What is SPF?
SPF stands for Sun Protection Factor, a number that lets you know how long you can stay out in the sun without burning. Let’s say your skin normally starts turning red after 10 minutes in the sun. An SPF of 15 allows you to stay out for 150 minutes without burning. That is 15 times longer than if you did not use sunscreen.
SPF has its limitations though. It only measures the protection you get from UVB, which are the sun’s rays that cause burning. An SPF does not tell you how much protection if any, you are getting from the sun’s UVA rays. These rays are responsible for tanning, and they are a culprit in premature aging of the skin.
To ensure that you are protected against UVA as well as UVB, your sunscreen must contain avobenzone (also known as ParsolÂ® 1789), titanium dioxide, or zinc oxide. These can be in combination with other sunscreen agents in the product. Sunscreens that protect against both UVB and UVA rays are often called broad-spectrum sunscreens.
How much SPF do you need?
A sunscreen with SPF 15 blocks close to 95% of UVB radiation, while an SPF 30 will block around 97% of UVB. Experts recommend everyone use at least SPF 15. For extended time outdoors, use SPF 30 or higher. Whichever SPF value that you use, be sure to reapply the sunscreen every two hours. Otherwise, it tends to rub off and wear off. This applies to waterproof sunscreen too, since, over time, it can be broken down by water and perspiration.
Mixing products with SPF does not necessarily add up to higher protection. For example, using an SPF 15 moisturizer with an SPF 15 sunscreen on top of that does not result in SPF 30 protection. If you want an SPF of 30, then be sure to apply a product with that SPF value in the first place.
Tips for sunscreen use:
- Don’t skip areas. All exposed parts of your body need sunscreen. Areas that are often missed are the ears and lips. Make all-over sunscreen application a daily habit, just like brushing your teeth or combing your hair.
- Be consistent. While sunburns are immediate signs of skin damage, other signs of damage may not be visible for many years. Without regular sunscreen use, you could eventually see premature aging, wrinkles, skin discoloration, and skin cancer. Sun damage accumulates over the years. If you skip sunscreen even once in a while, UV rays will be able to reach your skin and cause damage.
- Apply sunscreen properly. To ensure that you get the amount of SPF on the product label, you need to apply it generously and evenly all over your skin. A shot glass full of sunscreen is the amount experts recommend to use for your whole body. Slather on sunscreen at least 20 minutes before you go outside because the chemicals need time to bond with your skin before they are totally effective. Remember to reapply often.