4 things you didn't know about sunscreen

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105 Responses to “4 things you didn't know about sunscreen”

  1. Antinous / Moderator says:

    I generally try to avoid the Yellow Face, but if I have to go out, Epicuren clear-drying zinc oxide is the best. It dries really…dry, so you don’t feel greasy. However, at $40 for 2.5 oz, it’s only for the face.

  2. Cowicide says:

    That’s because, frankly, there already wasn’t such a thing. A sunscreen might be more water resistant than a competitor. But you can’t assume that one application of the “waterproof” stuff will stay with you through hours of pool time.

    I’ve surfed 8 hours straight in large waves with tons of thrashing around underwater with tropical sun bearing down on me. I don’t know about other brands, but clear Bullfrog stays on in those conditions and keeps me from burning wherever I put it. I was pleasantly surprised over the years to see Bullfrog grow from just surfers like me using it to the general populace.

    I honestly don’t know how healthy that kind of stuff is to be absorbed in the skin, but it definitely meets my definition of waterproof sun protection as far as burning goes.

    That said, before Bullfrog, I used to try other brands that claimed “waterproof” protection and I got burned.

  3. Kosmoid says:

    “I’ve surfed 8 hours straight in large waves with tons of thrashing around underwater with tropical sun bearing down on me.”

    That’s hot.

  4. Anonymous says:

    Very nice. Now can they include info about which sunscreens will stain the @&$*! out of your clothing if you have iron in your water, like many of us on wells do? I can’t tell you how many light-colored shirts and shorts I’ve ruined from those orange stains – but the labels on the stuff is next to useless when it comes to staining.

  5. lillyd says:

    Thanks, Maggie, for shedding some light on the sunscreen issue. People are grossly misinformed about it and this helps. However, there is a lot more to consider. Things are more complicated than you describe and certainly more than anyone can cover in a 3 minute slot on Good Morning America or a 5 minute doctor’s visit. This video of a lecture by Edward Gorham, PhD at UDSD has the most thorough examination I have found:

    http://www.ucsd.tv/search-details.aspx?showID=15770

    It is long and dull, but the guy is funny like my dad is funny…that is to say, not very, but endearing nonetheless.

    To summarize it as best I can (I know you could do way better!): UVA seems to cause melanoma (deadly) as it contains vastly more radiation. Both UBA and UVB can cause Basal Cell Carcinoma over years of tanning and burning but mostly in fairskinned people. Basal Cell Carcinoma is basically never deadly and is usually easily found and removed by a dermatologist. Both UVA and UVB cause melanin to be created deep in the skin. Melanin migrates to block cell nucleii from the radiation from UVA.

    Suncreens of ALL kinds prevent this process of melanin creation and protection from happening! It is important to get some sun. It is also important not to burn. Sunscreen that doesn’t contain Titanium Dioxide and Zinc Dioxide is WORSE than just getting sun until you start to burn because it blocks the UVB but doesn’t block UVA which is linked to Melanoma (deadly).

    I haven’t even mentioned Vitamin D yet, which is thought to be protective from cancer in general and is synthesized by the skin when exposed to the sun. It is synthesized in huge amounts, way more than you can get by any diet. Our skin is thought to have evolved with the sun, some evolving lighter pigmentation to synthesize more Vitamin D, some evolving darker pigmentation to have more protection from the radiation by the melanin.

    His advice is pretty simple really: Listen to your skin. If you burn easily, get a little sun (every day) and then cover up. If you tan, get a tan. Don’t burn. If you are dark skinned you need even more sun to make Vitamin D. If you start to burn, cover up. Go to a dermatologist to check for basal cell carcinoma every couple years for a mole check.

    I add: If you don’t want wrinkles, spots and moles, grow up. You’ll be happier if you’re healthy.

  6. earthmann says:

    People who spike junk should still wear seat belts, no?

  7. theredballoon says:

    These experiments are done with people, volunteers who have sunscreen applied to some parts of their bodies, but not to others. Then, they’re exposed to UV light, and researchers measure how much longer it took the protected parts to burn compared to the unprotected parts.

    As someone who actually participated as a “lab rat” in one of these sunscreen tests during college (hey, it paid like 100 bucks!), what I found amusing (and wasn’t mentioned in this article, darnit) was that the parts of their bodies has to be areas “not previously exposed to sunlight”, or in other words, how the experiment got the nickname of the “ass-burning” experiment among my friends. (Of course a bunch of us did it- that’s beer and pizza money!)

    Sigh- I miss doing stupid things for free money in college.

  8. jtegnell says:

    How dare the gubmint infringe on the freedom of speech rights of sunscreen manufacturers!!

    Communists!

  9. Itsumishi says:

    76 comments in and not a single mention of the humorous fact the sunscreen expert quoted is called Professor Tan?

  10. Anonymous says:

    “Electrons dispel the energy by moving to a higher orbital,” Tan says. “Then they come back to stable lower orbitals.”

    Not exactly. Electrons absorb energy in the form of a photon (light particle) and use it to transition to a higher-energy orbital. Then they dissipate that light energy in a nonradiative (non-light-emitting) form, via vibrational and rotational energy. Like if someone goosed you (electron goes up) resulting in lots of little goosebumps (vibrational dissipation).

    Or something.

  11. bcsizemo says:

    Implying that most sunscreen has titanium dioxide in them?…

    Well if it is, it’s certainly not an active ingredient in the vast majority of the ones I find at my local stores. I know, because I’ve looked at every single sunscreen that is local. My wife is allergic to any sun screen that isn’t based on the zinc/titanium setup. So she mostly uses the Neutrogena Baby kind that’s like $3+ an ounce.

    And if it’s not an active ingredient then why use nano size? I would think the whole point of adding it would be to lighten or make the cream white…

    • Anonymous says:

      TiO2 is definitely a component in some sprays here. But TiO2 is photo-active too: it is used to make window panes UV-activated self cleaning.

      Thus, I wouldn’t think that it is more innocent than more complex organic molecules. OTOH TiO2 will stay more on the skin surface and it would have to activate another molecule first before that would delever energy somewhere in living skin?

  12. nanite2000 says:

    This is going to sound like a really dumb question, but how do I get a tan with high factor sunscreen?

    I’ve got a relatively dark complexion (Mediterranean), and wearing SPF15 sunscreen prevents sunburn even if I only apply it once in the morning. Am I taking a huge risk by doing this?

    • gargoyle says:

      The short answer is yes, it’s a risk. If you are tanning, you are damaging your skin and exposing yourself to increased risk of skin cancer. How much is hard to say, but it’s a myth that tans are safe(or even protective!) and that only burns increase your risk of cancer.

  13. Anonymous says:

    “More and more Americans are using sunscreen. But that’s not the same thing as more Americans understanding sunscreen.”

    I’d be willing to bet you could pick almost any noun to replace “sunscreen,” and the statement would remain true.

  14. raneman says:

    Where can I find Carlsberg in a can? :)

  15. lillyd says:

    One more important thing: he says melanin is red in some people (people who don’t tan, I suppose). I don’t remember how to tell if you are getting a healthy melanin-pink or burning. I tan, so that part didn’t sink into my long-term memory. Sorry.

    I also want to add that I wear a hat when I’m in the sun a while because it would be nice to avoid too many wrinkles on my face at least. I didn’t want to sound too snarky about that. Nobody wants to look old.

  16. Cefeida says:

    I always use sunscreen. That is, always since the day I forgot to put some on, went sailing, and ended up with sun poisoning and oozing sores all over the top half of my face. They took days to scab, and the scabs took weeks to come off.

    Oh, and I had blisters on the top of my earlobes, too. Puffy, fat blisters filled with serum. I didn’t think that was even possible.

    The threat of not using sunscreen is no longer abstract to me, nor to any of the people who saw me the next day…

  17. parkar says:

    Very nice information. This message should be shared by everyone. This cosmetice peolpe making fool to us. This is really very unethical. If you are selling something must have some fact and it should work by making fool you can’t survive for a longer period.

  18. g0d5m15t4k3 says:

    This guy’s name is Reynold Tan. Lols.

  19. Anonymous says:

    ‘”Electrons dispel the energy by moving to a higher orbital,” Tan says. “Then they come back to stable lower orbitals.”‘

    If this is really what happens, then it worth noting that this process results in the emission of a photon – a “packet” of light – back out of the molecule equal in energy to the difference between the energy level of the orbital vacated by the electron and the orbital to which it drops. That photon, presumably, could go in any direction upon leaving the sunscreen, including back into your skin. Geometry would suggest that if the sunscreen molecule in question is positioned exactly on the surface of the skin, half of the stimulated photon emissions would do go into the skin and half would travel away from the skin. The wavelength of the emitted photon may or may not be better for you than the original light that came from the sun.

  20. g0d5m15t4k3 says:

    I also want to know more about how black people tan. My boyfriend is of the brown persuasion and insists on not wearing any sunscreen. This bothers me. I’m of the super pale persuasion and get burned if I’m in the sun for only 10 minutes. I know his color may not change as dramatically as mine, but I wonder if he still is at risk for cancer by not using sunscreen.

    • Antinous / Moderator says:

      White-skinned people get way more melanoma than dark-skinned people, but detection is a significant problem on dark skin.

  21. Anonymous says:

    Sunscreen is far too expensive, governments of the world need to subsidize it. The cost of subsidizing it would be easily paid for the money saved in skin cancer treatment.

  22. ackpht says:

    Visible light certainly can be scattered by particles smaller than the wavelength. It’s why the sky is blue.

  23. KBert says:

    So, where were all the skin cancers before sunscreen? Certainly there were plenty of folks getting major exposure to their hands, necks, arms prior to these products.
    Not so long after sun_screen_ was brought to market we begin the ‘epidemic’ of skin cancer.
    Interesting?!

    • blueelm says:

      Actually I collect old medical books of diseases of the skin and they had lots of skin cancers back then! They not only had cancers, they also didn’t know what to do with some of them and often got people in only after they had developed some amazingly disturbing symptom.

      History… it’s so much better when you don’t rely on your own recollection of the past.

    • Antinous / Moderator says:

      - The class of people who had any access to medical care, thus medical records, deliberately tried to stay as pale as possible as a sign of wealth and leisure.
      - Everybody stayed covered from neck to toe and wore gloves and hats, or went to jail for indecency.
      - Ozone layer?

      • Anonymous says:

        Cancer also used to be a fairly taboo subject; you would see a lot of families generalizing illness or calling it a mystery in public.

        • blueelm says:

          A lot of people did not know the difference between certain cancers and syphilis. It was a sign of depravity, and thus very shameful. Since a lot of people have something to be ashamed of…

  24. j9c says:

    If for some reason the sun screen thing doesn’t work well for you, or you want to limit how much you spend on the stuff, and you want to be outside in the sun, you still have a few other options for low exposure to solar radiation.

    Wear a UPF shirt or a “rash guard shirt” when outside. The rash guard shirt is useful when swimming. You’d still need to apply sun screen to your face. Not swimming? Wear a broad-brimmed hat and a UPF shirt. Check places like Patagonia, REI, Sierra Trading Post, LL Bean, Lands End. A UPF or rash guard shirt doesn’t get sweated off and you needn’t re-apply after a number of hours spent in the water. A rash guard shirt means no chemical warfare on marine life. Sure, the manufacturing process and fiber of that shirt is petroleum-o-riffic, but one decent shirt will last way longer than plastic tubes and bottles of annually purchased goo.

    Wearing one of these shirts also mean you don’t to wait the requisite 30-45 minutes so often specified in sun screen package directions. If you’re not applying your sun screen, then waiting 30 minutes before solar exposure and/or entering water, you’re doing it wrong. Sun screen needs time to sink into your skin in order to perform.

    Other option? Avoid the sun during its strongest period of radiation when it’s at its highest angles in the sky (for North Americans that’s something like 10 am – 4 pm).

    • cub says:

      “Other option? Avoid the sun during its strongest period of radiation when it’s at its highest angles in the sky (for North Americans that’s something like 10 am – 4 pm). ”

      if that’s the final word i’ll take it, but i remember coming across an article proposing that the low-angle times of day might be worse???

      and then there’s this: “Ultraviolet B (UVB): wavelength 280–315 nm. UVB can cause sunburn yet is also what enables vitamin D production in the skin. Depending upon the angle at which the sun’s rays reach the earth, optimal UVB exposure is between 10:00 am–2:00 pm and in the summer (70% of a person’s yearly dose is received in summer). UVB does not penetrate glass and most is blocked by the ozone layer.”
      http://www.arizonaadvancedmedicine.com/articles/skin_cancer.html

      so the best time of day to get cancer is also the best time to prevent it. i now see the value of those uv disc thingies they sell through thinkgeek– maybe. i think.

  25. Anonymous says:

    Maggie, I think I once heard that sunscreen expires (like milk eventually), but I don’t know if it’s true. I typically use sunscreen in the summer, then, it sits there on the shelf over the winter. I’ve never seen a bottle with an expiration date (I assume they won’t do it until they have to). Do sunscreens expire? I figure you might know. (Great article!)

    • Anonymous says:

      all of my sunscreens have expiration dates

      • Antinous / Moderator says:

        all of my sunscreens have expiration dates

        Moist make-up (as opposed to powders) should generally be dumped after six months. Unless you’re trying to flesh out your zombie look with styes and carbuncles. If you’re using sunscreen seasonally, you should consider dumping it at the end of the season and buying fresh every year.

  26. siuyeet says:

    A new type of motivation!

  27. sirkowski says:

    The FDA? Another evil gubmint organization that steps on the throat of the corporations who want nothing but our good?

    When you use sunscreen, you’re sunbathing with Stalin!

  28. Anonymous says:

    Ladies and gentlemen of the class of 1997… wear sunscreen!

  29. Anonymous says:

    I have never understood why anyone would want to put a chemical on their skin that makes it not work properly. It’s insane.

  30. Anonymous says:

    Great post! I posted an article about what’s inside sunscreen last month. I thought some readers might enjoy it. Here’s the link… http://www.drbunsen.org/home/2011/5/11/whats-inside-sunscreen.html

  31. rewhu says:

    Interesting. Definitely somethings I did not know. I’ll be rereading the backs of my SPF lotion bottles.

  32. forgeweld says:

    Thing number 5 you didn’t know about sunscreen-it can seriously damage coral reefs. I’m no expert on which are reef safe, but this site has some suggestions.
    http://www.sustainablewaters.com/green-sunscreen-protect-yourself-protect-coral-reefs/

  33. Lucky says:

    The ironic picture of sunscreen, beer and cigarettes. Really, why bother putting it on at all? Slather some coconut oil and and bake while you smoke and drink.

    In other news, sunburns are my least favorite thing, having had one so bad a few years ago that the only relief I could find from the subsequent itching involved cold concrete and ice baths.

    Great story on sunscreen btw, I didn’t know some of that.

    • treacle says:

      I have seen plain, non-fat yogurt —slathered on, wait for 15 minutes (or more), then rinse— take a sunburn to a tan, with no pain. It’s amazing. It has to be plain, non-fat. Others will make the pain worse.

      I’ma gonna try the apple cider vinegar thing that Trixie suggests, if I get a burn this year. Never heard that one before.

      But I know personally that the yogurt trick works.

    • Trixi says:

      Next time you have a sunburn, try apple cidar vinegar. You’ll stink, but it works.

      • Anonymous says:

        My best advice is barely-warm tub of water with a lot of baking soda. Soak until the water is starting to be too cool for comfort, which should take several minutes, so bring a book.

    • tiamat_the_red says:

      Your story is exactly why a person who smokes and drinks would bother with sunscreen. Sure, cancer may kill me later but sunburns suck NOW. Nothing like painful feedback to encourage sunscreen use.

  34. Patti says:

    It seems to me that the best answer is just to avoid the evil day star as much as possible. I’d much rather moderate my exposure than try to sort through complex and incomplete data about how products may or may not protect me from the dangers of the sun.

  35. arikol says:

    Great information Maggie.
    One question, what kind of energy do the electrons release when dropping down again? Is this energy released as heat or some other kind of radiation? (basically the question is, at what frequency is the energy that is released?)

    • Anonymous says:

      Typically sunscreens absorb light from 380nm-200nm and beyond they undergo non-radiative decay through heat, however there are some that can weakly fluoresce. If you get some sunscreen on your clothes and go moonlight bowling you’d glow a bit blue. Especially on your clothes.

      Some sunscreens are triplet sensitizers that can actually generate singlet oxygen (highly reactive oxygen species that essentially destroy any non-aromatic unsaturated hydrocarbon molecule and DNA). This is a double edge sword as singlet oxygen can actually cause cancer as well, however the permeability of sunscreen and singlet oxygen through the skin is very debatable as scientists haven’t studied it (to my knowledge) extensively.

      Full disclosure I’m getting my PhD in Photochemistry.

      • jennchlebus says:

        Oh, rats. All I get is some flourescence and heat? Here I was all set to get Henna-style body doodles with a circuit-drawing pen and charge my phone while I laid on the beach….

    • Anonymous says:

      yes, the energy released is in the form of heat.

  36. Anonymous says:

    I certainly agree that government regulation on advertising is helpful for the cause of public health. However, I noticed that this news gathered a surprising number of comments on CNN regarding government interference with personal rights. The issues of personal rights and corporations’ rights (which in this case is the right to make unsupported advertising claims) are clearly distinct. As such, it is frustrating to see people champion corporations’ rights as their own.

    Reading your thoughtful opinions regarding science and public policy is refreshing.

  37. siuyeet says:

    Using 2 milligrams per cm squared everyday you would prefer to buy a new one after 2 weeks! Anyway, some girls used to wear it just because avoiding getting darker skin. You can’t go outside under solar radiation without any protection. A label with “preventing cancers” shows a new generation for sunscreen!

  38. Anonymous says:

    “4 things you didn’t know about sunscreen” …do i get a cookie if i did indeed know those things? (plus at least two more not widely known) i demand for sake of scientific formality that error estimates be placed on any future wild use of the public “you”, e.g.: “you +/- 0.13%” thankewverrrymuch.

  39. blueelm says:

    This is the most helpful thing I have read on sunscreen ever, and I have actively looked for good information on what kinds of sunscreens are best to buy.

    I’ve been using sunscreen since I was a kid (I’m not fond of the sun anyway, but I really don’t want sun damage either) and I often wonder how much good what I have is doing or whether I’m better off with a physical block, whether the higher SPF is worth it because I spend most of my day indoors and it has probably worn off by the time I leave but it’s hard to find good straightforward information that isn’t more or less just advertising.

    Hats and clothing with sleeves help too. Where I live the sun is overwhelming, you really need some kind of sunscreen even if you don’t spend a lot of time outdoors.

  40. Anonymous says:

    5. Transparent sunscreens were one of the first wide-scale deployments of nanotechnology in a consumer product. They’re transparent because the TiO2 or ZnO particles are smaller than the wavelength of visible light, and so don’t scatter it. Scattering of visible light by large TiO2 particles is the reason that white paint is white, and also why ‘old fashioned’ sunscreen looks a lot like white paint. Nano-sized TiO2 and ZnO particles still absorb UV like their bigger cousins, so badda bing badda boom transparent sunscreen.

    Do smaller particles interact differently with our skin? We’re not really sure. Small particles means a higher surface area (important for chemical reactions) and also more chance of squeezing through protective barriers in the skin. The first link I could find on Google: http://www.nanowerk.com/spotlight/spotid=714.php

    The jury’s out but it’s one of those things that deserves far more testing before such wide-scale deployment.

  41. Anonymous says:

    Whats even more interesting is that most sunscreen contain KNOWN carcinogenic chemicals like Octinoxate (Octyl Methoxycinnamate) and Oxybenzone (Benzophenone-3).

    Read for yourself:
    http://articles.mercola.com/sites/articles/archive/2008/07/01/four-out-of-five-sunscreens-may-be-hazardous-to-your-health.aspx

    Be careful what you slather all over your skin…

  42. Neon Tooth says:

    Already beat to the irony of the photo featuring some Marlboro menthols….

  43. OldBrownSquirrel says:

    The yellow face, it hurts us.

  44. Kosmoid says:

    I’d rather have melodrama than melanoma.

    By your whitey thighs I can tell you could use some Vitamin D.

  45. teapot says:

    Australia has had these laws about honest sunscreen labeling for 20+ years. It tripped me out to see SPF 1,000,000+* sunscreens in stores in America. Do any brands in America currently list accurate figures for duration of waterproof effectiveness?

    *hyperbole

  46. Dman says:

    Not one mention of nanoparticles used now for almost all sunscreens? Nanoparticles can enter the blood stream quite easily through the skin. Also, titanium dioxide, the main ingredient in most sunscreens is a known carcinogen. It’s in a lot of makeup now as well. Added SPF protection was the “now with zero transfat” of 10 years ago. And who knows ago zinc oxide when it has been reduced to nano size. America, the human guinea pig!

    Effectively, when we use sunscreen we are turning ourselves into the tinman from oz (the movie version tinman, with the metal body paint). You used to be able to see the sunscreen as you slathered it on. But because of the nanoparticaling of the metals, it’s more translucent and people like that better. I worry about the aerosol version of sunscreen, the one I inhale as the overprotective mother sprays her childs entire face and body with.

  47. Anonymous says:

    It should be noted: The Environmental Working Group (EWG) really pushed for changes to sunscreen regulations. They also publish a list of sunscreens that actually work and don’t contain harmful chemicals.

    They are also not very happy with the final rules put in place and feel they are only a slight improvement of the previous rules.

    And everyone knows menthols have more vitamin C and so are better for you than regular cigarettes.

  48. Anonymous says:

    Although I agree that too much sun exposure isn’t good for the skin, I’m dubious about repeatedly slathering my body with chemicals that react with sunlight and then get absorbed into my body through the skin. The long terms of effect of this?….

  49. BennyMcBenBen says:

    The researcher’s name is Tan? Har har.

  50. blueelm says:

    I’m less worried about cancer. I’m probably going to die from cancer if I don’t have a heart attack. This is because I worked with high gloss enamel paints for years and I have an arrhythmia. So, I exercise, don’t smoke, try to drink lightly and whatnot but the truth is I’m probably going to die of cancer or a heart attack (if I don’t get murdered or die in a car accident of course)

  51. SamSam says:

    No one’s mentioned the clear nominative determinism here yet? Reynold Tan, Ph.D.? Dr Tan? Anyone?

  52. jasonq says:

    “You ever read the ingredients in sunblock? I’ve never seen those words anywhere!
    You don’t even know what you’re putting on your face, do you? ‘Oh no, the sun’s out, ahh’ – it could be zebra cum, you don’t know!”

  53. Anonymous says:

    Question, I always thought that sunscreen absorbed the energy by making your skin a color that’s invisible to us on the spectrum (like bee purple). I can’t remember if someone told me this, or if I made up the explanation myself. Any truth to this?

  54. Anonymous says:

    Most sunscreen is also tested by putting it on so thick the person looks like they have been slimed in it. Further, almost all sunscreens have ingredients that aren’t even deemed safe by the FDA. This website has the down low on just about every brand out there. You’ll be shocked…http://breakingnews.ewg.org/2011sunscreen/

    Look at this kid’s sunscreen for example, insane what is in it. http://breakingnews.ewg.org/2011sunscreen/about-the-sunscreens/381143/Coppertone_Kids_Sunscreen_Stick%2C_SPF_30/

  55. Anonymous says:

    Ever since they added UVB protection, I’ve noticed that the stuff gets EVERYWHERE and leaves grey/white stains on chairs, leather car seats, even handprints on cabinets. It’s gross. Any brands that are less disgusting? I wear a lot less of the stuff now, but my wife and kids still wear it and gets it all over everything. It did not used to be like this.

  56. TabulaRasa says:

    Not the pickled vegetables! Not my Krautsalat! Neeeiiiiin!

  57. Anonymous says:

    Maggie- you’d really enjoy speaking with John Barrow, a Harvard-educated, science-minded Aussie and entrepreneur based in Minneapolis. He started Coolibar.com several years ago and has been doing some extraordinary research in the area of sun protection.
    Rob

  58. Anonymous says:

    Another question.
    Why is the “good” sunscreen — the oxide-based kind — so much more expensive?
    Economies of scale?
    Simply more expensive?
    Low demand?

  59. owenbarron says:

    All you need to know here:
    http://www.newyorker.com/humor/2009/08/10/090810sh_shouts_borow

    I recommend:
    “SPF 233—Close your eyes. Good. Now imagine a world without poverty and disease, where children of all races and religions join hands and sing old Negro spirituals, a place where the vicious cycles of boom and bust are replaced by never-ending Wonder Wheels of boom . . . and boom. SPF 233 is not inexpensive. But, in the war against the evil that is the sun, can you put a price on freedom?”

    • collapsingwaves says:

      One of the most hilarious, belly laugh inducing pieces of writing I’ve read in weeks. Thanks for the link.

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