Can plastics protect us from the Coronavirus? (Part 1)

Every country is now affected by the new SARS-CoV-2 virus which causes COVID 19. In many countries, measures have been taken to keep the spread of infections at a minimum. Numerous appeals by famous people call on fellow human beings adhere to social distancing as well as staying at home.

Arnold Schwarzenegger calls on people to stay at home.

Arnold also stays at home and only goes out for his workout or shopping. However, also when shopping, people should keep a distance of 1-2 meters to other people.

That’s why many people use online shopping more frequently and receive their goods in packages. Someone in the warehouse packs the items and someone else delivers the package. These are potential threats where the virus could get onto the package.

And that is the point on which this title focuses on: How long does the virus live on surfaces? Can we get infected when touching a surface or a packaging foil?

source: pixabay.com, PIRO4D

In a study by the National Institutes of Health, CDC, UCLA and Princeton University scientists in The New England Journal of Medicine, slightly different results were found.

The exact risk of virus transmission cannot be deduced from laboratory tests, as the experiments were carried out under controlled conditions.

After 30, 60, 120 and 180 minutes a gelatine filter was used to determine the virus concentration in the air. In another experiment, surfaces made of plastic (polypropylene), stainless steel (AISI 304), copper (99.9%) and commercial cardboard were sprayed and the virus concentration was determined after 1, 4 and 8 hours and after 1, 2, 3 and 4 days.

As well as in the air as on surfaces the viruses were detectable until the end of the experiments. However, their concentration decreased exponentially.

The half-life of the viruses in air was examined in 2 studies and gave different results.

The half-lives for SARS-CoV-2 and SARS-CoV-1 in the air were each 2.74 hours according to the publication in medRxiv. According to the results in the New England Journal of Medicine, the half-life for SARS-CoV-2 in air was only 1.09 hours (95% confidence interval 0.64 to 2.64 hours) and for SARS-CoV-1 1.18 hours (0.78 to 2.43 hours).

Half-life in hours of the SARS-CoV-2 virus on surfaces and in the air.

The half-live of SARS-CoV-2 on copper surfaces is 0.774 hours (0.427 to 1.19 hours). According to the current publication, no “viable” viruses could be detected after 4 hours. It took 3.46 hours (2.34 to 5 hours) on cardboard, 5.63 hours (4.59 to 6.86 hours) on steel and 6.81 hours (5.62 to 8.17 hours) on plastic until half the viruses had disappeared.

Viability of SARS-CoV-1 and SARS-CoV-2 in Aerosols and on Various Surfaces. (www.nejm.org)

Researchers from Singapore had examined samples from rooms in which patients with COVID-19 were accommodated. According to their report in JAMA, the viruses were detectable on the toilet bowl, washbasin and door handle to the bathroom, while all air samples tested negative.

The concentration of the viruses leading to an infection is also unknown at present. There are probably differences between individuals in this respect.

The National Institute for the Control and Prevention of Viral Diseases in Beijing reports in the American Medical Journal on the analysis of 1,070 samples of excretions taken from 205 patients with COVID-19.

The tests were positive in the bronchial lavage fluid to 93 %. This was followed in frequency by sputum (72 %), nasal swab (63 %), bronchoscopic brush biopsy (46 %), throat swab (32 %), stool samples (29 %) and blood samples (1 %). In contrast, none of 72 urine samples were positive.

In conclusion, the virus SARS-CoV-2 does not exist very long on surfaces like a packaging foil or on the package itself, made of cardboard. We do not recommend to be careless about touching surfaces, e.g. when being shopping, but the data shown above indicates the virus can not spread easily through surfaces. In the end we can be happy that plastics and other packaging materials protect goods like food or articles of daily use.


Hopefully we were able to give you some new inputs. Don’t hesitate to share your thoughts and join the hubbub.

Peter & Herwig

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Articles:

N van Doremalen, et al. Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1. The New England Journal of Medicine. DOI: 10.1056/NEJMc2004973 (2020). link

Air, Surface Environmental, and Personal Protective Equipment Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) From a Symptomatic Patient, JAMA, 2020; doi: 10.1001/jama.2020.3227 link

Detection of SARS-CoV-2 in Different Types of Clinical Specimens, JAMA. 2020; doi: 10.1001/jama.2020.3786 link

4 thoughts on “Can plastics protect us from the Coronavirus? (Part 1)

  1. very interesting post – raises a lot more questions (eg validity of online shopping and the multiple handling of the ordered goods)

    Like

    1. I asked myself the same question. Looking at the half-lives, it seems like at least the last supplier should be virus free.

      Like

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