The Sun Protection Factor (SPF) is indicated by a number on a scale from 2 to 100. These numbers represent the ability of a product to block the sun’s rays. It’s wrong to say that the effectiveness of a particular SPF is the time required for the skin burns to correlate with the exposure value. The appearance of burns is actually influenced by many internal and external factors. From the external factors, the duration of sun exposure, the daytime, the geographical location and other weather conditions should be taken into account.
The official system for interpretation and labeling of SPF
– low protection SPF 5-10
– average protection SPF 15, 20, 25
– protection high SPF 30-50
– protection of very high level 50+
1) A composition with SPF 15 provides protection of about 94%
2) A composition with SPF 20 provides sun protection of about 95%
3) A composition with SPF 25 provides sun protection of about 96%
4) A composition with SPF 30 provides sun protection of about 97%
5) A composition with SPF 50 provides sun protection of about 98%
2. UVB radiation (290-320 nano meters) penetrates into the atmosphere and is associated with sunburns. UVB produce inflammatory reactions that manifest through redness, swelling and pain. The skin begins to degrade as the affected cells become dead cells.
3. UVA radiation (320-400 nano meters) penetrates deeper into the skin and is responsible for the skin aging and cancerous cells.
-the glass does not block UVA rays but only acts as a UVB filter
When tanning, the darkening of the skin is due to the effects of UVA and UVB rays that increase melanin production. Melanin is a pigment that has the ability to absorb the ultraviolet rays. Bronze is therefore a self-defense reaction of the body and its getting is a slower process that lasts for 2-3 days.
4. Chemical sunscreen filters
Because of a specific structure on a molecule level, chemical sunscreen filters make it possible to absorb some of the UV rays. The disadvantage is that they can often cause irritation and allergies, and from an environmental point of view they are not at all “eco-friendly”.
5. Hypoallergenic, for the sensitive skin.
If you have a sensitive skin or suffer from certain dermatological conditions, it’s recommended to buy special beach lotions with hypoallergenic ingredients from the pharmacy.
6. No perfume
Perfume lotions can often lead to the skin patching when it comes into contact with the sun’s rays.
7. Water resistance
“Water Resistant Sunscreens” retain their stated SPF value after a certain time (up to 80 min) in water or while sweating. The testing is conducted by an independent laboratory and involves application of sunscreen to a human subject’s arm, submerging that arm in water, then measuring the SPF via usual testing procedures. This is a very important characteristic that allows us to swim and submerge in water and still be protected against the sun.
Most products promise a water resistance of no more than two baths, but it is advisable to reapply every time.
8. Consistency and texture
Cream, body milk, spray or oil – it does’t matter what you choose if you meet the conditions above.
How to use sunscreen products?
Before using any product, it’s important to carefully read the instructions. Probably the biggest mistake regarding sun protection is the amount of product we are applying. Often we do not use a satisfactory quantity.
Remember that sunscreen products need time to penetrate the skin. To benefit from optimal efficacy, we need to use the lotion 15-20 minutes before sun exposure. Reapplying is normally done every 2-3 hours and after swimming / sweating.