What a Food Microbiologist Wants You to Know About COVID-19 - Modern Farmer

What a Food Microbiologist Wants You to Know About COVID-19

A Q&A with Rutgers University professor Donald Schaffner.

Photography by eldar nurkovic on Shutterstock

Food microbiologist Donald Schaffner hasn’t been shy about trying to debunk some of the myths and misinformation spreading on the internet about food and COVID-19. He spoke with Modern Farmer about best practices when it comes to buying, washing and eating food during the pandemic.

The following interview has been edited and condensed for clarity.

Modern Farmer: What practical advice do you have for people when they’re grocery shopping during the pandemic?

Donald Schaffner: Before you get to the grocery store, come with a list and a plan for getting through the store as quickly and as efficiently as possible. I believe that the single biggest risk from the grocery store is not from the food but from the people. Either there is somebody symptomatic who shouldn’t be there or somebody who is presymptomatic and they don’t know that they’re sick.

When you arrive at my supermarket, the first thing you see is a big sign that says “please sanitize your hands,” and there is hand sanitizer there. That’s not to protect me. That’s in case I have coronavirus on my hands and it will protect everybody else in the grocery store. So that’s a super good practice.

There’s discussion of whether you should use the cashless system. Personally, I use the self-checkout, but I would use that not in times of pandemic, because I’d just rather do it myself. But, obviously, if you have a cashier who’s wearing gloves and using hand sanitizer between transactions, those are best practices as well.

Hitting the same hand sanitizer stand on the way out is also a best practice. When you get home, wash your hands, or use hand sanitizer, put your groceries away, and then go ahead and wash your hands or use hand sanitizer again.

MF: Do people need to wear gloves when they’re out grocery shopping or is using hand sanitizer enough?

DS: I saw some people walking around the grocery store pushing a cart with plastic bags on their hands. That seems a little silly to me.

The issue with gloves is an interesting one. On the one hand, if it makes you feel better, wear gloves. But on the other hand, if there is a glove shortage, it’s probably better that they’re available for people in healthcare who really need those gloves.

MF: If people are using disposable bags or boxes, do you think those need to be disinfected, or do they need to throw them out immediately?

DS: No. I don’t think there is a risk from food packaging. We don’t know of any COVID-19 cases from food, and we don’t know of any cases from food packaging either.

If you’re preparing a meal, and maybe handling some of the same packaging again, a really good thing to do, even before the times of pandemic, is that before you sit down to eat that meal, wash your hands or use hand sanitizer again.

I’m not disinfecting my packaging. I’m not recommending other people disinfect it. Probably the most vulnerable people in my family are my 80-plus-year-old parents. I am recommending that they not go to the grocery store, but I’m not recommending they disinfect their packaging material. I just think it’s a little bit silly.


Donald Schaffner. Photo courtesy Donald Schaffner.


MF: Should people be using reusable bags?

DS: New Hampshire Governor [Chris] Sanunu has apparently banned reusable bags. I think that’s ridiculous. There is no evidence of conventional food-borne disease from reusable bags, and there is certainly no evidence of COVID-19 transmission from reusable bags.

If you do use reusable bags, you should probably wash them on a regular basis.

MF: Should people be worried at all about ordering food from restaurants?

DS: I’m not concerned about takeout or delivery from restaurants. In these tough times, it’s really important that we all have food. I’m doing my best to patronize local restaurants that I patronized before, because their business is down.

I don’t sanitize the takeout package or delivery package, but after I take the pizza out of the box, I am definitely going to wash my hands before I sit down to eat. But that’s a best practice at all times.

MF: You’ve said that not all grocery stores are contaminated, and simply touching produce won’t make you sick, but what will?

DS: Inhaling coronavirus from somebody next to you who sneezed or coughed and is breathing it out.

MF: Are there particular types of food, like canned foods, that you would recommend over other types?

DS: No. I haven’t changed my eating habits at all. It’s important to eat a balanced diet. I would hate it if people cut down on their consumption of fresh foods and vegetables just because of the pandemic. I don’t think that’s a good idea. We need to keep eating a diverse array of food.

MF: You’ve said hand washing is not magic. What did you mean by that?

DS: Hand washing does not sterilize your hands. Hand washing is a good thing to do. We should definitely do it, but depending on your technique, what kind of microorganism and what kind of soap you’re using, washing your hands will give you about a 90- to 99-percent reduction in the concentration of micro-organisms on your hands.

Hand washing is good. It reduces risk, but it doesn’t eliminate risk. I would say the risk reduction is moderate.

MF: Do people need to clean their food? And how should they be cleaning their food?

DS: I’m not doing anything different than I did before. I wash my fresh produce under cold water. If I get triple-washed lettuce from the store that comes in a package, I don’t wash that again.

Washing fruits and vegetables in soapy water is absolutely not recommended. Soap is for dishes and hands. It’s not for cleaning food. If you ingest soap, it can cause nausea, vomiting and diarrhea. Eating even a little bit of soap residue is not a good idea.

MF: How effective are veggie-wash products or vinegar when it comes to washing produce?

DS: Vinegar is no more effective than water, especially if you mix it with water. Veggie wash products are interesting. These got popular a number of years ago because they were purported to remove pesticides. Once people got concerned about ecoli, salmonella and listeria in their food, these veggie washes pivoted to claim to remove those organisms. I would say buyer beware. Be careful about purchasing these products. They’re probably not going to harm you, but they may not really help you and may not be worth the money you’re spending on them. There are very few of these products that actually have scientific peer-reviewed evidence that they work any better than just plain water.

MF: Did you have any other practical advice for people when it comes to buying, washing or eating food in times of pandemic?

DS: The real risks of COVID-19 come from being around other people. We’re only into a couple weeks of social distancing and probably have a couple months ahead of us. I know it’s really tempting to go out and be around people, but realize that social distancing is super important right now. So try to figure out a way to do it that works for you and doesn’t make you crazy.

It’s always a good idea to wash your hands and use hand sanitizer. With all of this handwashing that’s going on, some people are noticing that their hands are getting chapped. So in addition to hand washing, you might want to pick up some moisturizer for your hands. That chapping can lead to infection and it can make it harder to remove organisms that end up on your hands.

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Amadeus Guy
4 years ago

What is known is that the virus is viable for 2 to 3 days on metal and plastic. Possibly 24 hours on cardboard. Even if there are no cases due to food packaging yet confirmed means that we should be in error on the side of caution until we are certain. There is nothing silly about that.

4 years ago

I have created a DIY protector for hands for use in places such as supermarket.
It is like pocketed scarfs but modified to better suite the purpose.
It is there for you to slip on when you need it for activities like pushing
the shopping cart or opening store door. But you take your hands out like if you
were taking them out of your pockets when taking out your credit cards or
picking up food. I include a link to a youtube video to the protector.

Adair Ivie
4 years ago

Great article. We definitely need more informative, fact and science based news about the current Covid-19 pandemic. Thank you!