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How to Choose UV Protection: Physical Sunscreen vs. Chemical Sunscreen

physical sunscreen vs. chemical sunscreen
Photo: CC0 Public Domain / Pixabay – Skeeze

What exactly is physical sunscreen? What about zinc oxide sunscreen or mineral sunscreen? Is sunscreen bad for you? Or for the environment? What does SPF measure, again? What does “broad spectrum” mean? You’ve got questions, we’ve got answers. 

Somehow, when we weren’t looking, the topic of sunscreen has become mind-numbingly complex. We know that the last thing you want to do when you’re on your way out the door to the beach is do a deep dive into the literature on the subtle (and not so subtle) differences between types of sunscreen. So we’ve done the work for you. In this article, we’ll tell you everything you need to know about the difference between chemical and physical sunscreen, and what to look for when buying sun protection. 

Do I Really Have To Wear Sunscreen?

Wearing (physical) sunscreen is a must.
Don’t skip the sunscreen: you’ll thank yourself later. (Photo: CC0 Public Domain / Pixabay – Skeeze)

Yes. Why? Because skin cancer sucks. Whether you choose chemical or physical sunscreen (mineral sunscreen), some form of protection is an absolute must. Here’s what you need to know about how different kinds of UV light from the sun can damage your skin. 

UV radiation is divided into three main categories:

  • UVA: 320–400 nm
  • UVB: 290–320 nm
  • UVC: 260–290 nm.

UVC rays are mostly filtered out by the atmosphere, so we don’t have to worry too much about those. UVB rays burn the surface of your skin, causing things like sunburn and skin cancer. Recent studies suggest that 70% of new skin cancer cases diagnosed each year are the result of exposure to the sun. UVA rays penetrate deep into your skin, causing long-term damage like wrinkles and aging. To protect yourself against all of the harmful rays of the sun, the first thing to look for when buying any sunscreen is to make sure that broad spectrum protection is stated specifically on the packaging. All fully mineral-based physical sunscreens provide broad spectrum protection by design.

Okay, so we agree that wearing sunscreen is important, whether it’s physical or chemical sunscreen. Now what about SPF? What does that even mean? SPF (sun protection factor) is a measure of a particular sunscreen’s ability to protect you from UVB rays (note: NOT UVA rays). Most dermatologists recommend using sunscreen with a rating of at least SPF 30. You can read more about how SPF is measured here.

Physical vs Chemical Sunscreen: What’s the Difference?

Physcial sunscreen or mineral sunscreen works by deflecting the sun's rays.
Physical sunscreen protects your skin from UV light in a fundamentally different way than conventional chemical sunscreen. (Photo: CC0 Public Domain / Pixabay – Free-Photos)

Chemical sunscreen is the conventional sunscreen that you’ve always known and loved. It protects you from the UV rays of the sun by first absorbing into your skin, and then absorbing and transforming UV rays into heat, which is then released into the air. This is done using active ingredients like avobenzone, octinoxate, or oxybenzone, which are all organic (carbon-based) compounds. 

Physical sunscreen, sometimes called mineral sunscreen, contains tiny mineral particles which sit on top of your skin and act as filters, physically reflecting and deflecting the sun’s rays. The main active ingredients used in mineral sunscreen are zinc oxide and titanium dioxide. Zinc oxide sunscreen is often recommended as the safest and most environmentally friendly (more on that later).

Note: Although most sunscreen will fall into one of these two categories, combination products also exist. Always read the label carefully!

The Case Against Chemical Sunscreen: Two Problems

choosing the best sunscreen is difficult
Chemical sunscreen may be the most familiar kind of UV protection, but it can be damaging to your health and to the environment. (Photo: CC0 Public Domain / Pixabay – MBatty)

Many people choose chemical over physical sunscreen because it is easier to apply, it tends to be more waterproof, it can easily be combined with moisturizers, and less product is needed to get protection. But there are two really, really big problems with chemical sunscreen:

1: The Health Problem

The thing is, unlike mineral sunscreen, chemical sunscreen gets absorbed into your skin. That means the active ingredients that are in the sunscreen could also get into your body. And it turns out, they do. 

According to the EWG, studies show that compounds such as oxybenzone, octinoxate, octisalate, octocrylene, homosalate, and avobenzone are all systemically absorbed into the body after a single use, and can be detected on the skin and in blood weeks after application. In fact, the CDC estimated that about 97% of Americans have oxybenzone in their blood. Some of these chemicals have even been found in mother’s milk. Unhelpfully, the FDA states that it has insufficient data to determine whether or not these chemicals pose any safety risks. We find that more than a little bit disconcerting. 

To make it worse, many of these chemicals have been shown to disrupt hormones like estrogen, androgen, and progesterone, and have even produced thyroid and behavioral alterations in animal studies. If that’s not enough fun for you, ingredients like oxybenzone and octocrylene are reported to generate allergic reactions in the skin at a high rate. 

You can find the full chart of active ingredient toxicity here.

2: The Coral Reef Problem

physical sunscreen or zinc oxide sunscreen is less damaging for corals
Chemicals like oxybenzone and octinoxate are contributing to the destruction of coral reefs. (Photo: CC0 Public Domain / Pixabay – Mariamichelle)

While there might not be enough data to show whether or not chemical sunscreen is toxic for your body, there is more than enough evidence to prove that it is helping to destroy the world’s coral reefs

According to National Geographic, 14,000 tons of sunscreen are thought to wash into the oceans each year. Three active ingredients found in sunscreen made in the USA, oxybenzone, octinoxate, and butylparaben, have been shown to be incredibly damaging to coral reefs in numerous ways. These chemicals disrupt coral reproduction, cause coral bleaching, and damage coral DNA.

The Case For Physical Sunscreen 

Because physical sunscreen, or mineral sunscreen, works by sitting on top of your skin and doesn’t contain active chemical ingredients, you don’t run the risk of introducing possibly toxic chemicals into your body when you use it. Mineral sunscreen is also much less likely to cause allergic reactions, is broad-spectrum by nature, it won’t clog your pores. If you choose the right physical sunscreen, it can be completely safe for the environment (more on this below).

physical sunscreen or mineral sunscreen is safer for your health and the environment.
Mineral sunscreen is easily rinsed off. Remember to keep reapplying to stay protected. (Photo: CC0 Public Domain / Pixabay – AdamKontor)

How to Use Mineral Sunscreen

If you’re not used to using mineral sunscreen, there are a few things to pay attention to:

  • Mineral sunscreen must be applied generously, to make sure that there are no gaps between mineral particles. 
  • Physical sunscreen contains either zinc oxide, titanium dioxide, or both. Zinc oxide sunscreen is generally considered better, because titanium dioxide has been shown to be more irritating to the skin, and is significantly less effective at protecting you from UVA rays.
  • Physical sunscreen washes off easily, and must be reapplied if you are swimming, or sweating.
  • Avoid powdered mineral sunscreen: inhaling mineral particles is associated with lung cancer. 

Mineral Sunscreen: The Nanoparticle Problem 

The biggest complaint that people have about physical sunscreen is that it is more difficult to apply than chemical sunscreen, and is more visible on the skin since it does not become absorbed the way chemical sunscreen does. In order to combat this, many companies have tried to make the mineral particles in their sunscreens as small as possible. But particles that are very, very small, or nanoparticles, reintroduce environmental risks, because they can be ingested by coral reefs and other marine animals, causing internal damage. 

There has also been some concern as to whether nanoparticles could be absorbed into the human bloodstream. Although several studies have shown that nanoparticles in physical sunscreen do not penetrate the skin, the utter lack of FDA regulation surrounding nanoparticles still makes many people uncomfortable. 

Physical or Chemical Sunscreen: The Bottom Line

physical sunscreen: best products
Because product labeling can be so deceiving, data from third party testing is one way to help yourself make an informed purchase. (Photo: CC0 Public Domain / Pixabay – Marijana1)

We recommend physical sunscreen that has been certified by the Haereticus Environmental Laboratory as reef-safe and free of nanoparticles. 

Because manufacturers do not currently have an obligation to list particle size on sunscreens, and since the words “natural” and “organic” are not regulated by the FDA, plus the general permissibility of arcane labeling practices in the United States, it is incredibly difficult for consumers to make an informed decision when trying to purchase sunscreen. The help of a third party is essential. 

The Haereticus Environmental Laboratory, a non-profit scientific organization has developed a “Protect Land + Sea” Certification Seal. Physical (mineral) sunscreen that has been labeled with this seal has been laboratory‐tested using analytical‐forensic techniques to verify that the product is free of the chemicals that are on the “HEL LIST”, which are: 

  • Any form of microplastic sphere or beads.
  • Any nanoparticles like zinc oxide or titanium dioxide.
  • Oxybenzone
  • Octinoxate
  • 4-methylbenzylidene camphor
  • Octocrylene
  • Para-aminobenzoic acid (PABA)
  • Methyl Paraben
  • Ethyl Paraben
  • Propyl Paraben
  • Butyl Paraben
  • Benzyl Paraben
  • Triclosan

The Best Physical Sunscreens of 2021

And so, without further ado, the physical sunscreens that have managed to achieve “Protect Land + Sea” certification are: 

1. Badger: Clear Sport Sunscreen Cream in a Tin – SPF 40

2. Olen: Sunblocz Baby and Kids Sunscreen- SPF 50

3. Stream2Sea Sport Sunscreen-SPF 30

stream2sea mineral sunscreen

4. Tropic: Various Products

tropic physical sunscreen

Important Information regarding Health-related Topics.

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