SmartShield Your Skin and the Sun


What is SPF?
Is SPF 45 more effective than SPF 30?
What is UV and are there more than one type of UV?
How do you assess the UV exposure you can expect to receive during an outing?

What is SPF?

SPF is the abbreviation for Sun Protection Factor. In layman's language, one SPF is the amount of time in minutes that it takes your unprotected skin to become lightly reddened or irritated (erythemal) from being exposed to the sun. Each person has a different SPF based, among other things, on his/her skin type, amount of skin pigment (skin darkness), existing tan, and prior sun exposure.

The SPF number on sunscreen products indicates approximately how many times your normal SPF time is multiplied by correctly applying that product. As an example, if your personal SPF is 30 minutes and you choose to use an 8 SPF product, you would extend your time to reach the sensitivity to the sun as described above by eight (8) times.

The time would be calculated by multiplying your personal SPF time of 30 minutes by the SPF number on the sunscreen product which was 8. The total, in our example, is 4 hours (240 minutes). That means, in our example, the sun would have the same effect on your skin using properly applied SPF 8 sunscreen in four (4) hours as it would in one half hour without sunscreen.

Is SPF 45 more effective than SPF 30?

SPF 30 is very effective delivering 96.5% of UV protection without the side effects. SPF 45 and above provides minimal protection and the added active ingredients can be harsh to the skin and can result in allergic reactions. View this chart for details.



% of UV Protection

Very weak protection



Minimal protection



Dermatologist recommended protection     



Dermatologist recommended protection



Dermatologist recommended protection



High concentrations of active ingredients*



Very high concentrations of actives*



What is UV and are there more than one type of UV?

UV is the abbreviation for Ultraviolet Radiation. These invisible rays produced by the sun are commonly classified in one of three categories (UV- A, UV-B, or UV-C) and are the major cause of sunburn, skin aging, and in some cases, skin cancer.

UV-A rays remain rather constant in intensity throughout the year and penetrate more deeply into the skin's layers than UV-B rays. UV-A rays are major contributors to sunburn, wrinkling, and premature aging.

UV-B rays are more intense at locations closer to the equator, at higher altitudes, and during the summer months. They are stronger than UV-A rays and are the most common cause of sunburn as well as contributing to premature aging, and wrinkling of the skin. They also can contribute to skin cancer.

UV-C rays are the most dangerous and strongest of the UV band. However, they normally do not reach the Earth's surface because they are filtered out by the ozone layer of the atmosphere.

How do you assess the UV exposure you can expect to receive during an outing?

  • Your geographic location. UV rays are strongest near the equator and diminish as you go toward the poles.
  • Time of Day. The UV exposure is greatest during the sun's most intense period which, in most climates, is between 11 am and 3 PM.
  • Season of the Year. The summer months are not only when the sun and resultant UV rays are most intense but it is during this warmer period that you typically have more exposed skin due to lighter clothing.
  • Altitude. UV rays are present in much greater amounts at higher altitudes than at lower ones due to thinner, cleaner air. At altitude, the cooler air sometimes makes us forget we are getting high levels of UV exposure.
  • Total Time in the Sun. Remember all of the time spent in the sun, including the many small exposures each day, add to the total time in the sun.
  • Your environment. The surfaces around you can and do add to the direct sunlight and UV rays that you receive when outside. The surfaces you are on reflect the UV rays back to you in varying amounts but must be considered when thinking of your total exposure time. It may be useful to consider that clean snow reflects upwards of 80% of the rays that strike it, while sand and concrete reflect approximately 10-15%.
  • Cloud Cover. It is important to understand that UV rays, just like the rest of the sun's rays, pass through clouds and reach the Earth. Like the visible rays, the UV rays are filtered by the thickness and darkness of the cloud cover but there are still some that come through. A light cloud cover may make us feel cooler and therefore less concerned about the sun's rays but be aware that the UV's are still coming through at almost full strength.
  • Visit the EPA site:
    What action should I take to protect my employees, my clients, my family, and myself?
    A multifaceted approach is best. Assess your total sun and UV exposure potential considering the various factors mentioned earlier and make a plan to protect yourself such as:
  • Select your exposure times to limit maximum UV rays.
  • Use natural shade whenever possible. When you stop work or play to discuss a point, step into the shade when possible. Sun damage is cumulative.
  • Use the best quality sunscreen products with the proper SPF level. Make sure that your sunscreen has both UV-A and UV-B protection.
  • Wear a hat and protective clothing during peak sun times to lessen exposure.
  • Remember to give children extra protection since their skin is usually more sensitive than their parents'.
  • Apply your sunscreen evenly and totally, remembering to reapply after swimming or perspiring.
  • Wear good quality UV screening sunglasses. Sunglasses are not just to make you more comfortable but will help prevent cataracts and other eye problems which can be caused by UV exposure.