Sunscreen vs Sunblock

In Colorado we get roughly 400 per cent more exposure to UV radiation than the midwest states do. So use of a good sunscreen or sunblock along with appropriate outdoor clothing is important while fly fishing. After having three operations for skin cancer in 2010, I decided to research if my current sunscreen was very effective.

All of the brands available at the grocery store or the big box stores had the same ingredients in them. The only difference was the percentage mix. What was missing was titanium dioxide which had been in most of them. Whether titanium dioxide was removed due to FDA ruling or cost was irrelevant. That ingredient was a key to preventing deep sunburn.

What sunscreen or sunblock is supposed to do is protect us from UV rays. Specifically UVA and UVB radiation. UVA will penetrate deep into the skin and cause premature aging and wrinkles. UVB is the one that produces the bad sunburns. UVC is almost totally filtered out by earth’s atmosphere. Both UVA and UVB are known skin cancer producers over long exposure.

Sunblock works by reflecting the UV off the skin. The two most used ingredients in sunblock are zinc oxide and titanium oxide in a very fine particulate form. The small particles reflect the sun’s rays off the skin.

Sunscreen works to filter out the amount of UV rays that penetrate the skin but not block all of them. This is done by using a combination of chemicals to filter out most of the UV from penetrating the skin. Unfortunately, the chemicals used are known to cause cancer, DNA damage, skin damage, be absorbed through the skin to damage internal organs and more.

The active ingredients in almost all sunscreens are:

  1. Avobenzone – toxicity buildup benzoic acid and other by products
  2. Homosalate – salicyclic acid concerns
  3. Octisalate – allergies and immune issues
  4. Octocrylene – cellular changes and biobuildup
  5. Oxybenzone – reproductive changes, cellular changes, bio buildup in the body, allergies
  6. Vitamin A Palmitate – Cancer causing when used in sunlight – One year FDA study showed a 21% increase in lab animals coated with the vitamin a palmitate lotion and exposed to only 9 minutes of Florida level equivalent sunlight at noon.

This is the active ingredient list. The inactive list is almost as bad for many sunscreens and sunblocks.

The best sunblocks still use titanium dioxide and zinc oxide in a nano particle sunscreen grade as the main ingredient to block UVA and UVB from penetrating the skin. They don’t use much else except for a lotion to spread the blocker around the skin. While most people don’t like the look or feel of zinc oxide or titanium dioxide, they do work. Which is worse not looking too good or having surgery to remove skin cancer.

Of course the best way to prevent sunburn and skin cancer is to stay out of the sun especially during the hottest hours of 11 AM to 1 PM. If you can’t be indoors, wear a hat of SPF cloth, long sleeve shirts of an SPF 50 cloth and a good sunblock on your face, hands and other exposed skin. A good hat is made by Tilley. Bass Pro’s World Wide Sports brand offers some excellent SPF cloth shirts and other clothing for reasonable prices.

The final result was the SPF 50+ sunscreen I had used for the last six years may have contributed to my skin cancer.

For an extensive evaluation of sunscreens and sunblocks This is a dynamic database of over 1,400 sunscreens and sunblocks listed by best by type and hall of shame products. There is more excellent information on this site about sunscreen studies and sun safety tips.

For safety coverup and wear a good sunblock.

Tight Lines,

Marshall Estes, Author
“Successful Fly Fishing For Trout”


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