First of all, especially before getting into any detail regarding the doubts and questions surrounding the composition of sunscreen products, it is imperative to provide an answer to a very first question, and without any ambiguity, because this question alone justifies lingering on each point of the discussion.
Are sunscreen products indispensable?
We can often hear this question, which involves another obvious one: “Isn’t the protection provided by a sunscreen product more harmful than the sun itself?”
Let’s make it clear right now: YES, an adapted sunscreen product is indispensable in case of exposure, especially if it is prolonged (longer than 10 to 15 minutes) and repeated (in summer, on holidays, on a daily basis for outdoor workers…).
And NO, no matter what the product contains (we did say, no matter what the product contains), it is not more harmful, and still preferable to the damaging effects of UV rays. Experts at Cosmetic OBS really think it is better to use a “bad” product than none when staying in the sun.
Harmful effects in the short term (sunburns on the skin), in the medium term (premature skin ageing), and maybe especially in the long term (the increasing development of melanomas, these very serious skin cancers) are too well-known to pretend otherwise. A sunscreen product is not a luxury product, it is a public health imperative.
And what is true for adults is even more so for children, whose skin is more sensitive, more fragile, and less well-armed to protect itself: in short, more vulnerable.
If we do not feel like staying in the shade all the time, dressed from head to toe, and right up to the tip of our fingers, all summer long, then we must use a sunscreen product. But that is where it gets a bit tricky: which one is best?
Which level of protection is best?
Of course, the ideal degree of protection depends on each type of skin, and on its complexion, level of sun tan…
But in any case, the product chosen must protect against both UVBs, which are responsible for the skin’s inflammation phenomena (redness, burns, sunburns…) and UVAs, which result in premature skin ageing, and are also involved in the development of melanomas, the very serious skin cancers.
There is nothing mandatory regarding this issue in cosmetic regulations today. However, a European Commission Recommendation, which became mandatory in July 2013, includes several provisions to ensure the efficacy of sunscreen products.
This text thus defines a “minimum degree of protection that should be provided by sunscreen products”, that is:
• a UVB protection of sun protection factor SPF 6 (SPF),
• a UVA protection of UVA protection factor of 1/3 of the SPF,
• a critical wavelength of 370 nm.
It is to be noted that the SPF indicated only refers to the level of the anti-UVB protection, and therefore that the protection needs to be completed with an anti-UVA protection, within a UVB/UVA ratio ≤ 3. A logo – the letters UVA surrounded with a circle – is used by professionals to mark the compliance of the product with these specifications.
Is the SPF announced reliable?
It is a recurring debate which regularly makes the newspaper headlines: the SPFs displayed on labels are suspected to be overestimated, and much higher than the actual protection the sunscreens products provide.
This is the hobby-horse of Laurence Coiffard, professor and researcher at the Université de Nantes, France, who denounces these “false” SPFs on the basis of SPF measuring tests performed in her Laboratoire de Pharmacie Industrielle et de Cosmétologie (Industrial and Cosmetology Pharmacy Laboratory).
The whole controversy is about the measuring method. To this day, only an in vivo method is validated by the authorities (the French, European and international authorities, via an ISO standard) to measure the SPF. It is on this basis that manufacturers calculate and display their products’ level of protection.
However, Laurence Coiffard carries out her in vitro tests according to her own method, which is not validated by health authorities. She highlights in particular that adding ingredients with anti-inflammatory effects into sunscreen products (Allantoin, Bisabolol…) distorts in vivo results by delaying the main inflammation reaction of the skin, the sunburn.
Consequence: the natural warning message sent by the skin, meaning “I’ve had enough sun, you should take me away from it now”, is postponed. We remain exposed to the sun for a longer period of time than we should, and our skin always ends up suffering from it, because it absorbs more UVAs, among others.
The UVA protection can also be reduced, since its level is calculated as a function of that of the SPF.
And all this should be done in compliance with regulatory requirements.
Which SPF is best?
To this day, no decision has been made to bring the discussion to a close, and the ongoing work of official authorities – for instance the ISO – to develop an in vitro SPF measuring method that would be validated and recognized by all parties present, should not be over before the next two or three years.
In the meantime, what should we recommend?
First, let’s remind everyone that too low an index protects against almost nothing, and that a “sun block” does not exist, which means we can never be totally protected, or at least not 100%.
So if there is any doubt about the actual value of the SPFs displayed, we can only advise you to go for higher ones. Even if they protect less than they claim, they still provide a better protection.
Although of course, none of them excuses you from remaining sensible when it comes to exposing yourself to the sun:
• do not stay in the sun for too long, even if you have applied a protective product,
• renew the application frequently to maintain the protection, especially after having perspired, swum or wiped your face and body,
• do not reduce the quantity of product to be applied recommended by the manufacturer: by reducing this quantity, you do reduce the level of protection significantly.
Synthetic filters or mineral screens?
The efficacy of sunscreen products results from two types of ingredients: synthetic filters and mineral screens. However, they are both controversial as to their harmlessness, if not their efficacy.
Are synthetic anti-UV filters harmful?
They protect the skin by absorbing sun rays. Here is the first criticism usually formulated: this mode of action thus enables UV rays to penetrate the skin, and if this system does protect from sunburns, it does not protect the skin from melanomas in the long term.
What is sure is that some of them are suspected of having an oestrogenic activity, and therefore of acting as endocrine disruptors. This is already an issue for adults using them, and a real problem in case of repeated applications on a child’s skin. But it becomes a major concern when we think each swimmer covered with these substances leaves a small quantity of them in the sea or river waters… and as the natural chain goes, no doubt they will end up eating them through fish flesh…
What is also perfectly well-known and proven is that many of these synthetic filters are endowed with a strong allergenic potential. Some of these allergenic filters have been banned by regulations or abandoned by the cosmetics industry. However, others are known – such as octocrylene – whose safety of use is being reassessed by health authorities because of the numerous allergic and photo-allergic reactions related to their use, but which are still very commonly used.
It is true new synthetic filters have recently appeared on the sun care market. However, is it difficult to assess their qualities or defects: they are protected by “industrial secrecy” and exclusive patents, therefore they do not disclose any element enabling to make any judgment on the issue, and their use is much too recent for researchers to have enough hindsight and evaluate their potential undesirable effects.
To be absolutely clear, it has to be noted that all synthetic filters are not the same. Some are now considered as safe for use, photostable and well-tolerated, without any known undesirable effect. Those should not make you hesitate if you see they are part of a product composition, even though they are synthetic… provided they are not side by side with other, less commendable filters. And to be completely thorough on this issue, it has to be said that it is rarely the case, since filters are always used in complexes to obtain extended protection against UVAs and UVBs.
For exhaustive details on all anti-UV filters, their main characteristics and their potential undesirable effects, see our article “Anti-UV filters and sunscreens”.
Are mineral screens totally harmless?
As for these, they reflect the light and thus form a sort of protective barrier. There are two main ones: zinc oxide and titanium dioxide. They were presented as the natural alternative to synthetic anti-UV filters for a long time, and still often are, but neither are they completely harmless, no matter how natural they are.
If zinc oxide seems to be riskless for human health (it is harmful only when ingested in large quantities), it has been proven it is not devoid of toxicity for water aquatic organisms (which are necessarily concerned at some point or other if you go swimming covered with sun cream…).
As for titanium dioxide, it is classified by the IARC (International Agency for Research on Cancer) in the 2B category of substances likely to be carcinogenic for human beings. But the risk only exists when it is inhaled in great quantities in the form of powder, therefore neither with the texture nor in the concentration used in cosmetic products.
The actual risk associated with the use of these mineral screens thus lies in their being reduced to the size of nanoparticles, a technique used to avoid the typical “white film” of organic sun products, which does not look very nice, and is thus not too popular with consumers.
The problem is that preliminary studies show these particles, smaller than a billionth metre, could prove strongly toxic. On the one hand, their photoactivity (reaction to light) produces free radicals that can damage the skin’s DNA. On the other hand, they are suspected of penetrating the body quite easily (for instance through small skin lesions: eczema, microcuts…): in this case, their consequences on health are still mostly unknown, but they do raise concern, since we know that the very limited size of nanoparticles makes them all the more reactive to their environment.
Can a strong protection with mineral screens only be obtained without any nanoparticles or white film?
Cosmetic OBS already asked the question before summer 2013, and at that time, the answer was: “Yes, it is a challenge for our formulations, it is pretty complex to obtain, but it is definitely possible.” Then came a selection of products, whose manufacturers certified they contained 100% minerals, and 0 % nanoparticles, offered high SPFs, and also satisfied all the criteria established by experts for this category of products.
The answer is completely different today.
The reason for this reversal is in the Cosmetic Regulation, which became entirely applicable on July 11, 2013. It comprises the definition of a nanomaterial, which has since then been explicated through specification criteria defined by the SCCS (European Scientific Committee on Consumer Safety).
According to this definition, a cosmetic ingredient is now considered “nano” as soon as nanoparticles are involved at one point of its manufacturing process. Even if, in the end, it is not a nanomaterial as such.
What is the result? Some non-nano ingredients on July 10… became nano ingredients on July 11! Therefore they were subject to the labelling obligation, which also became effective for all cosmetic nanomaterials on July 11, 2013.
Consequence: organic products based on mineral screens, which until then had been claimed (and it has to be noted, in good faith) as “no nanoparticle” products, had to include the mention [nano] in their lists of ingredients, and delete the mention “no nanoparticle” from their sales leaflets.
Should they have disappeared from the market, since organic standards ban nanomaterials? This is an actual debate, and all its aspects are dealt with in this article.
Are they harmful to health? No, their manufacturers assert today: they declare that although their raw materials must be labelled [nano] to comply with regulations, there is no trace of any nanoparticle in the finished product, and that is proven by measurements.
Are there any alternatives? No, say the vast majority of organic cosmetic manufacturers, at least if we do not want to get back to the chalky textures and white films of the first organic creams.
And yet we can still find a few, though not many, products based on mineral screens that claim to contain no nano, on the basis of the certificates provided by their raw material suppliers. Are they reliable? Some seem to be, other much less.
Once again, it will be up to consumers to make a decision, depending on the level of trust they have or not in the brand.
What other selection criteria are there?
A sun protection product is not limited to its filters and protective screens. A cosmetic formulation is complex, and involves many other ingredients… including some which are simply to be avoided in case of sun exposure; which does not prevent them from being found in some products:
• alcohol: it is irritant and dries the skin, and it is a photosensitizer that can trigger reactions of the skin in contact with UVs,
• essential oils, especially that of citrus fruit, are also strong photosensitizers,
• allergenic ingredients and/or sensitizers increase the skin sensitivity, and are also to be avoided. This includes perfumes and their allergenic aromatic molecules, some preservatives…
We would also like to evoke the photostability of a sunscreen product.
Indeed a sun filter – or a complex of filters – may act differently under the effect of light, remain stable or degrade itself more or less quickly. That is exactly why we always recommend renewing the application of sun creams very regularly, and at least every two hours, so as to ensure a constant protection for the skin.
Photostability is measured (by in vitro tests) and could be indicated on the label. One could wish, or even ask manufacturers insistently to mention it, and thus provide consumers with this rather important information. But this is not required by regulations. And specialists in the matter do not foresee any change… before long. So in the meantime, you can only spread your cream generously on your face and body… and do it often!