Sunscreen: How to choose between chemical and mineral filters?
The sun is essential for our bodies, but its ultraviolet rays can cause irreversible damage to the skin. To protect yourself, there are two main types of sunscreens: chemical and mineral. Their mode of action, skin tolerance, and environmental impact differ. Here is a comprehensive guide to understanding their characteristics and determining the solution best suited to your skin and needs.
Understanding the two types of sun filters
Sunscreens are formulated to limit the absorption of UVA and UVB rays, which are responsible for sunburn, skin aging, and certain types of skin cancer. However, their mechanism of action varies:
- Mineral filters, also known as physical filters, rely on particles such as titanium dioxide or zinc oxide. They form a barrier on the surface that immediately reflects light.
- Chemical filters, They contain organic molecules that penetrate the skin slightly and absorb UV rays before converting them into heat or harmless light.
These differences influence not only their practical effectiveness, but also their tolerance and side effects.
The advantages and limitations of mineral filters
Mineral sunscreens work as soon as they are applied and are often recommended for sensitive, reactive skin or for young children. They present little risk of allergy because they remain on the surface of the skin.
However, they have long been criticized for their chalky white appearance, which is unattractive, especially on darker skin tones. Recent formulas have been improved, but their texture can remain thicker than that of chemical sunscreens.
In terms of the environment, mineral filters are generally better tolerated by marine ecosystems. However, when used in the form of nanoparticles, they can also have an impact on phytoplankton and other aquatic organisms.
Chemical filters: more attractive, but more controversial
Chemical filters are appealing due to their fluid and transparent texture, which is easy to apply and pleasant for everyday use. They are available in cream, lotion, gel, or spray form, offering a wide range of choices to suit individual preferences.
However, they must be applied 20 to 30 minutes before sun exposure to be fully effective. Certain ingredients, such as oxybenzone or octocrylene, are accused of causing skin irritation and are suspected of acting as endocrine disruptors. Environmentally, they are also blamed for contributing to coral bleaching and coastal water pollution.
Even though doubts do not concern all chemical filters, European regulations strictly regulate their use and their long-term safety is still a matter of debate.
How to choose based on your skin type and priorities
The choice between a chemical filter and a mineral filter depends primarily on your skin type and lifestyle:
- Sensitive, atopic skin or children : choose mineral filters without nanoparticles to limit the risk of reactions.
- Normal or combination skin : Chemical filters offer a better sensory experience and are easier to incorporate into a daily routine.
- Practice in a marine environment : choose coral-friendly products labeled “reef safe,” whether they are chemical or mineral-based.
In some cases, hybrid formulas combine both types of filters to offer skin tolerance, comfort of application, and broad-spectrum protection.
Best practices for optimal sun protection
- Choose a suitable SPF : SPF 30 is recommended for moderate exposure and skin types IV and above, while SPF 50 is recommended in strong sunlight and for fair, sensitive skin (skin types I to III).
- Apply enough product : most users apply too little, reducing the actual effectiveness (recommended dose 2 mg/cm² : approximately half a teaspoon for the face and neck).
- Refresh the application every two hours and after swimming or heavy perspiration.
- Protect yourself mechanically as well : hats, sunglasses, and protective clothing remain essential.
- Avoid exposure between 12 h and 16 h, when UV radiation is at its strongest.
