Home Health Beauty SunScreen Lotions or Sunblocks- known and unknown facts about SPF


Use sunscreen and lip balm regularly to protect yourself from the harmful rays of the sun. It’s easy!

Sunscreen Basic Info

Always choose and use a sunscreen that is:

An SPF 15 or higher
Broad-spectrum (protects from both UVA and UVB rays)
Waterproof or Sweatproof


Application tips

Apply the sunscreen generously to all exposed skin – most people do not use enough sunscreen and therefore do not get the maximum protection.
Reapply every two hours, and even more frequently if you are sweating, getting wet, or are in a windy climate.
Apply 30 minutes before going outside.
*Besides protecting you from sunburn, sunscreens help to prevent other skin damage related to sun exposure, such as premature aging and pre-cancerous growths.

Lip Balm

  • Always wear a lip balm with an SPF 15 or higher – remember that your lips can burn just like the rest of your skin.
  • Reapply often!

*Lip balm not only protects your lips from burning, but the moisture helps to prevent chapping and dryness as well.

Using sunscreen is an effective way to protect your skin from the sun’s damaging UV rays. However, since sunscreen cannot block all UV rays and many people do not apply it correctly, you should always practice additional sun safe behaviors such as wearing protective clothing and seeking shade when possible.

Definition and Workings of Sunscreen:

  • Sunscreen is a lotion formulated with unique chemical components to absorb UV light.
  • When sunscreen is applied to the skin, the chemical molecules form an invisible, protective layer on the skin that protects from penetrating UV rays.
  • All sunscreens protect from UVB rays, but only “Broad-Spectrum” sunscreens protect from both UVB and UVA rays.
  • UVB rays affect the top layers of the skin and are responsible for Burning.
  • UVA rays affect the lower layers of the skin and are responsible for Aging.
  • Remember to always buy a sunscreen that is broad-spectrum!

SPF… What’s it All About?

  • SPF stands for “Sun Protection Factor.”
  • Always wear a sunscreen with an SPF 15 or higher!
  • SPF was developed to describe the amount of protection that a sunscreen provides. No sunscreen can protect your skin from all of the UV rays, but a higher SPF number indicates protection from more rays.
  • The SPF number tells you how much longer you can stay outside without burning while wearing the sunscreen product as opposed to not wearing any sun protection product. SPF measures “time to burn.”

SPF Math

SPF Number x Time to Burn Without Sun Protection = Time to Burn while wearing sunscreen*

*assuming that sunscreen is applied properly

Example: If your skin would burn in 10 minutes in the afternoon sun without any sun protection, and you applied a sunscreen with an SPF 15, you would have 15 x 10 = 150 minutes (2.5 hours) before you would burn.

Percentage of Protection from damaging UV rays:
SPF 15 = 92%
SPF 30 = 97%
SPF 40 = 97.5%

There is some controversy about very high SPF numbers and just how much more protection they provide. As you can see from the percentages of protection of the different SPF numbers, the difference in UV ray protection in SPF numbers becomes minimal as the number increases past about 30 or 40. The difference of protection between SPF 15 and SPF 30 is great (5%), but the difference between SPF 30 and SPF 40 is minimal (0.5%).

The Confusing Part About Sunscreen

  • Many people think that SPF values can be added. Actually, SPF values cannot be added – if you apply a sunscreen of 8 and then one of 12, you will not have the protection of an SPF 20. You will only be getting the protection of an SPF 12.
  • Reapplication only helps to ensure that you have the amount of protection and time before you burn that you calculated when you first applied sunscreen that day. Since no sunscreens can protect your skin from all UV rays, some rays will get through.
  • After your calculated “time to burn” has expired, your skin has absorbed all the UV rays that it can handle before it will start to burn. Even if you reapply sunscreen at this point, you will still burn because some rays will get through to your skin and your skin has already been saturated with UV. Therefore, you need to get out of the sun at this point and let your skin rest before exposing it to more rays.
  • Reapplication only ensures that you have your original time outside – sunscreen can wear off because of sweat, wind, and other factors you need to reapply in order to be protected.
  • So what’s the lesson to be learned about sunscreen? If you know that you will be in the sun for a long period of time, start with a higher-SPF sunscreen in order to have protection for the entire time that you are exposed.

Sunscreen vs. Sunblock

  • Sunscreen contains chemicals that absorb UV rays before they damage the skin and sunblocks contain particles that physically block UV rays from reaching the skin.
  • Sunscreen needs to be applied about 30 minutes before sun exposure so that the chemicals have time to soak into your skin and form a layer of protection.
  • Sunblock does not need to be applied before going into the sun – it will begin to work as soon as you rub it on because it sits on top of the skin.

Sunscreen Use

  • Always make sure that your sunscreen is SPF 15 or higher, “broad-spectrum,” and waterproof or sweatproof.
  • A generous amount of sunscreen should be applied to all exposed skin (do not forget your ears and the back of your neck.) In the summer, it is recommended to use one ounce of sunscreen – the amount to fill a shot glass – to cover your exposed skin.
  • Allow at least 30 minutes for your sunscreen to absorb before you head into the sun so that the chemicals can form a protective shield.
  • Be sure to reapply another layer of sunscreen if you will be in the sun for more than 2 hours throughout the day under intense UV conditions, and especially when it’s windy or you’re sweating.

Incorporating Sunscreen Into Your Daily Routine

You can make sunscreen application easy to remember by making it a part of your day-to-day routine, like brushing your teeth. Keep a bottle of sunscreen with your other toiletries and apply it every day.

Women are lucky since many lotions and make-up products now include sun protection with an SPF of 15. Seek out these products and you can easily protect your skin from damaging UV rays.

Types of Sunscreen

Some people complain that certain types of sunscreens make them break-out, are too oily, or cause allergies. Improvements in sunscreen over the years have eliminated many of these problems. If you have sensitive skin, look for sunscreens that are:

  • PABA-free (PABA is a chemical that some people are allergic to – most sunscreens are now PABA-free.)
  • Noncomedogenic or oil-free sunscreens (will not clog pores.)
  • Sprays, lotions, gels, etc. – sunscreen comes in many different forms to suit various preferences.
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