Useful facts about Zinc oxide sunblock

[billie_morini]

Some useful facts about Zinc sunblock

1. The primary sun blocker in zinc sunblock is zinc oxide (ZnO)

2. Zinc is a metal element and not a chemical. When combined with oxygen, it is a metal oxide compound. This is where the concept of “chemical free” originates with zinc sunblock

3. Before you can say it is chemical free (e.g., safe for reefs), make sure your sun blocker does not contain petroleum hydrocarbons or petroleum distillates

4. Advertising and pseudo-science tells us, “Unlike oxybenzone and other sunscreen ingredients, there is no evidence that zinc oxide harms coral.” However, this may simply be the result of limited to no published research studies

5. Marketing often tells us nano-particle zinc oxide is ideal for preserving reef integrity. Nano means the zinc particles in the sunblock range in size from 1 nm to 100 nm. “They” often tell you that nano-particles possess intrinsic physical properties unlike those possessed by bulk zinc particles. This is wholly untrue when it comes to zinc. Zinc acts like zinc, no matter what size it is

6. Science and advertising tell us, Zinc “is a powdered mineral that will not dissolve in seawater and instead will eventually settle to the seafloor, like silt, and become buried in the sediment.” True, but before you think this is something good, know that zinc nano-particles are more toxic to nematodes (e.g., Caenorhabditis elegans [C. elegans]) and other organisms that burrow in sea floor sediments.

7. Nematodes are worms. Worms are very important in sea floor ecology

8. Why C. elegans? Because this nematode is an excellent model organism for ecotoxiological studies, specifically those investigating bioavailability and transition metal toxicology

9. In addition to nematodes, nano-particle zinc oxide is detrimental to the well-being of crustaceans, algae, fish, and mussels. Some specific organisms that suffer include marine diatoms (Skeletonema costatum and Thalassiosia pseudonana), the crustaceans Tigriopus japonicus and Elasmopus rapax, and the medaka fish (Oryzias melastigma)

10. There is no “free lunch.” By this, I mean that while zinc may be better for coral reefs, it may be worse for other important organisms

11. Conclusions: reefs are environmentally challenged. Use zinc oxide without petroleum ingredients around them, with the knowledge you are impacting other species to save the reefs. Conversely, do not use zinc oxide anywhere that does not have reefs

Figure source: Ecotoxicity of Zinc Oxide Nanoparticles in the Marine Environment (PDF Download Available). Available from: https://www.researchgate.net/publicatio ... nvironment [accessed Jul 3, 2016]. NPS = nanoparticles

[oldmansurfer]

Zinc oxide is a chemical

[billie_morini]

Yes, Ol' Man, zinc oxide is a chemical! Specifically, it is an inorganic chemical compound.
Previously, I stated zinc is a metal. When not combined with anything else, this is especially true, too.
Zinc, like gold or silver, occurs naturally as a precious metal (e.g. pure), as an oxide like used in sunblock, or as a sulfide like in deposits formed in the absence of free oxygen molecules.
(Sorry, you are dealing with a geochemist holding an advanced degree that just received a copy of a published book with yet another couple of chapters authored by yours truly )

[oldmansurfer]

I guess you may be tired of ignorant people shanghai-ing the terms such as chemical or organic...?

[RinkyDink]

I'm looking to buy a surf hat. I don't think they look stupid and, honestly, I don't care if they do. Anybody have recommendations? Something like this perhaps:

https://www.amazon.com/NP-Surf-Straps-G ... urfing+hat

[billie_morini]

Hi Rinky,
I have all kinds of surf hats, including some like at the link you provided. Here are some things I learned for me.
1. A flat bill blocks more vision when prone on board than curved bill (stopped using flat bill hats)
2. Long bill blocks more vision when prone on board (trimmed or completely removed bill based on specific hat)
3. I like some hats that have brim all the way around
4. Back of neck can get badly sun burned with some hats (my head and face were fine, so i did not realize my neck was completely exposed. This is why i like and most frequently us the hats like you linked. But, i removed the bill entirely)

[dtc]

A few guys I know have this one

http://www.mcsurf.com.au/products/prote ... hat/1031/1

although it may be an Australian only product

[billie_morini]

I've seen hats similar in the US to what dtc provided link for. Seen them in stores and in-use in the surf.

[dtc]

actually, as billie pointed out, the neck needs protecting too - this one looks good

http://www.mcsurf.com.au/products/indo- ... off/1821/1

not a big front brim but it is stiff so it doesn't flop into your eyes/keeps protecting, with a neck flap. Being Ocean and Earth it may be more easily available

I probably should wear one myself, skin cancers are a major issue in Australia. Probably see about 15% of surfers wearing a hat around my way - and pretty much all of them are middle aged or older ie the ones that are sensible (or have had skin cancer scares). I'm at the age where I'm on the cusp of becoming sensible. And it would keep my wife happier (she is a pale red head so the sun is her mortal enemy)

[billie_morini]

dtc,
Please do not grow up and become sensible!
billie

[oldmansurfer]

Also if you consider the studies that people are claiming to show that sunscreen is damaging reefs was done in an aquarium with artificial seawater and small bits of live coral. How to interpret that study? It means to me that someone needs to look at real life situations before we do something stupid trying to fix a problem caused by global warming.

[BoMan]

probably should wear one myself, skin cancers are a major issue in Australia. Probably see about 15% of surfers wearing a hat around my way - and pretty much all of them are middle aged or older ie the ones that are sensible

I like the protection the FCS gives for my ears and also use it while jogging.

The downside....My daughter says I look really stupid after a wipeout when the bill flops over my face or back over my head. At least she can spot me in the lineup.

https://www.amazon.com/FCS-Wet-Bucket-Surf-Hat/dp/B000F4EEL2

[RinkyDink]

Thanks for all the hat links. Lots of good choices there. My dad has had skin cancer removed from the top of his foot and his face. Now my sister has just had to have it removed from the side of her nose. I miss the ozone layer of my youth. I definitely need a good hat. Thanks again.

[billie_morini]

Rinky,
It's sad to hear about your family's woes with cancer. Some of my wife's family have had similar.

Now, I hope to provide some good news about your beloved ozone layer. Here's news that is only 2 days old.

"The Antarctic ozone layer is showing signs of healing, according to scientists from the US and UK. The finding marks a success for an international treaty set up to protect the ozone layer and phase out ozone-depleting chemicals."

Full story here: http://www.rsc.org/chemistryworld/2016/ ... yer-mend-1

[oldmansurfer]

So it seems the restrictions on CFCs is working? I had a skin cancer removed and have had numerous precancerous lesions removed.

[billie_morini]

CFC restriction plays a part in the ozone recovery. There are also some natural processes at work, too. The science related to ozone depletion and recovery is more easy to model and describe than global warming and sea level rise. Therefore, ozone depletion and recovery are not plagued with nearly as much conjecture and junk science associated with global warming and sea level rise.

Now, back to our regularly schedule program: ozone is an inorganic molecular compound. The formula is 03 (pretend the three is a subscript character). Ozone is also called trioxygen because it consists of three oxygen molecule. Ozone causes damage to mucous and respiratory tissues in humans and animals. It possesses relatively strong oxidation properties. Oxidation is the chemical process that removes electrons from compounds ozone comes into contact with. I employed this process to remove chlorinated solvents, dioxans, and furans from contaminated groundwater and process plant waste water streams earlier in my career.

Here are some slides from one of my presentations at an international science conference about 12 years ago. The first slide identifies the oxidation potential for various oxidants. The more negative the value, the greater oxidation power the oxidant possesses. The second slide generalizes primary characteristics associated with oxidants. The third slide is a cartoon showing how to inject ozone or other oxidants into groundwater for contamination treatment.

[billie_morini]

Slide 1, notes provided above

[billie_morini]

Slide 2, notes provided above

[billie_morini]

Slide 3, notes provided above

[dtc]

I'm so glad there are smart people in the world doing this important stuff so I can continue to live well.

Side note: in Australia we pick our school year 11 and 12 subjects at the end of year 10. Your performance in 11/12 is what gets you into, or not into, university (I guess equivalent to A levels in the UK). I picked chemistry; my chemistry teacher said 'umm, you realise you aren't very good at chemistry, to get good will require so much work that it will affect your other subjects'.

So I changed my mind and did history. Best decision I ever made as I turned out to be good at history and managed to get into uni.