linuxtim
commented
4 years ago Open linuxtim opened 4 years ago
linuxtim
commented
4 years ago linuxtim
commented
4 years ago Sorry, missed Stanford report link - see linked pdf (e.g. table 2, page 5 for respirator test data, and some other viral deactivation options ) https://aim.stanford.edu/covid-19-evidence-service/
Stanford AIM Lab (part of Stanford University) has done initial testing on heat treatment to deactivate SARS-CoV-2 (COVID-19) - the virus is completely deactivated at only moderate temperatures (e.g. 56°C for 15 minutes in previously published data for SARS-CoV-1). Based on virology advice, to allow an adequate safety margin, they have heat treated respirator masks at 70°C for 30 minutes (to confirm continued safe operation).
Fortunately face shields, masks (minus the actual filter media) etc. can be verified much more easily with mechanical inspection and tests which don't require specialist testing equipment, and a similar treatment regime (e.g. immersion in 70°C water for 30 minutes) will allow safe re-use (assuming the materials are sufficiently tolerant of the treatments.
I have been investigating this possibility for some time (and facilitating research where possible). I have collected a list of published papers with relevant data here: https://github.com/linuxtim/SARS-CoV-2-Deactivator/wiki#microbiology
For the avoidance of doubt, I will include the current data from that page here:
Serum samples were heated at 56°C for 1 hour before use to reduce risk from any potential residual virus in serum- from A serological assay to detect SARS-CoV-2 seroconversion in humans, Amanata et al. medRxiv pre-print, doi: https://doi.org/10.1101/2020.03.17.20037713BBC interview with lead author of above re SARS-CoV-2 at 19m 0s to 19m 40s in BBC Science in Action, 19 March 2020, Covid -19, are you carrying the virus?:
the sample, once we heat inactivate it is non-infectious, so it's much much easier to use(Fatima Amanata, lead author of above paper).Heat inactivation Example: Heat at 60°C or higher temperature for a specified minimum duration.From FAQ: On the Use of Samples/Materials Associated with SARS-CoV-2 (or the COVID-19 Virus), Singapore Govt publication. See also reference list:[9]within this publication for further references on heat deactivation.The virus is stable for 3 weeks at room temperature in a liquid environment but it is easily killed by heat at 56°C for 15 minutes[9].Source: The Effects of Temperature and Relative Humidity on the Viability of the SARS Coronavirus - K.H.Chan, J.S.MalikPeiris, S.Y.Lam, L.L.M.Poon, K.Y.Yuen,and W.H.Seto Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong. The reference[9]is to the WHO report in next item.WHO Report, First data on stability and resistance of SARS coronavirus compiled by members of WHO laboratory net-work, Emerging Infectious Diseases Volume 10 Issue 5.