9 votes

Copper-coated doorknobs to kill COVID? It makes sense, say scientists

6 comments

  1. WanderingMulberry
    Link
    Good on these guys for bringing attention to this, but overall this is a strange article that half reads like a promotional piece. The anti-bacterial nature of many metals is fairly well known...

    Good on these guys for bringing attention to this, but overall this is a strange article that half reads like a promotional piece.

    The anti-bacterial nature of many metals is fairly well known going back decades, especially for Group 11 elements[Copper, Silver, Gold] or their alloys.

    From what I see they are taking existing doorhandles and 3D printing a 5mm layer of copper over the top for $50-$100 a piece? That's more than the cost of a full copper doorhandle bought down the road.

    If replacing handles was of most utmost importance rather than buying new, it would be far less to get copper, silver or gold electroplating done and likely to last a lot longer, metal 3d printing is tough to do and in its infancy.

    On the whole this feels like an attempt to capitalise on a situation and get some free publicity rather than offering anything substantially new. The huge "activated copper" promotional sign next to the door in the article probably gives it all away. Can anyone comment on what "activated copper" actually is compared to straight up old copper?

    10 votes
  2. [2]
    skybrian
    Link
    I'm wondering about tarnish, but I suppose that also means not being cleaned is visible. I wonder if brass would be a good alternative?

    I'm wondering about tarnish, but I suppose that also means not being cleaned is visible. I wonder if brass would be a good alternative?

    2 votes
    1. NaraVara
      Link Parent
      Zinc is also supposed to have pretty pronounced anti-microbial properties (they even weave it into high-performance athletic wear to prevent malodorous bacteria from building up). Since brass is...

      Zinc is also supposed to have pretty pronounced anti-microbial properties (they even weave it into high-performance athletic wear to prevent malodorous bacteria from building up). Since brass is an alloy of copper and zinc I think it's a pretty good bet.

      4 votes
  3. [3]
    DanBC
    Link
    SARS-CoV-2 can remain "alive" on copper for about 4 hours. I'm not sure what benefit high traffic areas are going to see. I feel that it's probably better for people to think "this door handle is...

    SARS-CoV-2 can remain "alive" on copper for about 4 hours. I'm not sure what benefit high traffic areas are going to see.

    I feel that it's probably better for people to think "this door handle is disgusting and I need to wash my hands" than to think "eh, I'll probably get away with it this time".

    Better than copper-plated door handles would be hands-free entrance and exit as far as possible.

    1 vote
    1. [2]
      Algernon_Asimov
      Link Parent
      Did you read the article? So, whatever remains at the end of 4 hours is going to be only a tiny fraction of the initial deposit of virus particles. It might not be enough to infect a person....

      SARS-CoV-2 can remain "alive" on copper for about 4 hours.

      Did you read the article?

      SPEE3D, the company which has been 3D-printing copper door furniture, commissioned its own study from a Melbourne-based virus lab which showed copper reduced viral levels by 96 per cent within two hours.

      So, whatever remains at the end of 4 hours is going to be only a tiny fraction of the initial deposit of virus particles. It might not be enough to infect a person. Especially in an environment like a hospital, where copper door handles would be only one of many techniques used to prevent or reduce infections.

      The article contains a link to a study which showed "The coverings cut the risk of acquiring a hospital-acquired infection by more than half."

      This is like that furphy that the coronavirus can be detected for up to 72 hours on some surfaces. Yes, it can be detected, but the handful of virus particles remaining after 72 hours is not necessarily going to be able to infect someone.

      Don't let perfect be the enemy of good. Just because copper doesn't kill 100% of the coronavirus in 1 second, that doesn't mean it isn't providing some benefit. And any benefit is good.

      1. DanBC
        Link Parent
        i) I'm not going to pay much if any attention to self-funded, unpublished "laboratory testing" pushed out in a sales pitch press release. ii) 96% after 2 hours doesn't mean anything. We need to...

        i) I'm not going to pay much if any attention to self-funded, unpublished "laboratory testing" pushed out in a sales pitch press release.

        ii) 96% after 2 hours doesn't mean anything. We need to know how much they put on and how much remains. The infectious dose of SARS-CoV-2 is likely to be very small, so the 4% that remains after 2 hours is in real world settings easily enough to infect multiple people.

        iii) I mentioned 4 hours. The press release (you did read it, right?) said: "The results showed that 96% of the virus is killed in two hours and 99.2% of the virus killed in 5 hours".

        iv) I mentioned high traffic areas. In a high traffic area it doesn't matter much if it's 4 hours or 2 hours or 1 hour -- we need it to be minutes to make any difference.

        v) Copper is expensive. That money is better spent elsewhere.

        vi) The press release mentions that stainless steel is used in hygiene environments. The reason they use stainless steel is because it tolerates a wide range of cleaning chemicals. Copper doesn't. Bleach corrodes copper.

        This isn't about letting perfect be the enemy of good. It's about not being a gullible fool who swallows bullshit PR.

        2 votes