1. “The whiter a sunscreen is, the more effective it is”
No.
The well-known “geisha face” effect is mainly associated with inorganic (mineral) UV filters, such as zinc oxide (ZnO) and titanium dioxide (TiO₂). These filters can leave a visible white film on the skin because they scatter visible light.
However, contrary to a widespread misconception, modern mineral filters do not primarily protect by “reflecting” UV rays like a mirror. Studies show that their protective mechanism relies mainly on UV absorption, just like organic filters. Reflection and scattering account for only a small part of the protection.
Thus, a ‘mineral’ sun cream that is whiter is not automatically more protective than a more transparent formula.
In sun creams using only inorganic filters, a more pronounced white effect is often linked to larger particle size, or to a less uniform dispersion of the mineral filters within the formula. These particles scatter visible light more, which accentuates the white effect on the skin.
Conversely, finer, more evenly dispersed mineral filters can become almost transparent whilst still providing excellent UV protection.
2. “A 100% mineral sunscreen can easily achieve a true SPF 50+.”
Not really.
In Europe, mineral UV filters are limited to 25% concentration under cosmetic regulations. Achieving a true SPF 50+ using only mineral filters remains extremely difficult from both a technical and cosmetic standpoint.
Some formulations also use film-forming agents or soothing ingredients such as bisabolol, which may influence in vivo test results by reducing certain UV-related inflammatory reactions. As a result, the protection measured during volunteer testing may sometimes differ from the real-life protection obtained during everyday use, especially when insufficient amounts are applied.
In addition, some brands rely mainly on zinc oxide as the primary UV filter. With current regulatory and formulation limitations, these formulas often achieve a practical SPF closer to around 10–15 rather than the SPF 50+ claims sometimes marketed.
3. “SPF 30 and SPF 50 are dramatically different.”
Not as much as many people think.
- SPF 30 blocks about 96.7% of UVB rays
- SPF 50 blocks about 98% of UVB rays
The difference appears small on paper, but in real life, consumers usually apply far less sunscreen than the amount used during regulatory testing.
For children with phototypes I to VI, using the highest possible protection — ideally SPF 50+ — remains preferable.
For phototypes V and VI, the skin already benefits from partial natural protection due to melanin. In many common exposure situations, SPF 50 may therefore be sufficient while still helping prevent long-term UV damage.
4. “You don’t need to apply that much sunscreen.”
False.
SPF tests are performed using an application thickness of 2 mg/cm² of skin. In reality, most people apply 2 to 4 times less product.
A 6-year-old child has approximately 8,000 cm² of skin surface area. At the regulatory dose, this represents around 16 g of sunscreen for a full-body application.
Even if only one quarter of the body is exposed, that still represents around 4 g per application. With 3 applications per day — roughly reapplying every 2 hours during exposure — this corresponds to approximately 12 g of product per day.
A 50 ml tube can therefore be used up much faster than most people expect. Under normal daily use, a 50 ml tube for a child may last around one month. During beach holidays with frequent reapplication and heavy exposure, it may be consumed in only one week.
5. “Mineral = eco-friendly, organic = toxic.”
False.
The environmental reality of UV filters is far more complex than what social media slogans suggest.
Mineral filters such as ZnO or TiO₂ may also have environmental impacts depending on their form, particle size and exposure conditions.
The European Union and the OECD are currently working on harmonized environmental assessments for all cosmetic ingredients, including UV filters.
6. “The best sunscreen would be SPF 100.”
Not necessarily.
SPF 100 products do exist in Europe, but they are often closer to medical-device or highly specific-use products rather than standard cosmetic sunscreens.
SPF theoretically corresponds to the amount of UVB passing through the protection:
- SPF 50 → about 2% of UVB still reaches the skin (~98% blocked)
- SPF 100 → about 1% of UVB still reaches the skin (~99% blocked)
And “total sunblock,” as some brands claim, simply does not exist on our planet.
The real-life difference between SPF 50 and SPF 100 therefore remains relatively small.
SPF 100 formulas are extremely complex to develop. They generally require very high concentrations of UV filters, often combining multiple organic filters with film-forming agents to maintain performance. These products are mostly intended for medical contexts or extremely photosensitive skin.
Furthermore, in Europe, even when a formula tests above SPF 60, 70, or even 100, cosmetic regulations limit the displayed claim to “SPF 50+”.
For everyday use, a properly applied and regularly reapplied SPF 50+ sunscreen remains more than sufficient. The most important factor is not chasing SPF 100, but applying enough product and reapplying it consistently.
7. “Big brands automatically use dangerous ingredients.”
Not necessarily.
L'Oréal owns one of the world’s largest patent portfolios in photoprotection, covering:
- UV filters
- photostability
- water resistance
- textures
- film-forming polymers
- ultra-long UVA protection
Technologies such as Mexoryl and UVMune 400 are the result of several decades of scientific research.
Some smaller groups, such as SVR, also hold patents related to specific UV filter combinations or formulation systems. However, their research capabilities remain far more limited than those of L'Oréal.
Many smaller brands mainly rely on UV filters developed by large ingredient suppliers such as DSM-Firmenich or BASF, along with already-optimized formulation bases. As a result, formulations can sometimes become very similar from one brand to another.
In many cases, differences between sunscreens on the market are more from marketing, texture, brand positioning, packaging, or R&D budget than from major technological differences in UV protection itself.
8. “A simple and minimalist sunscreen formula is always better.”
Not necessarily.
Sunscreen is one of the most complex cosmetic formulations to develop.
Each UV filter has its own advantages and limitations regarding:
- stability
- UV spectrum coverage
- compatibility
- skin tolerance
- texture
Combining several filters often improves the overall stability, efficiency and tolerance of the formula.
9. “Sprays and sunscreen sticks are ideal for children.”
They can be practical but they require caution.
For children, sprays and sticks may seem convenient for sunscreen application.
However, sprays can lead to unintended inhalation of particles or solvents during application, especially on the face.
Sticks, on the other hand, can make it difficult to apply a sufficient and homogeneous amount of product over all exposed areas.
These formats can therefore be useful but they require careful use in children to ensure truly effective protection.
10. “There are perfectly appropriate sunscreens for babies under 3 years old.”
This should be strongly nuanced.
For very young children, primary protection should remain physical:
- protective clothing
- hats
- shade
- limiting direct sun exposure
Health authorities primarily recommend avoiding direct sun exposure in infants.
11. Can I reuse a tube of sun cream that I opened last year?
No, and this can actually be a problem with sun cream.
Sunscreens are subject to cosmetic regulations and their shelf life depends mainly on two factors:
• the PAO (Period After Opening),
• and the DDM / DLUO (minimum durability date).
Unfortunately, the minimum durability date is not mandatory for cosmetics with a stability of over 30 months, which is generally determined through accelerated stability testing. At LiLiKiWi, we choose to state it for the sake of transparency, but many brands do not include it. This also protects the interests of retailers and distributors, as consumers do not really know when the product becomes too old and the products can continue to be sold.
In most cases, consumers only have access to the PAO, often stated as 12 months, sometimes even 6 months for certain sun creams.
So, if your sun cream has been open for more than 12 months, we do not recommend continuing to use it.
Organic UV filters are relatively fragile: over time, exposure to heat, air and light can reduce their effectiveness. The texture, smell and, above all, the UV protection may then no longer be optimal.
📚 Scientific reference:
(1) Cole C, Shyr T, Ou-Yang H. Metal oxide sunscreens protect skin by absorption, not by reflection or scattering.Photodermatology, Photoimmunology & Photomedicine. 2016.