Have you ever woken up, skin red and peeling from sunburn? We’ve all been there, haven’t we? It hurts, it’s embarrassing at work and, somewhere in your mind you’re thinking to yourself, ‘Is this the one that could cause skin cancer?’. If you’re keen to never to get sunburnt again, you’ve come to the right place. Here you’ll find an investigation of the best kind of protection against the sun. As it turns out, there’s two competing kinds of sunscreen. That’s what I will consider here: physical vs chemical sunscreen.
Why use Sunscreen?
Whenever you’re out in the sun, you’re being bombarded by radiation from the sun. There are two kinds that reach us:
- Ultraviolet A (UVA) penetrates the skin deeply, causing the skin to age and wrinkle
- Ultraviolet B (UVB) acts on the surface of the skin, causing redness and sunburn
Both UVA and UVB can damage your DNA and are a factor in developing skin cancer. So, it’s important to be able to protect yourself, so you can enjoy being out in the sun. That’s where sunscreen comes in.
What’s the difference between physical and chemical sunscreen?
On a molecular level, the two kinds of sunscreen – physical and chemical – are very different. Even so, they work in similar ways to protect us from the sun. A commonly asked question is, does sunscreen absorb or reflect UV?
If you read about the subject, you’ll see that most people say physical and chemical sunscreen each protects us in completely different ways. They say that,
- Chemical sunscreen absorbs the ultraviolet rays before they reach the skin
- Physical sunscreen reflects the ultraviolet rays away from the skin
However, this is an oversimplification. Both types absorb ultraviolet light, the only difference is that while physical sunscreen absorbs UVB, it also reflects UVA.
Another difference is that while physical sunscreen protects against both UVA and UVB, chemical sunscreen may protect only against UVB. There are chemical sunscreens which also protect against UVA. To make sure the sunscreen you are buying protects against both kinds of ultraviolet light, look for one labeled ‘broad spectrum,’ or ‘UVA/UVB protection’.
Why choose physical sunscreen?
While deciding which kind of sunscreen was better, I decided to write out a list of pros and cons for each type. Here are the pros and cons I found for physical sunscreen:
- it protects against both UVA and UVB
- it should last longer in the sun
- it immediately after application (no wait time)
- it is less likely to cause skin irritation
- it’s harder to find in stores
- it’s usually more expensive
- it can be harder to apply (may have a thick consistency)
- some leave a white residue on skin (particularly if water-resistant)
Why choose chemical sunscreen?
Here are the pros and cons I found for chemical sunscreen:
- it’s available everywhere
- it’s cheaper than physical sunscreen
- it’s a thin liquid and is easy to apply
- it’s invisible when applied
- it may not protect against UVA
- it starts degrading as soon as you’re in the sun and so may need more frequent reapplication
- it usually takes 20 minutes to dry on the skin before going outside
- it may cause irritation if you have sensitive skin
Are there health risks in using physical or chemical sunscreen?
Much has been written about potential health risks posed in the physical sunscreen vs chemical sunscreen debate.
- Physical sunscreen – There are concerns that the nanoparticles of zinc oxide and titanium dioxide could be small enough to pass into the bloodstream. These have caused aging and cancer in rats. To remedy this most physical sunscreens are now ‘non-nano’.
- Chemical sunscreen – Some people may have allergic reactions. Additionally, studies in rats suggest chemicals can also pass into the bloodstream and cause hormonal disruption.
While these may seem worrying, it is worth remembering that these studies have been in laboratories where rats have been injected or bathed in sunscreen. This is not how sunscreen is used by humans. No ill-effects have ever been observed in humans. As Doctor Henry Lim of the Henry Ford Health System in Detroit said ‘there are no recorded health issues associated with sunscreen’s proper use’.
Remember, the health benefits of using sunscreen are immense: they can literally save your life. If you follow the application instructions you are at no risk.
In the battle between physical vs chemical sunscreen, physical sunscreen may be the better environmentally friendly option. An ingredient commonly found in chemical sunscreen, oxybenzone, has been found to damage coral reefs.
If you’re swimming in an area where there’s coral, you should consider using physical sunscreen, or a chemical one without oxybenzone.
Which sunscreen is better?
Ultimately, the best sunscreen is the sunscreen you wear and reapply regularly. Without it, you face the risk of sunburn and potentially skin cancer. Whether chemical or physical sunscreen is best for you depends on your personal preference.
For instance, I have quite photosensitive skin that has reacted with chemical sunscreens in the past. This is I mainly recommend physical sunscreens as they offer better protection against more of the damaging UV spectrum. In particular, I use zinc oxide-based physical sunscreens. However, if you’re made of stronger stuff and make sure your sunscreen has all the right stuff in it, a readily-available chemical sunscreen should do the trick. So long as you take care to apply the sunscreen correctly, you’ll be fine.
At the end of the day, it’s less about physical vs chemical sunscreen, and more about finding which one works best for you. Now that you’ve learned about the types of sunscreen out there, I hope you’ll never get sunburn again!