Properly applying sunscreen – Effective sun protection is essential for your skin health. Discover now why applying sunscreen daily is so important, how much you should use, and what can affect its longevity.
Why Should You Apply Sunscreen Daily?
Daily sun protection protects the skin from the harmful effects of UV radiation.
UV radiation is differentiated between UVA and UVB rays.
UVA rays have a longer wavelength and account for about 95% of UV radiation. These rays penetrate deeper into the skin and affect the deeper skin layers. This leads to both tanning and premature skin aging. Tanning studios therefore primarily use UVA rays. UVA rays are also involved in the development of skin cancer. UVA rays are present all year round, even on cloudy days. They can also penetrate through window panes. Appropriate sun protection is therefore required at all times.
UVB rays have a shorter wavelength but are much more energetic. They account for about 5% of UV radiation and predominantly attack the upper skin layers. UVB rays are the main cause of sunburn and play a significant role in the development of skin cancer. The intensity of UVB radiation varies depending on the time of day, season, and geographical location, and they are also blocked by window glass.
Sunscreen acts as a barrier that deflects these harmful rays and protects the skin.
When and How Often Should You Apply Sunscreen? Explanation of SPF and LSF
Sunscreen should be applied daily and during every outdoor activity. It is especially important to reapply every two hours, particularly after swimming, sweating, or drying with a towel. Even water-resistant sunscreen loses its effectiveness after these activities and must be reapplied.
What Are LSF and SPF?
LSF is the German version and stands for Lichtschutzfaktor, and SPF is the English version: Sun Protection Factor.
These factors indicate how long the sunscreen can reliably protect your skin. If you get sunburn after 5 minutes in the sun, a sunscreen with SPF 15 will protect you for 75 minutes (5 x 15). Generally, a minimum of SPF 15 is recommended for daily protection, while SPF 30 or higher is recommended for longer stays outdoors or in strong sunlight (midday, southern holiday destinations).
Even if your calculation shows you should be protected for significantly longer than two hours, it is advisable to reapply every two hours. Due to rubbing of clothing, sweating, or uneven application, sun protection can no longer reliably work after a certain time.
How Much Sunscreen Should You Use Per Day? Proper Dosage for Optimal Protection
An adequate amount of sunscreen is crucial; otherwise, the indicated SPF is not achieved. Most people use less than half the recommended amount, which significantly reduces the effectiveness of the protection. Here is a list of the amounts an adult needs for application:
- Face and neck: 0.5 teaspoon
- Arms: 1 teaspoon per arm
- Legs: 1.5 teaspoons per leg
- Torso: 1 teaspoon for the front, 1 teaspoon for the back
In total, you need about 7 teaspoons for your entire body, or approximately 35ml. Since you probably don’t want to carry spoons or measuring cups all the time, here is a small measuring tip: Cover your index and middle fingers with two lines of sunscreen. This amount corresponds to about 0.5 teaspoon.
How Long Can You Use Sunscreen?
Most sunscreens have a shelf life of about three years. Check the printed expiration date and replace the sunscreen accordingly. Expired products may lose their effectiveness and may no longer provide the stated protection.
Using Opened Sunscreen: Tips for Storage and Shelf Life
Open sunscreens should be used within a year. Store them in a cool, dry place and avoid direct sunlight and high temperatures to extend shelf life. Heat and moisture can impair the effectiveness of the ingredients. If the sunscreen develops a strange odor or the consistency changes, it should no longer be used.
Properly Applying Sunscreen: Tips for Effective Application
- Apply sunscreen to clean, dry skin
- Apply sunscreen at least 15 minutes before going outside to allow it to fully absorb
- Use an adequate amount: better a bit too much than too little
- Distribute evenly on all exposed body parts, don’t forget the backs of hands and feet
- Reapply every two hours or after swimming or sweating
With these tips, you are now perfectly equipped for your next outdoor activity. Whether cycling, sailing, or just going for a walk: properly apply sunscreen and head outdoors!
