Hacker News Reader

Comment by MangoToupe | Hacker News Reader

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.

View on HN

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.

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.

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]

> I'd bet that some of them have very nasty long-term side effects.

Why?

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.

TIL that chemical sunscreen does go into the bloodstream: https://www.fda.gov/news-events/fda-brief/fda-brief-fda-anno...

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.

AFAIK Bemotrizinol is the only(?) chemical sunscreen active which is shown to not be an endocrine disruptor (this chemical https://pubmed.ncbi.nlm.nih.gov/36738872/)

It's hard/impossible to find in US formulations but in AU and EU some higher end brands use it. I like the La Roche Posay Anthelios series of sunscreen - I believe they all use Bemotrizinol as the active but I am 100% sure this one does: https://www.laroche-posay.com.au/sun-protection/face-sunscre... - Note that the formulation for the specific product is different in different regions, this is the Australian version.

Reply on news.ycombinator.com