A. Know your skin type
See chart below
TABLE 1: Classification of Sun-reactive Skin Types2*
| Skin Type |
History of Sunburning or Tanning |
| I |
Always burns easily, never tans |
| II |
Always burns easily, tans minimally |
| III |
Burns moderately, tans gradually and uniformly(light brown) |
| IV |
Burns minimally, always tans well(moderate brown) |
| V |
Rarely burns, tans profusely(dark brown) |
| VI |
Never burns, deeply pigmented(black) |
* Based on 45 to 60 minutes of sun exposure after winter or no sun exposure.
B. Know your area’s daily UV index
See chart below
This index is formulated by the National Weather Service based on altitude, cloud cover, sun position, and other elements.
TABLE 2. Exposure Levels Predicted by the UV Index43*
| Index Value |
Exposure Level |
Time in Sun Needed for Burn |
| 0 to 2 |
Minimal |
1 h |
| 3 to 4 |
Low |
30-60 min |
| 5 to 6 |
Moderate |
20-30 min |
| 7 to 9 |
High |
13-20 min |
| 10 to 15 |
Very High |
<13 min |
* These UV effects are on unprotected skin type II, which usually burns easily and tans minimally
Above charts taken from American Academy of Pediatrics Policy Statement. "Ultraviolet light: a hazard to children (RE9913)." Volume 104, Number 2. August 1999, pp. 328-333. Available at http://www.aap.org/policy/re9913.html.
C. All sunblock is not created equal – need both UVA/UVB coverage
UVA,UVB,UVC radiation definitions:
- UVA (320-400 nm): long wavelength, reaches biosphere, little affected by ozone. Causes deep tissue damage especially loss of collagen and wrinkling. Now found to be responsible for skin cancer. These are the rays used in tanning booth bulbs.
- UVB (280-320 nm): shorter wavelength, reaches biosphere, very affected by ozone which can block UVB, causes skin cancer, cataracts, macular degeneration. Considered the "burning" rays.
- UVC (100-280 nm): very short wavelength, little reaches biosphere due to absorption and scattering by atmospheric oxygen, nitrogen and ozone, can be dangerous but little reaches humans.
From paper titled: Ultraviolet Radiation by E. C. Weatherhead.
D. What is SPF?
Sun protection factor is the amount of radiation it takes to produce a pink color (burn) on sunscreen-protected skin 24 hours later compared to the amount of UVR required to produce the pink color on skin without sunscreen. The higher the SPF, the greater the protection; a person who would normally experience an effect within 10 minutes can be protected up to about 150 minutes (10 x 15) with an SPF of 15. Gilmore GD. Sunscreens: a review of the skin cancer protection value and educational opportunities. Journal School Health. 1989;59: 210-213.
This is based on appropriate amount applied, reapplication, and only refers to UVB rays, not UVA.
E. Amount of sunscreen to apply:
- a full ounce for your body and a full teaspoon for your face. So one 8 oz. bottle of suntan lotion should only last for 8 applications.
- Sunscreen precautions (apply to skin 30 min before going out–allows protective chemicals to bond with skin cells, reapply every 2 hrs and after swimming, sweating, or toweling dry).
- Date your suntan lotion. Get a new bottle every six months. These are chemicals and they have a limited shelf-life.
F. Seek shade whenever possible.
Remember that sun reflects off many surfaces
- Grass reflects from 2.5 to 3 percent of UV rays hitting its surface.
- Sand reflects 20 to 30 percent of UV rays
- Snow and ice can reflect 80 to 90 percent of UV rays.
- Depending on the angle of reflection, water can reflect up to a full 100 percent of UV rays striking the surface
http://www.cdc.gov/excite/skincancer/mod06.htm Accessed on 05-29-03
Cloudy skies doesn’t mean you’re protected.
- Clear skies allow 100 percent of UV rays to reach the surface.
- Scattered clouds allow 89 percent of UV rays to reach the surface.
- Overcast clouds allow 32 percent of UV rays to reach the surface.
http://www.cdc.gov/excite/skincancer/mod06.htm Accessed on 05-29-03
Beware of medications that may affect sun exposure. Many antibiotics, antihistamines, birth control pills, diuretics, and antidepressants can increase the skin’s sensitivity to the sun leading to a quick and intense burn.
Apply a sun protective lip balm with an SPF of 30.
People who are bald, have thin or light colored hair should use a spray sunscreen on their scalp.