An easy way to limit your exposure to COVID-19 is to quit going out grocery shopping and buy groceries online instead. But there's a problem: This review found that coronaviruses can persist on inanimate surfaces for up to 9 days at room temperature (EDIT: Maybe as many as 17 days, actually. See this.) There's no way to know how many infected people handled your package before it got to you.

This is a protocol my roommate and I came up with for handling packages safely. Although it looks like a lot of steps, most individual steps aren't all that long. I chose to err on the side of including extra steps that you can cut if you want to save time. Obviously, if you're at increased risk of mortality from COVID-19, extra steps are going to be more worthwhile. (In addition to the elderly being at greater risk, the WHO's report says that people with cardiovascular disease, diabetes, hypertension, chronic respiratory disease, or cancer have a mortality rate of 5-15%.)

Your time will be spent most efficiently if you process multiple boxes at once.

You will need

Note: It's been estimated that practically everyone in the US will have the virus by mid-May. So even if you think this procedure looks overly paranoid, you might want to buy these items now so you have them on hand in case things get worse. (How you gonna disinfect your box of disinfecting supplies without any disinfecting supplies?)

Anyway, you'll want (optional things in italics):

  • A long sleeve shirt and long pants--ideally clothes you don't care very much about that are too big for you (they might shrink when you put them through the dryer on high heat for disinfection)
  • 3 pairs of gloves
  • A knife
  • Bleach. If bleach isn't available, get hydrogen peroxide or concentrated ethanol, and use disposable gloves instead.
  • Immunostimulants or similar (Edit: OR NOT). This paper has a list of supplements you could try in Table 1. Might as well get some Vitamin D too (Edit: OR NOT).
  • Moisturizer/lotion
  • Rubber bands
  • Mask/eye protection

If you want to use items in your boxes soon:

  • A spray bottle
  • A washcloth

Note that most of these items, including gloves and a jug of bleach, can purchased for $1 each at Dollar Tree. They even have glucosamine, one of the supplements recommended in the paper.

Getting started

To economize on time, I recommend waiting until you were about to take a shower anyway before starting this procedure, since showering is one of the last steps. Ideally, get set up for your shower before you start the process.

And it's probably better to work during the day so you can see what's touching what.

Preparation steps (optional steps are in italics):

  • Take Chris Masterjohn's recommended supplements (garlic consumption details) and/or things recommends.
  • Moisturize your hands. You'll be washing your hands at the end, and you want to be moisturizing regularly so your skin doesn't dry out and develop cuts.
  • If you have long hair, tie it back. If you have facial hair, shave it so your mask will fit better.
  • Put on your long sleeve shirt & long pants. Use rubber bands to pull your shirt tight around your wrists so it covers your forearms as well as possible.
  • If you're impatient to use the things in your boxes, prep disinfection solution in spray bottle:

The analysis of 22 studies reveals that human coronaviruses... can be efficiently inactivated by surface disinfection procedures with 62–71% ethanol, 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute. Source * Bleach products are typically around 5% sodium hypochlorite, so if you dilute 10x (1 part bleach 9 parts water), you'll have 0.5% sodium hypochlorite--5 times as strong as needed. * Also grab a washcloth and put a clock within viewing distance of where you'll work so you can time a 60-second wait.

  • Otherwise, designate a place inside your house for letting potentially infected items sit for 9 (edit: or 17!) days. The ideal place is warm and dry (e.g. near a heater vent--not so near that air streaming from the vent will blow virus everywhere though). Sunlight exposure can't hurt either.

Disinfection procedure

  • Turn on lights, open doors, open washing machine, open recycle bin, etc. so you won't have to touch these things during disinfection. Turn on an air filter if you have one.
  • If you'll be disinfecting lots of boxes, get your boombox so you can play a disaster movie soundtrack on loop in the background.
  • Put on 1st pair of gloves plus eye protection and mask.
  • Might as well handle your mail first. Wearing gloves, open your mailbox (your mailperson touched it!) and slice open envelopes with your knife. Dump the contents of the envelopes in your 9-day wait spot and drop the empty envelopes in the recycle bin.
    • The envelope has probably been handled by more people than whatever's inside. So try not to move virus from the envelope to the contents--keep your knife cuts shallow, or even cover your knife in bleach before you start.
  • Open all boxes with the first set of gloves and your knife. Push box flaps down. Set gloves & knife aside. Try not to touch the outsides of the boxes from now on. (Who knows how many people handled them.)
  • Take off 1st pair of gloves (when removing gloves, be sure not to touch the outside of the glove with your bare hand) and put gloves+knife in an "infected items" spot. Put on 2nd pair of gloves.
  • If you're impatient to use box contents, disinfect them using your spray bottle. Pick up an item and spray 6 inches from it until it's wet all over. Once all items have been sprayed, allow spray to remain for 60 seconds.
    • If you want to leave items in boxes during the 60 second wait, you might also spray the inside of the box so items don't just pick up virus from the inside again. But it's probably better to put the items somewhere else.
    • Put on 3rd pair of gloves. (The 3rd pair won't get infected, they're just to protect your skin from disinfectant.) Use the washcloth to wipe disinfectant off.
      • Bleach can leave a residue--be sure to wipe it all off, instead of letting it evaporate off, if you don't want residue.
  • Otherwise, use 2nd pair of gloves to move box contents to designated 9-day wait spot.
  • Put 2nd pair of gloves in "infected items" spot.
  • Go take a shower. Be careful with your clothes because they might have virus on them. Wash areas of your skin that might have touched infected surfaces.
  • Put your clothes in the laundry. (Be sure to wash+moisturize your hands after putting possibly-infected items in the washer but before using washer controls.)
    • If you're alright with ruining the colors on your clothes, use bleach and throw in the gloves as well.
    • Otherwise wash normally, then dry on the highest heat setting for at least 28 minutes (wash+moisturize hands after transferring from washer to dryer--clothes haven't been disinfected yet!) Then do a 2nd load with bleach and the gloves (does double duty cleaning both the gloves and the washer itself).
  • Turn off your boombox.
  • If you're using the wait option, I suggest you make a record of the date and the things that were left in the waiting spot. We have a whiteboard near the waiting spot that we use for this.

I think the simplest way to deal with the empty boxes is actually to leave them in your yard, then slice them up for recycling while wearing the 1st pair of gloves the next time you go through the disinfection procedure. (Remember, coronaviruses appear to survive ~indefinitely at colder temperatures, so just because a box has been sitting in your yard for 9 days doesn't mean it's disinfected!) If you have a backyard that's bigger than your front yard, you might want to move boxes to your backyard right after putting on the first pair of gloves, to avoid cluttering your front yard up.

Excessive? Maybe. I say this is the one time this century that germaphobes are 100% right. (Well, hopefully there won't be more times later in the century...)

EDIT March 29: Some commenters in this thread convinced me the procedure was excessive, so I relaxed it, and now I'm sick with something that I suspect is COVID-19. Only the paranoid survive.


Please comment or send me a personal message if you have any suggestions:

  • More steps that could be added
  • Steps that don't seem very essential
  • Reorganization for greater efficiency
  • Incorrect factual claims (I'm not an expert on any of this)
  • Etc.

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27 comments, sorted by Click to highlight new comments since: Today at 1:41 AM

UPDATE: Former head of CDC says to be super-safe, wait 3 days, not 1 as I suggested. Otherwise, they seem to agree with my assessment that the above procedure is way overboard. (And John, I hope you're feeling better - the last facebook update I saw from you said it didn't seem to be COVID, but I haven't seen any updates.)

Original Comment: I've seen less paranoid suggestions in biosecurity laboratories get (correctly) dismissed as unnecessary and a waste of time. Note that If the virus were as transmissible as you seem to assume, China wouldn't ever have contained it with "only" masks, isolation, and handwashing. Even if you're worried the mail carrier coughed onto your box picking it up before delivery or on the way to your house - the only plausible way there could be enough viable virus on the box to make anyone sick given the data from the linked paper, there's a far simpler procedure that is just as effective - wait a day, and the virus will be dead to an extent that you can't get infected. (To be fair, I'm assuming coughing on the box, not large globs of spit that could remain viable without drying out. So if you want to be extra paranoid, wait 2 days. Also note that an exception to this is ordering fresh fruits and vegetables from a store, since you're putting those into your mouth. In that case, you'll be fine if you wash them with vegetable wash, and then wash your hands.)

If you really can't wait, you can open the box outside, wash your hands correctly before touching the things inside, remove the contents, then put the box in the garbage, and wash your hands correctly. Do not touch your face during this approximately 1-minute time period, and even if it's been coughed on by someone with COVID-19, you'll be fine. And bleach is unnecessary and bad for your lungs, which you'll need if you want to be likely to stay healthy if you do contract COVID-19. And there are no spores that would fly off and attach to your clothes, so if you're reasonably careful not to rub against the box, then (unless you are using the box as a percussion instrument) any droplets on the box shouldn't spread to your clothes.

wait a day, and the virus will be dead to an extent that you can't get infected.

The paper that I've seen that tried to estimate this only reported TCID50/mL; how do you convert from that to infection risk?

[I think their methodology also might have been the equivalent of 'licking the box' instead of, say, touching the box with your finger and then touching your lips with your finger and then licking your lips, but for simplicity's sake let's assume I'm licking the box.]

First, please don't lick the box. Second, I'm not a virologist, but the review he cited says that the survival time on paper, which will be similar to that of cardboard. That's also assuming the droplets stay wet, which under non-laboratory testing conditions they will not.

I can't find the full paper anywhere, but the PubMed abstract of the paper it cited says:" SARS coronavirus in the testing condition could survive in serum, 1:20 diluted sputum and feces..." - That also sounds like they preserved the droplets from drying, as they did in similar studies that were cited - - though I can't tell.

I'm working off this paper, which did test cardboard.

I'm not a lab scientist, and haven't worked in a lab since undergrad, but they say the method was end-point titration on Vero E6 cell - i.e. they put the sample on a bunch of cells that come from a standard line (of monkey kidney cells) for it to infect those cells, and tested those cells using titration.

That sounds like licking to me.

Also, +25 points to that paper for using Stan for the markov-chain monte carlo modeling, and only -10 for having appendixes in MS Word format.

Edit: and they do say the results for cardboard were unusually noisy, so it's less reliable, but either way the virus was dead in a day.

Do you have citations for these claims?

I agree that China's success is evidence this procedure is overkill. Edit: this comment has some potential caveats though--seems the US is probably doing worse than China in terms of ensuring delivery people aren't infected.

wait a day, and the virus will be dead to an extent that you can't get infected.

I linked to a meta-analysis finding that the virus can remain infectious on surfaces for much longer than a day, especially in colder temperatures.

And bleach is [...] bad for your lungs

Good to know. Hopefully wearing a mask will help with that.

1) That wasn't a meta analysis, it was a review.

2) The viral load in a cough droplet is rarely as high as - and the review only said 9 days for viral loads of , which is silly. The paper in question -
- also incubated the virus in a suspension, instead of leaving it to dry. And much of the literature is talking about stool samples rather than cough drops. Lastly, the infectiousness of a droplet that hasn't dried, which isn't relevant to the current discussion, still depends on the surface. You're talking about cardboard, which will perform similarly to paper, and the results noted in the review are clear that it's not a very hospitable surface

3) Typical masks don't filter out chemical fumes. Odor respirators will help, but unless that's specifically what you have, your masks aren't doing anything to help reduce how much of the bleach fumes are reaching your lungs

  1. That wasn't a meta analysis, it was a review.

Thanks, fixed.

  1. The viral load in a cough droplet is rarely as high as 10^5, and the review only said 9 days for viral loads of 10^7, which is silly.

Silly, eh? What if it's not a cough droplet? What if the delivery person is picking their nose?

You're talking about cardboard, which will perform similarly to paper, and the results noted in the review are clear that it's not a very hospitable surface

The review cites a study which allegedly found that SARS persisted 4-5 days on paper. Paper may very well be an inhospitable surface, but that fact does not seem clear from the review...

If you wash your hands after handling the box, again, none of this matters.

We do clothes etc same but wear mask spray box all over with 3 per cent peroxide wait a minute put box inside a tight tied plastic bag.wait 14 days.wear mask take out wash soap water all contents.wash mask clothes shower.does this make sense.I have immune 2 problems. Mail is a pain as hav do same and often trash mail we put boxes after 14 days then open in bag tie take dump,

Just edited the post with updated info re: which supplements are likely to be helpful.

It's possible that the easier solution is just put everything in a box with an ozone generator. Faster too. Evidence of efficacy needs reviewing.

Please don't use ozone - it's really bad for your lungs, and it's unclear that it works to dry the droplets. (And if they are wet, it seems likely they will be buffered from exposure to the ozone.)

This would be inside a sealed container that you then open outside.

Thanks for writing this up. Since the time you published this, and given the comments and other developments, I'm curious if you still feel that this is necessary? The CDC and FDA websites both don't rule out food-borne transmission but say it's unlikely, and suggests from a federal study that it can live on cardboard for up to 24 hours, and on plastic and stainless steel up to 72 hours.

Update: I've come down with something which I think may be COVID-19. Even if it isn't, it goes to show that you can't be too careful. (In addition to following a relaxed version of the above disinfection protocol, my roommate and I also went for a hike the other week, but we went off the trail in order to stay a solid 20 feet away from the few other hikers we saw.)

Definitely wishing I had ignored the skeptics in this thread and maintained full paranoia.

Well that sucks. Take care of yourself and stay sane during isolation!

BTW this video might be worth a watch:

The website for this product says it's used for training in major hospitals, so I think it's reasonable to guess that germs really do spread as easily as the video suggests.

Me and my roommate both work from home (and were doing that well before the pandemic). So packages, letters, and maybe the trash person touching our trash bins are essentially the only possible way for us to get infected. It takes less time & attention for us to be paranoid about external contacts than it takes for us to make sure to not touch our face, wash our hands frequently, etc. etc. Comments in this thread updated me in the direction that the procedure I described is excessive, but I'm still handling packages with gloves + bleaching the gloves afterwards (not right away but before using them again) and letting packages dry out for multiple days before touching them or their contents with bare hands. I actually think taking these precautions takes less time & attention than doing a sufficiently careful read of the literature to figure out if I can be less cautious (and remember, even if the literature says X, X is not necessarily true since studies don't always replicate). I also think that as things peak, for those who are immunocompromised, you might as well be really paranoid since your life is at stake and most packages will probably be handled by someone who's infectious.

Just saw this (h/t Stefan Schubert):

SARS-CoV-2 RNA was identified on a variety of surfaces in cabins of both symptomatic and asymptomatic infected passengers up to 17 days after cabins were vacated on the Diamond Princess but before disinfection procedures had been conducted (Takuya Yamagishi, National Institute of Infectious Diseases, personal communication, 2020). Although these data cannot be used to determine whether transmission occurred from contaminated surfaces, further study of fomite transmission of SARS-CoV-2 aboard cruise ships is warranted.

This isn't necessary. The half life of free CV is estimated at 1-2 hours. While it's true that CV DNA can still be detected after several days, this says more about detection technology than CVs virulence. After 12 hours we'd expect the number of active virus particles to be reduced by over 99% rendering the risk very minimal.

This seems to be

(a) news coverage - so not necessarily reliable, of

(b) a preprint - so not peer reviewed

My article is a peer-reviewed [edit: maybe not very peer reviewed] literature review, aggregating results from multiple studies (that's important).

The 1-2 hour number you cite is for aerosolized virus. The article says the number is 24 hours for cardboard.

However, variability between studies is quite high. Look at Table 1 in my article. Search for the keyword "Paper" and you'll see that for the same amount of virus at room temperature on paper, one study got 3 hours and another study got 4-5 days. (It's possible this is because different strains were used, but that doesn't reassure me either--it suggests that the virus could quickly mutate to be viable on surfaces much longer.)

While it's true that CV DNA can still be detected after several days, this says more about detection technology than CVs virulence.

A quote from the Results section of the paper I cited (emphasis mine):

Most data were described with the endemic human coronavirus strain (HCoV-) 229E. On different types of materials it can remain infectious for from 2 hours up to 9 days.

See my responses in the other thread below.

The drop-off in infectiousness is documented in the papers reviewed in the paper you cited, which agrees with the parent comment.

And variability between cited studies is expected when the review failed to distinguish between wildly different conditions - it ignored differences between stool, urine, and cough droplets, and between different methods, since some of the papers allowed the droplets to dry, and others incubated them.

Finally, again, the paper you cited isn't a meta analysis, it's a review. And the preprint isn't just a preprint, it's a paper being reviewed for NEJM by a very well respected group, while the published paper is by a first author who is on the editorial board of, and is listed as being accepted the day it was received in, "Journal of Hospital Infection." I'm thoroughly unimpressed by the supposed peer review that occurred.

Edited to add - The accepted preprint is now live on NEJM

The drop-off in infectiousness is documented in the papers reviewed in the paper you cited, which agrees with the parent comment.

Is your claim that the paper I cited agrees with Josh's comment? That's what it sounds like you're claiming. Can you cite the specific sentence in the paper I cited that agrees with Josh's comment? Because all I see is the review repeating the claim "Human coronaviruses can remain infectious on inanimate surfaces for up to 9 days" over and over.

And elsewhere in this thread you said "the results noted in the review are clear that [paper] is not a very hospitable surface", but that is very much not clear as noted in the review--in Table 1, you can see they're citing a study that they summarize as SARS-CoV persisting for 4-5 days on paper.

It could be that the review is summarizing these studies inaccurately. But if you want to earn my trust you have to say something like "yes the review says X but really Y is true", instead of confidently misrepresenting things that I can easily check for myself.

I find it plausible that this review was slapped together quickly in response to the COVID-19 pandemic and a closer look at these studies would find the 9 day figure cited in the abstract to be unjustified. But until that's done in a formal way, I don't see why I should trust you more than the first author of this review (who seems to be a professor at a German university who's written many papers on topics related to this for a variety of journals)--your comments are looking very slapped together as well. BTW, the Journal of Hospital Infection seems legit to me.

Source 25 in the review paper, which is what the review cites for multiple days on paper, and the point you're defending, is the one I cited in the reply below, and even quoted, where I pointed out it wasn't relevant. I'm not just confidently stating things, I linked to it in the comment I pointed you to when I said "See my responses in the other thread below."

And I don't think the review was citing anything inaccurately, it was doing what a review article should, which is summarize the sources. It did that. I'm objecting to your conclusions. And if the source paper disagrees with the conclusion you made from the review, you should go to the original paper, not return to the review. In this case, the full paper is not available online because it is from before the journal had PDF versions. The summary, however, notes that despite storing the samples so they wouldn't dry, "The survival abilities on the surfaces of eight different materials and in water were quite comparable, revealing reduction of infectivity after 72 to 96 h exposure." It seems they didn't test before that amount of time, and so the source for 4 days is an upper limit. This even agrees with most of the other results - see the next paragraph - because they didn't dry the sample, and after the test exposure, they put the remaining virus into cells, in ideal conditions, and looked at whether they could still reproduce ("cytopathic effect".)

Look at source 26, the other source cited in the review that discussed paper: "SARS-CoV GVU6109 can survive for 4 days in diarrheal stool samples with an alkaline pH, and it can remain infectious in respiratory specimens [that are kept wet] for >7 days at room temperature. Even at a relatively high concentration (104 tissue culture infective doses/mL), the virus could not be recovered after drying of a paper request form..." This seems to match what the other paper says, despite using a different variant of SARS, but note the actually relevant point that if the sample dries, it's going to be safe. Which as I keep saying, is the key point. (And if it isn't, you can just wash your hands. That works. It's enough.)

Finally, I didn't say JHI wasn't legit - it's in NCBI - - but I object to dumping on a paper by a half dozen people, including those at NCIRD and NIAID, as "just a preprint" compared to a review paper that wasn't itself peer reviewed, and didn't follow PRISMA guidelines for systemic reviews. Both papers are perfectly fine, so I took issue with you dismissing one of them.

OK, I think I see what's going on--I didn't realize you were pointing to your reply to Vaniver.

I don't think the assumption of drying is necessarily justified--the package could be getting delivered on a humid day. These kind of questions might be really important to someone who has diabetes or something like that.

Thanks for weighing in btw, I'm learning stuff about how to evaluate research here :)

Why wouldn't you just leave the whole package sitting around for 9 days in a warm place? Then any virus on both the outside of the package and whatever is inside would be killed by then.