula. Most know they want a nice texture and an SPF of x. On the flip side, I’ve had other conversations with individuals who are deeply curious and wanting to provide an incredibly in-depth brief on what they are looking for. When development is a rich process that is mutually engaging and one of deep discovery, then there will be less chance of formulas being created that check certain boxes but ultimately miss the mark in being safe and effective.
My final challenge is for consumers to continue to educate themselves on the vast discrepancies that exist between available sunscreens. I did not even touch on the many issues that we as a company feel exist in regulations, human safety, ecological impact etc. I did not get to expound like I normally do on how SPF is a useless metric anyways and completely neglects the more important measure of UVA protection, which is ultimately crucial in terms of protecting against skin cancer and photo-aging. Sunscreens are an iceberg that continue forever under the surface. I think that is why I love developing them. I have seen first-hand the edification of the sunscreen customer. The level of questions that I get from our direct customer surprise and delight me every day. Keep it up, sunscreen consumers. You have an incredible amount of power to effect change- the industry will meet you where you need us to be, one day.