Skip to content
Are there different types of sunblocks?

July 12th, 2020 by Dr. Hannah Sivak

That suntan that used to be fashionable (and still is in some circles) is a signal that the UV in the sunlight has damaged your DNA. Nothing to celebrate, right? Ultraviolet light is classified into three categories: UVA (315 to 400 nm), which causes tanning, UVB (medium wave, 280 to 315 nm), which causes sunburn, and UVC (short wave, germicidal, 100 to 280 nm), which is filtered out by the atmosphere and does not reach us. Incidentally, the ozone (O3) layer of the atmosphere absorbs 97–99% of the UV in the range 200 nm to 315 nm, which is why the destruction of the ozone layer by some chemicals is…

READ MORE