Sunscreen Worries Grow as Another Potential Carcinogen Found | Hacker News Reader

Sunscreen Worries Grow as Another Potential Carcinogen Found

bloomberg.com

38 pointsmegacorp20 comments

Clearly we need to return to the social convention of wearing hats.

As I get older and see my father getting cancers cut out of his face(the man never wore sunscreen), I more and more wear sunscreen.

So far my brand, think sport, has avoided all of these chemicals and it works really well. I’m sure there are other options out there that don’t contain the reported chemicals.

The tinted one is nice too, if iron oxide seems acceptable.

If you don't want to wear sunscreen at all, you can use UV Index calculators like this, which take into account the hourly UV index, location, and your skin type to calculate safe sun exposure times:

https://sunburnmap.com/

Just be cautious because the time still stacks up - eg. walking to and from the beach in the morning/afternoon. When UV indexes are very high, eg 8 and above, the margin for error is also lower.

And here’s a research article pointing out that octocrylene degrades to benzophenone over time. is this the original study?

> Benzophenone Accumulates over Time from the Degradation of Octocrylene in Commercial Sunscreen Products

https://pubs.acs.org/doi/10.1021/acs.chemrestox.0c00461

Use mineral sunscreen that had minimal additives and hats.

My family have used this for years:

https://www.neutrogena.com/pure-and-free-baby-mineral-sunscr...

It's a mineral sunscreen with no chemical UV absorbers. It's the only sunscreen I've found that doesn't burn my eyes, and doesn't make me look pale like a vampire.

Everything is a chemical. Zinc oxide is just nicely inert.

That sunscreen has plenty of funny sounding chemicals, don't worry!

Ingredients: Active Ingredient: Zinc oxide 21. 6% (sunscreen) Inactive Ingredients: Water, C12-15 alkyl benzoate, styrene/acrylates copolymer, octyldodecyl citrate crosspolymer, phenyl trimethicone, cetyl PEG/PPG-10/1 dimethicone, dimethicone, polyhydroxystearic acid, glycerin, ethyl methicone, cetyl dimethicone, silica, chrysanthemum parthenium (feverfew) flower/leaf/stem juice, glyceryl behenate, phenethyl alcohol, caprylyl glycol, cetyl dimethicone/bis-vinyldimethicone crosspolymer, acrylates/dimethicone copolymer, sodium chloride, phenoxyethanol,

> Everything is a chemical.

In this context, chemical UV absorber commonly refers to soluble chemicals such as benzophenones, as opposed to mineral barriers with low solubility such as zinc and titanium oxides.

> Zinc oxide is just nicely inert.

No, ZnO is not "inert" in any sense of the word. It's amphoteric, and reacts readily with a wide variety of salts and acids, including carboxylates. It's highly reactive with sulphur, which makes it uniquely suited as a crosslinking activator for example.

The properties that most endear ZnO to sunscreens are its wide optical absorption spectrum and low rate of absorption into the skin.

> Ingredients:

I'd be happy to explain the functions of most of these if you'd like.

>I'd be happy to explain the functions of most of these if you'd like.

Please do if you have the time? I think that would be incredibly interesting, to know what all those compounds are actually doing.

This is from old notes, and I'm not familiar with Neutrogena's formulations, so don't take any of this as authoritative.

Keep in mind that ingredients in foods and cosmetics are listed in descending order of predominance, so the first ingredients comprise the largest proportion of the product. Ingredients less than 1% can be listed in any order.

- Water is the first ingredient, which tells us this product is an oil-in-water system. This is the case for almost all modern lotion products.

- C12-15 alkyl benzoate - This oil forms the bulk of the dispersed phase of the emulsion. It functions as a carrier for oil-soluble ingredients, and provides water resistance for the applied film. It has some antimicrobial properties as well. In a moisturizer product you'd see a more conventional oil in this place, like mineral oil or shea butter or something like that. But a "dry-feel" sunscreen needs a more specialized light and dry feeling oil, and this is a common one.

- Styrene/acrylates copolymer - I'm guessing this is Dow's Sunspheres product. Dow markets it as a sort of "sunscreen multiplier", which allows a formulator to reduce the quantity of other active UV filters or blockers. BASF and other companies supply similar products that are marketed as opacifiers and colorants.

- Octyldodecyl citrate crosspolymer - This is a texture modifier sold under the brand CosmoSurf, marketed as a sort of designer oil phase that provides ideal structure and spreading characteristics.

- Phenyl trimethicone - Anti-foaming agent. Foam is bad in lotions.

- Cetyl PEG/PPG-10/1 dimethicone - This is an emulsifier for silicone in water emulsions. It keeps the silicone components from glomming together. Without this the product would sort of curdle and get clumpy.

- Dimethicone - This is just silicone oil. It's an important component of the dispersed phase of the emulsion. Silicone oil is lovely stuff: very light and dry, and very water resistant.

- Polyhydroxystearic acid - This is a dispersant for the zinc oxide. It mates the ZnO particles to the oily components. Without this the ZnO would gather in the continuous water phase and form an uneven slurry, or settle out as clumps of clay.

- Glycerin - I don't know why they use this. It's most well known as a humectant, but I don't know why that would be useful here.

- Ethyl methicone, cetyl dimethicone, cetyl dimethicone/bis-vinyldimethicone crosspolymer - These are silicone oils and texture modifiers that contribute to the dry and sheer feel, and provide antifoaming properties as well. The products I'm familiar with are made by Siltech, sold under their SilWax brand.

- Silica - I don't know why this is here. Filler and color?

- Chrysanthemum parthenium (feverfew) flower/leaf/stem juice - I have no idea what this is for.

- Glyceryl behenate - This is a fat of just the right molecular weight to give body to the product from the bottle, but which will melt at the right moment under the hand. Some products combine mono-, di-, and tri-behenyl glycerides to build particular textures. The triglyceride also helps stabilize the emulsion at higher temperatures, like in a hot car.

- Phenethyl alcohol - A preservative, similar to phenoxyethanol (listed later) but less stinky.

- Caprylyl glycol - I see this is a lot of ointments as a skin conditioner. I'm not sure why it's here, but it could be part of a preservative product called Optiphen, which also contains phenoxyethanol, which is listed later.

- Acrylates/dimethicone copolymer - This is a film former. Contributes to a hard, dry finish and water resistance.

- Sodium chloride - Salt, does a lot of stuff.

- Phenoxyethanol - A preservative. Dow recommends this particular preservative in the Sunspheres tech literature. Could also be evidence of Optiphen as I mentioned earlier.

My beef with mineral and “natural” sunscreens that emphasize being mineral vs chemical is most of them load them up with plant extracts.

Sure at least it’s not 10% oxybenzone or whatever chemical absorbant sunscreen chemical but just because it came from a plant doesn’t make slathering 0.5% of understudied mystery chemical cocktail on ones skin smart.

To add to your agreeable pedantry, I would like to say that not everything is a chemical. Electrons for example. You could argue most things are not chemicals since dark matter by itself is 85% of matter in the observable universe.

Yesh, basically anything that the body doesn't requires to function normally is just capitalist junk.

Do you think it's required if you live at a latitude further south than your skin tone is evolved for?

It's not hard to just cover your skin with clothing. I haven't used sunscreen in the last 10 years and generally have avoided any sun burn. I gauge how much sun I'm getting and just cover up. Each summer I get quite tan and can tolerate long periods of sun exposure before having to cover up (this increases over the course of the summer obviously). Fear of skin cancer is over blown and the increased sun exposure while avoiding sun burn will more than outweigh the risk with other benefits for health.

Like you, never use it. I do try to get a tan starting in the spring. A tan is the best sunscreen. Plus, blocking UV-B means blocking vitamin D3 production in the skin.

https://ods.od.nih.gov/factsheets/Vitamin%20D-HealthProfessi...

I'm lucky in that my skin type is tannable, I know for some people that's not an option.

It is over-hyped and overused. I see people out for a half-hour run at 7 AM (UV index=0), wearing sunscreen.

I'm 32 and last year I had a melanoma taken off my back. This was about three months after my GP told me I had a Vitamin D deficiency. Sometimes you just can't win.

mRNA for melanoma is likely to be the prescription. Sunscreens were a useful shim until we can modify the body to resist sun caused cancer.

https://thehill.com/changing-america/well-being/medical-adva...

Even drugs? Legal or otherwise?

Despite that I´m an avid pro-cannabis user, yes, I do agree that we can live without it. That´s the best way to be healthy I guess, but well, us humans found ways to transcend mere animal life, so we might enjoy the trip then.

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