How Much Sunscreen Is Enough? A Complete Guide to SPF, UVA, and UVB

We often hear a lot about the importance of wearing sunscreen – that if we don’t protect ourselves from the sun, we could get a sunburn, experience the signs of premature aging, and of course, there’s the risk of getting a skin disease.

But how much and how often should we use sunscreen? This guide will help you understand the basics of SPF, UV radiation, and we’ll also discuss other common questions and myths related to sun protection.

 

What Do SPF, UVA, and UVB Really Mean?

SPF products seem to come in all forms, from cosmetics to clothing. And regardless of weather or season, when you’re outdoors, you should be conscientious of the damaging UVA and UVB rays. We often see these acronyms, but what do they mean?

Here’s a quick primer:

• SPF means Sun Protection Factor.
• UVA means Ultra-Violet A (long wave).
• UVB means Ultra-Violet B (short wave).

 

Sun protection factor (SPF) found in our sunscreen products gives you an idea of how long you can stay in the sun before your skin starts to get red.

UVA and UVB are two very different types of radiation that can damage your skin. To make it simple, remember UVA – A for Aging, as these are the rays that age your skin. And think UVB – B for Burning, as these are the rays that burn your skin.

 

UVA rays cause skin aging.

UVA rays are responsible for skin aging and wrinkling and can contribute to skin diseases. Because UVA rays pass easily through the ozone layer, they make up the majority of exposure. UVA rays can pass through clouds, glass, and even some clothing. You might not be able to feel them, but they will affect your skin.

 

UVB rays cause sunburn.

UVB rays are responsible for sunburns and cataracts, and they can affect the immune system. Most importantly, UVB rays also contribute to skin diseases.

SPF only applies to the UVB rays. It does not apply to the UVA rays, so when purchasing sunscreen products, always look for “broad spectrum protection” on the label to ensure you are protected against both UVA and UVB rays.

 

What SPF Should You Use?

SPF products come in various levels, including SPF 15, SPF 30, SPF 50, and more. Here’s how they work: let’s say that your skin will start to redden when exposed to the sun in just 10 minutes. You would take that ten minutes and multiply it by the SPF number you’re using.

For example, if you’re using an SPF 30 product, multiple 30 by 10 and you get 300 minutes. So, the result will be around 5 hours of standard sun protection for an SPF 30 product.

But if you’re at the beach or in direct sunshine for extended periods, always be cautious with sunscreen and your chosen sun protection factor. Many products are not water-resistant, so you wouldn’t be able to rely on five hours of protection if you’re swimming or exercising.

Also, most sunscreens are intended for normal everyday sun exposure, not a full day in direct sun. At the beach or while exercising in the sun, you should consider a water-resistant sunscreen. And as always: apply, apply and reapply.

 

Make sure to keep your sunscreen in a cool area. Sun exposure can degrade the active ingredients in the product and cause it to be less effective

 

How Much Sunscreen Should You Apply?

The proper amount of sunscreen for your body is about 1 oz. (or 30ml), which is just enough to fill a shot glass. You need a teaspoon (5 grams) of sunscreen just for your face.

Remembering to apply sunscreen to your face, arms, and legs is easy, but it’s important to protect every exposed area of the skin.

The most commonly missed spots include:

• Your ears
• The tops of your feet
• The back of your neck
• Your lips
• Your hairline and any bald spots
• Around your armholes. When you move about, so do the armholes in your sleeves.

 

Also, if you’re concerned with signs of aging, you must protect the back of your hands. They are always exposed to the elements, and the sun is no exception. Whether your hands are resting on your steering wheel, pushing a lawnmower, or baby buggy or even just gripping your handlebars while riding your bike, they are susceptible to burning, aging, and sunspots.

You should also wear protective clothing such as long-sleeved shirts, long pants, and wide-brimmed hats. Wear sunglasses that provide UVA and UVB protection. Not only can your eyelids burn, but exposure to UVB rays can lead to cataracts.

 

How Often Should You Apply Sunscreen?

Be sure to apply your sunscreen for at least 30 minutes before going into the sun. If you’re outdoors and your skin has already started to redden, then the damage has begun.

Try to reapply at least every two hours, and even more frequently if you’re swimming, sweating, or if you ever dry yourself with a towel after swimming. It’s easy to forget about reapplication when you’re having fun at the beach or pool. Keep your sunscreen in a visible place so it doesn’t go unnoticed.

 

Other Common Questions Related to Sun Protection

Here are some frequently asked questions related to sunscreen usage:

If I have darker skin, do I still have to use sunscreen?

Yes, no matter how dark- or light-skinned you are, sunscreen is important. Everyone’s skin is subject to burning, premature aging or developing a skin disease when left unprotected. Don’t believe for a second that if you have dark skin, you can skip the sunscreen. Everyone, regardless of their skin color, should wear sunscreen on a regular basis.

 

If my makeup has SPF, do I really need more sunscreen?

I used to get very excited at the idea of having my sunscreen needs covered by my makeup. Talk about being lulled into a false sense of security. Unfortunately, what I learned was the opposite. Foundations, blush, and bronzing powders all seem to contain SPF these days, but it isn’t enough.

Makeup with SPF is usually applied unevenly. Think about the quick dusting of blush or the little dab of foundation we often apply. It’s simply not enough coverage to offer appropriate protection. While it’s a nice, added benefit for those areas that need ample coverage, it’s very important to double-up on your protection and use sunscreen as well. Opt for a daily moisturizer with SPF 30 broad-spectrum protection. You’ll get added moisture and protection in one easy step.

 

Are children’s sunscreens better than adult formulations?

Sunscreens contain the same active ingredients whether they’re for kids or adults. If you’re looking at two products labelled with the same sun protection factor, whether for kids or adults, the protection is about the same.

There are different types of formulations, however, and many sunscreens made for children have been developed for more sensitive skin. They can be fragrance-free, chemical-free, paraben-free, and more. Also, many products for kids are tear-free to avoid any stinging of the eyes. Otherwise, the SPF number is pretty reliable.

 

Do I have to wear sunscreen when it’s cloudy or if I’m inside a car?

The sun’s damaging rays are present all year long – even in the cold winter months. UV rays can penetrate through clouds, so make sure to wear sunscreen before you head outdoors.

Don’t think you’re protected inside your car or looking out a window either. The sun’s rays can penetrate glass, so protect yourself even if you’re not in direct sunlight.

If you use sunscreen daily and properly, you’ll realize that a bottle won’t last you very long. A good rule of thumb is to not treat your sunscreen as a seasonal product, but realize its importance year-round.

Written by: Laura Chacon-Garbato

Director, Worldwide Nutrition Product Training and Education, Herbalife Nutrition