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Sun protection is an important factor in skin health, as the sun's ultraviolet (UV) rays can damage our skin cells' DNA and lead to sunburns, photo aging (wrinkles and dark spots), or worse, skin cancer.

Sunscreen Bottle

Understanding SPF

Sun Protection Factor is a worldwide standard of how well a sunscreen will protect skin from UVB rays.

SPF Sun Protection Factor Chart

Broad Spectrum

Sunscreens that protect against both UVA and UVB light rays are often described as being “broad-spectrum.” UVA (UVA = aging) are longer wavelengths. UVB (UVB = burning) are shorter wavelengths.

Broad Spectrum UVA and UVB Chart Wavelength (nanometers)

SPF vs. Broad Spectrum

Sun Protection Factor

Measures the sunscreen's ability to prevent UVB and some UVA rays from damaging the skin.

It is based on how quickly redness forms on sunscreen-protected skin compared to unprotected skin. This is measured as MED (minimal erythema dose, or ‘‘the smallest UV dose that produces perceptible redness of the skin with clearly defined borders at 16 to 24 hours after UV exposure").

Broad Spectrum

For sunscreens to be labeled broad spectrum they must pass a critical wavelength test, which measures how far they protect into the UVA region.

If 90 percent of the formula's ultra violet (UV) absorbance occurs at 370nm, the sunscreen passes the test.

SPF Sun Protection Factor Rating Chart

Physical vs. Chemical Sunscreen

Physical vs. Chemical Sunscreen chemical physical
- Physical Sunscreen - Chemical Sunscreen


Starts protecting immediately upon application.


20 minute wait after application for effective protection.

Deflecting vs. Absorbing

Bounces sunlight away from skin.

Deflecting vs. Absorbing

Absorbs UV light, preventing penetration into the skin.


Tends to leave a white cast or tint.


Rubs in easily, and is more cosmetically elegant.


Does not cause allergic reactions. Is good for sensitive skin.


May be irritating, and can occasionally cause allergic reactions. Additionally, may cause watering of eyes and stinging.


Generally safe.
May inhibit production of Vitamin D in the skin; however, normal use of sunscreens does not affect vitamin D levels.
Small particle size (nanoparticles) raises questions about absorption, although risk to health not proven.


Generally safe.
May inhibit production of Vitamin D in the skin; however, normal use of sunscreens does not affect vitamin D levels.
Oxybenzone has shown estrogenic effects in rats with extreme doses; it is considered safe as we humans use it.

Active Ingredients

Titanium dioxide (TiO2)
Zinc oxide (ZnO)

Active Ingredients


Prevention Guidelines



Mostly affect the outer layers of the skin. Responsible for sunburns and tanning that increase risk of skin cancer.


Deeply penetrate skin layers, damaging collagen and DNA. Responsible for wrinkling, loss of elasticity and pigmentation.

Sunburns Wrinkling
Tanning DNA Damage
Skin Cancer Skin Cancer

More than 90% of all skin cancers are caused by sun exposure.

Sun Exposure Clouds

Even on overcast days, UV can penetrate through clouds and haze.

Use 1/2 Teaspoon
of Sunscreen

Sunscreen Bottle


recommends consumers choose a sunscreen that states on the label:

SPF 30

SPF 30 or Higher

Broad Spectrum

Broad Spectrum

Protects the skin from ultraviolet A (UVA) & ultraviolet B (UVB) rays, both of which can cause cancer.

Water Resistant

Water Resistant

Use 2 Tablespoons
of Sunscreen


Sunscreen goes on after moisturizer and other skin treatments but before makeup.

Long Day

During a long day at the beach, one person should use around one quarter to one half of an 8 oz bottle.


Apply sunscreen 20 minutes prior to going outdoors.

10 AM         4 PM

The Skin Cancer Foundation recommends avoiding the sun during peak hours, from 10 a.m. to 4 p.m.

2 Hours

If you are out in the sun or physically active, reapply sunscreen every 2 hours at the very least.

1 In 5

1 in 5 Americans and 1 in 3 Caucasians will develop skin cancer in their lifetime. Choosing the right sunscreen can help reduce the risk of skin cancer and early skin aging caused by the sun. See your physician every year for a professional skin exam.

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