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While sunscreen is an important part of any beauty kit, we now know it’s not as easy as simply going to the store and grabbing any old SPF off the shelf. There are many factors to consider when purchasing the safest and most effective sunscreens, and sunscreen ingredients are the best place to start.

If you’ve read anything on sunscreens in the past few years, you know that mineral sunscreens are safest. They offer optimal protection from both UVA and UVB rays and are safer than chemical sunscreen ingredients.

But what, exactly, is so bad about chemical sunscreens? We used them for years, right?

When we talk about synthetic ingredients in cosmetics, it's usually all about the negative health effects they inflict. From allergic reactions to cancer, there are a host of good reasons to stay away from toxic cosmetic ingredients.

The chemical sunscreen issue is two-fold. Yes, there are the nasty things they can do to your health. Obviously, not good. But chemical sunscreens are also not nearly as effective as mineral sunscreens at protecting against UV damage.

What’s Wrong With Chemical Sunscreen Ingredients?

Let’s start with a little primer in how UV rays potentially damage our skin and health. Ultraviolet (UV) rays carry ionizing radiation, which causes a chemical reaction in the body. There are three types of UV rays: UVA, UVB, and UVC. UVA rays penetrate the top layers of the skin, reaching deeper layers with the potential to cause long-term damage, like premature aging and skin cancer. UVB rays affect the top layers of skin and are responsible for sunburn. UVC rays are absorbed by the ozone layer before ever reaching the earth, and are not a hazard to our health.

Mineral and chemical sunscreens work differently in protecting us from UV exposure. Chemical sunscreens soak into skin and absorb UV rays, preventing UVB rays from causing sunburns while still allowing UVA rays to reach those deeper layers and do their damage. Mineral sunscreen ingredients like zinc oxide and titanium dioxide form a barrier on top of skin and reflect UV rays, preventing UVA rays from finding their way to deeper layers.

Then there are the negative health effects associated with commonly used chemical sunscreen ingredients. The main concerns with chemical sunscreen ingredients are hormonal disruption and allergic reaction. Some widely used chemical sunscreens have been found to act like estrogen in the body, causing hormonal disturbances, altering sperm, and may play a role in endometriosis.

The latest research by the Food and Drug Administration (FDA) shows that chemical sunscreens may be absorbed by the body and can linger in the system for days and, sometimes, weeks. While the biological effects and purported danger of absorption of these chemicals through the skin has yet to be proven, five applications over a two day period showed elevated levels of the top six chemical sunscreens (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate) in the bloodstream for up to three weeks. Levels ranged from three times the FDA threshold of concern to up to 500 times.

While the FDA doesn’t include a warning against using these chemical sunscreens at this time, it does advise use of other sun protective measures with sunscreen, like protective clothing.

How to avoid those not good for your health or skin chemical sunscreens? First of all, you know you cannot judge a cosmetic product by its front label. If a sunscreen says “mineral” on the front, that does not necessarily mean it is free of chemical sunscreens. Yes, marketing in action again. Here’s a breakdown of the most commonly used chemical sunscreen ingredients and why to avoid them.

Common Chemical Sunscreen Ingredients and Why to Avoid Them

Sunscreen ingredients to avoid.

Sunscreen ingredients to avoid.

Concerns With Mineral Sunscreens and Nanoparticles

So, with all we know, why on earth would people still be using chemical sunscreens? Maybe because they can’t stand the greasy feel and weird white glow mineral sunscreens give off?

Oh wait, that was totally last decade. The new generation of mineral sunscreens give that high performance UV protection, plus they don’t feel greasy or look ghostly white on skin. Win, win, and win.

That said, no cosmetic is perfect. Mineral sunscreens do pose their own problems, predominantly linked to the issue of particle size.

The particle size of zinc oxide and titanium determine how they look on skin, which is where nanoparticles come in. The smaller the particle size, the less chance the product will leave a white cast on skin.

But particle size also determines how mineral sunscreen protects against UV rays. Smaller sized particles also provide better SPF protection, or protection against UVB rays. That said, tiny particles are less effective in protecting against UVA rays (usually, because of particle size, zinc oxide provides better UVA protection than titanium dioxide). And there is some (yet unsubstantiated) concern over whether these nanoparticles are absorbed into the skin and the body. At this point, there are no studies that show the skin absorbs nanoparticles at any significant level. And they are certainly not able to be absorbed at the level of chemical sunscreen ingredients, which are designed to be absorbed to be effective.

Another concern over nanoparticles is with the use of powders and sprays. The Environmental Working Group (EWG) recommends against using powder and spray sunscreens due to the inhalation risk, which they report has a more direct route to the system than absorption through the skin. The FDA has proposed further testing on spray sunscreens for the presence of smaller particles that could penetrate and cause damage to lungs. 

Because some research suggests titanium dioxide and zinc oxide may be photoreactive when in contact with sunlight, potentially forming free radicals that could damage other cells in the body, some sunscreen manufacturers use coated nanoparticle mineral sunscreen ingredients. Other manufacturers opt instead for larger nanoparticles due to concerns over the substance used to coat the particles.

Whichever you choose, one thing is sure: using sun protection is safer than not, and mineral sunscreen, nano or not, does not appear to absorb into the body at the same level as the chemical sunscreens in the table above. 

If you are concerned about steering clear of nanoparticle sunscreens, read product labels to see if a product you are shopping contains nanos. Manufacturer websites will often give information as to whether or not they include nanoparticles in their formulas and if they use coated minerals or not. Our product recommendations in our Sunscreen Guide share details on nanos and other useful information to help you when purchasing sun protection. 

Other Ingredients to Avoid in Sunscreen

Chemical sunscreen ingredients aren’t the only toxins to be aware of in sun protection products. As with all cosmetic and personal care products, it’s important to read labels and choose items made with safe, natural ingredients. When shopping for sunscreen, check ingredient listings for the following. 

Petrolatum, petroleum jelly, and mineral oil show up in sunscreens to make them feel moisturizing, but these ingredients are commonly contaminated with carcinogens. They are also occlusive, meaning they block pores from releasing toxins and absorbing moisture from the air. Petro-ingredients often cause skin irritation and acne.

Silicones, like dimethicone, are used in sunscreens to create a smooth feel and provide water resistant qualities. Silicones are another group of occlusive ingredients, clogging pores and sometimes leading to skin irritation.

Many conventional sunscreens contain synthetic preservatives, like parabens and methylisothiazolinone (MIT), which can cause neurotoxicity, allergic reaction, fetal impairment, and hormonal disruption.

Is your sunscreen full of synthetic fragrance ingredients? These toxins have links to headache, nausea, dizziness, skin irritation, and are associated with asthma and even cancer.

While retinyl palmitate (a form of vitamin A) is not a toxic ingredient, it has been shown to be photosensitive, meaning it may increase the chances of developing skin cancer, skin damage, and skin aging when exposed to sunlight. Incidental exposure to vitamin A through plant oils that contain it is less of an issue than using sunscreens that contain the more concentrated retinyl palmitate. Look for “retinyl palmitate” or “vitamin A palmitate” on sunscreen ingredient listings.

So, with all we know, why on earth would people still be using chemical sunscreens? Maybe because they can’t stand the greasy feel and weird white glow mineral sunscreens give off. Oh wait, that was totally last decade. The new generation of mineral sunscreens give that high performance UV protection, plus they don’t feel greasy or look ghostly white on skin. Win, win, and win.

As with all cosmetics, the only way to make sure a product is safe is to read the ingredient listings. If it contains any chemical sunscreens from the list above, put it back on the shelf, step away, and buy yourself some super safe, ultra-effective sun protection from our latest Sunscreen Guide.

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* This article was updated August 12, 2020 with the latest research from the FDA. 

** Note! This article contains affiliate links that are independently sourced and vetted by our editorial team which we may earn a commission on. This helps us reduce the number of ads we serve on Organic Authority and help deliver you a better user experience. We are here to help you navigate the overwhelming world of consumer products to source and uncover thoughtfully made, conscious clean products for you and your family.

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