The Right Sunscreen

Sunscreens should meet specific criteria to be safe for both humans and the environment:

• They should not be absorbed through the skin, or if they are, only within the uppermost layer of the epidermis

• They should not have hormonal or hormone-like effects

• They should not enhance the absorption of other chemical substances

• They must be photostable, meaning their effectiveness should remain stable during sun exposure and not be reduced or deactivated by UV rays

• They should not trigger allergies or photosensitivity

• They should not be bioaccumulative (i.e. build up in the human body over time)

• They must be easily biodegradable in the environment and must not harm flora or fauna

  
  

An ideal sunscreen meets all of these criteria, providing effective UV protection without harming human health or the environment.

Conventional sunscreens often contain chemical UV filters, which penetrate the skin and are absorbed by the body. Within the skin, UV rays are converted into heat through a chemical reaction. These filters are now considered controversial due to their potential health and environmental risks.

Recent studies show that physical (mineral) UV filters, such as zinc oxide (ZnO), meet the above criteria, mainly because they are not absorbed by either healthy or damaged skin. It is especially important to ensure that no nanoparticles (ultrafine solid particles ranging in size from 15 to 1,000 nm) are used.

Physical UV filters form a layer on the skin’s surface and protect against UV-related damage to skin, cells, connective tissue, and genetic material by reflecting harmful UV rays.