How To Choose the Right Outdoor Sunscreen

From SPF ratings to safe and unsafe ingredients, here’s what you need to know to stay safe in prolonged, mid-day sunshine.

There are clear ways of avoiding the harmful effects of extended sun exposure.  According to the Environmental Working Group (EWG), a worldwide nonprofit dedicated to protecting public health, prevention boils down to the following three steps: Cover up with hats and clothing, seek shade, and be outside in the early or late hours of the day when the sun is low in the sky.

But for outdoor adventurers, those steps aren’t so simple, or always possible. Mid-day activities, especially those in which you might not be fully covered in sun-blocking clothing, make arming yourself with sunscreen a necessity. That demand for sun protection begs the question: How do you choose the sunblock, or sunscreen, that’s right for you? (Knowing the difference is a good start).

This following guidance highlights the factors to help you decide, explaining key terms used to describe the options. It’ll then lay out what ingredients are deemed safe to both you and to the world’s ocean reefs, and outline other questionable ingredients that need further testing. (Sunscreen ingredients are a hot topic among environmental and public health scientists.)

“Sport” Sunblock/Sunscreen Versus Regular Sunblock/Sunscreen

Products intended for sport use, and thus advertised as such, are water-resistant to either 40 minutes or 80 minutes. No product is considered waterproof. Therefore, it’s important to reapply “sport” or “water-resistant” products after prolonged use.

Spray Versus Lotion Versus Stick

Generally speaking, lotions and sticks are considered safer than sprays. The reason is twofold. With sprays, it’s hard to know if you’re fully covered, as much of the spray gets released into the air and not on your skin (and many sprays are clear). And since much of the spray is released into the air, particles can also be inhaled into your lungs. What isn’t inhaled or applied to your skin is released into the environment, which isn’t good either.

Broad Spectrum and SPF

The American Academy of Dermatology (AAD) Association reports that the FDA’s definition of “broad-spectrum” is that the sunblock/sunscreen can protect you from the sun’s harmful ultraviolet A (UVA) and ultraviolet B (UVB) rays. Protection from both types of rays can help prevent skin cancer, early skin aging, and sunburn. (UVB rays are the ones that cause sunburn.)

Also according to the AAD, SPF 15 blocks 93% of the sun’s UVB rays, while SPF 30 blocks 97% of UVB rays. The association recommends using SPF 30 or higher, while noting that no sunblock/sunscreen blocks out 100% of the sun’s UVB rays. The EWG points out that “consumers should be wary of SPF value claims, especially SPF numbers over 50+, and should not use sunscreen to prolong their time in the sun.”

Physical Sunblocks

Physical sunblocks work by containing ingredients—namely, zinc oxide and/or titanium dioxide—that deflect the sun’s rays. These types of products are called “sunblocks,” since they physically block the sun’s rays. They’re also referred to as “mineral sunblocks” because of their ingredients being zinc oxide or titanium oxide. These ingredients are the only ones considered completely safe and effective by the FDA, and are considered safer to use because many chemicals found in chemical sunscreens have not been sufficiently tested. (Some companies call their physical sunblocks “mineral sunscreens,” which can be confusing.)

The downside to sunblocks with these ingredients is that they take longer to rub in and can leave a white residue. That, however, is a small price to pay to ensure safety for both you, and the environment. Plus, the whitish residue lets you see exactly what parts of your skin (or your child’s skin) you’ve covered, whereas clear sunscreens can make that difficult. Some formulas also use both physical and chemical sunscreen ingredients.

Camping woman applying sunscreen sun cream in tent

Chemical Sunscreens

These contain active ingredients that absorb the sun’s rays. However, you need to be selective when choosing which ingredients those are, and in what concentrations. The EWG can help. It lists these following chemical sunscreen ingredients as having “insufficient data and significant data gaps” as far as their safety approvals go:

  • Avobenzone (fewer data gaps)
  • Homosalate *
  • Octinoxate
  • Octisalate
  • Octocrylene *
  • Oxybenzone *

And it lists the ingredients below under “insufficient data.”

  • Cinoxate
  • Dioxybenzone
  • Ensulizole
  • Meradimate
  • Padimate o
  • Sulisobenzone

Finally, the organization lists para-aminobenzoic acid (PABA) and trolamine salicylate under “None to be unsafe” (so, avoid at all costs). 

* Recent European Commission consumer safety studies found that both oxybenzone and homosalate are “unsafe to use at current levels” of concentration in UV-filtering cosmetic products, but that homosalate is safe for the consumer “up to a maximum concentration of 0.5%” in the final product, while octocrylene is safe “up to 10% in cosmetic products when used individually.”


Sadly, many ingredients in common sunblocks have been proven to kill the ocean’s coral reefs. Considering how many beachgoers use products containing these types of ingredients, reefs all over the world have been suffering. Legislation in places like the state of Hawaii have banned the usage of sunblocks containing certain ingredients.

The Haereticus Environmental Laboratory (HEL), is the leading organization studying the dangers of sunscreen ingredients on reef health, and lists the following ingredients as harmful:

  • Oxybenzone
  • Octinoxate
  • Octocrylene
  • Homosalate
  • 4-methylbenzylidene camphor
  • PABA
  • Parabens
  • Triclosan
  • Any nanoparticles or “nano-sized” zinc or titanium (if it doesn’t explicitly say “micro-sized” or “non-nano” and it can rub in, it’s probably nano-sized)
  • Any form of microplastic, such as “exfoliating beads”

Have a headache yet? You might. But knowing what ingredients are in sunblocks and sunscreens you’re applying to your skin, or the skin of your children, and releasing into the environment, is critical. Knowledge is power and educating yourself on current research regarding ingredients, and making your shopping and usage decisions accordingly, makes you a well-informed consumer—and a well-protected outdoor user and advocate.

All articles are for general informational purposes.  Each individual’s needs, preferences, goals and abilities may vary.  Be sure to obtain all appropriate training, expert supervision and/or medical advice before engaging in strenuous or potentially hazardous activity.