5 Interesting Facts About Sunscreen You Probably Didn’t Know About

by beautifulwithbrains
facts about sunscreen

How well do you know your sunscreen?

I bet that little tube you’re using every day (because you are using it every day, RIGHT?) has been keeping secrets from you.

It probably evaded the question when you asked it what the heck SPF is. And it may have forgotten to mention that not all members of its family are the same. Some are more physical than others, for example.

It’s time to have that tough talk with your sunscreen. The talk that sets the record straight about what it is, what it does and how to use it.

Ready? Let’s all sit down and have a chat then:

What Is sunscreen?

Sunscreen is the most important skincare product in your stash. I don’t say that lightly.

Sunscreen protects your skin from UV rays. It either reflects them off your skin or absorbs them and turns them into a less damaging form of energy (heat). Either way, it prevents those pesky UV rays from ruining your skin.

It can come in many forms: lotions, creams, ointments, gels, sticks and sprays. Pick the one you like the most (but NO sprays!) and use it religiously.

UV rays are responsible for up to 90% of premature aging. You can use the best anti-aging products in the world, but if you skip sunscreen, it’s all for nothing.

Related: Why You Should Avoid Spray Sunscreens

What Does SPF mean?

SPF is short for Sun Protection Factor.

It’s a number (15, 30, 50) that says how long you can stay in the sun without sunscreen before you start to burn. Not before your skin gets damaged enough by wrinkles or dark spots.

Nope, SPF doesn’t care about those “little details”. It’s there only to prevent you from getting a sunburn.

How is it calculated? Easy. By comparing the length of time it takes for your sunscreen-protected skin to get a sunburn with the time it takes unprotected skin to sunburn.

To know how long your sunscreen is effective for, simply multiply its SPF factor by the amount of time it takes for you to burn. For example, if you burn after 10 minutes without sunscreen, SPF 15 will keep you safe for 150 minutes.

That’s why you need to reapply sunscreen so often, by the way.

P.S. This is true in a lab. IRL, the sun is more intense at noon and less intense at 8:00am, for example. What does this mean? Even with the same SPF, you’ll burn sooner in the early afternoon than the early morning.

FYI, Because SPF relates only to sunburns, it’s not uncommon to find sunscreens that protect only from UVB rays (the ones responsible for sunburn). But UVA rays are just as dangerous. They cause wrinkles and cancer, too. If a sunscreen doesn’t protect from both, leave it on the shelf. How can you tell? Look for “broad spectrum” on the label. That covers everything.

Related: Take A Number: How To Choose The Right SPF For You?

mad hippie facial spf 30+ review

Are There Different types of sunscreen?

Yep, there are two different types of sunscreens:

  • Chemical sunscreens: They use synthetic UV filters, like avobenzone and oxybenzone, that turn UV rays into a less dangerous form of energy (heat). They go on clear but can be irritating for sensitive skin.
  • Physical sunscreens: They use mineral pigments, like zinc oxide, that turn UV rays into heat. They also reflect a small part of UV rays off your face. They often leave a white cast behind, but are much gentler on the skin.

P.S. Some sunscreens are a mixture of the two. For example, they can contain zinc oxide (physical) and mexoryl (chemical). They’re great for people who want the best of both worlds. But, if your skin is sensitive, check the label carefully.

Related: Chemical VS Physical Sunscreen: Which One Should You Use?

How Do You Apply Sunscreen?

Here are a few pointers:

Related: How Much Sunscreen Do You Really Need?

badger balm zinc oxide sunscreen cream spf 30

Is sunscreen necessary in winter?

YES! Just because the sun is hiding behind thick, black clouds, it doesn’t mean it isn’t there. Those pesky UV rays can penetrate through clouds and even get reflected on snow. So, rain or shine, put your sunscreen on.

Not sure the sunscreen you’re eyeing is up to the job? Click on the image below to subscribe to my newsletter and download the “Sunscreen Audit” to find out:

Did you know your sunscreen as well as you thought? Are there any more secrets you’d like it to reveal? Let me know in the comments and I’ll share them with you.



Dao September 22, 2008 - 2:08 pm

Hi Gio,

Very well-written article! I love physical sunblock more as it’s more stable.

Lydia September 22, 2008 - 2:14 pm

Hi Gio,
I need to wear mine more often!

Anastasia September 23, 2008 - 3:22 pm

Taking tablets with PABA in activates the melanin in your skin, you skin’s natural defence against sunlight. It’s great during the summer because it makes your skin more likely to tan rather than burn, which is good news for any fair-skinned people :3

I don’t know about the states but here tan tablets cost about $6 for 100, and have a lot of PABA in them.

beautifulwithbrains September 23, 2008 - 6:13 pm

Dao: thank you. I prefer them too for the same reason. 🙂

Lydia: you should always wear it! I always use either a moisturizer or foundation with SPF and in the summer sunscreen on my body.

Anastasia: thanks for the info, I’ll probably try them. I usually try to keep out of the sun because my skin is very fair and burns so easily!

Jessica Dee September 25, 2008 - 5:19 pm

Sadly, the only SPF I get is on my foundation, which may be the reason my face is lighter than my neck? HAHA. And yea, also bust out the SPF 70 when I go to the beach!! Hope you don’t mind me linking you to my blog ;]

beautifulwithbrains September 26, 2008 - 12:54 pm

Jessica: Of course I don’t mind. I’m glad to know you’re using sunscreen. At the moment I’m only using a foundation with spf as well, I don’t ned more cos the weather is so cold here now.

Maya March 11, 2017 - 3:28 pm

Thanks for a great post. My question is this: I read on consumer reports that every physical sunscreen they tested wasn’t as good as the chemical ones. They say that without any caveats, simply that they are not as effective (after describing the rigorous testing they perform). Did you happen to see that? What do you think about that? Thx 🙂

Gio March 12, 2017 - 8:19 pm

Maya, I didn’t see this report. Can you please send me the link so I can check it out and give you my opinion? Thanks!

Maya March 13, 2017 - 7:49 pm



Here’s the quote:
“In our tests over the years, so-called “natural” or mineral sunscreens—those that contain only titanium dioxide, zinc oxide or both as active ingredients—have tended to perform less well than those that have chemical active ingredients, such as avobenzone. None of the mineral sunscreens in our tests this year did well enough to make our list of recommendations.”

Gio March 22, 2017 - 1:07 pm

Maya, thanks! To be honest, it’s difficult to tell. Consumer Report is not a scientific organisation and, while I was doing some research on this, I came across a press release by Elta MD complaining that CR hadn’t tested the sunscreens using the FDA protocols.

Also, CR places a big emphasis on texture. Physical sunscreens tend to be thicker and greasier, which may cause people to apply less. If that happens, they’re right that you won’t get the SPF stated on the label. But that’s not because the sunscreen doesn’t work. It’s because you’re not using it right.

That sentence above may very well refer to this and in this case, you could say they’re right. But that doesn’t make physical sunscreens themselves less effective.


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