FOR WHICH INDEX TO CHOOSE?
The regulations have put claims in order: there are now four protection categories and eight indices, also called SPF (sun protection factor). Indices 6 and 10 correspond to “low” protection; at 15, 20 and 25, “medium” protection; “high” protection corresponds to indices 30 and 50, while at 50+, “very high” protection is achieved. Terms such as “sunblock” have been banned because no cream filters out 100% of the sun’s ultraviolet (UV) rays.
Except in the particular case of children (see below), the appropriate index depends on your skin type: the higher ones are suitable for very light complexions with blue or green eyes and blond or red hair; dark skins that do not experience sunburn will be satisfied with little protection. All this is to be nuanced according to the context: in skiing, even dark browns will opt for an index 50 whereas, for a short exposure in spring, porcelain tints can be satisfied with an index 10.
To make an informed choice, there is nothing better than knowing what the clues really correspond to. They reflect UV transmission to skin according to formula : 1/ index. With an index 6 cream, the amount of UV transmitted will be 1/6, or 16.6%; with an index 50 cream, it will be 2%. There is therefore little difference between close indices: 25 is considered as “average” protection, whereas cream only allows 4% of UV rays to pass through, 30 falls into “high protection” category with 3.33% unfiltered UV rays.
Note that the UV considered when calculating index are UVB. They are most “nasty” in the short term, those responsible for sunburn. But UVA rays are also formidable: if they do not leave visible traces, they are just as involved in genesis of skin cancers. Since 2006, therefore, regulations have required creams to protect against both types of UV rays, with a ratio of 1 to 3: a cream with a sun protection factor (SPF) of 30 must guarantee protection against UVA rays with an index of 10. Unfortunately, as our tests show, protection against these two types of UV is not always consistent with posted index.
APPLY OFTEN AND GENEROUSLY
The indices are calculated by taking into account a very generous application which corresponds, for example, to 6 teaspoons (36 grams) for body of an average adult. The application of a smaller quantity leads to a disproportionate reduction in protection: with half as much product used, protection can fall to one-third. It is therefore necessary to apply the cream generously and repeat the application regularly, especially after perspiring, swimming or wiping.
WHICH CREAM TO CHOOSE FOR YOUR CHILD?
A baby should always be covered with light clothing, even anti-UV clothing, a hat and left in the shade. A principle that it is less and less realistic to want to apply to letter as the child grows. It is then necessary to apply sun cream regularly on parts of body not covered. The index chosen should be as high as possible, as unprotected sun exposure during childhood is a risk factor for skin cancer in adulthood.
Should I choose a “special child” sun cream? Admittedly, there is a share of marketing in mentions relating to children which are often synonymous with rising prices. But our last test of sun creams for children showed us that allergens were practically absent. It therefore seems that manufacturers are taking care to offer safer formulas for their ranges intended for smallest. Impression confirmed in view of two products a priori very close to La Roche Posay : the mention[nano] appears in the list of ingredients of reference “all coming” Anthelios index 30, which is not the case of reference Anthelios Dermo-pediatrics index 50+.
WHAT ARE ORGANIC SUN CREAMS WORTH?
The advantage of organic specifications is that they exclude several undesirable compounds; on the other hand, organic cosmetics are not, in principle, free of allergens. Within “special for children” range, the differences in composition between organic and conventional creams are not obvious. In terms of effectiveness, the former tend to be characterized by insufficient anti-UVA protection.
It was long believed that organic products were taking lead in preserving marine environment. Indeed, chemical filters, released into sea when we swim, are very toxic to algae on which corals depend for survival. Mass tourism and the widespread use of sunscreens are leading to coral bleaching, synonymous with death. The idea that physical filters used in bio products (titanium dioxide and zinc oxide) did not cause this phenomenon has long prevailed. Unfortunately, some studies show that they are indeed capable.
NANOPARTICLES: TO BE MONITORED
Sunscreens are one of the few products where[nano] can be found after an ingredient on the composition list. It means that ingredient in question has been used in nanometric form, therefore at an infinitely small size (one nanometre equals one millionth of a millimetre). This precision is not insignificant, because nanomaterials have specific properties: a compound can see its usual behaviour completely modified when it changes to nanometric size. This makes it very difficult to assess the safety of nanomaterials, many aspects of which are still unknown to scientists.
The opinions of Scientific Committee on Consumer Safety (SCCS) on compounds concerned are not reassuring because they are full of unanswered questions. For example, the opinion on titanium dioxide admits in black and white: “It is important to note that assessment of nanomaterials in general still suffers from important gaps in knowledge. There are also uncertainties about the validity of tests used. Although experts conclude that titanium dioxide is safe for skin, they caution against its inhalation toxicity and recommend that it not be used in powder or spray formulations. Inhalation toxicity is one of major concerns for nanomaterials in general, because their size allows them to penetrate very deeply into respiratory system and pass into blood via the pulmonary alveoli.
All the uncertainties about safety of nanoparticles have prompted the world of organic cosmetics to be extremely cautious. The specifications therefore exclude use of ingredients in “nano” form. But this ban is not easy to comply with in the case of sun products, because the filters traditionally used in organic cosmetics – zinc oxide and titanium dioxide – are physical barriers that have an unfortunate tendency to leave white traces on skin. The finer particles, the less visible traces. The challenge is to miniaturize both substances as much as possible without reaching nanometric size. A challenge that ingredient suppliers have not been able to meet in recent years. The Cosmos specification, which concerns the majority of organic cosmetics sold in France (those labelled Ecocert, Cosmebio and BDIH) therefore allows the use of nanoparticles for sun filters but frames their content.
There remains question of reliability of labelling. For to impose the mention[nano] after each ingredient concerned, as a European regulation applicable since 2013 has done, is good; to be able to monitor compliance with this obligation is better. However, there is still a lack of reliable and standardized analytical methods. In the Fraud Repression Directorate, we admit that we are satisfied with documentary controls for lack of a validated method. But a certificate whose veracity cannot be verified in the laboratory is easy to falsify. As a result, not all manufacturers would be equally zealous in labelling the nanomaterials they incorporate into their formulations. Some would risk not mentioning them. Without recognized methods of analysis, it is impossible for us to confirm or refute this suspicion.