Tachi Skin Care ~ Specializing in rejuvenation for aging skin and comprehensive acne treatments

Tachi Skin Care Advice & Specials

Selecting the Right Sunscreen

Chemical or Physical?

The UV radiation in sunlight consists of UVA, UVB, and UVC rays. UVA and UVB ore both responsible for photoaging, skin cancer, sunburn, tanning and wrinkling. UVC is not a factor in skin health, as it is absorbed by the Earth's atmosphere and does not reach us in significant amounts.

Broad-spectrum sunscreen protects against both UVA and UVB. This protection can work in one of two ways: chemical or pysical.

Chemical UV filters

  • Works by absorbing UV radiation, creating heat and inflammation in the skin.
  • Usually requires a cocktail of chemical sunscreens to give broad-spectrum protection.
  • Require application 30 minutes before sun exposure.
  • May irritate the skin and eyes.
  • Not regualted for safety by the FDA; some may even be carcinaogenic.
  • Not photostable (exposure to sunlight degrades effectiveness).

Avobenzone has been found to generate free radicals beyond acceptable safety levels after sitting on the skin for just one hour, and children and pregant women have been advised not to use products containing it.

Octocrylene, which is known to act as an endocrine disrupter, is used in manny suncreens as a stabilizer. It can aso cause skin irritation. According to the Archives of Dermatology, "Octocrylene appears to be a strong allergen leading to contact dermatitis in children and mostly photoallergic contact dermatitis in adults.

Chemical UV filters can also have harmful effects on the enviornment. Octocrylene does not seem to be effectivley contained in wastewater treatment plants, and studies in Switzerland have indicated that is accumulates in fish. Oxybenzone, a chemical UVB filter often used in combination with avobenzone, has been found to negatively impact reef ecosystems and biodiversity.

Physical UV filters

  • Work by reflecting UV radiation, keeping your skin cooler and calm.
  • Start protecting immediately upon use.
  • Provide full broad-spectrum protection.
  • non-irratating to skin and eyes.
  • Safe, as particles do not penetrate the skin.
  • Highly photosable.
  • Zinc oxide and titanium dioxide are the most comonly used physical filter ingredients.

Physical UV filters have an excellent safety profile. The FDA has long considered zinc oxide to be a safe ingredient for both external use and as a food additive.