Search

How do we kill SARS-CoV2 on surfaces?

Updated: Apr 4

Understanding the virus means we can take back some of its power.


Summary: the virus can live a long time on many surfaces, including bank notes, but it can be easily killed with most household cleaners or heat. Heat (56C/133F) is very effective at killing the virus within 30 minutes. Most household clothes dryers, set to high heat, will reach 125-135F and should efficiently inactivate the virus. Ironing will also work!


But low temperature preserve the virus for a long time. At typical fridge temperatures the virus will survive on surfaces for over 14 days.


Acid or base cleaners, such as vinegar, were ineffective at inactivating the virus.


We found out today that SARS-Cov2 can remain infectious on the following surfaces:

  • printing paper - <1 hour

  • tissue paper - <1 hour

  • Wood - 1 day

  • Cloth - 1 day

  • Cardboard - 1 day (2 papers support this)

  • Glass - 2 days

  • Banknotes - 2 days (paper notes) / I am guessing it will be longer on the Australian polymer notes

  • Steel and plastic - 3-4 days (3 papers support this)

  • Respirator masks - 7days! (2 papers support this)

Effective Disinfectants

  • Bleach e.g. 1 part bleach to 99 parts water or stronger

  • Soap

  • 70% ethanol

  • iodine

  • chloroxylenol (0.05%) e.g. Dettol antiseptic

  • chlorhexidine (0.05%)

  • Benzalkonium chloride (0.1%) e.g. chlorox, Lysol, Dettol wipes

Ineffective

  • vinegar - the virus was found to be highly stable over a wide range of pH's (pH3-pH10)

Temperature

  • at 4C / 40F - the virus was stable for over 14 days

  • at 56C / 133F - the virus is stable for less than 30 minutes

  • at 70C / 160F - the virus is stable for less than 3 minutes.

Caveat: remain infectious means the scientist could recover the virus from the surface or transport media and that virus was able to infect Vero cells (African green monkey cells) in vitro. This is a typical lab assay. However, just because there is enough virus to infect these cells does not mean that there would be a high enough viral titer to infect and cause disease in a human. It is believed that the assay is more sensitive than the infectious dose in humans. Bottom line: the times given above are maximum survival times.


Heat kills it, cold preserves it, most household cleaners destroy it.


References

https://www.medrxiv.org/content/10.1101/2020.03.15.20036673v2


https://www.nejm.org/doi/full/10.1056/NEJMc2004973?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed




0 views

©2020 by Erin Bromage PhD: Disease musings. Proudly created with Wix.com