How to get groceries without bringing home coronavirus On Coronacast


Tegan Taylor: Hello, this is Coronacast, a podcast all about the coronavirus where we answer your questions. I’m ABC health reporter Tegan Taylor.

Norman Swan: And I’m physician and journalist Dr Norman Swan, presenter of ABC’s Health Report on Radio National.

Tegan Taylor: So, Norman, everyone has been really good at staying at home as much as possible, but one of the few things that we are able to do during this social distancing period is going out to the supermarket. So it’s no surprise we are getting lots of questions about how to stay safe at the shops. So we decided we’re going to do a whole episode on it today.

Norman Swan: Yes, because it’s our whole world, the supermarket.

Tegan Taylor: That’s right!

Norman Swan: So what are we starting with, Tegan?

Tegan Taylor: Let’s start with social distancing in the shops itself. How far should we be staying apart from other shoppers when we are at the supermarket?

Norman Swan: The rule for supermarkets is the same as the rule for everywhere else. You’ve really got to maintain about a two-metre difference, about six feet away from other people and you’ve just got to be tempted not to barrel up towards them, just keep back and think about that quite carefully and step back if other people are getting in your way, don’t get upset about it, just get out of the way. Social distancing is really important.

Tegan Taylor: What about with staff? You have to stand a bit closer than six feet from staff sometimes, and also should they be wearing masks and gloves and that sort of thing?

Norman Swan: We get a lot of questions about staff. So there’s two elements to staff, one is people at the tills, and increasingly in supermarkets you’re seeing those Perspex screens, which stop customers transmitting their droplets to the staff and staff transmitting their droplets to you, so you would assume that they are pretty effective.

And staff serving the shelves, there’s not a lot of advantage to gloves, we’ve spoken about this before. Gloves can give you a sense of invulnerability when in fact it’s not merited because if you touch a surface with gloves that’s infected with coronavirus, the gloves are going to get infected and you can pass it on to something else. So you’re much better, almost certainly, not to wear gloves in that situation and to just wash your hands regularly before and after you touch objects. So it does mean the staff need to be using hand sanitiser a lot.

Masks are controversial. The main reason for wearing masks in an environment of a supermarket is if you’re asymptomatic, you’re less likely to pass it on to other people. So it will be up to the policies of the supermarket or the person involved. It’s probably not going to make a huge amount of difference but if you choose to wear a mask, it will help.

Tegan Taylor: You mentioned shelves before, people stacking shelves and stuff, what are the chances of me as a shopper picking up coronavirus from a product that’s on a supermarket shelf?

Norman Swan: You’re much more likely to pick up coronavirus from coming close to somebody who is coughing or sneezing or breathing out the virus, from the droplets in the air rather than on surfaces. We have talked a lot about surfaces and you can get it from surfaces, but the reality is it’s a lower-risk situation than just the general close contact with somebody and sharing the air that they breathe. It sounds disgusting but it’s the way it is. So products from shelves, the risk is low, and simply if you observe hand hygiene, you take the products off the shelves, you put them in the trolley, and then you wash your hands or you use hand sanitiser, then that’s a pretty safe place to be. And most of the products on the shelves that you’re going to be buying are cardboard or paper, and the coronavirus doesn’t last that long on there, up to a day, but it decreases quite quickly. Products on the shelves are pretty safe, they are not entirely safe, but if you’re just prudent about hand hygiene, not touching your face when you’re shopping, that’s going to keep you pretty well protected.

Tegan Taylor: That actually leads really well into the next question which is from Jim. He’s 80, so obviously he’s in that higher age group, maybe a higher risk of having a bad outcome if he gets coronavirus. He’s got himself on the priority list for home deliveries, they are going to be left on the front porch. He is wondering whether he should be trying to sterilise any items. He’s got hand steriliser and some alcohol spray. Should he be spritzing his groceries before he brings them inside?

Norman Swan: I think, again, it’s a bit like the shopping situation where to be really prudent you might want to just leave the outside packaging outside and just take in the products themselves, even though that may be a little bit more laborious. And once you’ve done that, then it wouldn’t do any harm with plastic or steel, those hard surfaces, to spray it with isopropyl alcohol if you have it. That’s a way of ensuring the situation for yourself. If you want to dispose of the packaging itself then it would be pretty safe to go outside, put it in the bin and then wash your hands with soap and water afterwards. And again, after you’ve handled the products, soap and water afterwards just on your hands to actually make sure that you are protecting yourself.

Tegan Taylor: We’ve got Tricia asking about how to keep surfaces clean, especially at home, what the best concentration is for a bleach and water solution or should you just lather everything in soapsuds. What do we know?

Norman Swan: I think there is no question that the safest and simplest thing to use for surfaces is detergent. Detergent gets rid of this virus because it knocks off the fat around the virus and exposes it and the virus dies. So that’s the most effective thing. You can go to bleach and peroxide, but the problem with bleach is you’ve got to then get to the right concentration of sodium hypochlorite which is the active chemical in bleach, and the concentration is 0.1%. Not 1% but 0.1%. And you’re better Googling a calculator for bleach dilution because inevitably if I tell you how to dilute it, it’s going to get wrong and you’re going to make a mistake. But the key message here with bleach is if you’re dilating it yourself to 0.1%, you’ve got to be super careful and don’t add any other chemicals other than bleach. But detergent works well, so why bother with bleach is really what I think.

Tegan Taylor: What about washing other things, fruit and veg, should we be using detergent for that? Can you use hot water, should you use cold water? Help us!

Norman Swan: If only we really knew the answer to this question.

Tegan Taylor: Exactly.

Norman Swan: I think most people say the risk from fruit and veg is low and you should just wash it the way you would normally wash it, which is in cold water, thoroughly, and dry it off as you would normally dry it off. That is going to be fine. And the reality is by the time you get home, these surfaces that are organic, the virus may well not survive that long on them. And so the key here is just wash the way you would normally, the risk is extremely low, and you’re much better off having fresh fruit and vegetables than the small risk of catching coronavirus from them.

Tegan Taylor: The questions are coming thick and fast. I’ve got hot questions and cold questions for you. So, first of all…

Norman Swan: Let’s go hot.

Tegan Taylor: Let’s go hot first. Does boiling water kill the virus? If you poured boiling water on your car keys or something like that, would that kill it?

Norman Swan: Well, it would certainly kill your car keys. As we have just said, all you need is detergent. There is no question that cooking and high temperatures will kill this virus, but that doesn’t mean to say you want to douse everything in boiling water. That’s dangerous, you could scald yourself, you could scald the kids that are around, and you don’t need to do it. And it’s not going to convincingly catch all the virus. Because, just think about it, let’s imagine that you pour boiling water on packaging or something like that. At the point where you’re impacting the piece of cardboard or whatever, yes, there might not be very much coronavirus left, but there might be coronavirus down at the bottom that you haven’t actually dealt with. So you’re much better dealing with this with what we know, which is detergent, if you’re talking about surfaces, if you’re talking about cleaning products or alcohol, spraying 70% alcohol on it, that’s going to be much more effective and you’ll still be able to start the car in the morning.

Tegan Taylor: Okay, so now for my cold question. We’ve got Andrew asking about buying milk that goes in a fridge or things that are going in the freezer, frozen meats wrapped in plastic. Do we know about how much the virus survives at low temperatures?

Norman Swan: I think we can safely say that the virus will survive in the fridge and it probably will survive in the freezer as well. Not absolutely convincing evidence on that but the safe assumption to make is that it could survive both the fridge and the freezer. So it does mean that if you want to be really sure and you have a milk carton, then just get some detergent and wipe down the milk carton before you put it in the fridge, the same with a bottle of milk and so on. And then it’s unlikely that there is any virus on it at all. You probably just want to…I think just general hygiene, you probably just want to be cleaning the fridge frequently with detergent, so that you’re not leaving things lying around. And frozen meats, again, if it’s in a package, if you wipe the package with detergent before you put it in and then rinse that detergent off so that there’s not soap going around your freezer, then when you take it out there is not going to be any virus on it. But if you put it in without washing it and there was virus, then it probably will still be on it. So I think that you just need common sense there and treat each touch as a potentially risky touch and wash your hands before and afterwards.

Tegan Taylor: So we know that washing our hands is a really important part of stopping that virus getting into our faces which is how we get sick. Tony is asking; should he coat his hands in liquid antibacterial hand wash before he goes to the shops? Is there any value in this or does he need water to activate the soapiness?

Norman Swan: You need to actually create a soapy effect to get the surfactant going, the stuff that breaks down the fat. So just putting on the soap itself will get you some surfactant effect, but actually diluting it with water and getting some lather up is really what you want to see to kill the virus.

Tegan Taylor: So there’s the detergent itself and then there is also the actual rubbing that works together.

Norman Swan: The rubbing and the foaming are really important parts of it.

Tegan Taylor: Well, that’s it for Coronacast today. We are planning a mental health episode for next week, with special guest Ian Hickie, so if you have any questions related to mental health, jump on to, and just make sure to add the word Coronacast into your question so we can find it easily.

Norman Swan: And we’ll see you tomorrow. And tomorrow we’ll be publishing our social media myths episode, so subscribe and keep an eye out for that. See you then.

Tegan Taylor: See you later.

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