Useful facts about Zinc oxide sunblock

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
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