This is a topic where the details matter a lot. A sunscreen which is labeled SPF 50 but performs at SPF 45 is such a minimal difference that it would be impossible to notice in the real world. The variance of your application technique and applied thickness would actually matter more. There is also a lot of testing variability, so if a sunscreen rated to block 98% of certain rays only gets 97% in the test that would be acceptable in the real world, but it would get counted for this clickbait headline.
If a sunscreen comes with a high SPF rating and performs close enough in random testing (which is hard to replicate) then I wouldn’t have any concerns in the real world.
The body of the article has some more details about how the number of majorly deficient brands was much smaller, but that makes for less clickbaity headlines:
> The measured sunscreen efficacy of 4 models were below SPF15, of which 2 were sunscreen products with very high protection i.e. labelled with SPF50+
Knowing which 2 brands were labeled SPF 50 but performed below 15 would have been helpful, but the article is not helpful.
hn_throwaway_99 21 hours ago [-]
This is related to an article from yesterday, https://news.ycombinator.com/item?id=45145624, about the Choice Australia investigation that found that some sunscreens (named in that article) provided around SPF 4 when it was labeled as SPF 50+. It is a big deal because many people (like the 34 year old woman in the article who had skin cancer removed from her face) use a specific brand for years, believing it to be as effective as the label proclaims.
MangoToupe 20 hours ago [-]
As someone who burns extremely easily, I'm confused how this happens. I can feel the difference immediately; as little as ten minutes in direct sunlight makes me tinged red; and if I don't cover every inch I can tell which parts I missed the next day. If it doesn't work why would you use it?!
I do have sympathy for those with dark(er, which is basically everyone) skin who may not be able to directly tell the efficacy.
My concern is that mineral sunscreens are difficult to apply and leave a film on the skin (which is the entire point, I guess?); i hate that feeling, so I use chemical sunscreens. I'd bet that some of them have very nasty long-term side effects. So in the end i almost always go with trying to cover my skin with clothes/shade/whatever if at all possible.
daneyh 20 hours ago [-]
Why are you confused? You can be (and are likely) doing deep, long term damage to your skin even if your skin doesn't have an immediate reaction to sun exposure (i.e sunburn). This is a key point that cancer council australia are constantly trying to drill into peoples heads.
15 hours ago [-]
19 hours ago [-]
scrollop 13 hours ago [-]
Chemical sunscreens:
Endocrine disruption: Oxybenzone (BP-3) and related benzophenone-type UV filters have demonstrated endocrine-disrupting properties in vitro and in animal studies, with some human data suggesting possible hormonal alterations and increased risk of uterine fibroids and endometriosis.[6-7] However, most human plasma concentrations are much lower than those producing effects in bioassays, and current evidence suggests low intrinsic biological activity and risk of toxicity for most organic UV filters except oxybenzone.[8-9]
Contamination: Benzene, toluene, and styrene have been found in a large proportion of sunscreen products, likely due to manufacturing processes rather than the UV filters themselves. Benzene contamination is a particular concern due to its established carcinogenicity.[1]
Aurornis 19 hours ago [-]
Many people don't burn so quickly.
They could also have a lot of short exposures, like someone who is only outside for 5-10 minutes at a time but 2-3 times per hour every day, as was the case with one of my early jobs that involved walking between buildings a lot.
A common mistake to make is believing that if you're not burning, you're not accumulating damage.
hn_throwaway_99 19 hours ago [-]
> I'd bet that some of them have very nasty long-term side effects.
Why?
MangoToupe 19 hours ago [-]
Mineral sunscreen works very intuitively, and feeling that grime makes sense. If you have dark skin, many if not most mineral sunscreens will be quite visible. You're trying to literally cover your skin with a screen and you should be able to feel it and probably see it. You can also wash it off quite easily (to the extent it's a problem at the beach).
Chemical sunscreen that avoids this is designed to sink into the skin like lotion. So there's something literally in your skin blocking uv or it won't work very well. I'd say this increases the odds of circulating something carcinogenic or otherwise toxic into your bloodstream.
Recently I went into the whole rabbit hole of sunscreens as I moved to Brazil from Switzerland, and now need to use it everyday (ok I know, theoretically also back home would be nice!). So I bought a mineral sunscreen. It feels "healthier" but also doesn't have that good lotion-like characteristic that you can just apply and forget. I really hope sunscreen companies are able to crack this one up.
manwe150 20 hours ago [-]
I assume your numbers are just made up, but if 98% is SPF 50 (1/50 or 2% reaches the skin), 97% is SPF 30 (1/30 or 3% reaches the skin). Both seem pretty good, but that is still a fairly marked difference.
cenamus 17 hours ago [-]
Yeah that would be like 50% more sun getting to your skin
KolibriFly 11 hours ago [-]
I think the real concern here isn't the slight variances, it's the outliers. Two products labeled SPF50+ testing under 15 isn't just a rounding issue, that's straight-up consumer deception
mcdeltat 22 hours ago [-]
Have you tried living in Australia? I would like SPF 100 sunscreen pronto, please and thank you
josu 21 hours ago [-]
SPF is a Sun Protection Factor, meaning it multiplies the time it takes for your skin to burn. For example, if very light skin normally burns in about 10 minutes, SPF 20 stretches that to ~200 minutes, which is already over 3 hours. Since dermatologists recommend reapplying every 2 hours regardless, going beyond SPF 30–50 (which blocks ~97–98% of UVB) doesn’t add much practical benefit. Even for very fair skin, correct application and reapplication are far more important than chasing SPF 100.
noosphr 21 hours ago [-]
Where I live in summer I regularly get days with UV index above 15.
If you burn in 15 minutes under UV index 6 on the worst days that I've seen you'd burn in 5 minutes. So a SPF of 60 is as useful here like an SPF of 20 is wherever you live.
anonym29 19 hours ago [-]
Jesus H Christ, UV index of 15? I thought the 12 we see in the middle of Texas summers was bad. I've burnt in 10 minutes through a windshield with that.
3uler 18 hours ago [-]
The UV index in the southern hemisphere goes a lot higher than anything you experience up in the northern hemisphere. Do yourself a favour and go have look at the UV index on a hot summers day in Sydney in January.
dbetteridge 17 hours ago [-]
For example today in sw Australia in late winter/spring it's a uv index of 5.
Summer time it sits at 13+ at noon on a clear day.
In the risk of not picking up your hyperbole, I did think the windshields block UV and thus you cannot get sunburned through them.
loeg 8 hours ago [-]
In new vehicles, yes.
anonym29 4 hours ago [-]
The protection factor from that degrades over time / with exposure, too.
loeg 20 hours ago [-]
This kind of SPF fatalism doesn't really make sense to me. There's absolutely no reason to quantize sun damage into "below burn time" and "above burn time." Damage is dose-dependent. Even burns come in different classes at different exposure durations; and maybe you'd prefer to get, you know, 30 seconds unprotected equivalent of sun damage instead of 3 minutes equivalent, at the same re-application interval.
If someone can make a true SPF 200 economically, it's valid for consumers to prefer that to a true SPF 100 or true SPF 50.
01HNNWZ0MV43FF 20 hours ago [-]
No, it should be like car speedometers where even a slight misreading on the wrong side is regulated harshly. [1]
I don't care for "close enough" brinksmanship.
The same is true for speed limits but y'all aren't ready for that
[1] Might be rumor but I heard that car speedometers often read high because there's a big penalty if they read low by even 1 MPH
schiffern 20 hours ago [-]
Yes, this is how consumer labeling works today. Net weights, cash register scales, gasoline pumps, etc. Errors are only allowed if they're in the customers' favor.
That said, sunscreen is hard to apply precisely. One interesting emerging option is personal "makeup mirrors" that use a UV camera.
gmueckl 17 hours ago [-]
Cars show higher speeds especially when the model has an option for larger tire diameters, but is equipped with smaller ones. There typically isn't a setting for tire diameter, so they compute speed using the larger diameter in all cases.
madog 20 hours ago [-]
It's not a rumour. They usually read somewhere between 5-10% over actual speed. Use a more accurate GPS speedometer on your phone to check that.
Fade_Dance 18 hours ago [-]
5-10%, definitely not. Wrong tire size will do that though.
Have had a GPS speedo on the dash for a good dozen cars through the years and never seen more than a few mph off on a flat surface. That's something I actually noticed and looked for, for some reason. A few mph over speed is fairly common, but we're talking 1-2% at most. (confirmed with Tesla Model 3, Corolla, Fusion, Prius, Elantra, Mirage, etc etc).
Huppie 15 hours ago [-]
I know it sounds like a lot but in my experience the difference is mostly a fixed offset plus a tiny percentage due to tire pressure/size.
A fixed 2mph difference at 20mph is 10% so imho they're at least _technically correct_.
madog 9 hours ago [-]
5% at 70 mph is 3.5 mph
10% at 30 mph is 3 mph
I saw this with various European cars.
My experience is that it seems to be a fixed percentage rather than a fixed amount i.e. the absolute difference increases with speed.
9 hours ago [-]
doctorhandshake 21 hours ago [-]
Independent lab testing of consumer packaged goods is so important, expensive, unprofitable, and downright risky from a libel standpoint that I dare say it should be the role of government to do it.
pljung 20 hours ago [-]
You essentially describe the motivation for Stiftung Warentest [0]. They’re massively successful in Germany, and I rely on their tests for many consumer goods I buy. Access isn’t free though, typically costs around 5EUR per test. Coincidentally, they recently tested sunscreen [1].
In the US I like labdoor.com and examine.com and ewg.org but they’re not nearly what I’d like them to be.
EDIT: to clarify, of the three only labdoor does independent testing
KolibriFly 11 hours ago [-]
Feels like one of those classic cases where the market alone can't sort it out, and strong public infrastructure should step in
socalgal2 20 hours ago [-]
Yes, because government inspectors are flawless and would never take bribes to let things pass or force them to fail. Nope, they'd never do that.
andreasmetsala 14 hours ago [-]
Certainly a flawed system is better than an outright broken one? At least the former can be improved.
unethical_ban 20 hours ago [-]
False implication and assuming private companies with solely a profit motive are themselves angels.
...
oh, excuse me. "No siree, never would a for-profit company put out false products, nope, not ever"
numpad0 11 hours ago [-]
These SPF craze sounds a bit ridiculous once you realize how sunscreens work: sunscreens are just ZnO and/or TiO2 dispersed in oil. They're fundamentally just base white oil paint(in the way donuts are topologically just coffee mugs).
The core operating principle of sunscreens is that, the more your skin is covered in opaque inorganic metal oxides, the less it is exposed to harmful UV lights. There would be a lot of little tricks and additional paints to make it less irritating and less crazy looking to wear, but the point is, sunscreens fundamentally rely on opacity.
I think just knowing that lets one have a lot more of intuition about sunscreens than reading bunch of sales brochures on SPF or PA figures or wondering if the fancy ones are worth it.
LeafItAlone 8 hours ago [-]
> sunscreens are just ZnO and/or TiO2
Those are mineral based sunscreens.
Most popular sunscreens (including most from the study) in the US have neither. Usually it’s only the super-reef-safe and baby targeted ones that do.
sfjailbird 8 hours ago [-]
There are SPF 50 sunscreens that are practically invisible.
10 hours ago [-]
Insanity 1 days ago [-]
Why does it not list the brands? The article is both informative and useless simultaneously
Seems like it's not that simple. The CHOICE study[0] suggest that some brands do have some good "models" of sunscreen, but some are bad. It's also possible that there's a process issue at the manufacturers, and the quality of different lots can vary:
> Ultra Violette announced it was removing the Lean Screen product from shelves. Across eight different tests, the sunscreen returned SPF data of 4, 10, 21, 26, 33, 60, 61, and 64.
> The CHOICE study[0] suggest that some brands do have some good "models" of sunscreen, but some are bad.
For reference, the results were:
Ultra Violette Lean Screen SPF 50+ Mattifying Zinc Skinscreen 4
Cancer Council Ultra Sunscreen 50+ 24
Neutrogena Sheer Zinc Dry-Touch Lotion SPF 50 24
Aldi Ombra 50+ 26
Bondi Sands SPF 50+ Zinc Mineral Body Lotion 26
Cancer Council Everyday Value Sunscreen 50 27
Woolworths Sunscreen Everyday Tube SPF 50+ 27
Banana Boat Baby Zinc Sunscreen Lotion SPF 50+ 28
Bondi Sands SPF 50+ Fragrance Free Sunscreen 32
Cancer Council Kids Clear Zinc 50+ 33
Banana Boat Sport Sunscreen Lotion SPF 50+ 35
Invisible Zinc Face + Body Mineral Sunscreen SPF 50 38
Nivea Sun Protect and Moisture Lock SPF 50+ Sunscreen 40
Sun Bum Premium Moisturising Sunscreen Lotion 50+ 40
Nivea Sun Kids Ultra Protect and Play Sunscreen Lotion SPF 50+ 41
Coles SPF 50+ Sunscreen Ultra Tube 43
Mecca Cosmetica To Save Body SPF 50+ Hydrating Sunscreen 51
Cancer Council Kids Sunscreen SPF 50+ 52
Neutrogena Ultra Sheer Body Lotion SPF 50 56
La Roche-Posay Anthelios Wet Skin Sunscreen 50+ 72
> It's also possible that there's a process issue at the manufacturers, and the quality of different lots can vary
If you read the article, that variable test result was provided by Ultra Violette themselves. Choice tested it three times with three different independent testers and got results of 4,5,5. It's possible Ultra Violette is just trying to muddy the waters here.
SilverElfin 23 hours ago [-]
Is this saying the Neutrogena and La Roche did better than stated?
cjensen 22 hours ago [-]
Yes. The original article[1] is clear about that. However only for one of the two Neutrogena sunscreens.
I feel like this is mostly bullshit because high SPFs are mostly bullshit. A promised SPF of 50 and a tested value of 40 means it blocks 97.5% instead of 98% of the sun.
Anything higher than 30 or even 15 isn't really meaningful. At that point how long it lasts and how resistant it is to water is far more important.
cameronh90 22 hours ago [-]
SPF 50 blocks 25% more UVB than SPF 40 does. Measuring it as percentages makes it non-linear in a way that most people find confusing. Imagine we had one sun cream that blocked 99.9% and another that blocked 99.5%. Sounds like nothing; only an 0.4p difference, but is actually 5 times as effective.
You're right about how long it lasts also being an important factor. UV-A protection is also another very important factor. But as someone with pale skin even by Scottish standards, the difference between SPF 40 and SPF 50 around noon is significant, even through I consistently re-apply every hour. I won't get burnt, but I'll end up with more sun damage - and that lasts until late autumn.
treis 20 hours ago [-]
>99.9% and another that blocked 99.5%. Sounds like nothing; only an 0.4p difference, but is actually 5 times as effective.
I disagree. Both effectively stop all damage to the skin. It's like having 10 inches of steel armor for bullet proofing instead of 1. A bullet isn't getting through either so they are equally effective.
aero_code 19 hours ago [-]
But sunscreen doesn't stop all damage to skin. I spent weekdays working inside on a computer, then sometimes spent summer weekends outside in the sun. I get sunburned easily, sometimes in like 10 minutes of direct sun. You wouldn't try to deny a light sunburn isn't skin damage? SPF 50 suncreen, blocking 98% of sun, extends the 10 minutes by 50x to 8.3 hours, but that is still not that great. I can still exceed that in two days. And I don't see why having light skin and wanting to spend the weekend outside would be unusual. Blocking 99% of UV and doubling the time over 98% would help quite a bit.
treis 18 hours ago [-]
That isn't how sunscreen works. If you put SPF 50 on and spend 8 hours in the sun you're coming back a lobster.
Say you burn in 5 minutes. SPF 50 means you burn in 250 minutes. But it's more like 100% protection for 245 minutes and then 0% for the last 5. It's not a steady cooking at 2.5% intensity.
rcxdude 8 hours ago [-]
Got any source for that? Everything I can find (and the intuitive explanation of it) points to the opposite: SPF is how much of the UV blocks, not at all how long the sunscreen stays on your skin (which varies wildly with what you're doing).
That's my entire point. The way they generate SPF measures how much of the sun it blocks in the lab shortly after it's applied. That one blocks 97.5% and another 98% is meaningless for the real world.
istjohn 19 hours ago [-]
Your metaphor is not at all apt. No bullet is going through ten inches of steel. Some UV radiation will penetrate the strongest sunscreen.
actuallyalys 7 hours ago [-]
It seems situational. Someone with your skin at noon absolutely benefits from a higher SPF. Someone with even slightly darker skin [0] going out a few hours before sunset might still want to wear sunscreen, especially if they’re going to be in direct sun the whole time, but a high SPF doesn’t seem very critical.
That being said, I am not a dermatologist, and it’s easy to underapply sunscreen so erring on the side of higher SPFs probably makes sense.
No, it seems clear that it is 0.4% more effective. It all depends on what you use as your base case hypothetical.
gblargg 22 hours ago [-]
I had to look it up. SPF is a reciprocal value 1/SPF=amount of sun that gets through. So 1/50 allows 2% of UV through, and the difference between say SPF 2 and 3 is enormous but 49 and 50 tiny.
miladyincontrol 19 hours ago [-]
Aside from what others have said, it does matter because few people apply the proper amount. If you're applying only 1/3 the "proper" amount of a 60 SPF product you still at least get 20 SPF of protection as it scales rather linearly.
And as someone paler than most makeup brands go, for many of us it absolutely does make a difference even when using the proper amount.
I ride or die LRP uvmune 400, few protect as well as it does.
XorNot 23 hours ago [-]
The point is you sell a product, it better be what it claims to be.
I didn't buy SPF30, I bought SPF50. When I made that choice, I expect at least SPF50.
But you are also dismissing a 25% difference in total transmitted UV - and that's before degradation in the field due to usage and practical concerns, which is why we want SPF50 in the first place.
23 hours ago [-]
theteapot 23 hours ago [-]
SPF isn't bullshit, it just measure one specific thing, not everything. AFAIK most sunscreens also list expected hours of protection and whether they are water resistant or not.
evolve2k 24 hours ago [-]
Unhelpful, I’d say avoid these brands until they get their house in order; this is a major scandal and the market should be punishing those who clearly did not cover their basic duty of care when selling products that claimed to offer specific SPF sun protection.
While true there could be a process issue, it’s very clearly incumbent on manufacturers to correctly prepare and test their product before sending it on to consumers and representing that the product has properties that it may indeed not have.
Negligence law covers this well.
It’s why you don’t get poisoned too often when you buy food products not prepared in your own home.
summarity 24 hours ago [-]
Exactly, especially since some brands initially pushed back only to then recall products or fire their labs. Lies all the way to the bottom
I guess it would also depends on where in the world you are as well. You burn easier closer to the equator (hence different melanin expression).
inkyoto 20 hours ago [-]
For one, it is a US study. In Australia, anyone will get sunburnt, and moreso in summer. Going to an Australian beach at the height of the summer is akin to getting irradiated with a UV gun of epic proportions.
The article also notes the difference between the sunburn incidence rate vs sunburn severity rate:
Those who identified as Hispanic and Black with darker skin tones (FSP V-VI) had more severe and painful sunburns compared to those who identified as White. In contrast, those who identified as Hispanic with a similar average skin tone to those who identified as Asian (FSP I-IV), reported higher sunburn incidence rates.
Awareness levels also vary across different ethnic groups. From the linked study:
68% Relative to those who identified as White, Hispanics were 68% more likely to describe sunscreen as important for health, but 2.5 times less confident in their knowledge about skin cancer.
Those who identified as Asian were 70% and Hispanic 79% more likely to believe the sun’s rays are the most important cause of skin cancer relative to those who identified as White.
24x Those who identified as Hispanic were 24 times more likely than Whites to say it is not worth getting sunburned for a tan.
ikr678 22 hours ago [-]
Also, it's not specific brands, its specific product lines. Some of these brands make performant sunscreen, and then will have a variant (say, 'sport waterproof 12hr' or 'spray on') which underperforms.
willsmith72 1 days ago [-]
It's impossible, essentially every accessible brand has some products test way below advertised
On the other hand, if your product said it was 50 and it tested 30, the practical difference isn't actually that big. Our parents did ok with spf5
geerlingguy 24 hours ago [-]
Heh, we didn't always wear sunscreen until I was in my teens... my skin does not thank me.
We do SPF50 or 100 on the kids (and us, of course). I think besides shady products, a lot of them are too hard to apply evenly, so you either spend 10 minutes trying to get it to spread, or you look funny with white smears here and there.
OneMorePerson 23 hours ago [-]
If you look into advice from non-manufacturers (some other groups who are a bit less biased) it's widely recommended to max out at SPF 30, because any higher means sunscreen is harder to re-apply (meaning psychologically you are likely to not re-apply as often as needed) and also because it really doesn't make a difference unless you are ultra sensitive and have some kind of skin condition.
tehjoker 20 hours ago [-]
Using higher SPF can help cover for thin application
mvdtnz 20 hours ago [-]
> it's widely recommended to max out at SPF 30,
You're going to have to bring some receipts for a claim like that. I have never seen such a recommendation, ever.
OneMorePerson 2 hours ago [-]
I can't remember where I first heard it but here's a few links.
Potentially I slightly overstated, what I intended to say was "there's clear reasons why SPF 30 would be preferable in many/most cases". If you are a pale white person who is hiking through the Sahara with no hat SPF 50 might be the way to go.
stevage 24 hours ago [-]
Don't know where your parents grew up or how ok they are. In Australia, many boomers have skin cancer, and that was before the hole in the ozone layer made things much worse.
OneMorePerson 23 hours ago [-]
Did they actually apply sunscreen? Or is there a big divide between people who at least tried (something like SPF 15) vs those that just didn't wear any?
Reason077 23 hours ago [-]
Nivea 50+ is my go-to sunscreen brand because it’s reliable, in my experience, and available pretty much anywhere in the world where I look for it. I burn pretty easily and it certainly works better than a lot of other random brands.
La Roche-Posay also very good, but expensive and harder to find.
renewiltord 23 hours ago [-]
Why would I avoid Nivea? Their 50 SPF tested as 56.
apwell23 24 hours ago [-]
can't belive there a sunscreen brand called cancer council
shitloadofbooks 23 hours ago [-]
Cancer Council is an Australian charity which raises funds for cancer research and support.
Buying their products supports them (and you would expect they hold themselves to even higher standards for the effectiveness of their product than a random company).
mryall 23 hours ago [-]
It’s an Australian charity group that does a lot of cancer prevention and education activities. One part of it is having stores and lines of sun protection products like hats, swimming shirts and sunscreen.
Yeah because skin cancer is a big fucking deal here mate. No joke if you're light skinned and go outside in the sun for a few hours with no sun protection you will get fucked up
stevage 24 hours ago [-]
Trying to figure out whether this action was triggered by the investigation by the Australian magazine Choice, which found most Australian sunscreens were much worse than claimed.
There's just this weird statement at the bottom of the page:
> The Consumer Council reserves all its right (including copyright) in respect of CHOICE magazine and Online CHOICE
johnneville 23 hours ago [-]
I think it's a coincidence. The Hong Kong CHOICE article is from 2020. The Australian CHOICE article is from 2025. I don't think there's any connection between the two publications other than the name and their general purpose.
Best to wear a hat with a brim and a long sleeved shirt.
Salgat 24 hours ago [-]
I bought a uv a+b meter and unfortunately shade, while helping a lot, is still way above levels that cause sun damage. The sun jacket though is a very good idea. I use one myself.
adamors 1 days ago [-]
Agreed, I’ve picked up an UPF 50+ shirt that can be used for swimming as well, I’m much more comfortable on the beach now. Dries as fast as any swimwear.
umeshunni 16 hours ago [-]
How do you know that the shirt shirt is correct SPF?
jerlam 16 hours ago [-]
Sun protective clothing is measured and given a UPF rating. SPF ratings are only for sunscreens.
jcims 24 hours ago [-]
I started wearing a cheap sombrero while doing yard work in the summer. It's a game changer. Going to Mexico this winter and hoping to find some nice ones to bring home.
brewdad 23 hours ago [-]
This summer I started following the lead of my tour guides in Mexico and the local day laborers. Both favor spandex arm sleeves that are remarkably breathable and can be put on or removed as conditions change. They have been great for hiking and kayaking, though the maker warns that they aren't as effective if they get fully wet.
humanlion87 22 hours ago [-]
I live in North America and use full sleeve sun hoodies for hiking in the summer. I sweat a lot but these hoodies are breathable enough that it doesn't bother me. So I need to apply sun screen only on my palms and fingers. And paired with a wide brim hat, I can get away with applying sunscreen only to the lower part of my face and neck.
skeeter2020 8 hours ago [-]
Applying sunscreen to your palms? And if your still applying it to "the lower part of my face and neck" what's the savings from doing the upper at the same time (plus this will get your palms & fingers too, if that's your jam)?
dsego 24 hours ago [-]
Is mineral sunscreen a safer bet than regular sunscreen, since it physical blocks the sunrays?
no. there might be some mild advantages (less environmental damage? also protection from excessive IR+VIS?) But in the published testdata listed above there are mineral sunscreens promising 50 SPF and not getting there either. Combined with the often more difficult application you might end up with even less protection. So buyer beware (or wear hats and shirts).
24 hours ago [-]
stevage 24 hours ago [-]
No. I saw a good video on this recently. Essentially there is no fundamental difference in efficacy between different active ingredients.
cj 21 hours ago [-]
Much worse, if for no other reason than applying it and having it leave behind a white residue on your skin makes people much less likely to reapply once it rubs off.
I always pack my own sunscreen when traveling to islands that ban normal sunscreen. I feel bad if it actually damages the reefs, but reef safe sunscreen is terrible at protecting from the sun.
NegativeK 21 hours ago [-]
That's not okay. If reef safe sunscreen isn't sufficient for what you need, then you should find a different way to protect yourself than one that damages reefs.
loeg 20 hours ago [-]
The sunscreen x reef safety research isn't very good, and the marketing is well out in front of the science on this issue.
cj 20 hours ago [-]
It’s okay. I’m not actually spending time in the ocean. More of a “sit by the pool and explore the island” kind of guy!
loeg 20 hours ago [-]
Reef-safe sunscreen is bullshit anyway. The marketing is well out in front of the science. There's no real evidence it's harmful to reefs and there's no real evidence (or reason to believe) the other kinds of sunscreen aren't just as harmful to reefs. It's just marketing jibber jabber.
It's not "safer" from the sun, but could be safer from side effects of the chemicals used in typical sunscreen.
The FDA listed 12 typical sunscreen ingredients, such as avobenzone, octinoxate, and oxybenzone, as not currently having sufficient data to be recognized as safe and effective. They're absorbed into the bloodstream and studies have found them to persist for weeks.
Based on current data, the FDA categorized only two sunscreen ingredients as safe and effective, the mineral-based ones: zinc oxide and titanium dioxide, which don't permeate the skin much.
"Although the protective action of sunscreen products takes place on the surface of the skin, there is new evidence that at least some sunscreen active ingredients are absorbed through the skin and enter the body. This makes it important for FDA to determine whether, and to what extent, exposure to certain sunscreen ingredients may be associated with any safety risks. FDA has requested data from industry to confirm the safety of sunscreen active ingredients."[0]
Maybe? But it's probably easier to wipe or sweat off. I'm also a huge fan of mechanical sun protection (hats, sun shirts, rash guards, etc etc)
loeg 24 hours ago [-]
No.
inkyoto 19 hours ago [-]
Today's sunscreens are complex cocktails of different molecules. The most advanced and efficient ones use both, inorganic and organic, chemicals, e.g.:
Zinc oxide – for the broadest UV-A and UV-B absorption.
Titanium dioxide – for UV-A absorption.
Diethylamino hydroxybenzoyl hexyl benzoate (DHHB) – for UV-A absorption.
Octyl methoxycinnamate – for UV-B absorption.
Octocrylene – for short-wave UV-A and UV-B absorption.
Bemotrizinol – a broad-spectrum UV absorber, absorbing both UV-A and UV-B rays.
Octyl triazone (ethylhexyl triazone) – for UV-B absorption.
The actual composition varies, but it is going to have a combination of multiple compounds due to them having different absorption peaks, e.g. bemotrizinol has two absorption peaks, 310 and 340 nm, and DHHB peaks out at 354 nm.. The compounds also have synergistic effects when blended with one another, so the sunscreen design is a science on its own.
globular-toast 15 hours ago [-]
Yep. I hate wearing suncream. Hate the feeling of it and the smell. I often spend all day in the sun on long walks so I do as you say: cover up. I've recently got a peaked cap with a neck guard to try as well.
If you're a man especially you might as well just start wearing a hat because the thick hair probably won't last forever!
One tip I got from South Africa is when you find shade take your hat off as you cool down a lot through your head.
KolibriFly 11 hours ago [-]
Bonus: they don't expire
andrepd 24 hours ago [-]
Should we go swimming with a hat? :)
I'm white enough that 5 mins of near midday sun gives me sunburns. In summer spf >30 is a must. Even day to day some sunscreen on my face and neck is a must.
stephen_g 23 hours ago [-]
Probably says a lot about where people live. The OP’s advice is a recipe for still getting skin cancer here (we get a max UV index at or over 11 every day for months where I live) - sunscreen is unavoidable to stay safe for a lot of the country because even little bits of incidental exposure add up. Whereas if you’re in the northern parts of US/Europe it’s probably OK.
globular-toast 15 hours ago [-]
I thought it was only sunburn that was dangerous rather than incidental exposure. This has been the advice for years now, has it changed?
rkomorn 15 hours ago [-]
"it's only sunburn that's dangerous" stopped being the advice years ago, probably because people (younger dumb me included) were like "I only get sunburn once a year and after that I don't need sunscreen!"
stevage 24 hours ago [-]
Yes. I do! If I'm mucking around in the water at the beach I'm in long sleeve top, hat and sunglasses.
cortesoft 21 hours ago [-]
That's wading, not swimming
brewdad 23 hours ago [-]
I opt for sunscreen on my head and legs. Coverage for the rest of my body. I also wear a hat when feasible.
WalterBright 22 hours ago [-]
> midday sun
In more equatorial regions I'd stay out of the sun from 9-3.
globular-toast 15 hours ago [-]
Mad dogs and Englishmen go out in the midday sun...
It's still so true today. In England we savour the sun. In hot places they are wary of it.
matsemann 24 hours ago [-]
Lots of sunscreen brands should be avoided as they don't meet the advertised SPF.
Lots of sunscreen brands should also be avoided as they contain allergy inducing-, hormone altering- or environment damaging- ingredients.
Not easy making a good choice.
bboygravity 23 hours ago [-]
Got recommendations? Here in Europe the formulations seem to be almost all the same (which I'm assuming means that they're all very bad for you).
Very hard to find any mineral sunscreens here. Decathlon has one in the most terrible packaging: a roller which means it's close to impossible to get the stuff out.
I have vitiligo and basically no skin pigment above my neck line - this product is excellent, reasonably priced, and ethical
mrspuratic 12 hours ago [-]
Seconded. Been using Altruist for a few years now. Hybrid mineral (TiO2)/chemical. Unscented, light fluid, slight white cast once dry (Caucasian/north European skin type).
Also I don't get eye irritation as with many other types after an hour or two. Available easily online if you can't find it locally.
flexagoon 23 hours ago [-]
There's no reason to avoid chemical sunscreens unless you have an individual allergy to some of the components. The concerns about them being "carcinogenic" or "disrupting hormones" or "killing the environment" is fearmongering and marketing bullshit pushed by "clean beauty" companies.
Endocrine disruption: Oxybenzone (BP-3) and related benzophenone-type UV filters have demonstrated endocrine-disrupting properties in vitro and in animal studies, with some human data suggesting possible hormonal alterations and increased risk of uterine fibroids and endometriosis.[6-7] However, most human plasma concentrations are much lower than those producing effects in bioassays, and current evidence suggests low intrinsic biological activity and risk of toxicity for most organic UV filters except oxybenzone.[8-9]
Contamination: Benzene, toluene, and styrene have been found in a large proportion of sunscreen products, likely due to manufacturing processes rather than the UV filters themselves. Benzene contamination is a particular concern due to its established carcinogenicity.[1]
reducesuffering 22 hours ago [-]
The FDA listed 12 typical sunscreen ingredients, such as avobenzone, octinoxate, and oxybenzone, as not currently having sufficient data to be recognized as safe and effective. They're absorbed into the bloodstream and studies have found them to persist for weeks
Based on current data, the FDA categorized only two sunscreen ingredients as safe and effective, the mineral-based ones: zinc oxide and titanium dioxide, which don't permeate the skin much.
We have millions and millions of people using these substances on their skin for dozens of years. If they were remotely harmful, it would be pretty obvious.
andrepd 24 hours ago [-]
The regulator should get rid of those + impose fines, not the user. It's unreasonable to hope the consumer deals with this themselves, that's what the regulator is there for.
cogman10 23 hours ago [-]
Agreed. The free market solutions to this problem are completely ineffectual. Nobody is paying a 3rd party to test sunscreen and even if they were, the results wouldn't likely be public and/or would be buried under the giant weight of mommy influencer blogs telling you to use apple cider vinegar instead of sunscreen.
The only way to solve the problem of bad actors in a consumer products market is government regulations, testing, and fines/dissolution of the bad actors.
ekianjo 22 hours ago [-]
Not the only way. There used to be 3rd parties defending consumers by testing products back in the days, and publishing their results, not sure if those still exist today. The problem with mass manufactured products is that you need to keep testing them. Changes in formulation are a thing so you need to continuously sample and test them.
The problem with government being involved is that this opens the door for easy corruption (haven't we seen this before)
cogman10 21 hours ago [-]
> There used to be 3rd parties defending consumers by testing products back in the days
And what happened to them? Why did they go away?
It wasn't due to the government outlawing them.
> The problem with government being involved is that this opens the door for easy corruption
And 3rd party reviewers aren't easily corrupted? There are at least some mechanisms to address government corruption in a democracy (elections). What mechanism can be employed against a 3rd party reviewer that simply lies about a product it's reviewing?
That's the reason this has to be government ran. Corruption happens regardless of who's doing it, government at very least faces some accountability.
cortesoft 21 hours ago [-]
The question is always, where do those third parties get the money to do their research?
If you are against the government funding them, where do you suggest they get their money?
A company like Consumer Reports was funded by subscriptions to their reports, but they don't make enough from that anymore to test enough products.
Another issue is the sheer number of companies producing products these days. It would be very expensive to test all the products sold.
ekianjo 15 hours ago [-]
> The question is always, where do those third parties get the money to do their research?
in the 80s they were selling magazines.
FridgeSeal 22 hours ago [-]
> There used to be 3rd parties defending consumers by testing products back in the days, and publishing their results, not sure if those still exist today.
CHOICE in Australia does this, and was the group that did the efficacy tests on a bunch of sunscreens sold in Australia where they found that many were massively underperforming.
KolibriFly 11 hours ago [-]
You basically need to do homework before going to the beach
aradox66 5 hours ago [-]
You want to always use mineral zinc and to learn for your own body and the sun conditions of your environment whether and how often you need to reapply. You're not going to be doing that math based on SPF anyways.
jihadjihad 21 hours ago [-]
Supergoop all the way. Best stuff I’ve found and it doesn’t feel or look like I’ve just smeared my body with grease or chalk.
miladyincontrol 19 hours ago [-]
On an aside, most people def dont even use the right amount for labelled SPF values even when the sunscreens do work as intended.
I'm in the SF Bay Area. I spend a lot of time outside. I haven't worn sunscreen since I was a child.
40 yrs old now. Gfs and strangers comment about how good my skin is. No products ever, no sun screen is all I can say.
Obviously if you're in a cave all spring and get dropped off in Cabo in July, put on some sunscreen.
But if you can get constant exposure to work your skin up to it, you really don't sunburn.
bob1029 10 hours ago [-]
I have found a strong correlation between what I eat and how much my skin reacts to the sun. I've been out as long as 2 hours in the Texas summer (zero sunscreen) without any kind of ill effect afterward. This is the best case though. If my diet has recently been trash, I can barely go 20 minutes before I start to feel it. I think consuming high concentrations of seed oil is a big part of what causes it. I don't know the exact mechanics of it biologically, but I do know that if I eat that whole bag of Sun Chips I'll effectively become a vampire for the next 3 days.
MaKey 15 hours ago [-]
However, your risk of getting skin cancer still increases with exposure even if you don't burn.
xutopia 12 hours ago [-]
Evidence to the contrary exists through. That our body is an antifragile system. If you apply the right stimulus it gets better at fending off for itself. We know from ample studies that darker skin gets less skin cancer. We know gradual exposure makes skin darker. Why is it so hard to fathom that maybe it’s a good mechanism for making our body more capable? Is it because a cute song tells us to always wear sunscreen?
jokethrowaway 3 hours ago [-]
It would be nice to compare skin cancer rates before and after sunscreen arrived on the market
Today it's hard to get any sunscreen which is not a complete sunblocker so people want to get _some_ sunlight just avoid some sunscreen altogether.
Broken_Hippo 12 hours ago [-]
Because those are usually sold as tanning lotions instead of sunscreens. A little bit of protection so that folks don't burn as easily.
WorkerBee28474 22 hours ago [-]
Yeah, I hardly see anything under SPF15, which lets 1/15th of the light in (6.7%). I'd be interested in using an SPF 5 or so (1/5th or 20% of sunlight gets in).
Broken_Hippo 12 hours ago [-]
Those are usually sold as tanning lotions instead of sunscreens.
singularity2001 5 hours ago [-]
But these usually contain chemicals that burn your skin to make them look brown? Like the oval office orangutan clown?
jtickle 21 hours ago [-]
I know ultraviolet CCD sensors exist and are probably expensive, specialty scientific equipment. I've kinda had this hope that one smartphone manufacturer (any of the big ones) would go to the trouble of including a UV camera and drive costs down. On the one hand you can market a unique and fun photography tool that lets you see the world in a different way. And then in the more serious part of the commercial, you show friends at the beach taking UV pictures of each other after applying sunscreen and one person says "You missed a spot right there, mate."
Plus I'd imagine you could immediately tell if your sunblock were BS and do an even better job of holding these folks accountable. You and buddy of similar skin tone both buy SPF 50 and apply it, take pictures, and see that one of you is not as well protected.
socalgal2 20 hours ago [-]
I've wanted this!
Also, cheap chinese UV camera tablets ($25) that just showed you yourself through a UV camera. This seems more likely to happen than getting Apple to add a UV camera. They already sell cheap LCD photo frames. I'm sure they can make them cheap. A few influencers and suddenly everyone would get one for checking their UV protection.
fragmede 20 hours ago [-]
Camera sensors are already sensitive to UV, and in fact, have a UV filter that, if you remove it, will let any camera see UV.
1. Only 12% of US adults have vitamin D levels in the recommended range [0] and while vitamin D levels are strongly associated with nearly every marker of health, supplementing vitamin D does not improve health [3]
2. Vitamin D levels are strongly correlated with overall health, quality of life, and decreased mortality (incl. cancer mortality, CVD mortality, et cetera [5.]) This association is quite robust. "Lower 25(OH)D concentrations were also associated with increased all-cause mortality among participants who reported being in good to excellent health" [5] When you adjust for age/sex/race/smoking, a lot of health indicators (such as BMI!) fall apart; this is why we now consider waist to hip ratios as better predictors [6, 7.] Vitamin D levels, however, remain a robust predictor of health, even adjusted for age/sex/race/health factors [5.]
3. Annual deaths from melanoma, 8430; median US age at death from melanoma, 72 [1] (just a few years off the median US age at death from any cause!)
4. Age-adjusted melanoma deaths by race per 100k: flat since the 80s [2.] "By race" is important here because different racial groups have wildly differing melanoma risk, and the racial makeup of the US is not constant with time.
In other words, in terms of risk-reward, there is no question: the median person should trade off even a large increase in melanoma death risk for a small increase in vitamin D levels. Can you, or is that a false argument?
Bit of background: "Terrestrial ultraviolet radiation (UVR) is the main determinant of vitamin D status. Stratospheric ozone absorbs all solar UVC (100–280 nm), attenuates UVB (280–315 nm) but not UVA (315–400 nm). The sun's height determines the UVR pathlength through the ozone layer. Thus, UVB intensity (irradiance) depends mainly on latitude, season and time of day. The ratio of UVA to UVB also varies with the sun's height because of the differential effect of the ozone layer. Thus, terrestrial UVR typically contains ≤ 5% UVB (~295–315 nm) and ≥ 95% UVA. The minor UVB component is responsible for vitamin D synthesis" [4]
The steelman case for sunscreen is: you have a ~0.2% chance of dying a few years early from melanoma. Rigid sunscreen use will reduce some, not all, of that risk. We have not yet had the time to see exactly how much that risk is reduced (people only started using sunscreen en masse in the 90s) and sunscreen is usually not applied as directed [4.] Although existing studies are poor quality and do not take into account the many factors in vitamin D production and sun exposure (type of light, body surface area exposed, life of vitamin D in the body, etc) some of them - funded by industry - claim that you can still, somehow, produce sufficient vitamin D.
The anti case: the majority of sunscreen sold has been shown to be toxic; decades of sunscreen use has not had any appreciable impact on melanoma death rates; all improvements in mortality are associated with improved treatment, not sunscreen. The establishment says the reason mortality is not down is that everyone uses sunscreen incorrectly; imagine if condoms had no effect on birth rates, or airbags didn't decrease mortality because "you're using them wrong"... it is an outrageous defense. Sunscreen is designed to block the overwhelming majority of UVB, which is responsible for vitamin D synthesis; this would _trivially_ cause less vitamin D synthesis. The contra argument, that your body can still make sufficient vitamin D despite blocking the main pathway for its synthesis, is designed and funded nearly entirely by industry.
I’m sending mine back for a refund. Maybe a lawsuit.
mensetmanusman 22 hours ago [-]
It is hard to make transparnet materials that are colorless block a lot of UV. Not surprised most fail the test.
gtowey 22 hours ago [-]
I don't think anyone is going to argue that it's hard to do that, but I think overstating their efficacy is what we should be worried about.
elchief 23 hours ago [-]
I've heard the zinc kind is less likely to leach bad chemicals into your blood stream. is this true?
OneMorePerson 23 hours ago [-]
I don't know if its been conclusively proven yet, but the more natural zinc sunscreens (not all zinc sunscreens are that natural, some of it is marketing) have mostly zinc (and a bit of some other stuff of course), while some of the chemical ones have an impressively long list of random chemicals. On that basis I personally believe a zinc sunscreen is less likely to have future unknown side effects.
azinman2 23 hours ago [-]
Avoid nano zinc and yes, it sits on the surface. The chemical ones absorb into your skin.
loeg 20 hours ago [-]
It's all very safe; certainly safer than sunburns.
Tepix 24 hours ago [-]
I've found that wearing SPF 50 is way too much for me, even in the tropics. SPF20 and being careful and seeking shade after a while is sufficient. Remember SPF 20 means you can stay in the sun 20 times longer than normal!
I only use SPF 50 for my nose.
LeoPanthera 22 hours ago [-]
> Remember SPF 20 means you can stay in the sun 20 times longer than normal!
No it doesn't. It means you will receive 1/20th of the UV. That is not the same.
It's very heavy and uncomfortable. Induces more sweat.
loeg 20 hours ago [-]
That is going to be a brand and product specific issue; not a general quality of SPF 50 sunscreens.
skeeter2020 8 hours ago [-]
that seems more likely the brand or product; some are thicker all the way across the SPF offerring; others not so much.
DrSAR 23 hours ago [-]
resulting in an unhealthy, pale appearance /s
globular-toast 15 hours ago [-]
A skin tone coming from lots of vegetables like carrots and tomatoes has been shown to look more attractive than one from lots of sun. The "pasty skin" is because you actually are just unhealthy and/or malnourished. Nothing to do with the sun.
There are brands like Neutrogena that have passing & failing products, suggesting a process issue.
mgh2 1 days ago [-]
Not isolated case, also US brands
> An investigation by the Australian Broadcasting Corporation found that a single US-based laboratory had certified at least half of the products that had failed Choice's testing, and that this facility routinely recorded high test results.
It's a worldwide problem, first reported in Australia.
bee_rider 23 hours ago [-]
Sunscreen is probably better than nothing.
But, it seems very prone to inducing overconfidence… It has to be reapplied more than you expect. You need more of it than you expect. It is less waterproof than you expect.
I mean, to preemptively retreat to the obviously defensible position: I’m not saying it is negative, but it is better to just cover up and avoid staying in the sun for too long, right?
mgh2 23 hours ago [-]
Yeah better than none, balance outdoor benefits (exercise, myopia, vitamin C, overall health) which far outweight staying indoors (~80% of your time).
Track UV levels < 2 (avoid 10am-4pm), wear at least 50 SPF sunscreen (to compensate for lower tested numbers as in this article), wear a watch to time reapplication every 1.5 hrs vs. recommended 2hrs (to be safe)
ninetyninenine 20 hours ago [-]
Pretty sure it’s the exact same story in the US. Nothing is regulated and nothing can fully be trusted.
It's yet another reminder that consumers need third-party lab validation and transparent labeling, especially for health-related products
23 hours ago [-]
xyzelement 23 hours ago [-]
I suspect that in X years we'll learn that sun is not bad for us while the chemicals we apply to our skin are problematic.
What I find personally works is to build up a base tan. I probably did a little sunscreen application back in May but just spend a lot of time outdoors so by the time it got really sunny I had enough tan that I didn't need sunblock to not get burnt.
Even my wife who is very light and "can't tan" - I saw a picture of her when she was a lifeguard in highschool - she's bronze and probably wouldn't need sunblock either.
Obviously people make money when you buy sunscreen so the message that you don't need it doesn't get a lot of amplification.
As always, the issue is that people want things to be simple, when the reality is in nuances.
_the poison is in the dose_.
People spending hours everyday under direct sunlight are at risk.
And so does people putting sunscreen everyday, even when they don't go outside but they seat next to a window.
The amount of sunscreen you need depends on your genetics, your history with sun exposure, the place you live and the amount of time you spend under direct sunlight.
There is no "sunscreen is a scam" and "life is not sustainable without sunscreen".
skeeter2020 8 hours ago [-]
it feels like you're setting up a false eqivalancy; I didn't read anything here about people putting on sunscreen religiously who never go outside, nor you'll die without sunscreen. It seemed to be clearly seperated themes:
1. people are mad about the original topic - false claims of effacicy, when sun exposure can be very damaging and cause cancer.
2. alternatives to these sunscreens, including mechanical like hats and clothing; questions about mineral alternatives
3. wild theories like this one, where a base tan or early season burn somehow protects you. These are wrong and should be called out.
xyzelement 7 hours ago [-]
How do you know? I would default to the natural approach of yes sure keep in the shade but also man people evolved / were created spending a lot of time outdoors.
loeg 20 hours ago [-]
Nah; sunburn and skin cancer are very bad.
seabrookmx 19 hours ago [-]
The message doesn't get a lot of amplification because it's not backed by science. Just because you don't turn red or scab doesn't mean you aren't increasing your risk of skin cancer even with a "base tan."
xyzelement 18 hours ago [-]
Humana lived without sunblock for millennia, often in sunnier places than you and I.
wao0uuno 14 hours ago [-]
And they rarely lived for more than 30 years.
sethammons 12 hours ago [-]
> Data is lacking, but computer models provide the estimate. If a person survived to age 20, they could expect to live around 30 years more
The average life expectancy was dragged down by high infant and adolescent mortality.
If this is a honest perspective on sunscreen I can't imagine what they potentially believe about vaccines...
skeeter2020 8 hours ago [-]
You're free to hold these "beliefs" but they are patently and completely incorrect. The "base tan" theory was debunked decades ago.
"What I find personally works..." is ridiculous when it comes to sun damage and skin cancer, unless you are a wild outlier of humanity or a mutant. The simple answer is it takes some (but not much!) time to see the damage and you're likely to encounter it sooner or later.
>> Obviously people make money when you buy sunscreen so the message that you don't need it doesn't get a lot of amplification.
Yes, a shadow-global-conspiracy promoted by the mega-national sunscreen cabal. That's the most likely answer.
If a sunscreen comes with a high SPF rating and performs close enough in random testing (which is hard to replicate) then I wouldn’t have any concerns in the real world.
The body of the article has some more details about how the number of majorly deficient brands was much smaller, but that makes for less clickbaity headlines:
> The measured sunscreen efficacy of 4 models were below SPF15, of which 2 were sunscreen products with very high protection i.e. labelled with SPF50+
Knowing which 2 brands were labeled SPF 50 but performed below 15 would have been helpful, but the article is not helpful.
I do have sympathy for those with dark(er, which is basically everyone) skin who may not be able to directly tell the efficacy.
My concern is that mineral sunscreens are difficult to apply and leave a film on the skin (which is the entire point, I guess?); i hate that feeling, so I use chemical sunscreens. I'd bet that some of them have very nasty long-term side effects. So in the end i almost always go with trying to cover my skin with clothes/shade/whatever if at all possible.
Endocrine disruption: Oxybenzone (BP-3) and related benzophenone-type UV filters have demonstrated endocrine-disrupting properties in vitro and in animal studies, with some human data suggesting possible hormonal alterations and increased risk of uterine fibroids and endometriosis.[6-7] However, most human plasma concentrations are much lower than those producing effects in bioassays, and current evidence suggests low intrinsic biological activity and risk of toxicity for most organic UV filters except oxybenzone.[8-9]
Contamination: Benzene, toluene, and styrene have been found in a large proportion of sunscreen products, likely due to manufacturing processes rather than the UV filters themselves. Benzene contamination is a particular concern due to its established carcinogenicity.[1]
They could also have a lot of short exposures, like someone who is only outside for 5-10 minutes at a time but 2-3 times per hour every day, as was the case with one of my early jobs that involved walking between buildings a lot.
A common mistake to make is believing that if you're not burning, you're not accumulating damage.
Why?
Chemical sunscreen that avoids this is designed to sink into the skin like lotion. So there's something literally in your skin blocking uv or it won't work very well. I'd say this increases the odds of circulating something carcinogenic or otherwise toxic into your bloodstream.
If you burn in 15 minutes under UV index 6 on the worst days that I've seen you'd burn in 5 minutes. So a SPF of 60 is as useful here like an SPF of 20 is wherever you live.
Summer time it sits at 13+ at noon on a clear day.
https://www.bom.gov.au/climate/maps/averages/uv-index/?perio...
If someone can make a true SPF 200 economically, it's valid for consumers to prefer that to a true SPF 100 or true SPF 50.
I don't care for "close enough" brinksmanship.
The same is true for speed limits but y'all aren't ready for that
[1] Might be rumor but I heard that car speedometers often read high because there's a big penalty if they read low by even 1 MPH
That said, sunscreen is hard to apply precisely. One interesting emerging option is personal "makeup mirrors" that use a UV camera.
Have had a GPS speedo on the dash for a good dozen cars through the years and never seen more than a few mph off on a flat surface. That's something I actually noticed and looked for, for some reason. A few mph over speed is fairly common, but we're talking 1-2% at most. (confirmed with Tesla Model 3, Corolla, Fusion, Prius, Elantra, Mirage, etc etc).
A fixed 2mph difference at 20mph is 10% so imho they're at least _technically correct_.
10% at 30 mph is 3 mph
I saw this with various European cars.
My experience is that it seems to be a fixed percentage rather than a fixed amount i.e. the absolute difference increases with speed.
[0] https://en.m.wikipedia.org/wiki/Stiftung_Warentest
[1] https://www.test.de/Test-Sonnencreme-und-Sonnenspray-fuer-Er...
EDIT: to clarify, of the three only labdoor does independent testing
...
oh, excuse me. "No siree, never would a for-profit company put out false products, nope, not ever"
The core operating principle of sunscreens is that, the more your skin is covered in opaque inorganic metal oxides, the less it is exposed to harmful UV lights. There would be a lot of little tricks and additional paints to make it less irritating and less crazy looking to wear, but the point is, sunscreens fundamentally rely on opacity.
I think just knowing that lets one have a lot more of intuition about sunscreens than reading bunch of sales brochures on SPF or PA figures or wondering if the fancy ones are worth it.
Those are mineral based sunscreens. Most popular sunscreens (including most from the study) in the US have neither. Usually it’s only the super-reef-safe and baby targeted ones that do.
[1] https://news.ycombinator.com/item?id=45145624
[2] https://labmuffin.com/purito-sunscreen-and-all-about-spf-tes...
[3] https://www.abc.net.au/news/2025-07-04/questions-over-lab-th...
> Ultra Violette announced it was removing the Lean Screen product from shelves. Across eight different tests, the sunscreen returned SPF data of 4, 10, 21, 26, 33, 60, 61, and 64.
[0] https://www.choice.com.au/health-and-body/beauty-and-persona...
For reference, the results were:
> It's also possible that there's a process issue at the manufacturers, and the quality of different lots can varyIf you read the article, that variable test result was provided by Ultra Violette themselves. Choice tested it three times with three different independent testers and got results of 4,5,5. It's possible Ultra Violette is just trying to muddy the waters here.
[1] https://www.choice.com.au/health-and-body/beauty-and-persona...
Anything higher than 30 or even 15 isn't really meaningful. At that point how long it lasts and how resistant it is to water is far more important.
You're right about how long it lasts also being an important factor. UV-A protection is also another very important factor. But as someone with pale skin even by Scottish standards, the difference between SPF 40 and SPF 50 around noon is significant, even through I consistently re-apply every hour. I won't get burnt, but I'll end up with more sun damage - and that lasts until late autumn.
I disagree. Both effectively stop all damage to the skin. It's like having 10 inches of steel armor for bullet proofing instead of 1. A bullet isn't getting through either so they are equally effective.
Say you burn in 5 minutes. SPF 50 means you burn in 250 minutes. But it's more like 100% protection for 245 minutes and then 0% for the last 5. It's not a steady cooking at 2.5% intensity.
That's my entire point. The way they generate SPF measures how much of the sun it blocks in the lab shortly after it's applied. That one blocks 97.5% and another 98% is meaningless for the real world.
That being said, I am not a dermatologist, and it’s easy to underapply sunscreen so erring on the side of higher SPFs probably makes sense.
[0]: Note that even people with a lot of melanin still need sunscreen: https://www.pbs.org/newshour/amp/health/why-its-important-ev...
And as someone paler than most makeup brands go, for many of us it absolutely does make a difference even when using the proper amount.
I ride or die LRP uvmune 400, few protect as well as it does.
I didn't buy SPF30, I bought SPF50. When I made that choice, I expect at least SPF50.
But you are also dismissing a 25% difference in total transmitted UV - and that's before degradation in the field due to usage and practical concerns, which is why we want SPF50 in the first place.
While true there could be a process issue, it’s very clearly incumbent on manufacturers to correctly prepare and test their product before sending it on to consumers and representing that the product has properties that it may indeed not have.
Negligence law covers this well.
It’s why you don’t get poisoned too often when you buy food products not prepared in your own home.
https://www.bbc.com/news/articles/c4gzl41rpdqo
Ex. not mentioned: Ethnicity sunburn varies w/ Caucassian more prone vs. “ppl of color” due to melanin variance (also responsible for younger look)
https://kenvuepro.com/en-us/clinical-resources/sunburn-exper...
The article also notes the difference between the sunburn incidence rate vs sunburn severity rate:
Awareness levels also vary across different ethnic groups. From the linked study:On the other hand, if your product said it was 50 and it tested 30, the practical difference isn't actually that big. Our parents did ok with spf5
We do SPF50 or 100 on the kids (and us, of course). I think besides shady products, a lot of them are too hard to apply evenly, so you either spend 10 minutes trying to get it to spread, or you look funny with white smears here and there.
You're going to have to bring some receipts for a claim like that. I have never seen such a recommendation, ever.
https://www.ewg.org/sunscreen/report/whats-wrong-with-high-s...
https://www.mdacne.com/article/why-spf-30-is-better-than-spf...
This one (https://www.skincancer.org/blog/ask-the-expert-does-a-high-s...) doesn't directly say its better or worse, but alludes to the idea that when you combine the various factors there's definite cons to SPF 50.
Potentially I slightly overstated, what I intended to say was "there's clear reasons why SPF 30 would be preferable in many/most cases". If you are a pale white person who is hiking through the Sahara with no hat SPF 50 might be the way to go.
La Roche-Posay also very good, but expensive and harder to find.
Buying their products supports them (and you would expect they hold themselves to even higher standards for the effectiveness of their product than a random company).
https://www.cancercouncil.com.au/about-us/
There's just this weird statement at the bottom of the page:
> The Consumer Council reserves all its right (including copyright) in respect of CHOICE magazine and Online CHOICE
https://en.wikipedia.org/wiki/Consumer_Council
https://en.wikipedia.org/wiki/Choice_%28Australian_consumer_...
I always pack my own sunscreen when traveling to islands that ban normal sunscreen. I feel bad if it actually damages the reefs, but reef safe sunscreen is terrible at protecting from the sun.
https://www.consumerreports.org/health/sunscreens/the-truth-...
The FDA listed 12 typical sunscreen ingredients, such as avobenzone, octinoxate, and oxybenzone, as not currently having sufficient data to be recognized as safe and effective. They're absorbed into the bloodstream and studies have found them to persist for weeks.
Based on current data, the FDA categorized only two sunscreen ingredients as safe and effective, the mineral-based ones: zinc oxide and titanium dioxide, which don't permeate the skin much.
"Although the protective action of sunscreen products takes place on the surface of the skin, there is new evidence that at least some sunscreen active ingredients are absorbed through the skin and enter the body. This makes it important for FDA to determine whether, and to what extent, exposure to certain sunscreen ingredients may be associated with any safety risks. FDA has requested data from industry to confirm the safety of sunscreen active ingredients."[0]
[0] https://www.fda.gov/drugs/understanding-over-counter-medicin...
If you're a man especially you might as well just start wearing a hat because the thick hair probably won't last forever!
One tip I got from South Africa is when you find shade take your hat off as you cool down a lot through your head.
I'm white enough that 5 mins of near midday sun gives me sunburns. In summer spf >30 is a must. Even day to day some sunscreen on my face and neck is a must.
In more equatorial regions I'd stay out of the sun from 9-3.
It's still so true today. In England we savour the sun. In hot places they are wary of it.
Lots of sunscreen brands should also be avoided as they contain allergy inducing-, hormone altering- or environment damaging- ingredients.
Not easy making a good choice.
Very hard to find any mineral sunscreens here. Decathlon has one in the most terrible packaging: a roller which means it's close to impossible to get the stuff out.
I have vitiligo and basically no skin pigment above my neck line - this product is excellent, reasonably priced, and ethical
This is a good summary of the topic:
https://labmuffin.com/sunscreen-myth-directory/
https://labmuffin.com/factcheck-low-tox-sunscreen-swaps/
Endocrine disruption: Oxybenzone (BP-3) and related benzophenone-type UV filters have demonstrated endocrine-disrupting properties in vitro and in animal studies, with some human data suggesting possible hormonal alterations and increased risk of uterine fibroids and endometriosis.[6-7] However, most human plasma concentrations are much lower than those producing effects in bioassays, and current evidence suggests low intrinsic biological activity and risk of toxicity for most organic UV filters except oxybenzone.[8-9]
Contamination: Benzene, toluene, and styrene have been found in a large proportion of sunscreen products, likely due to manufacturing processes rather than the UV filters themselves. Benzene contamination is a particular concern due to its established carcinogenicity.[1]
Based on current data, the FDA categorized only two sunscreen ingredients as safe and effective, the mineral-based ones: zinc oxide and titanium dioxide, which don't permeate the skin much.
The only way to solve the problem of bad actors in a consumer products market is government regulations, testing, and fines/dissolution of the bad actors.
The problem with government being involved is that this opens the door for easy corruption (haven't we seen this before)
And what happened to them? Why did they go away?
It wasn't due to the government outlawing them.
> The problem with government being involved is that this opens the door for easy corruption
And 3rd party reviewers aren't easily corrupted? There are at least some mechanisms to address government corruption in a democracy (elections). What mechanism can be employed against a 3rd party reviewer that simply lies about a product it's reviewing?
That's the reason this has to be government ran. Corruption happens regardless of who's doing it, government at very least faces some accountability.
If you are against the government funding them, where do you suggest they get their money?
A company like Consumer Reports was funded by subscriptions to their reports, but they don't make enough from that anymore to test enough products.
Another issue is the sheer number of companies producing products these days. It would be very expensive to test all the products sold.
in the 80s they were selling magazines.
CHOICE in Australia does this, and was the group that did the efficacy tests on a bunch of sunscreens sold in Australia where they found that many were massively underperforming.
Insanely so for the relatively light dusting spray sunscreens do even in the best of circumstances https://labmuffin.com/do-sunscreen-sprays-actually-work-the-...
40 yrs old now. Gfs and strangers comment about how good my skin is. No products ever, no sun screen is all I can say.
Obviously if you're in a cave all spring and get dropped off in Cabo in July, put on some sunscreen. But if you can get constant exposure to work your skin up to it, you really don't sunburn.
Plus I'd imagine you could immediately tell if your sunblock were BS and do an even better job of holding these folks accountable. You and buddy of similar skin tone both buy SPF 50 and apply it, take pictures, and see that one of you is not as well protected.
Also, cheap chinese UV camera tablets ($25) that just showed you yourself through a UV camera. This seems more likely to happen than getting Apple to add a UV camera. They already sell cheap LCD photo frames. I'm sure they can make them cheap. A few influencers and suddenly everyone would get one for checking their UV protection.
A sunscreen scandal shocking Australia - https://news.ycombinator.com/item?id=45145624 - Sept 2025 (110 comments)
1. Only 12% of US adults have vitamin D levels in the recommended range [0] and while vitamin D levels are strongly associated with nearly every marker of health, supplementing vitamin D does not improve health [3]
2. Vitamin D levels are strongly correlated with overall health, quality of life, and decreased mortality (incl. cancer mortality, CVD mortality, et cetera [5.]) This association is quite robust. "Lower 25(OH)D concentrations were also associated with increased all-cause mortality among participants who reported being in good to excellent health" [5] When you adjust for age/sex/race/smoking, a lot of health indicators (such as BMI!) fall apart; this is why we now consider waist to hip ratios as better predictors [6, 7.] Vitamin D levels, however, remain a robust predictor of health, even adjusted for age/sex/race/health factors [5.]
3. Annual deaths from melanoma, 8430; median US age at death from melanoma, 72 [1] (just a few years off the median US age at death from any cause!)
4. Age-adjusted melanoma deaths by race per 100k: flat since the 80s [2.] "By race" is important here because different racial groups have wildly differing melanoma risk, and the racial makeup of the US is not constant with time.
In other words, in terms of risk-reward, there is no question: the median person should trade off even a large increase in melanoma death risk for a small increase in vitamin D levels. Can you, or is that a false argument?
Bit of background: "Terrestrial ultraviolet radiation (UVR) is the main determinant of vitamin D status. Stratospheric ozone absorbs all solar UVC (100–280 nm), attenuates UVB (280–315 nm) but not UVA (315–400 nm). The sun's height determines the UVR pathlength through the ozone layer. Thus, UVB intensity (irradiance) depends mainly on latitude, season and time of day. The ratio of UVA to UVB also varies with the sun's height because of the differential effect of the ozone layer. Thus, terrestrial UVR typically contains ≤ 5% UVB (~295–315 nm) and ≥ 95% UVA. The minor UVB component is responsible for vitamin D synthesis" [4]
The steelman case for sunscreen is: you have a ~0.2% chance of dying a few years early from melanoma. Rigid sunscreen use will reduce some, not all, of that risk. We have not yet had the time to see exactly how much that risk is reduced (people only started using sunscreen en masse in the 90s) and sunscreen is usually not applied as directed [4.] Although existing studies are poor quality and do not take into account the many factors in vitamin D production and sun exposure (type of light, body surface area exposed, life of vitamin D in the body, etc) some of them - funded by industry - claim that you can still, somehow, produce sufficient vitamin D.
The anti case: the majority of sunscreen sold has been shown to be toxic; decades of sunscreen use has not had any appreciable impact on melanoma death rates; all improvements in mortality are associated with improved treatment, not sunscreen. The establishment says the reason mortality is not down is that everyone uses sunscreen incorrectly; imagine if condoms had no effect on birth rates, or airbags didn't decrease mortality because "you're using them wrong"... it is an outrageous defense. Sunscreen is designed to block the overwhelming majority of UVB, which is responsible for vitamin D synthesis; this would _trivially_ cause less vitamin D synthesis. The contra argument, that your body can still make sufficient vitamin D despite blocking the main pathway for its synthesis, is designed and funded nearly entirely by industry.
[0] NHANES 2009-2014, adults
[1] https://seer.cancer.gov/statfacts/html/melan.html
[2] https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6421a6.htm
[3] https://www.nejm.org/doi/full/10.1056/NEJMoa1809944
[4] https://pmc.ncbi.nlm.nih.gov/articles/PMC6899926/ (financed by L'Oréal and written by L'Oréal employees; the overwhelming majority of the research is industry funded)
[5] https://pmc.ncbi.nlm.nih.gov/articles/PMC6388383/
[6] https://pmc.ncbi.nlm.nih.gov/articles/PMC3154008/
[7] https://jamanetwork.com/journals/jamanetworkopen/fullarticle...
I only use SPF 50 for my nose.
No it doesn't. It means you will receive 1/20th of the UV. That is not the same.
https://www.fda.gov/about-fda/center-drug-evaluation-and-res...
https://www.bbc.com/news/articles/c4gzl41rpdqo
The original CHOICE investigation names brands & products:
https://www.choice.com.au/health-and-body/beauty-and-persona...
There are brands like Neutrogena that have passing & failing products, suggesting a process issue.
> An investigation by the Australian Broadcasting Corporation found that a single US-based laboratory had certified at least half of the products that had failed Choice's testing, and that this facility routinely recorded high test results.
https://news.ycombinator.com/item?id=45145624
But, it seems very prone to inducing overconfidence… It has to be reapplied more than you expect. You need more of it than you expect. It is less waterproof than you expect.
I mean, to preemptively retreat to the obviously defensible position: I’m not saying it is negative, but it is better to just cover up and avoid staying in the sun for too long, right?
https://www.youtube.com/watch?v=wQJlGHVmdrA
Track UV levels < 2 (avoid 10am-4pm), wear at least 50 SPF sunscreen (to compensate for lower tested numbers as in this article), wear a watch to time reapplication every 1.5 hrs vs. recommended 2hrs (to be safe)
A sunscreen scandal shocking Australia
https://news.ycombinator.com/item?id=45145624
What I find personally works is to build up a base tan. I probably did a little sunscreen application back in May but just spend a lot of time outdoors so by the time it got really sunny I had enough tan that I didn't need sunblock to not get burnt.
Even my wife who is very light and "can't tan" - I saw a picture of her when she was a lifeguard in highschool - she's bronze and probably wouldn't need sunblock either.
Obviously people make money when you buy sunscreen so the message that you don't need it doesn't get a lot of amplification.
As always, the issue is that people want things to be simple, when the reality is in nuances.
_the poison is in the dose_.
People spending hours everyday under direct sunlight are at risk.
And so does people putting sunscreen everyday, even when they don't go outside but they seat next to a window.
The amount of sunscreen you need depends on your genetics, your history with sun exposure, the place you live and the amount of time you spend under direct sunlight. There is no "sunscreen is a scam" and "life is not sustainable without sunscreen".
1. people are mad about the original topic - false claims of effacicy, when sun exposure can be very damaging and cause cancer.
2. alternatives to these sunscreens, including mechanical like hats and clothing; questions about mineral alternatives
3. wild theories like this one, where a base tan or early season burn somehow protects you. These are wrong and should be called out.
The average life expectancy was dragged down by high infant and adolescent mortality.
https://en.m.wikipedia.org/wiki/Life_expectancy
"What I find personally works..." is ridiculous when it comes to sun damage and skin cancer, unless you are a wild outlier of humanity or a mutant. The simple answer is it takes some (but not much!) time to see the damage and you're likely to encounter it sooner or later.
>> Obviously people make money when you buy sunscreen so the message that you don't need it doesn't get a lot of amplification.
Yes, a shadow-global-conspiracy promoted by the mega-national sunscreen cabal. That's the most likely answer.