Article by: Perry Romanowski

Here is a story that caught my interest about the ingredients in sunscreens harming ocean life. It turns out that the active ingredients in mineral sunblocks, Titanium Dioxide (TiO2) and Zinc Oxide (ZnO), undergo a chemical reaction that produces hydrogen peroxide. sunscreen-phytoplankton

The way it works is that when a photon hits the molecule it is converted to heat and a free electron. The free electron reacts with Oxygen to produce an oxygen radical which reacts with free hydrogen which then combines with another to form hydrogen peroxide.

Anyway, this increased level of hydrogen peroxide in the ocean water can kill off some of the marine phytoplankton. This is a significant food source for larger sea creatures so when phytoplankton is reduced it has devastating effects on other animals.

Unintended Consequences

This just makes me think of the advice that is given by organizations like the Environmental Working Group (EWG). They do an annual recommendation for sunscreens and always choose TiO2 and ZnO based products as the “safest” choice for consumers. There is no good evidence that organic sunscreen ingredients like Oxybenzone or Octinoxate are dangerous for people but that doesn’t stop the EWG from suggesting they are.

As this story about the effect of TiO2 on aquatic life demonstrates, there may be unintended consequences to what you think is good advice. If you care about the environment it is probably better for you to use sunscreens based on different UV filters that don’t include mineral sunscreens.


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    Would you say Zinc or Titanium sunscreens are actually worse? I have very fair skin and I use Badger sunscreens. I get the feeling from reading your blog that you are not their biggest fan, but would you say they are bad or ineffective sunscreens? Thanks!

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      Perry Romanowski

      As far as being bad for sea life, probably Titanium sunscreens are worse but it’s hard to say since both minerals will build up in the environment.

      You are right I’m not the biggest fan of Badger but not because of the functionality of their products. You can have faith that their products are effective sunscreens. Anyone who sells sunscreens in the US have to follow the FDA sunscreen monograph which says exactly what active ingredient can be used and the levels required. Badger complies with the law so they are definitely effective products.

      My complaint with Badger is that they don’t use proper preservatives so their products are prone to bacterial contamination. This puts people at risk of disease especially children. Until they start using functional preservatives I recommend avoiding them.

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    nicholas molubi

    Hi Perry.just want to know ,we are a manufacturing primary cooperative that makes small scale perfumes ,paint and cosmetic and we need to be incubated or be helped by any company that specialize in what we do.we are a group of about five people from disadvantage area like Sharpeville in South Africa in Gauteng in the craft hub centre.
    My question is in what category as a small scale manufacturing do we fall under.
    We sometimes be ignored to whether we are crafters or not.

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    PJ van Kralingen

    Interesting article — here is more food for thought:
    In Australia the organic sunscreens are having a damaging effect on the coral reefs, and Zinc Oxide and Titanium Dioxide are preferred – go figure…
    Excellent examples of initiating mass confusion.

    1. Avatar
      Perry Romanowski

      Interesting! I didn’t see that organic sunscreens were also a problem.

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