Dear Photobiologists....

[Andrea B.]

I have listed below four sunscreens. Which one is best? I do know that a higher SPF is better. But it is the ingredients I'm asking about. There seems to be a split between organic and non-organic formulations these days in the Land of Sunscreen, although the third one below has a little of both.

 

There is quite a list of inactive ingredients in each of these potions, but I'm going to ignore that stuff for now.

 

Thank you for any insights about this! I have tried to be very careful with my summer UV shooting. I do use a hat these days -- at least for awhile until it begins to annoy me and I fling it away -- and use long sleeves and button up my collar for as long as I can stand it. B)

 

(1) SPF 30 spray on: "organic", "natural", "no synthetic chemicals", "reef safe", "no-nanos".

• 12% zinc oxide
  

 

(2) SPF 30 lotion: "organic", "no chemicals", "non-gmo", "cruelty free".

• 6.0% titanium dioxide
  
• 6.4% zinc oxide
  

 

(3) SPF 50 gel: "reef friendly", "oxybenzone free", "no added octinoxate", "no animal testing".

• 4% octocrylene
  
• 5% zinc oxide
  

 

(4) SPF 100 lotion: Definitely not organic and no bunny symbols. But I was thinking this might be good stuff for the face and neck and back of hands?? Unless it killed some bunnies. If that happened, I'm returning it.

• 3% avobenzone
  
• 15% homosalate
  
• 5% octisalate
  
• 10% octocrylene
  
• 6% oxybenzone
  

[Dmitry]

Bit offtopic but names of ingredients remind me oil pigments used by painters and tested in UV and IR, I hope you can translate and read it - https://invis-light.livejournal.com/1043.html

[JMC]

Andrea, meet "can of worms". Current recommendation is I believe SPF30 and applied regularly - every 2 hours. Higher than that can lead to a false sense of security, and people leaving it for longer, when by then most of it has sweated or rubbed off. Organic or inorganic is up to you. I prefer inorganic personally, as some of the organic products are extremely greasy feeling. They all need to be slapped on at quite high doses to achieve the measured SPF scores. Most people don't apply enough. Hat and long sleeves are ideal, so well done.

 

Other ingredients can be extremely important - 1% of a film former ingredient can boost SPF from 10 to 30 without changing any of the UV absorbing material levels. If the product doesn't spread evenly then the sun protection filters don't form a good layer and SPF drops drastically.

 

Number 2 is a bit confused. It says "organic" but the 2 SPF ingredients are inorganic. Actually so is number 1, that's inorganic too.

 

Make sure you're not handling your Baader U after this. It gets everywhere and screws up anything UV imaging related.

[JCDowdy]

It depends on how UV sensitive you are and if you have any history of skin cancer. Specially sun protective clothing and hats is the safest and designed for comfort in the heat. Good protective clothing combined with sunscreen in exposed areas is sound advice!

You will get burned on the spots you forget to apply sunscreen, like the tops of your ears or the crown of your head if your hair is thinning ... :( like I did when I forgot my hat at the Desert Botanical Gardens in Phoenix last April. Shade is also your friend and helps to avoid lens flare too!

 

I tend to favor broad spectrum SPF 30 or higher lotions with a balance of both chemical and physical (titanium or zinc oxides) agents and which have some water resistance. The higher SPF products do have a considerable total percentage of active sunscreen agents. That can be a concern for users generally sensitive to excess chemical exposure and the titanium dioxide and zinc oxide based options may be preferred.

 

If you are going to Hawaii, they have recently banned some of the sunscreen agents due to environmental protection, hence the reef safe advert. The Environmental Working Group (EWG) is a good source of information on that subject, they publish a review of their concerns. I have never fully bought into the nano is bad argument, optically speaking smaller is better in terms of scattering UV. I do however think that anti-inflammatory activity of sunscreen agents is a real problem.

 

Very high SPF can provide a bit of a safety net for users who tend to apply a bit to sparingly or forget to reapply. I will admit guilt on both counts. There may be some logic to that approach when handling UV photography gear because you certainly do not want to contaminate expensive gear with sunscreen. Sunscreen is very very difficult to wash off your fingers. Somewhere I have a set of photos of UV black fingertips remaining after 4-5 reps of vigorous soap scrubbing!

[Andy Perrin]

I had heard there was a preference for inorganic sunscreens (ZnO, TiO2). Any comments, JMC, JCDowdy? (I am not sure of the reasoning there.)

[JCDowdy]

Yes, if you are concerned about excess chemical exposure the titanium dioxide and zinc oxide based options may be preferred. They don't mimic hormones or mask sunburn via anti-inflammatory activity or tend cause allergies or inflame overly sensitive skin.

[DaveO]

From the sun cancer capital of the world here's their latest thinking and you will find lots of good stuff on their website

 

https://www.cancer.org.au/preventing-cancer/sun-protection/about-sunscreen.html

[Andrea B.]

Dear Photobiologists and Friends -

Thank you all very much for all this good into and all the links !!!!

Sincerely yours -

Andrea B.

 

I'm still thinking over that SPF 100 chemical sunscreen. You know how ladies are about their faces !! However, I need to read more about those chemicals.

 

I did get a chuckle about all the labeling on the sunscreen containers. The "organic" refers to all the glerp in the lotions which is considered to be "Inactive Ingredients" and not to the Ti or Zn pigments.

 

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Dmitry, I remember, of course, how to pronounce the Russian words, but my Russian vocabulary has faded greatly. Still, I enjoyed attempting to translate the captions and the names of the pigments.

 

The study that Dmitry linked is about various artist pigments and how the look under UV or IR light in both reflected UV or IR photos and UV- (IR-) induced fluorescent photos.

 

 

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Dave, holy cr@p0ly !! Two in three Australians will be diagnosed with a skin cancer by the age of 70. That is a truly horrifying statistic.