gcsescience.com                                                 43                                                 gcsescience.com

Atomic Structure

How are Nanoparticles used in Sunscreens?

Sunscreens are used to protect skin against the harmful
effects of UV light (ultraviolet light) from the Sun.

The wavelengths of UV light which cause skin damage
are divided into two ranges called UVA and UVB.

What is UVA?

UVA contains the longer wavelength of UV light which can
damage cells deep inside skin tissue and lead to skin cancer.
Zinc oxide and titanium dioxide can effectively reflect UVA
and prevent it from reaching the skin. These two compounds
are made even more effective in sunscreens when used in the
form of nanoparticles because of their high surface area.
There is however some concern that nanoparticles may be
harmful to health and products containing nanoparticles may
need further investigation before they can be known to be safe.

What is UVB?

UVB contains the shorter wavelength of UV light which causes
sunburn but is less likely to cause cancer. Some sunscreens may
be more effective at blocking either UVA or UVB but not both.

What is SPF?

Sunscreens may also have a SPF (sun protection factor) rating.
The higher the number, the greater the protection given.
You must use care when using sunscreen to avoid being
over confident that you will have enough protection.
Read the instructions thoroughly and follow the
recommendations for re-applying the sunscreen
especially if you are swimming, as water will
remove some sunscreen from the surface of the skin.

        Links        Revision Quizzes        Revision Questions