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Everything you need to know about sunscreens

"No need for sunscreen on a cloudy day," "when you have dark skin, daily sunscreen is not necessary." Here are two myths about sunscreen that you've probably heard before. In this article, we're going to debunk these myths by sharing with you what we've learned about sunscreens.

 Why should you use sunscreen?

Sunscreens or sunblock are used, as their name suggests, to block the sun, more specifically to block the electromagnetic waves emitted by the sun. We usually call them sun rays. There are several types of radiation waves:

- Short wave rays (UVC, X-rays, beta rays etc.). These are very dangerous but nature being well made, they do not cross the ozone layer. 

- Long-wave rays are the rays which penetrate the ozone layer.  Among the long-wave rays, those that are harmful to the skin are ultraviolet A (UVA) and ultraviolet B (UVB).

  • UVA rays make up 95% of the rays on earth. They penetrate deep into the skin, reach the second layer of the skin called the dermis and cause stress on the skin cells. They affect the elasticity of the skin because they destroy collagen and elastin fibers. This loss of skin tonicity is one of the main causes of skin aging. Long-term exposure to UVA rays causes the development of cancers.


  • UVB rays are the culprits when it comes to sunburn and hyperpigmentation because they burn the epidermis, which is the first layer of the skin.  They are the cause of most skin cancers.

According to the International Agency for Research on Cancer, "80% of skin cancers are linked to excessive exposure to the sun.

What type of sun protection is there?

There are several types of sun protection:


  • Mineral sunscreens are protections that act by reflection and dispersion of UVA and UVB rays. This means that after applying the sunscreen, the active ingredients act directly without being absorbed into the skin. They are composed of titanium dioxide or zinc oxide. They are recommended for sensitive skin and for children because there is hardly any risk of allergy.The downside of these protections is that they leave a white cast on the skin. 


  • The organic sunscreens and the "chemical" or "synthetic" sunscreens have an absorbing action of the UVA and UVB rays. This means that they must be applied at least 20 minutes before sun exposure because they must be absorbed by the skin to protect it properly. The downside is that some protections contain ingredients such as cinnamates, benzophenones that are harmful to the environment or endocrine disruptors (octocrylene, octinoxate) that can impact human health.


How to know the efficiency of sun protection products?

The sun protection factor (SPF) indicates the level of protection of a sun protection product. The higher the SPF, the greater the photoprotection action.

SPF  Level of protection Percentage of UV rays blocked
6 à 10 Low 90%
15 à 25 Medium 93%

30 à 50

High 95 %
50 + Very high 98%


No protection filters 100% of the sun's ultraviolet rays.

To choose your sun protection, you should not only look at the protection indexes, it is important to choose the protection adapted to your phototype, i.e. your skin type.

  • For very fair and mature skin, SPF 50+ protection is recommended.
  • For sensitive skin, a mineral sunscreen SPF 50 + is recommended.
  • For darker skin types, a sun protection factor of 30 to 50 is recommended.

How to apply sun protection?

Sunscreen should be applied every day after moisturizer and before makeup. It should be reapplied every two hours to ensure that the protection level is as high as the indicated index.

To conclude, it is important to remember that suncreens protect the skin against cancer, hyperpigmentation and skin aging. 

Feel free to comment and tell us if this article has helped you in your quest for information on sun protection.


Image from Pexels  by Rfstudio

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