Choosing a sunscreen may be difficult when there’s so many options on the market. You can start by looking for those of at least SPF 30.

If you spend any time outside, chances are you’ve heard a warning or two about how important it is to wear sunscreen.

While wearing sunscreen is better than not wearing any, if you have a choice, it’s best to choose a sunscreen with broad-spectrum UV protection of at least SPF 30. These recommendations apply to people of all skin tones. Ideally, you should also apply sunscreen to your skin 30 minutes before going out into the sun.

Read on to learn more about SPF and how to protect your skin in the sun.

SPF is short for sun protection factor. In sunscreen, SPF helps to block your skin from the sun’s radiation.

The sun emits two types of radiation: UVA and UVB rays. UVA rays contribute to the signs of aging in the skin, like wrinkles and sagging. UVB rays are more carcinogenic and often responsible for sunburns. UVA rays also make UVB rays more reactive, so combined, the two can be deadly.

You’re exposed to harmful radiation from the sun virtually anytime you’re outside or near a window that has sunshine. That radiation has an effect on your skin even if you aren’t prone to sunburns.

SPF works by extending your skin’s natural defenses against the sun’s rays. For example, an SPF of 15 provides about 15 times more protection than just your normal skin without sunscreen. An SPF of 50, then, would provide 50 times more protection than skin without sunscreen. Choosing a broad-spectrum sunscreen means it’s a type of sunscreen that will block out both UVA and UVB rays.

Do I still need a high SPF if I have dark skin?

Many people mistakenly believe that individuals with darker skin don’t need sunscreen, but one study found the rates of deadly skin cancer were higher among Black participants.

You should avoid using sunscreen on babies under 6 months old. That doesn’t mean they aren’t at risk of damage from the sun. Sunscreen can be potentially harmful in young babies because they may be at greater risk of side effects from the chemicals in sunscreen. It’s best to keep babies under 6 months old in the shade and dress them in protective clothing to prevent sun exposure.

When choosing a sunscreen for your baby, choose one of at least SPF 30. Most baby sunscreens are SPF 50. You don’t have to use baby-specific sunscreen, but a lot of baby sunscreens contain special ingredients to help prevent a baby’s delicate skin from breaking out or getting irritated by the sunscreen.

Sunscreen lasts an average of two hours. That means you should plan to reapply every two hours. If you sweat a lot, notice your skin burning, or spend time in the water, you’ll want to reapply more frequently.

For low exposure to the sun, a moisturizer or makeup with a base of SPF 15 built in is sufficient. However, for other situations, you’ll want to consider your outdoor activity to determine what kind of sunscreen you should use. There are many different types of sunscreen you can choose. Read more about what to consider when choosing a sunscreen.

Water-resistant sunscreen

Water-resistant sunscreen can offer good protection for water activities, but it may not be appropriate if you’re playing a sport that will cause the SPF to drip into your eyes. It’s also important to note that no sunscreen is truly waterproof.

Spray sunscreen

This type of sunscreen is very popular, especially among parents of wiggling and running children. However, spray sunscreen has become a concern for some experts who recommend that parents choose a cream-based sunscreen first, instead of spray. Spray sunscreen may release harmful chemicals that your child can breathe in.

Broad-spectrum

Broad-spectrum sunscreen means that the sunscreen blocks against both UVA and UVB rays. It’s a great idea to always choose a broad-spectrum sunscreen.

All-natural sunscreen

Consumer Reports found that most mineral-based sunscreens don’t work as well as sunscreens with chemicals for active ingredients. Sunscreens labeled as “natural” are typically mineral-based. If you’re looking for an all-natural sunscreen, one study found that choosing a sunscreen with a base of olive oil or coconut oil would help provide the most protection. Both olive oil and coconut oil have natural SPF protection of around SPF 8, so sunscreens that use them as a base have a good natural SPF foundation.

Low vs. high SPF

Consumer Reports also found that many sunscreens don’t work as well as advertised, so be careful when choosing a very low SPF. There isn’t any more protection after SPF 50, but there’s a chance that a bottle that says 50 is actually less SPF. When in doubt, go with the 50.

You can still get a tan while wearing sunscreen. Sunscreen needs to be continually applied and it can be rubbed off, sweated off, or washed away if you’re spending a lot of time in the pool or water.

Using sunscreen is an important way to reduce negative side effects from harmful UVA and UVB radiation from the sun. Adults of all ages and skin color should use at least an SPF of 30 during all outdoor activities. Children over 6 months old should wear a cream-based sunscreen of at least SPF 30. Additionally, you shouldn’t rely on just sunscreen as a way to avoid the sun’s radiation. Protective clothing and shade can also help protect you from the sun.