Chemical sunscreens versus physical sunscreens – are they safe?

How does mexoryl based sunscreen compare to zinc based? Will it cause allergy, endocrine disruption? Does it block UVA and UVB?

Okay …..I’m so glad you asked this since there is so much confusion on it.  There are two issues here.  First, how much radiation from the sun (UVB & UVA) is this sunscreen really blocking.  And secondly, which of these sunscreen ingredients are safe?

At our clinic, for years, we have been promoting primarily zinc based sunscreens so here’s why below.  When a sunscreen says it has zinc in it, turn the tube over and look at the back, to see what the zinc percentage really is!!   You want between 8-9 to 18-20% depending on what you’re doing. You can find sunscreens I recommend, here.

Here’s how much radiation your sunscreen it really blocking:

Ideally, you want the whole UVA and UVB spectrum blocked (290nm-400nm).  Best to worst order. Most of the ones below partially block outside the range below, but it’s not a full block
  • Zinc – 290-380  – by far the best!
  • Titanium  – 350-370  (should be avoided around coral reefs – does not biodegrade)
  • Avobenzone  – 340-350
  • Meradimate  – 290-300, 320-340
  • Oxybenzone – 300-320  (banned for coral reefs by Hawaii)
  • Octocrylene – 300-320
  • Octinoxate – 310-320 (banned for coral reefs by Hawaii)
  • Homosalate – 300-320
  • Ensulizole  – 300-315
  • Octisalate – 310-320
  • Ecamsule – Mexoryl –  chemical sunscreen – there’s very little non pharma info I can find on this, so I’ll dig further. Peak absorbance at 345 with some reduction from 290-400.

Which sunscreens are safe?

Only the top two above are mineral based sunscreens, NOT chemical.  Zinc is the safest because it’s naturally present in our bodies.  Titanium (mineral)  is the next best ….but we don’t really know yet, where titanium goes when it is “nano-ed.” For now, manufacturers are not required to tell you if a product has nano particles.  Other minerals like iron oxides are also excellent but there’s no rating system for them yet here.

Chemical sunscreens, especially if you are just using them on a small area like your face, may be fine! Yes…..if you feed mice lots of these they will develop problems like cancers and endocrine disruption.  But are you eating sunscreen??  I know I’m not.

The greater concern is when these sunscreens are being used on the whole body when it’s a larger surface area, or on small children or babies.  This should be avoided.  Try to use zinc or cover up with protective clothing like rash guards, tights, hats, and sunglasses.

Hope this helps,
Dr. Brandith Irwin
Founder, SkinTour
Director, Madison Skin & Laser Center
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Dr. Brandith Irwin, MD

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Hi, I’m Dr. Irwin. I believe that consumers deserve a medically trained and unbiased skin care advocate.

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