In this post we focus on the best zinc-based options for water-resistant sunscreens that are reef friendly. The research points towards these mineral based sunblocks being the safest options for humans and wildlife while also protecting skin from the sun when playing on rivers, lakes and the ocean. Skip to recommended sunscreens. Read about making a DIY reef-friendly sunscreen.

Do a little research and you will find the commercial sunscreen industry is full of dishonest claims. In the fall of 2021, an Environmental working group (EWG) peer-reviewed study of sunscreens concluded that most U.S. sunscreens provide inadequate UVA sun protection relative to the listed SPF. Similarly, Consumer Reports states that sunscreens don’t work as advertised. Sorting through the mess of inaccurate claims is challenging. In addition many products claiming to be “reef safe” turn out to be reef harmful. Questions loom about hormonal-disruptions and carcinogenic issues with chemical (non-mineral) active ingredients used in numerous sunscreens. Find your favorite sunscreen’s safety and protection rating by EWG.

Cover-up vs. Screening-up

Around 10 years ago, Australia switched from a lather up to a cover up campaign for sun protection, leading to a major reduction in skin cancer cases. In the US we’ve been seeing an increase in skin cancer rates while people are using more sunscreen. When possible, stay out of the direct sun particularly between 10 AM and 4 PM. If you go out, cover up with a UPF rated long sleeve shirt, hat and sunglasses. Then apply sunscreen to your face and other areas that are exposed to the sun.

rafters protect themselves by sitting in shade
Shade is the best sunblock.

Avoid Spray Sunscreen

There are multiple problems with spray sunscreens. Studies have shown with any sort of breeze people do not apply enough spray sunscreen. That is the main reason Australia recommends using lotions and pastes instead of aerosol sprays. In addition, spray sunscreens are commonly inhaled and sunscreen chemicals like titanium dioxide can cause cancer in the lungs. Recent studies have also found toxic benzene as a contaminant in many sprays. Numerous companies (but not all) have recalled their spray sunscreen products because of this.

Applying Enough Sunscreen

Another common problem with spray sunscreen is people do not apply enough of it to the skin. This can be seen in the video below. While most common with spray sunscreen, this can also be a problem with lotions, pastes and stick sunscreens. If someone were to use 1/2 the amount of SPF 50 sunscreen that they should, the protection factor of the sunscreen is square rooted. That means a protection of around SPF 7 for a sunscreen listed as SPF 50 if only half the necessary amount is applied. Make sure to use a thick layer of sunscreen.

Informative Sunscreen Video

Zinc Oxide and Mineral Sunscreens

Sunscreens containing titanium dioxide and/or zinc oxide as active ingredients are considered “mineral sunscreens.” Many mineral sunscreens have other active chemical ingredients in addition to zinc and/or titanium. Zinc oxide is the only active ingredient blocking high amounts of both UVA and UVB light without the use of toxic chemicals that are absorbed through your skin. Titanium is better at blocking UVB than zinc but it is much worse at blocking UVA light (90% of light is UVA).

The best manufactured sunscreens seem to use 20%+ non-nano zinc oxide and potentially also include non-nano titanium dioxide at around 5 to 7%. Many manufactured sunscreens claim to be SPF 50 with the only active ingredient being 20% zinc oxide. From my reading this appears to be highly unlikely and probably the reason Consumer Reports is so down on mineral sunscreens. Consumer Reports seems to focus on light weight mineral sunscreens that go on clear while EWG recommends mineral sunscreens but focuses on ones that leave faces ghostly white.

Avoiding Other Active Ingredients

The FDA recognizes titanium and zinc oxide as the only safe and effective active sunscreen ingredients. FDA studies on the toxicity of other active ingredients remain in progress. However, third party research has shown problems with other active ingredients in sunscreen. These problematic chemicals are absorbed through the skin into the bloodstream where some are hormone-disrupting, have carcinogenic effects and are not recommended for use on children. For example, oxybenzone has been linked to birth defects in the colon of babies. Alternatively, mineral based sunscreens (zinc and titanium) are not absorbed through the skin but stay on the surface and believed to be non-toxic.

Mineral sunscreens that don’t leave your face white are probably not protecting you that well. Also, if the sunscreen isn’t hard to wipe off then it probably will not stay on when playing in the water.

Reef Safe Sunblock

Be careful when looking for a “reef safe” sunscreen, since there is much misleading information. Numerous sunscreens like SunBum claim to be reef safe when the active ingredients (in SunBum’s case Octocrylene 10.00%) are know to cause problems for reefs. Nano-zinc oxide and nano-titanium dioxide causes problems for coral while the large particled non-nano zinc and titanium are not absorbed by the coral.

As a result, Hawaii has banned many sunscreen ingredients. One of them, oxybenzone causes the activation of dormant virus that lead to the bleaching of corals. Mineral based sunscreens (zinc and titanium) are believed to be less likely to rub off in the water and the particles are large enough to not be absorbed by the coral.

In general, it seems that if a chemical is bad for other organisms it’s best for humans to avoid it. When possible look for products with ingredients that we know our bodies are designed to consume like olive oil and coconut oil.

Chemicals bad for reefs

List of Chemical found in sunscreen that are known to be harmful to reefs.

  • 4-Methylbenzylindene camphor
  • 3-Benzylidene camphor
  • Avobenzone
  • Benzophenone-1
  • Benzophenone-8
  • Homosalate
  • OD-PABA, Octinoxate
  • Octisalate
  • Octocrylene
  • Oxybenzone
  • Paba
  • Parabens
  • Triclosan
  • Microplastics (like “exfoliating beads”) 
  • Nanoparticles or nano-zinc or nano-titanium (if it doesn’t say “non-nano” and it can rub in, it’s probably nano-sized)
make reef safe homemade sunscreen
Mineral based sunscreen are best for our ocean reefs.

How Strong are Sunscreens Really

Since we can’t count on manufacturers giving us honest data regarding the SPF of sunscreen, we have to find another option. Supposedly, you can approximate based upon the weight of zinc oxide used to get idea. For every 1% of zinc oxide per the total weight of the sunscreen, zinc oxide provides about an SPF of 1.6.

If a sunscreen is 10% zinc oxide by weight then it has an SPF of around 16. This is assuming no other active ingredients. Ideally we’d want to have a percent weight of zinc oxide in our sunscreen between 20% and 30% to have an SPF in the 30 to 50 range. (***The idea that 1% zinc oxide gives 1.6 SPF and 1% titanium oxide provides 2.6 SPF is all over the internet but I could not find any scientific support for this claim though it appears more conservative than most published SPFs.)

Sunscreen IngredientEstimated SPF Per 1% Weight
Titanium dioxideSPF 2.6 (for UVB)
Zinc oxideSPF 1.6

Commercial Sunscreen Lotions versus Pastes

To have a squirt bottle of sunscreen with zinc, most manufactures need to add a bunch of chemicals to achieve the desired lotion consistency, but Badger brand is a notable exception (see below). Alternatively, most sticks and tins (pastes) seem to be able to be produced with minimal chemicals. All the products below are non-nano zinc-based, “reef friendly” and water resistant for 80 minutes. Pretty much all of these products will leave your face white (except Badger) and the sunscreen will be difficult to remove. It seems like any mineral sunscreen that isn’t a bit pasty doesn’t do a good job of protecting your skin.

***Remember the SPF ratings are self tests by the manufacturers. The zinc % seems like a better way to compare protection. Badger has the best lotion/cream and paste on the market while the Waxhead stick is the best stick for the price. The sunscreens listed that have few ingredients are usually easy on sensitive skin. Mineral sunscreens also protect dry skin since they form a protective barrier on the surface.

Cream and Lotion Sunscreens

(See mobile friendly version of tables)

SunscreenLink to ProductCostIngredients
Badger Sunscreen Cream
Like: minimal ingredients,
reef friendly,
water resistant 80 minutes,
unscented
Note: Badger uses a “clear”
zinc that is non-nano


SPF 40
$15.29
2.9 ounces
$5.30/ounce

This image has an empty alt attribute; its file name is Buy-Online.jpg
22.5% Uncoated
Zinc Oxide,
Organic Sunflower Oil,
Organic Beeswax,
Sunflower Vitamin E
Thinksport
Like: budget friendly
reef safe
water resistant 80 minutes
Dislike:
many chemicals
only 20% zinc

SPF 50
$18
6 ounces
$3/ounce

This image has an empty alt attribute; its file name is Buy-Online.jpg
20% non-nano Zinc,
caprylic triglyceride, polyglycery-4
isosterate, cetyl dimethicone, hexyl
laurate, glycerin, hycrogenated
methyl, pinewood resin, epsom salt,
caprylhdroxamic acid, glyceryl
caprylate, sorbitan sesquioleate,
currant fruit, sunflower oil, jojoba
seed oil, tocopherol, olive fruit oil,
hyalurounic acid, grapefruit
Reef Repair Sunscreen
Like:
lots of zinc
water resistant 1 hr,
budget friendly
reef friendly
Dislike:
lots of chemicals
scented

SPF 50
$20
4 ounces
$5/ounce

This image has an empty alt attribute; its file name is Buy-Online.jpg
25% non-nano Zinc,
coconut oil, avocado oil, vegetable
emulsifying wax NF, shea butter, red
raspberry seed oil, glyceryl oleate
citrate & caprylic/capric triglyceride,
glycerin, beeswax, ethylhexylglycerin
& propanediol, polyhydroxystearic
acid, sodium gluconate, coconut
essential oil, vanilla essential oil
By purchasing through links you help fund this website.

Paste and Stick Sunscreens

SunscreenLink to ProductCostIngredients
Badger 50 SPF Tin
Like: reef friendly
80 min water resistant,
lots of zinc,
minimal chemicals
Note: Badger uses a “clear”
zinc that is non-nano

SPF 50
$15
2.4 ounces
$6.25/ounce

This image has an empty alt attribute; its file name is Buy-Online.jpg
25% Uncoated Zinc Oxide,
Sunflower Seed Oil, Beeswax,
Tocopherol (Sunflower Vitamin E)
Raw Elements Baby + Kids
Like: reef friendly
water resistant 80 min
good ingredients and lots of zinc

SPF 30
$18
3 ounces
$6/ounce

This image has an empty alt attribute; its file name is Buy-Online.jpg
25% non-nano Zinc,
organic sunflower seed oil,
organic beeswax, organic
coconut oil, cocoa seed butter,
organic calendula flower extract,
organic chamomilla, rosemary
leaf extract, sunflower vitamin E
Waxhead Sunscreen Stick
Like: reef friendly
water resistance 80 min
lots of zinc,
Bonus: Tinted Version

SPF 30
$24
3.7 ounce
$6.50/ounce

This image has an empty alt attribute; its file name is Buy-Online.jpg
25% non-nano Zinc,
Virgin coconut oil, Beeswax, aqua,
ethanol, vanilla planifolia extract
EiR NYC Surf Mud Pro Stick
Like: reef safe, water resistant
lots of zinc + titanium
Dislike:
expensive
Note:
cardboard container

SPF 50
$30
1.5 ounces
$20/ounce

This image has an empty alt attribute; its file name is Buy-Online.jpg
25% non-nano Zinc,
5% non-nano Titanium,
Beeswax, Organic Cocoa Butter
Organic Coconut Oil
Organic Cocoa Fruit Powder
Tables Updated 5/10/2022

Concluding Thoughts on Sunscreen

While there are numerous sunscreen options, finding a high quality product can be challenging. Staying out of the sun and wearing clothes that protect from the sun is the best defense from sunburns and skin damage. At the moment the best sunscreen option seems to be mineral sunblocks with a high percentage of zinc oxide (greater than 20%) and potentially some additional titanium dioxide. Just because a sunscreen says it is reef safe does not make it so. Double check a sunscreen by using our list of reef harmful chemicals above or go to Save the Reef.org. If you’re the DIY type, check out our recipe for homemade zinc-based sunscreen to save money and ensure your sunscreen is safe for your health.