Difference Between Sunscreen and Sunblock

Difference Between Sunscreen and Sunblock

It is amazing how many people are unaware there are any differences at all between sunscreen and sunblock. If you just look closely at the names they can be pretty much self-explanatory. Sunblock will reflect the sun rays, and block them from reaching the skin. Sunscreen will absorb the UV radiation. One blocks, the other absorbs.

There are very effective sunblocks such as titanium oxide and zinc oxide, that do a great job of protection you against UVB and UVA rays. These are the kinds of UV radiation that will cause your skin to burn and can cause skin cancer. When applied to the skin sunblocks will often appear white in color.

The sunscreens are usually less visible when applied to the skin. They will most often contain ‘benzophenones’ that help protect your skin against UVA rays. They may also contain salicylates and cinnamates that protect against UVB.


  • Octyl Salicylate
  • Oxybenzone
  • Octyle Methoxycinnamate

One of the weakest points about these particular sunscreen ingredients is how they’ll break down many times after being exposed to the sunlight for a few hours. They need to be re-applied after a while.

The good news is that now we have a couple of new sunscreens (Helioplex and Anthelios SX) that can deliver longer-lasting protection against both the UVA and UVB rays.

Studies show that the Anthelios SX (FDA approved since 2006) is able to retain 80% of its normal UVA protection, and at least 90% of the UVB protection, up to five hours after an application.

The AAD (American Academy of Dermatology) has recommended the use of a sunscreen that carries at least an SPF rating of 15. Fair-skinned people or those who are at high risk for developing skin cancer, might want to go a bit higher. The higher the rating number, the longer that product will protect against exposure to the sun.

Sunscreen Ratings and Choices

The SPF (Sun Protection Factor) you see written on the sunscreen labels can range from between 2 and 50 in their ability to screen out or block harmful rays from the sun. An easy way to gauge effectiveness is like this:

If your sunscreen has a rating of 15, then you can be out in the sun 15 times longer than you could without sunscreen, before your skin would burn. However, be aware that the increase in the SPF number does not increase the protection proportionately. An SPF 2 absorbs 50% of UV radiation and an SPF 15 can absorb 93%, while an SPF 34 will absorb 97%.

Choosing the Right Sunscreen for You

The way to choose your sunscreen can be confusing, with so many products out on the market today. A few tips and guidelines should help you find the right one for you.

1. Most all dermatologists suggest a sunscreen no less than SPF 15.
2. Assess you skin type, the more fair the skin, the higher the SPF.
3. Remember that any sunscreen you choose will need to be re-applied.
4. A gel type sunscreen can sweat off easily and need re-applied more often.
5. Choose a sunscreen that is ‘broad-spectrum’ to guard against both UVA and UVB rays.

Remember that it is the UVA (ultraviolet A) rays that penetrate the deepest into your skin, and these are the culprits behind premature aging and wrinkles.

NOTE: That SPF rating on your sunscreen only indicates its ability to protect against UVB rays. To date, no FDA-approved rating system exists for measuring UVA protection levels.

Water Resistant vs. Waterproof

Another very important factor in choosing your sunscreen is understanding the difference between ‘water-resistant’ and ‘waterproof’. It is vitally important to know how well the sunscreen you use holds up after taking a dip in the pool, bathing, or even perspiring. This is every bit as important as the SPF level. The FDA rates these products like this:

It is water-resistant only if it maintains the SPF level, 40 minutes after being exposed to water. If it can maintain its SPF after 80 minutes of water exposure then it’s consider ‘waterproof’. People who engage in outdoor activities involving water might want to purchase the ‘waterproof’ sunscreens.

It is important for anyone who is exposed for the sun for over 20 minutes every day, to use a sunscreen every day. This is not a long time and lots of people engage in activities that expose them to the sun for way longer performing daily tasks.

Sunscreens can be applied beneath make-up. Many of your newer cosmetics contain sunscreens to help protect the skin from sun damage. It helps to prevent the premature aging and wrinkles as well as skin cancer. When used regularly a good sunscreen actually promotes the repairing of damaged skin.

Another good tip for people concerned about their skin, is to remember that the sun has awesome reflective powers (17% on sand, 80% on snow). That means you should not limit yourself to using sunscreen only during summer months. Even during summer when the sky is cloudy, 80% of the ultraviolet rays still pass through those clouds.

The Proper Use of Sunscreen

Sunscreen needs to be applied a full 30 minutes prior to going outside. Special attention should be given to your hands, arms, face, and ears. Use your sunscreen liberally on these areas. Even your lips will get sunburned, so don’t leave out any exposed areas.