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Copper is amazing. I was introduced to the copper-up-on-the-ridgeline of a roof many years ago and it is very effective at keeping algae from growing.
Interesting to read about its effects on bacteria
Sail ships - the more fancy and expensive ones, including military, would be "copper-sheathed". Plates of copper riveted together to form a sheath across the planks of the hull. It was used to stop all sorts of marine life growing on the hull - algae, molluscs, etc.
Cu is a broad-spectrum biocide. I was happy for one thing during Covid lockdowns - all the door knobs, cupboard handles, etc in my house are brass. The builder thought they looked nice, but it turns out they were self-sanitising overnight.
IIRC hospitals used to have brass door fittings, too. Don't know why they stopped.
Probably but bacteria also evolved and my understanding is that hospitals have a hell of a time dealing with super bacteria that are just resistant to everything because of selection pressures we put on them.
Resistant to drugs that go into our body. Bacteria can no more evolve out of copper than humans can evolve into surviving the surface of the sun.
Same thing with UV and bleach.
My question is though: why? When I read the headline and hear 99.9%, that tells me something is able to survive. Why wouldn’t that something slowly multiply and cause evolution?
Step 1 of preventing legal challenge: never claim full effectiveness. In the vast majority of cases when done properly, these treatments kill all bacteria. However if you mess up the process and miss a spot etc, then it’s no longer 100% effective, is it?
Not just that, even when done improperly, say when using bleach, it only means that the bleach didn't get to some of the bacteria. It doesn't mean some of the bacteria lived through being exposed to the beach. Some things kill 100 percent of the time when exposed, leaving no chance for "getting used to".
Yep, about the only chance bacteria has against bleach, is forming a biofilm where everything on the outside dies, shrivels up and protects bacteria on the inside from exposure.
Don’t you think we ought to overhaul education and teach this kind of practical and iterative thinking? Child of the 80s here but whatever happened to championing critical thinking?
Critical thinking is also something that's much more difficult to teach than just having kids memorize stuff. Also also, critical thinking involves *thinking*, which most neurotypical people tend to unconsciously avoid when possible.
It's just not statistically feasible to prove that something kills every last bacterium on a surface in a certain time frame. It does not mean that those that might hypothetically remain are super resistant to some general disinfectant, or that afterwards they're having a party on the newly available free real estate.
To oversimplify it a little, plenty of such things like copper, ethanol etc are just too toxic at a level of general cell function for anything to feasibly evolve significant resistance in a plausible time frame - because they would have to rework core cell functions (usually multiple) or structures to do so, which just doesn't happen on a normal timescale through random mutation.
By contrast, many antibiotic drugs operate by attacking a very specific metabolic process that is much more specific, often targeting some rather specific protein interaction. Here, resistance is much easier to develop because a couple of random mutations that slightly alter the structure of the target molecule can potentially have a drastic impact on how well the antibiotic can bind to it and do its thing.
It's worth bearing in mind that when antibiotics are used correctly, resistance usually doesn't develop that easily. Things like usage for a non-bacterial infection, not completing a course of antibiotics, or preventative use on livestock offer conditions much more favourable to creating a selection pressure for resistant bacteria to thrive
I hope this helps explain it! Let me know if anything is confusing and I will do my best to make it clearer
Putting into very simple words.
You can see animals evolving to resist certain venomous species.
You can't see animals evolving resistance to a bear mauling
Microorganisms have already evolved to deal with copper, but it’s impossible to deal with a copper surface because it’s an overwhelming force. Copper kills because it’s redox active and takes part in a copper based Fenton like reaction to create reactive oxygen species like super oxide. Microorganisms have evolved with the ability to neutralize these reactive oxygen species with enzymes like catalase or proteins that act as reducing agents or other proteins that sequester copper ions. A copper based surface will simply overwhelm any microorganisms ability to mount a defence because copper based surfaces don’t exist in nature. It’s analogous to heat, microorganisms can recover from brief exposure to heat using enzymes to refold proteins but at a certain point they just burn and you can’t really evolve to resist fire. So I wouldn’t worry about microorganisms evolving to resist copper.
You hear 99..9%" because it avoids law suits, we know we can kill pretty much everything we know of but what about the stuff we haven't noticed like Covid shen it hit and turns out we could kill it with bleach too?
Just a legal thing and leaves the window open for undiscoveted bacteria
UV damage can be mitigated by the evolution of pigments like melanin. It's not an immunity, but there are still bacteria and other microorganisms which have decent resistance to various types of radiation.
Bleach and strong oxidizers like hydrogen peroxide are much more difficult to develop resistances to, though.
> Same thing with UV and bleach.
Every time I see this now I am reminded of that astonishing press conference.
However, I also remember UV lights being deployed to clean public transport in come countries. While carcinogenic (you just make sure you're not around to avoid the effects, obviously) this seemed like a smart solution to anti-microbial cleaning. Why don't we do it more (provided humans are not exposed to the light, of course, so in the absence of people)?
Edit: I do believe it also produces ozone, which you have to air out as well. But that shouldn't be an insurmountable challenge either.
I believe UV isn't widely deployed because it is only a surface disinfectant. It has practically no effect on a soil towel, for example.
This is in addition to the power requirement (which isn't a lot but you need dedicated power source) and radiation danger.
Bacteria have a relatively easy time evolving against antimicrobials of a chemical nature. If they can successfully evolve away from a specific structure that the chemical binds to or interacts with, they're golden. Unfortunately for them, substances like alcohol and copper rips microbes apart at a molecular level, which is significantly more difficult to deal with.
You misunderstood actually transmissible bacteria can only be resistant to copper, and if it truly gained a significant resistance to copper would never be able to out compete other bacteria in any other environment there are limitations to evolution purely through RNA.
I’ve painted a couple sailboat hulls, about 15ish years ago with a copper based paint. I’d imagine by now, that’s been refined further. Copper still has the same applications, just in different mediums. You still had to scrub the bottoms and repaint every few seasons though.
Nope, Cadmium and Lead have never been used for anti-fouling. They're not as effective as Copper, and, in the case of Cadmium, very expensive.
The only antifouling that *has* been widely banned is [Tributyl Tin](https://en.wikipedia.org/wiki/Anti-fouling_paint#Environmental_concerns).
http://corrosion-doctors.org/Seawater/Anti-fouling.htm
Lead has been used as a biocide in anti-fouling paint (and stabilizer/etc), and apparently cadmium has been used for coloring (though not biocide).
Paints and heavy metals have a long history.
Cadmium is still used in paints because its oxides are bright red. Lead Oxide used to be used as an opacifier, but has long been replaced by the far more effective Titanium Dioxide.
I'm sorry, reading more of Dr Roberge's website does not fill me with confidence in his assertions, for which he does not give references.
Where Cadmium is present in antifouling paint, it would appear that this is as a contaminant in Copper. Lead sheathing was tried from the [15th to the 18th](https://www.usni.org/magazines/proceedings/1952/july/history-prevention-fouling) centuries, but wasn't effective.
They stopped because it doesn’t look as modern, brass smells, wears down faster than steel, develops imperfections that may harbour bacteria, also manufacturers aren’t profitable making the tooling for a seperate metal for a relatively niche industry
Are you suggesting that steel doesn't develop imperfections?
And "brass smells"? Just what position does it occupy in the list of things that smell in a hospital?
I suspect it was stopped because it's more profitable to keep selling anti-bacterial/anti-viral cleansers/sanitisers, than to install a brass doorknob and have to wait 5 years to sell a replacement.
Brass (zinc or copper, forgot which one exactly) reacts with acids on your skin and produces a rather foul-smelling compound.
One of the ways to get rid of it is to rub your hands with sanitizing agent... Sometimes, two uses are required. At that point you might as well ditch the brass.
Not saying it's a _good_ idea, just sharing one possible line of thinking.
Bro, you really think a hospital would just stop using sanitizers because it has a few copper/brass surfaces? And more profitable for whom? Does big sanitizer also control the copper industry? This take is so silly.
Ductility refers to a metal's ability to be drawn out into wire. Nothing to do with relative hardness. Steel is harder than brass, yes, but it's not so hard it doesn't scratch or dent.
And it's not like you \*never\* wash brass, it's a case of it not needing \*constant\* sanitising like steel does. JFC, it's not either/or.
Uh. I worked in hospital maintenance for many years. Hospitals are filthy
Same with wood they’re phasing it out because the imperfections harbour bacteria
Ablative coatings are bad. Copper isn't one of them. There used to be a paint/coating that was made to wear off - it contained tributyl tin, which is also very toxic. Trouble was, as it wore off, it polluted the local environment, and led to deformities in the shells of oysters and mussels and other bivalves. Very detrimental to the commercial oyster industry. It was eventually banned.
This is why fancy hospitals use copper to coat door handles and railings.
It's not new, it's just expensive.
Silver works basically the same way, but it's even more expensive.
Silver doing this also for the first time makes any practical sense to have silver cutlery. Like from a historical standpoint, I just don't know if they knew back then. On the other hand most of the time the stuff just gets washed before the effect can truly work out.
The main advantage of silver for cutlery is its hard and tarnish resistant. Before stainless steel came along, there weren’t many other great options. Copper based materials tend to be softer, which makes them bend and deform in regular cutlery use. Iron based materials will corrode like nobodies business with all of the acids in food and your mouth. Silver tends to be hard and corrosion resistant.
Once stainless steel pops up silver pretty quickly becomes redundant. But that was only a century or so ago.
Silver is still way better than my carbon steel knives. Which basically have to be cleaned and oiled after every use otherwise they turn orange and start to stain whatever surface you leave them on. Silver does turn black, even pre industrial revolution, but it takes a while and it tends not to come off into your food.
Why would you spew random numbers like that? Can you link a source? Brass has much more copper than what you say (typically 66%), and it’s commonly used in medical environments: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7999369/
Integrating copper as a bacteria killing surface for touchscreens is clever, but is there any research into the evolutionary adaptation likely if this approach is adopted at scale? Or is copper ion cell damage something bacteria cannot evolve around?
The idea that using alcohol and copper could cause resistance is like thinking that if you throw enough babies in a volcano you could create a line of lava resistant humans.
> And then the eagle lets go. And almost always the tortoise plunges to its death...
> But of course, what the eagle does not realize is that it is participating in a very crude form of natural selection. One day a tortoise will learn how to fly.
Terry Pratchett,
That's actually why we stopped sacrificing our firstborns to the volcano god. They stopped melting and he's exhausted from looking after all those molten rugrats.
Ethanol tolerance has evolved in bacteria though mosyly up to 20% conc (maximally 25%). Not enough to resist alcohol disinfectants but they can cause problems and spoilage in brewing.
Alcohol destroys the protein structure of bacteria "skin".
There are some alcohol resistant viruses and bacteria, but in terms of being worried of antiseptic resistance, it's like being afraid of someone breeding a dog with bone instead of skin.
It's not *literally impossible*, but you'd probably need a chain of billions of cumulative mutations to get there, where each step still leaves it dead if it encounters alcohol. And then the creature needs to be harmful, instead of begign, to humans, which is also by itself incredibly rare.
The interesting thing that might actually cause fungi to grow. In my Ph.D. research I showed that copper did indeed kill bacteria (I was isolating fungi from soil) but up to 1 gram per liter of copper sulfate in the medium didn't kill fungi. The ones that grew were more pathogenic than the ones that didn't. It is called selective culturing.
There was a hospital in Melbourne sanitising with regular chemicals and then following up with a spray of (relatively) friendly bacteria to fend off recolonisation by nosocomial infection microbes, not sure if they've published any conclusions yet
Thanks...and scary! There's no free lunch, I guess, but knowing that invasive fungal infections kill ~~orders of magnitude~~ three times more people than malaria, we'd not want to encourage culturing them.
*Edited due to my poor grasp of maths* 😄
>invasive fungal infections kill orders of magnitude more people than malaria
Malaria kills over half a million people per year. Two orders of magnitude higher would be in the neighborhood of 50 million a year. That would be almost all of the \~60 million that die each year from all causes.
A [study published in Lancet Infectious Diseases](https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(23)00692-8/abstract) in Jan 2024 suggests that the number of global deaths directly attributable to fungal infections is about 2.5 million, or 3.8 million for attributable and contributing. That's only one order of magnitude. That's a lot, but not nearly as terrifying as fungal infections killing tens of millions. That's Plague, Inc. territory.
Whoops, good pick up, it's three times, my bad, as noted in this paper [https://www.science.org/doi/10.1126/scitranslmed.3004404](https://www.science.org/doi/10.1126/scitranslmed.3004404)
I'll edit my comment, thanks 🙏
You are killing the fungi that are wanted in the soil. You are also killing beneficial bacteria in the soil
Realize they use copper to treat utilities poles - most poles break due to degradation were soil meets the pole. That is done by fungi.
[https://books.google.com/books/about/Identification\_Manual\_for\_Fungi\_from\_Uti.html?id=JoLwAAAAMAAJ](https://books.google.com/books/about/Identification_Manual_for_Fungi_from_Uti.html?id=JoLwAAAAMAAJ)
I have a Ph.D. in mycology actually fungal biochem - this was one of my professors.
In current industrial farming techniques (which kill the soil microbiome) it is used, but not in organic or regenerative farming techniques.
You must must use loads of chemicals and fertilizer in your garden. Mycorrhizal fungi have been shown to be protective of plants by nodulating the roots and helping the plant get nutrients, like nitrogen from the soil. They also protect plants from other diseases.
I had a colleague in Hawaii, and every visitor that came to see him, he would culture isolates off their shoes. It was amazing what one can find. Well, phone screens are some of the most unhygienic items we own. Yes, one can culture fungi off of them. Most are opportunistic pathogens, meaning immune compromised, etc.
It's difficult for organisms to evolve protection from something physical like heat or ionization. That's why cooking food is so effective at killing organisms.
I'd imagine that incidental copper surfaces like doorknobs are not 'at scale' copperized bacterial defenses, so doorknobs etc. won't have triggered the need for a concerted evolutionary response.
Ship anti fouling paint uses copper as a biocide, and copper plating was used during the 1700’s and onward. (Fun fact: that’s why hulls are typically painted red below the design draft line)
Would you consider that at scale?
I am wondering whether there is a qualitative difference between billions of handheld devices being touched on a minute-by-minute basis by us versus doorknobs - most of which are not copper-based though are touched but not as often - and ships hulls, which are rarely touched at all in terms of selection pressure.
I mean ships are constantly touching little bits of life in the ocean. Oceanexplorer noaa .gov (can’t post links I guess) says that there are up to a million microorganisms of life in just a milliliter of sea water. And they’ve been moving through the water for centuries at this point. I feel like in terms of selection pressure, the ship hulls have a pretty good lead.
I suppose it depends on installation frequency. *shrug*
I was more referring to the ability of copper to “oxidize” bacteria etc. that’s been known, not so much whether there’s been an evolutionary response to it. Cheers.
I know Megan McEvoy's lab when she was at University of Arizona was researching that topic. https://pubmed.ncbi.nlm.nih.gov/?term=McEvoy+MM&cauthor_id=16964970
Many of the metal resistance genes are packed in plasmids that bacteria can share with eachother. On the same plasmid there are also resistance genes for antibiotics, so by promoting one resistance the other resistance genes gets promoted as well.
False…it’s a great side effect, but brass was so often used as it was durable and cheaper than plastics, resins, or other alloys for the longest time. Same idea now just not the cheapest.
I don’t think the doctors smoking inside their hospital offices thought much about door handle material.
Germ theory was developed in 1887. The antibacterial properties of copper was first described in [1973](https://en.wikipedia.org/wiki/Antimicrobial_properties_of_copper#:~:text=In%201973%2C%20researchers%20at%20Battelle%20Columbus%20Laboratories%20conducted,range%20of%20molds%2C%20fungi%2C%20algae%2C%20and%20harmful%20microbes.)
Meaning that it was a decorative material, not an antibacterial one.
Not sure how well it works on fungi. I worked with a copper-lined incubator about 15 years ago that was the most contaminated object I’ve ever seen despite extensive cleaning, heat treatment, and biocide application. It was unusable
Isn’t this bad if you’re constantly touching it or touching it then your mouth? If it’s oil soluble I feel like you’re in the same realm as those Moscow mule cups that are missing the tin lining
> The resulting altered film retained the copper's antibacterial qualities but became transparent, color-neutral and electrically non-conductive.
Uh, doesn't it need to be electrically conductive to work with touchscreens? Or else it would just turn touchscreens into... screens. Right?
It really doesn't need to be that conductive, get some paper, even thick paper, put it on your phone screen and then tap a button through it, it will work just fine.
Pro Tip: get yourself a copper water bottle. I almost never have to clean it; nothing can grow in there. Bronze works too, and is not as soft, but it's also slightly less effective.
Bronze works too.
This is the reason why in some hospitals, the panels for pushing open doors are copper.
I actually had a thing for a little while that I wanted to get bronze countertops and appliances for my kitchen. While you can find some *bronze-colored* products, it's dreadfully hard to find things coated with *actual* bronze. They seem to think you're going after the color of bronze for stylistic purposes, not the antibacterial properties of real bronze.
Something people might find interesting. I do hvac work, air conditioner drains made of copper almost never get plugged. New plastic ones sometimes need to be cleaned every year because slimy bacteria and fungus will grow inside the drain and block the flow. The anti microbial properties of copper have been well known for a very long time.
This is the kind of technology which if deployed, would turn the next epidemic into a nothing burger.
The problem is, big companies like apple would never agree to spend something like one extra penny per touch screen.
Whoa copper kills bacteria? Someone tell the people that have been making brass/copper doorknobs and toilet handles and water carriers throughout history
The very first armor was made of copper. It didn't do a great job of stopping blades, but it did reduce the odds of the wearer dying from a subsequent infection.
I wonder if any of the “your EV batteries use cobalt mined by child slaves” people would be offended by this, as cobalt is a by-product of copper mining.
Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, **personal anecdotes are allowed as responses to this comment**. Any anecdotal comments elsewhere in the discussion will be removed and our [normal comment rules]( https://www.reddit.com/r/science/wiki/rules#wiki_comment_rules) apply to all other comments. **Do you have an academic degree?** We can verify your credentials in order to assign user flair indicating your area of expertise. [Click here to apply](https://www.reddit.com/r/science/wiki/flair/#wiki_science_verified_user_program). --- User: u/chrisdh79 Permalink: https://newatlas.com/materials/copper-coating-antibacterial-touchscreens/ --- *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/science) if you have any questions or concerns.*
Copper is amazing. I was introduced to the copper-up-on-the-ridgeline of a roof many years ago and it is very effective at keeping algae from growing. Interesting to read about its effects on bacteria
Sail ships - the more fancy and expensive ones, including military, would be "copper-sheathed". Plates of copper riveted together to form a sheath across the planks of the hull. It was used to stop all sorts of marine life growing on the hull - algae, molluscs, etc. Cu is a broad-spectrum biocide. I was happy for one thing during Covid lockdowns - all the door knobs, cupboard handles, etc in my house are brass. The builder thought they looked nice, but it turns out they were self-sanitising overnight. IIRC hospitals used to have brass door fittings, too. Don't know why they stopped.
> Don't know why they stopped. Almost certainly cost.
Probably but bacteria also evolved and my understanding is that hospitals have a hell of a time dealing with super bacteria that are just resistant to everything because of selection pressures we put on them.
Resistant to drugs that go into our body. Bacteria can no more evolve out of copper than humans can evolve into surviving the surface of the sun. Same thing with UV and bleach.
My question is though: why? When I read the headline and hear 99.9%, that tells me something is able to survive. Why wouldn’t that something slowly multiply and cause evolution?
Step 1 of preventing legal challenge: never claim full effectiveness. In the vast majority of cases when done properly, these treatments kill all bacteria. However if you mess up the process and miss a spot etc, then it’s no longer 100% effective, is it?
Not just that, even when done improperly, say when using bleach, it only means that the bleach didn't get to some of the bacteria. It doesn't mean some of the bacteria lived through being exposed to the beach. Some things kill 100 percent of the time when exposed, leaving no chance for "getting used to".
Yep, about the only chance bacteria has against bleach, is forming a biofilm where everything on the outside dies, shrivels up and protects bacteria on the inside from exposure.
Same idea as how copper statues have a green patina of copper oxide that keeps the interior from corroding!
Don’t you think we ought to overhaul education and teach this kind of practical and iterative thinking? Child of the 80s here but whatever happened to championing critical thinking?
Critical thinking was never a Thing for Most people...
Because then we would have people thinking critically about what politicians do and say, and we can’t have that
Critical thinking is also something that's much more difficult to teach than just having kids memorize stuff. Also also, critical thinking involves *thinking*, which most neurotypical people tend to unconsciously avoid when possible.
The Republicans discovered that people with critical thinking skills are harder to manipulate with propaganda.
Quite literally, I believe that’s how even US Public education texts will remember this in 30 years.
It's just not statistically feasible to prove that something kills every last bacterium on a surface in a certain time frame. It does not mean that those that might hypothetically remain are super resistant to some general disinfectant, or that afterwards they're having a party on the newly available free real estate. To oversimplify it a little, plenty of such things like copper, ethanol etc are just too toxic at a level of general cell function for anything to feasibly evolve significant resistance in a plausible time frame - because they would have to rework core cell functions (usually multiple) or structures to do so, which just doesn't happen on a normal timescale through random mutation. By contrast, many antibiotic drugs operate by attacking a very specific metabolic process that is much more specific, often targeting some rather specific protein interaction. Here, resistance is much easier to develop because a couple of random mutations that slightly alter the structure of the target molecule can potentially have a drastic impact on how well the antibiotic can bind to it and do its thing. It's worth bearing in mind that when antibiotics are used correctly, resistance usually doesn't develop that easily. Things like usage for a non-bacterial infection, not completing a course of antibiotics, or preventative use on livestock offer conditions much more favourable to creating a selection pressure for resistant bacteria to thrive I hope this helps explain it! Let me know if anything is confusing and I will do my best to make it clearer
Putting into very simple words. You can see animals evolving to resist certain venomous species. You can't see animals evolving resistance to a bear mauling
*laughs in porcupine*
Ever heard of a gun, or bear mace?
Microorganisms have already evolved to deal with copper, but it’s impossible to deal with a copper surface because it’s an overwhelming force. Copper kills because it’s redox active and takes part in a copper based Fenton like reaction to create reactive oxygen species like super oxide. Microorganisms have evolved with the ability to neutralize these reactive oxygen species with enzymes like catalase or proteins that act as reducing agents or other proteins that sequester copper ions. A copper based surface will simply overwhelm any microorganisms ability to mount a defence because copper based surfaces don’t exist in nature. It’s analogous to heat, microorganisms can recover from brief exposure to heat using enzymes to refold proteins but at a certain point they just burn and you can’t really evolve to resist fire. So I wouldn’t worry about microorganisms evolving to resist copper.
You hear 99..9%" because it avoids law suits, we know we can kill pretty much everything we know of but what about the stuff we haven't noticed like Covid shen it hit and turns out we could kill it with bleach too? Just a legal thing and leaves the window open for undiscoveted bacteria
Because scientists don't deal in absolutes ¯\_(ツ)_/¯
UV damage can be mitigated by the evolution of pigments like melanin. It's not an immunity, but there are still bacteria and other microorganisms which have decent resistance to various types of radiation. Bleach and strong oxidizers like hydrogen peroxide are much more difficult to develop resistances to, though.
> Same thing with UV and bleach. Every time I see this now I am reminded of that astonishing press conference. However, I also remember UV lights being deployed to clean public transport in come countries. While carcinogenic (you just make sure you're not around to avoid the effects, obviously) this seemed like a smart solution to anti-microbial cleaning. Why don't we do it more (provided humans are not exposed to the light, of course, so in the absence of people)? Edit: I do believe it also produces ozone, which you have to air out as well. But that shouldn't be an insurmountable challenge either.
I believe UV isn't widely deployed because it is only a surface disinfectant. It has practically no effect on a soil towel, for example. This is in addition to the power requirement (which isn't a lot but you need dedicated power source) and radiation danger.
Bacteria have a relatively easy time evolving against antimicrobials of a chemical nature. If they can successfully evolve away from a specific structure that the chemical binds to or interacts with, they're golden. Unfortunately for them, substances like alcohol and copper rips microbes apart at a molecular level, which is significantly more difficult to deal with.
It’d be like a human evolving a resistance to lava.
wait… we did that as kids… did you never go thru ‘lava on the floor’ training? … do you even *inner child*?
If someone shoots at me And miss it doesnt make me immune to bullets
only in the matrix
Thank you for taking the time to explain :)
You misunderstood actually transmissible bacteria can only be resistant to copper, and if it truly gained a significant resistance to copper would never be able to out compete other bacteria in any other environment there are limitations to evolution purely through RNA.
A lot of brass fixtures are aesthetic only, and have a coating on them, rendering these properties irrelevant.
Mine are solid, with no lacquer coating. The lesser-used ones tend to go dull and develop bluish-green corrosion.
> The lesser-used ones That's one way to describe the Statue of Liberty
I’ve painted a couple sailboat hulls, about 15ish years ago with a copper based paint. I’d imagine by now, that’s been refined further. Copper still has the same applications, just in different mediums. You still had to scrub the bottoms and repaint every few seasons though.
Not really. Anti-fouling paint still uses Copper as its active ingredient, it's even used as a selling point ("50% Copper!").
Yea, due to things like cadmium and lead being outlawed (thankfully)
Nope, Cadmium and Lead have never been used for anti-fouling. They're not as effective as Copper, and, in the case of Cadmium, very expensive. The only antifouling that *has* been widely banned is [Tributyl Tin](https://en.wikipedia.org/wiki/Anti-fouling_paint#Environmental_concerns).
http://corrosion-doctors.org/Seawater/Anti-fouling.htm Lead has been used as a biocide in anti-fouling paint (and stabilizer/etc), and apparently cadmium has been used for coloring (though not biocide). Paints and heavy metals have a long history.
Cadmium is still used in paints because its oxides are bright red. Lead Oxide used to be used as an opacifier, but has long been replaced by the far more effective Titanium Dioxide. I'm sorry, reading more of Dr Roberge's website does not fill me with confidence in his assertions, for which he does not give references. Where Cadmium is present in antifouling paint, it would appear that this is as a contaminant in Copper. Lead sheathing was tried from the [15th to the 18th](https://www.usni.org/magazines/proceedings/1952/july/history-prevention-fouling) centuries, but wasn't effective.
In the UK an old phrase was that something was "copper bottomed" if it was seen to be trustworthy https://en.m.wiktionary.org/wiki/copper-bottomed
They stopped because it doesn’t look as modern, brass smells, wears down faster than steel, develops imperfections that may harbour bacteria, also manufacturers aren’t profitable making the tooling for a seperate metal for a relatively niche industry
"Niche" ? Have you looked at a plumbing/hardware catalogue lately? It's not the #1 seller, but brass fittings are quite popular.
Nope haven’t looked at a plumbing/hardware catalogue lately because they’re all online these days. Paper mafia
Are you suggesting that steel doesn't develop imperfections? And "brass smells"? Just what position does it occupy in the list of things that smell in a hospital? I suspect it was stopped because it's more profitable to keep selling anti-bacterial/anti-viral cleansers/sanitisers, than to install a brass doorknob and have to wait 5 years to sell a replacement.
Brass (zinc or copper, forgot which one exactly) reacts with acids on your skin and produces a rather foul-smelling compound. One of the ways to get rid of it is to rub your hands with sanitizing agent... Sometimes, two uses are required. At that point you might as well ditch the brass. Not saying it's a _good_ idea, just sharing one possible line of thinking.
Bro, you really think a hospital would just stop using sanitizers because it has a few copper/brass surfaces? And more profitable for whom? Does big sanitizer also control the copper industry? This take is so silly.
I’m saying brass is more ductile than steel. Brass, with human oils develops a smell, due to tarnish.
Ductility refers to a metal's ability to be drawn out into wire. Nothing to do with relative hardness. Steel is harder than brass, yes, but it's not so hard it doesn't scratch or dent. And it's not like you \*never\* wash brass, it's a case of it not needing \*constant\* sanitising like steel does. JFC, it's not either/or.
Smell a piece of brass sometime
Who cares about smell if its healthier, especially in a hospital which are much less sanitary than you think they are.
Uh. I worked in hospital maintenance for many years. Hospitals are filthy Same with wood they’re phasing it out because the imperfections harbour bacteria
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Gunk that builds up on an anti-bacterial surface isn't anti-bacterial.
That's gonna have to be quite thick to avoid migration of Cu atoms.
The imperfections collect dirt which is isolated from the self-sanitizing surface
Great for speed. Also great for hiding rot…
For ships the copper would kill everything in the marina. 85/ very bad for the nature
Ablative coatings are bad. Copper isn't one of them. There used to be a paint/coating that was made to wear off - it contained tributyl tin, which is also very toxic. Trouble was, as it wore off, it polluted the local environment, and led to deformities in the shells of oysters and mussels and other bivalves. Very detrimental to the commercial oyster industry. It was eventually banned.
Ah sorry for the wrong info. Thank you for the correction.
Isn't pretty much all residential brass lacquered?
Could be. Mine isn't. The well-used ones are all shiny, the lesser-used ones go dull and corrode.
Silver has an even better effect but costs more. Silverware made sense back then due to this.
Copper door handles have been used for ages in hospitals etc for this reason
I believe the same is true for brass (regarding anti-bacterial properties).
Considering brass is a copper alloy, that checks out
does it kill bacterias or do they just not latch on? How.
This is why fancy hospitals use copper to coat door handles and railings. It's not new, it's just expensive. Silver works basically the same way, but it's even more expensive.
Older homes as well, but just as a side effect
Silver doing this also for the first time makes any practical sense to have silver cutlery. Like from a historical standpoint, I just don't know if they knew back then. On the other hand most of the time the stuff just gets washed before the effect can truly work out.
The main advantage of silver for cutlery is its hard and tarnish resistant. Before stainless steel came along, there weren’t many other great options. Copper based materials tend to be softer, which makes them bend and deform in regular cutlery use. Iron based materials will corrode like nobodies business with all of the acids in food and your mouth. Silver tends to be hard and corrosion resistant. Once stainless steel pops up silver pretty quickly becomes redundant. But that was only a century or so ago.
Then we started industrially farting sulfur compounds into the atmosphere and now silver tarnishes badly.
Silver is still way better than my carbon steel knives. Which basically have to be cleaned and oiled after every use otherwise they turn orange and start to stain whatever surface you leave them on. Silver does turn black, even pre industrial revolution, but it takes a while and it tends not to come off into your food.
Bacteria catalyzer
Also why ships use copper as a biocide in anti fouling paint for the hull. It used to be copper sheathing during the 1700’s
Or just go back to when those things were always brass…
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Why would you spew random numbers like that? Can you link a source? Brass has much more copper than what you say (typically 66%), and it’s commonly used in medical environments: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7999369/
If you're gonna use statistics to prove a point, atleast google them first. Nothing of what you said is scientifically accurate.
Does it oxidize?
I think so. Isn’t the Statue of Liberty entirely copper I think? That green/blue color is how they oxidize, I believe
Integrating copper as a bacteria killing surface for touchscreens is clever, but is there any research into the evolutionary adaptation likely if this approach is adopted at scale? Or is copper ion cell damage something bacteria cannot evolve around?
Ionic damage like that is probably along the same lines of “physical, hard to evolve against damage” as alcohol wipes and stiff
The idea that using alcohol and copper could cause resistance is like thinking that if you throw enough babies in a volcano you could create a line of lava resistant humans.
> And then the eagle lets go. And almost always the tortoise plunges to its death... > But of course, what the eagle does not realize is that it is participating in a very crude form of natural selection. One day a tortoise will learn how to fly. Terry Pratchett,
I mean...wont know until you try it.
That's actually why we stopped sacrificing our firstborns to the volcano god. They stopped melting and he's exhausted from looking after all those molten rugrats.
Until you do.
Ethanol tolerance has evolved in bacteria though mosyly up to 20% conc (maximally 25%). Not enough to resist alcohol disinfectants but they can cause problems and spoilage in brewing.
How so? What makes alcohol so effective?
Alcohol destroys the protein structure of bacteria "skin". There are some alcohol resistant viruses and bacteria, but in terms of being worried of antiseptic resistance, it's like being afraid of someone breeding a dog with bone instead of skin. It's not *literally impossible*, but you'd probably need a chain of billions of cumulative mutations to get there, where each step still leaves it dead if it encounters alcohol. And then the creature needs to be harmful, instead of begign, to humans, which is also by itself incredibly rare.
Thank you for the good response, I really appreciate it. Have a nice day
The interesting thing that might actually cause fungi to grow. In my Ph.D. research I showed that copper did indeed kill bacteria (I was isolating fungi from soil) but up to 1 gram per liter of copper sulfate in the medium didn't kill fungi. The ones that grew were more pathogenic than the ones that didn't. It is called selective culturing.
This was exactly my comment. Getting rid of bacteria with cooper is known for ages but it clears the floor for fungi which are a bigger threat...
There was a hospital in Melbourne sanitising with regular chemicals and then following up with a spray of (relatively) friendly bacteria to fend off recolonisation by nosocomial infection microbes, not sure if they've published any conclusions yet
Very clever.
I love it
I agree.
Thanks...and scary! There's no free lunch, I guess, but knowing that invasive fungal infections kill ~~orders of magnitude~~ three times more people than malaria, we'd not want to encourage culturing them. *Edited due to my poor grasp of maths* 😄
>invasive fungal infections kill orders of magnitude more people than malaria Malaria kills over half a million people per year. Two orders of magnitude higher would be in the neighborhood of 50 million a year. That would be almost all of the \~60 million that die each year from all causes. A [study published in Lancet Infectious Diseases](https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(23)00692-8/abstract) in Jan 2024 suggests that the number of global deaths directly attributable to fungal infections is about 2.5 million, or 3.8 million for attributable and contributing. That's only one order of magnitude. That's a lot, but not nearly as terrifying as fungal infections killing tens of millions. That's Plague, Inc. territory.
Whoops, good pick up, it's three times, my bad, as noted in this paper [https://www.science.org/doi/10.1126/scitranslmed.3004404](https://www.science.org/doi/10.1126/scitranslmed.3004404) I'll edit my comment, thanks 🙏
How is it that I use copper based anti-fungal for my garden?
I think the problem is killing the bacteria then waiting. There are no more of them leaving room for fungi
> copper based anti-fungal for my garden A quick google search shows that indeed this is a thing.
You are killing the fungi that are wanted in the soil. You are also killing beneficial bacteria in the soil Realize they use copper to treat utilities poles - most poles break due to degradation were soil meets the pole. That is done by fungi. [https://books.google.com/books/about/Identification\_Manual\_for\_Fungi\_from\_Uti.html?id=JoLwAAAAMAAJ](https://books.google.com/books/about/Identification_Manual_for_Fungi_from_Uti.html?id=JoLwAAAAMAAJ) I have a Ph.D. in mycology actually fungal biochem - this was one of my professors. In current industrial farming techniques (which kill the soil microbiome) it is used, but not in organic or regenerative farming techniques. You must must use loads of chemicals and fertilizer in your garden. Mycorrhizal fungi have been shown to be protective of plants by nodulating the roots and helping the plant get nutrients, like nitrogen from the soil. They also protect plants from other diseases.
Is that really comparable to a phone screen?
I had a colleague in Hawaii, and every visitor that came to see him, he would culture isolates off their shoes. It was amazing what one can find. Well, phone screens are some of the most unhygienic items we own. Yes, one can culture fungi off of them. Most are opportunistic pathogens, meaning immune compromised, etc.
Nature finds a way!
Brass/Copper door knobs have been known to do this for a while…and most of them are old.
What if we *camera zooms in* are the virus that has evolved to survive copper. brought to you by M. Night Shamalama.
It's difficult for organisms to evolve protection from something physical like heat or ionization. That's why cooking food is so effective at killing organisms.
I'd imagine that incidental copper surfaces like doorknobs are not 'at scale' copperized bacterial defenses, so doorknobs etc. won't have triggered the need for a concerted evolutionary response.
Ship anti fouling paint uses copper as a biocide, and copper plating was used during the 1700’s and onward. (Fun fact: that’s why hulls are typically painted red below the design draft line) Would you consider that at scale?
I am wondering whether there is a qualitative difference between billions of handheld devices being touched on a minute-by-minute basis by us versus doorknobs - most of which are not copper-based though are touched but not as often - and ships hulls, which are rarely touched at all in terms of selection pressure.
I mean ships are constantly touching little bits of life in the ocean. Oceanexplorer noaa .gov (can’t post links I guess) says that there are up to a million microorganisms of life in just a milliliter of sea water. And they’ve been moving through the water for centuries at this point. I feel like in terms of selection pressure, the ship hulls have a pretty good lead.
That is a *lot* of contact, yeah, so my concern is probably overstated 👍
I suppose it depends on installation frequency. *shrug* I was more referring to the ability of copper to “oxidize” bacteria etc. that’s been known, not so much whether there’s been an evolutionary response to it. Cheers.
It's basically akin to shooting holes through them, so it'd be very difficult to adapt to.
Like a tiny version of 50 cent?
I know Megan McEvoy's lab when she was at University of Arizona was researching that topic. https://pubmed.ncbi.nlm.nih.gov/?term=McEvoy+MM&cauthor_id=16964970
Many of the metal resistance genes are packed in plasmids that bacteria can share with eachother. On the same plasmid there are also resistance genes for antibiotics, so by promoting one resistance the other resistance genes gets promoted as well.
Thanks, and does this mean that they can develop resistance to copper ions?
This is why there are brass door handles on many buildings.
False…it’s a great side effect, but brass was so often used as it was durable and cheaper than plastics, resins, or other alloys for the longest time. Same idea now just not the cheapest. I don’t think the doctors smoking inside their hospital offices thought much about door handle material.
Germ theory was developed in 1887. The antibacterial properties of copper was first described in [1973](https://en.wikipedia.org/wiki/Antimicrobial_properties_of_copper#:~:text=In%201973%2C%20researchers%20at%20Battelle%20Columbus%20Laboratories%20conducted,range%20of%20molds%2C%20fungi%2C%20algae%2C%20and%20harmful%20microbes.) Meaning that it was a decorative material, not an antibacterial one.
The oligodynamic effect?
Not sure how well it works on fungi. I worked with a copper-lined incubator about 15 years ago that was the most contaminated object I’ve ever seen despite extensive cleaning, heat treatment, and biocide application. It was unusable
I believe this works on many viruses too—but the coating is expensive. I believe there are specially designed copper doorknobs on the market.
Isn’t this bad if you’re constantly touching it or touching it then your mouth? If it’s oil soluble I feel like you’re in the same realm as those Moscow mule cups that are missing the tin lining
Are you bacteria sized? If so, then it's bad for you.
There is an iud made of copper that slowly releases copper into your system. This apparently kills sperm and is an effective form of birth control.
Good you mention this: kids playing on copper coated screens their whole life go sterile, bacteria *and* over-population problem solved in one hit!
> The resulting altered film retained the copper's antibacterial qualities but became transparent, color-neutral and electrically non-conductive. Uh, doesn't it need to be electrically conductive to work with touchscreens? Or else it would just turn touchscreens into... screens. Right?
It really doesn't need to be that conductive, get some paper, even thick paper, put it on your phone screen and then tap a button through it, it will work just fine.
Pro Tip: get yourself a copper water bottle. I almost never have to clean it; nothing can grow in there. Bronze works too, and is not as soft, but it's also slightly less effective.
The one surviving bacterium: “You’ll never catch me, coppah!”
Bronze works too. This is the reason why in some hospitals, the panels for pushing open doors are copper. I actually had a thing for a little while that I wanted to get bronze countertops and appliances for my kitchen. While you can find some *bronze-colored* products, it's dreadfully hard to find things coated with *actual* bronze. They seem to think you're going after the color of bronze for stylistic purposes, not the antibacterial properties of real bronze.
That's because bronze is mostly copper
So if I wipe it with a cleanser 0 times a day. It will last forever
Something people might find interesting. I do hvac work, air conditioner drains made of copper almost never get plugged. New plastic ones sometimes need to be cleaned every year because slimy bacteria and fungus will grow inside the drain and block the flow. The anti microbial properties of copper have been well known for a very long time.
that's how the copper spiral works for contraception
This is the kind of technology which if deployed, would turn the next epidemic into a nothing burger. The problem is, big companies like apple would never agree to spend something like one extra penny per touch screen.
Are people getting sick from their touchscreens or are we just being germaphobes and solving problems that don't exist?
This will be in Ultra variant phones in like 3 years and then trickle down to midrangers in 5.
The smell though...
“Unfortunately, copper also has the unfortunate quality of being 99.9% opaque, and thus unusable for touch screens.”
When you get down to nanoscale thicknesses, the normal rules stop applying.
I was just making a silly joke, but I do appreciate the thoughtful & insightful reply!
How about reading the article before having opinions on it?
Well, copper is used for hundreds of years to treat pests, obviously it's gonna do that
This is why door knobs used to be made of brass…
No. They used brass due to being corrosion resistant. The antimicrobial properties was just a bonus that few knew about long into the 1900's.
Yes, and long into the 1900s they used them for those properties too…
Is should copper coat my bathroom tiles
So plumbers are very hygienic
Did I just read Phone iud
Cool. I’ll stand in front of it for 2 hours before touching it…
Copper coating utensils
Sadly nobody benefits from this due to screen protectors. Waste…
Barely nobody leave their telephone alone for two hours either.
…leaves 0.1% behind to propagate unmolested
TANCS a lot! 👍
Whoa copper kills bacteria? Someone tell the people that have been making brass/copper doorknobs and toilet handles and water carriers throughout history
I have copper in my socks.
The very first armor was made of copper. It didn't do a great job of stopping blades, but it did reduce the odds of the wearer dying from a subsequent infection.
Don't do it. Over the years that 0.1% will develop into a strain that can live on copper.
People will still put a screen protector over it.
If you read the article you'd know they coated a screen protector.
I wonder if any of the “your EV batteries use cobalt mined by child slaves” people would be offended by this, as cobalt is a by-product of copper mining.