What are UVA and UVB?
They are simply different wavelength bands of ultraviolet light with different ranges of wavelengths. UVB has shorter wavelengths and higher energy and does not penetrate the surface of the skin. It causes sunburn. UVA has longer wavelengths and penetrates below the surface of the skin where over time it causes permanent sun damage consisting of wrinkling, “aging,” and pigment changes. A sunblock that protects against both UVA and UVB is called “broad spectrum.”
What is the significance of SPF?
SPF stands for “sun protection factor.” It is defined as the time it takes to develop sunburn using a product compared to the time it takes without any protection. SPF 15 is considered to be the minimum effective protection and SPF 30 is more optimal.
What are the merits of physical and chemical sunblocks?
Chemical sunblocks are organic compounds whose molecular structures absorb ultraviolet light. Many of them are not broad spectrum, and certain ones cause allergies or acne. Physical sunblocks consist of either titanium oxide or zinc oxide. They are broad spectrum and tend to remain on the surface of the skin where they primarily reflect and scatter ultraviolet light, although some is absorbed as well.
Did you know?
A white Tshirt has an SPF of 7 – 8 and thus by itself is insufficient sun protection. Darker, thicker material such as denim has an SPF of 28 – 30 – much better!
Althea sunblock is a pure, broad spectrum physical sunblock that consists of 17% zinc oxide and has an SPF of 30. Pick some up on your next visit to our spa!