At the suggestion of a reader who is in a high-risk group for COVID-19, we present these instructions from University of Colorado Boulder professor Dr. Sara Sawyer:

If you are in the high-risk group for COVID-19, you are presumably staying at home now (good) but your biggest vulnerability may be things coming into your home — delivered groceries, Amazon packages, food from neighbors, etc. Like door handles, these things can harbor viruses too, at least for a short time.

If you are sheltering-in-place and feel that you need to take extra precautions for a high-risk member of your household, you can decontaminate things before they come into your house.  Read on if you want to know how. This post addresses common questions that I am getting about mail, fruits, groceries, etc.

The following advice is my own, tailored for this specific situation, and is the best advice I can come up with based on the extensive biosafety training that I have received as a research scientist who works with human viruses.

Most importantly, don’t get too stressed out.

1. Your risk of getting infected by deliveries showing up at your door is very low.
2. The virus doesn’t live for long on surfaces, and your items have usually been in transport for some time.
3. Over the short window of stability of the virus, your items have probably been handled by few people, rather than the many that you would encounter by going to the store yourself.  So delivery is a good option.
4. The main route by which viruses on packages would infect you would be by contaminating your hands. Washing your hands with soap and water is STILL the most important thing you can do

Tools at your disposal

You have two tools at your disposal for decontaminating items:

1. Time
2. Disinfectant

Time — Researchers at the National Institutes of Health have shown that no viable COVID-19 virus could be measured after 24 hours on cardboard. So, with mail and boxes, you could just let these items sit for a day before you handle them.

However, they also found that the virus is stable for up to three days on plastic and stainless steel. So, for Amazon boxes and non-perishable food, you would need to let them sit for three days before you unpackage them or start rummaging through.

Disinfectant –  For perishable things like milk, or things to which you need urgent access, you can spray these things with a disinfectant either before bringing them into your home, or in a dedicated area of your house after you bring them in (see below).

The CDC is recommending the following as disinfectants for COVID-19:

1. 2% bleach (meaning, 2 parts household bleach to 100 parts water)
   1. Do not ever mix bleach with other chemicals as it is highly reactive
   2. Unfortunately, bleach solutions need to be made fresh every day
   3. Make with 5 tablespoons (1/3rd cup) bleach per gallon of water, OR
   4. Make with 4 teaspoons bleach per quart of water
2. 70% alcohol (isopropyl alcohol is the easiest to acquire)
   1. Adjust to 70% with water if what you buy is greater than 70%
   2. This solution is pretty stable if kept in a spray bottle
3. Many common household disinfectants should be effective, things like Lysol and Clorox products, including many of the ones that say something like “kills 99.9% of germs.”
   1. The Environmental Protection Agency, or EPA, has a list of specific approved product names on the web; even though the website is sort of maddening, it’s worth looking up the particular chemicals that you happen to have since it’s hard to buy anything new at this point: www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2.
   2. These chemicals, if on the approved EPA list, should have equal efficacy if they are in wipe or liquid form.

Note: Wear gloves and make sure you have good ventilation when using these products.

Steps to setting up your decon station in your home, if you feel that you need one

Materials you will need:

1. Plastic trash bags
2. Disposable medical gloves (which you will re-use)
3. A spray bottle of a disinfectant, or disinfectant wipes.

Steps:

1. Chose a location. This could be your porch or garage. If you don’t have these things, chose somewhere in your house and cover an area of the floor with plastic trash bags. If you happen to have a utility sink, this could be turned into a dedicated decon station (please don’t sue me though if this ruins your sink, this is just “emergency” advice from a person with good intentions).  Always test your disinfectant on the area to make sure it is not going to destroy things.
2. Keep these things nearby:  1) your gloves, 2) your spray bottle or wipes, 3) another trash bag into which you will immediately put all “unwrapping” trash.
3. Everything that comes into your house should go straight to the decon station, either laid on the plastic or in your dedicated sink.  Spread your items out. Then, if you don’t yet have your gloves on, go clean your hands elsewhere with soap. When cleaning your hands, touch faucet with a tissue or dedicated cloth if it’s not the lever kind you can’t turn on with the back of your hand.
4. Come back to your station and put on the gloves.
5. Spray every item with disinfectant.  Use your gloved hands to then spread the disinfectant around all of your items.  Let them air dry – disinfectants require contact time to work property.
6. Spray your gloves with disinfectant, rubbing your hands so that all surfaces of the gloves get covered, and then carefully take them off and leave them at your station.
7. When your items are dry, you can handle them with your bare hands and put them away.

What about fruits and vegetables?

So, about those fruits and vegetables, which are delicate…. Many people are having fruits and vegetables delivered to their homes, with the checker, the shopper and maybe even a driver touching the food or the bags along the way. Washing them with water and a vegetable brush should be effective, especially if you combine this with time.

I would suggest letting them sit for 1 day, and then washing them well with water and a brush. If you really want to be safe, you can add a little soap to the wash. Or, you can put some 2% bleach solution (see above) in a large ziplock back and roll your fruits and vegetables around in it a little. You would then want to rinse them well before eating. Keep in mind there is not any science on this exact question of fruit and COVID-19, but this advice reflects my most educated guess.

Is there a safe way to get take-out from local restaurants?

Here is some advice for hot food that is delivered to your home. Cooking food kills enveloped viruses such as this one. So, the main risk comes from the food packaging, which has been handled by people but not decontaminated like the cooked food itself. If you feel that you need to take extra precautions, this is what I would recommend.

1. Take one of your own pans/casserole dishes to a clean place near your decon station.
2. Put your gloves on, unwrap your takeout, dump food into your own dish.
3. Dispose of takeout containers, sanitize gloves, and remove them.
4. Go pick up your dish with your food and re-heat it thoroughly before eating.