Sun Protection

1
Sun Protection

• How it Works

2
SPF factor and sun tanning
Take notes from the ppt to answer the following
questions

1. What does SPF stand for?
2. How do UVA rays differ from UVB rays?
3. What does SPF on sunscreen indicate?
4. What should you consider when using a sunscreen?
5. How much sunscreen should you apply?

3
SPF

• SPF stands for Sun Protection Factor
• The SPF rating system was developed in 1962 by
  Franz Greiter.
• The SPF rating system applies to UVB rays, the
  rays responsible for sunburn.

4
UVA Rays

• UVA - UV rays that have the longest wavelength.
  
• UVA rays account for up to 95 of the UV
  radiation reaching the Earths surface and damage
  skin by penetrating deeper than UVB rays. UVA
  rays cause skin cancer and wrinkles.
• Tanning booths primarily emit UVA rays.
• There is currently no approved SPF rating system
  that measures UVA rays.

5
UVB Rays

• UVB - UV rays that have shorter wavelengths than
  UVA rays.
• UVB rays damage the skins more superficial
  layers. The intensity of these rays varies by
  season, location, and time of day (the most
  significant amount hits the U.S. between 10 am -
  4 pm from April to October).

6
Sunscreens

• SPF indicates how long it will take for UVB rays
  to redden skin when using a sunscreen, compared
  to how long skin would take to redden without the
  product. Example Someone using a sunscreen
  with an SPF of 30 will take 30 times longer to
  redden than without the sunscreen.
• You need protection from both kinds of rays.
  Look for a sunscreen with an SPF of 15 or higher,
  plus some combination of the following
  UVA-screening ingredients stabilized a
  avobenzone, ecamsule (a.k.a. Mexoryl),
  oxybenzone, titanium dioxide, and zinc oxide. You
  may see the phrases multi spectrum, broad
  spectrum or UVA/UVB protection on sunscreen
  labels, and these all indicate that some UVA
  protection is provided. However, because there is
  no consensus on how much protection these terms
  indicate, such phrases may not be entirely
  meaningful.
• You should apply 1 ounce (2 tablespoons) of
  sunscreen to your entire body 30 minutes before
  going outside. Reapply every two hours, or
  immediately after swimming or excessive sweating.

7
Sunprint Paper from the Sunscreen Lab
SPF 4
SPF 0
SPF 8
SPF 15
SPF 45
Unknown