Comment by duffpkg | Hacker News Reader

Comment by duffpkg | Hacker News Reader

As someone that has built and operated large multipractice and acute care facilities some of the most vicious fights I've had with medical entities and boards is about changing hardware back to the older brass/copper which is inherently antibacterial and only needs cleaning with soap/water to self disinfect versus stainless steel which needs cleaning with bleach and can foster or even lead to the creation of resistant and other problematic bacteria. The objections were mostly about the visual appearance. I am not sure I see the advantage to this new material over the good old brass/copper. There is a perceived cost premium to it but it isn't meaningful in practice. This paper alleges this new process is cheaper but I would be incredibly dubious of that. At ClearHealth we were successful in substantially reducing hospital acquired infection (HAI) rates at managed facilities to industry best in part because of our "reversion" to copper/brass hardware.

One of the most obvious signs you are in a well managed health system is seeing copper/brassy touch surfaces instead of stainless.

https://www.copper.org/publications/newsletters/ba-news/2010... https://en.wikipedia.org/wiki/Antimicrobial_properties_of_co... https://www.statnews.com/2020/09/24/as-hospitals-look-to-pre...

Do the useful properties of copper change with oxidation?

Silver is also antimicrobial, and also expensive.

FWIU nanospikes in silicon achieved virucidal outcomes in small trials as well.

Is copper virucidal without nanospikes?

(On this topic, Hemp textiles are antimicrobial / bactericidal: https://news.ycombinator.com/item?id=39196781#39197019 )

"Scientists create virucidal silicon surface without any chemicals" https://pubs.acs.org/doi/10.1021/acsnano.3c07099 https://news.ycombinator.com/item?id=39196822

Oxidation is a problem as is physical debris but touch surfaces are cleaned at least daily in a hospital setting anyway. Plain old Copper/brass that has been used since forever is virucidal without any special treatment.

Is the claim then that copper nanospikes on stainless steel are of no greater value than copper for healthcare applications?

Is that claim supported by evidence?

The claim is that spikes kill faster, but probably not fast enough to matter since spikes are destroyed with shear cleaning.

A frequently touched surface isn’t going to have a problem with oxidation:

https://en.m.wikipedia.org/wiki/Statue_rubbing

So the people rubbing breasts of statues to a shine were doing it for uh... serious reasons?

For medical reasons thank you very much

You should see the brass bull on wall st

I looked at the wiki article but it did not touch on the anti-bacterial effects. Are there any studies?

P.S. I am really curious (if just mildly) if anyone knows.

Edit: Ok it did touch on the subject.

"It is also possible to acquire a bacterial infection from touching statues."

The is even a reference to an article (https://atlasbiomed.com/blog/european-biome-monument-study-r...). Have not read yet but looks interesting.

Copper and silver express the "oligodynamic effect," a tendency for antibacterial action, most strongly.

Brass is a useful alloy of copper that does not oxidize and also exhibits this effect.

https://en.wikipedia.org/wiki/Oligodynamic_effect

From the Wikipedia page:

> The oligodynamic effect was discovered in 1893 as a toxic effect of metal ions on living cells, algae, molds, spores, fungi, viruses, prokaryotic, and eukaryotic microorganisms, even in relatively low concentrations.[7] This antimicrobial effect is shown by ions of copper as well as mercury, silver, iron, lead, zinc, bismuth, gold, and aluminium.

So I can justify wearing a bunch of oversized gold chains as “for my health”?

Go the whole-hog and dip yourself in mercury.

Terracotta army style. I like it!

Yes, and that means you can buy the jewelry with FSA/HSA funds

Copper is of course, chemically incompatible with most disinfectants and cleaners and will corrode. Which is one reason it stopped being used when ammonia/etc became super common. They are less common now in straight form (even Windex is no longer mainly ammonia unless you use the original formula version)

So solid copper/brass i can get behind because it probably doesn't affect lifetime meaningfully, but I am very curious how the coating in the article withstands splashes of ammonia or peroxides or other things used to clean the floors or windows.

I was wondering about this too, it's not viable to have a coating which necessitates changing equipment periodically. It will add logistical problems and waste. I think you are right in that using solid metals instead, makes more sense, given antibacterial properties have been known to exist for these for a while. The question is if all types of pathogens can be removed without damaging the equipment, or if material research could create an alloy which just like stainless steel, could make the metal form an oxidation layer which would protect it in case of contact with corrosive liquids.

Nosocomial infections are terrifying because they're often things that have as you said survived in a very harsh environment. Thank you for doing your part to reduce them.

Set up a company selling remarkably over-priced “medical” door handles and healthcare providers will fall over themselves to buy them.

Changing handles in busses/trains from metal to plastic probably killed more people than a lot of other common causes. Everyone is touching those things, they are dirtier than cash.

Wood also has excellent antimicrobial properties e.g. makes a much safer cutting board than plastic

...but you can easier wash plastic in the dishwasher, while wooden cutting boards get warped and destroyed.

Wash wood or eat microplastics from the cutting board.

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