Novel Coronavirus Detectable After Six Days on Stacked Materials: REALM Project

Returning to materials tested in the first round of research, scientists found the virus remains on hardcover books, paperbacks, a DVD case, and mylar protective book cover jackets longer when stacked.

The REopening Archives, Libraries, and Museums (REALM) Project released results from its fourth round of testing, which shows stacking items keeps the novel coronavirus (SARS-CoV-2) alive on materials longer than if they are unstacked. 

According to the report, "Results show that after six days of quarantine the SARS-CoV-2 virus was still detected on all five materials tested. When compared to Test 1, which resulted in nondetectable virus after three days on an unstacked hardcover book, softcover book, plastic protective cover, and DVD case, the results of Test 4 highlight the effect of stacking and its ability to prolong the survivability of the SARS-CoV-2 virus." 

The REALM project, supported by Institute of Museum and Library Services (IMLS) funding, is a multi-phase research project designed to give librarians information to create an evidence-based protocol for safety when reopening during the continued threat of the novel coronavirus. 

Read the full release on this latest test from IMLS below.

Scientists Find Virus Still Detectable After Six Days on Four Common Library Materials When Stacked

Washington, DC— Scientists have found that the virus SARS-CoV-2 that causes COVID-19 is still detectable after six days on four common library materials when they are stacked, which is a significantly longer attenuation period than had been detected on similar materials when they were not stacked.

The findings are part of the REopening Archives, Libraries, and Museums (REALM) project designed to generate scientific information to support the handling of core library, museum, and archival materials as these institutions begin to resume operations and reopen to the public. Scientists at Battelle have now completed four separate tests on groups of commonly found and frequently handled materials in these institutions.

In the most recent test, scientists tested four materials similar to those in the first test group—the cover of hardcover books (buckram cloth), the cover of softback books, a DVD case, and mylar protective book cover jackets—only this time, the materials were stacked to simulate common storage configurations in libraries and archives. While the virus was not detectable on the materials laid flat after three days in the first test, the virus was still detectable on similar materials after six days when the materials were stacked. (See Test 4 results .)

"The REALM project continues to produce results about the coronavirus and how it interacts with library and museum materials,” said IMLS Director Crosby Kemper. “This fourth set of research findings will help librarians and museum professionals continue to offer services and begin to welcome patrons back to public spaces. This ongoing research helps provide an up-to-date and fuller understanding of the virus so that libraries and museums can develop and implement protocols with care in service to their communities."

“There is still a great deal that we don’t know about the coronavirus and its spread,” said Skip Prichard, OCLC President and CEO. “Our goal is to add to this knowledge in ways that help libraries, archives and museums plan with greater confidence as they re-open and put in place processes to better protect their users and their staffs.”

“The findings in this latest test strengthen the need for the continued coronavirus research we are conducting,” said Will Richter, Principal Research Scientist at Battelle and a leader of the research being done for the REALM project. “We have to approach each situation with an open mind and determine next steps based on the data generated.”

The REALM project is supported by the Institute of Museum and Library Services (IMLS), the primary source of federal funding for museums and libraries; and OCLC, a nonprofit library technology and research organization; in partnership with Battelle, a not-for-profit global scientific research and development organization.

Project updates are posted at as they become available. Those interested can also sign up through the project website to receive timely email updates when new information is released.

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Ahhh Ahhh

We are working on a design that helps sanitize books faster and get hem out and ready to read quicker. Our design includes, a foil lined box that has a UV sanitizing light shining out from the bottom and reflect the light al over the books. We have been using a method of just quarantining the books for a whole week, so we want to find a way to get them back on the shelves quicker.

Posted : Sep 21, 2020 02:32

Stephen Morton

My question regarding the testing is what do they actually mean by “stacking”. The closest thing that I have found so far in the various linked documents is in the Test 4 Report where it states, “This [the stacked] configuration resembles the common practice used by libraries when handling book returns.” Does this assume that we all stack our returns in the same way? Does it mean flat stacked in a pile? Or perhaps upstanding in a row? Or even standing on the edge of the page that you touch with your finger when turning the page (there’s probably a unique term for this edge, but I’m not going searching for it at present)?

If “stacking” is flat stacked, then may we assume that the weight of the items above is what increases the attenuation period of the virus on the items below? If so, does the items at the bottom of the pile have a longer attenuation period than the items at the top? Does the 6-day period actually apply to this items on the bottom of the stack? How high was the stack, and what is the variation in attenuation period downwards through the stack? How should we actually stack items to minimise the period of attenuation?

There are so many unanswered questions. ☹

Posted : Sep 10, 2020 11:31


We have been wiping the outside of our books down before quarantining then for 72 hours. I’m wondering if this is sufficient? The article has no mention of disinfecting first.

Posted : Sep 10, 2020 03:23

Leslie Bendt

I have been placing returns in a large, rolling Tupperware bin, loosely laying flat. What if the bin were to spend several hours in the Florida sun, lid on, with the books inside?

Posted : Sep 09, 2020 03:41

A Coleman

"only this time, the materials were stacked to simulate common storage configurations in libraries and archives. While the virus was not detectable on the materials laid flat after three days in the first test, the virus was still detectable on similar materials after six days when the materials were stacked. (See Test 4 results .)" Stacked to simulate storage configurations leads me to believe they had the books on the shelves as we would normally place them. Therefore, books laid flat, as they are when placed in a return bin, are free from the virus sooner. Possibly due to increased air circulation as they do not pile up in neat "stacks" or "piles" when deposited.

Posted : Sep 08, 2020 08:30

Lisa Kissel

Have there been any tests done on the pages of a book? Because isn't a book just a stack of papers? So even if you spread them out, you are not spreading out the inside, only the covers are considered safe.

Posted : Sep 05, 2020 04:48

SLJ User

I understand that the virus is detectable, but is it a risk? It is my understanding that part of transmission is not just exposure but viral load. How worried should we be about this new information?

Posted : Sep 04, 2020 05:03

Mike Coffman

Additionally there is a difference in presence of viral material and actually intact virus capable of transmission. If they are just testing for the presence of the genetic information of the virus, it would potentially show up positive even when the virus has shed its envelope which contains the spikes and receptors that they use to get into your cells and begin the infection/reproduction process.

Posted : Sep 25, 2020 02:11

Mary Charters

Can someone please clarify how the term stacked is used?

Posted : Sep 04, 2020 02:45

Denise Wilson

I quarantine my returned books stacked in a box for seven days. I guess that'll have to change!

Posted : Sep 03, 2020 07:49

Kathy Garcia

If books are returned into a return bin, they are essentially stacked. This could apply to public libraries as well as school/academic libraries. If books are left in the bin, piled on top of each other, how long does the virus last on them? Is it known yet how long it would take for the virus to die off in this situation? This could also apply to books on the shelves - if an infected person transmitted the virus onto a book on a shelf, shelved upright as they normally are in a library, how long would the virus survive? I appreciate all the information so far - it helps make sound decisions. Thanks for sharing it.

Posted : Sep 03, 2020 07:24

Denise Taggart

Yes, I agree with L. Mittelbrun. It would be helpful to know the effect on books kept standing up side by side. Or is that considered stacked?

Posted : Sep 03, 2020 07:19

Laura Mittelbrun

But library books are not typically stacked on top of each other, they are side by side on a shelf or cart. I would like to see you do a study of that, and test to see if covid is present on the shelf or cart. Thank you for doing this research, it's so helpful for us librarians.

Posted : Sep 03, 2020 05:50

Denise Taggart

Yes, I agree with L. Mittelbrun. It would be helpful to know the results from books that are kept standing up side by side.

Posted : Sep 03, 2020 07:17

D Lucas

Whether stacked (horizontal) or shelved (vertical) isn't the the issue that books touching each other closely keep the germs active longer than books that are spread out, say across a table or counter? That's what I got from this, but am I missing something?

Posted : Sep 11, 2020 10:17



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