Is the SARS-CoV-2 coronavirus resistant to cold or heat?
Text updated on 2020-05-20
The virus fears heat. It's gonna get hot!
The coronavirus has good cold tolerance. Indeed, in the laboratory, researchers keep these viruses in the freezer for several weeks. In a refrigerator, at 4°C, it shows almost no decrease in its virulence after two weeks.
On the other hand, the coronavirus is not heat-resistant: at 70°C, the SARS-CoV-2 coronavirus is inactivated within 5 minutes. Thus, after passing through an enclosure at 65°C (+/-5°C) and 85% humidity for 30 minutes, followed by drying in the open air for 12 hours, the quantity of viral particles deposited on a protective FFR mask is reduced by more than 1000-fold.
For the coronavirus responsible for SARS and other coronavirus-based diseases, humidity accelerates the effect of heat on the inactivation of the virus.
At room temperature, the lifetime of the coronavirus varies depends on the surface. It is therefore likely that the rate of inactivation of the virus on heat surfaces also depends on the type of surface on which the virus is found.
Currently, a possible decontamination method for FFR/FFP protective masks is a conventional oven run (we recommend 70°C (place the thermostat between 2 and 3) for 30 minutes, in the presence of a large bowl of water to increase the humidity) and for fabric masks a wash with water at least 60°C. For plastic objects, it is recommended to clean them with detergent and water, rather than using a heat treatment, in order not to contaminate the oven with toxic fumes.
SourcesChin, A., Chu, J., Perera, M., Hui, K., Yen, H. L., Chan, M., ... & Poon, L. (2020). Stability of SARS-CoV-2 in different environmental conditions. The Lancet Microbe.
Heimbuch, B. K., Wallace, W. H., Kinney, K., Lumley, A. E., Wu, C. Y., Woo, M. H., & Wander, J. D. (2011). A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. American journal of infection control, 39(1), e1-e9.
Chan, K. H., Peiris, J. S., Lam, S. Y., Poon, L. L. M., Yuen, K. Y., & Seto, W. H. (2011). The effects of temperature and relative humidity on the viability of the SARS coronavirus. Advances in virology, 2011.
Casanova, L. M., Jeon, S., Rutala, W. A., Weber, D. J., & Sobsey, M. D. (2010). Effects of air temperature and relative humidity on coronavirus survival on surfaces. Appl. approx. Microbiol, 76(9), 2712-2717.
Rabenau, H. F., Cinatl, J., Morgenstern, B., Bauer, G., Preiser, W., & Doerr, H. W. (2005). Stability and inactivation of SARS coronavirus. Medical microbiology and immunology, 194(1-2), 1-6.
A 30 minute treatment at 75°C maintains the filtering properties of N95 masks.Liao, L., Xiao, W., Zhao, M., Yu, X., Wang, H., Wang, Q., Chu, S., & Cui, Y. (2020). Can N95 Respirators Be Reused after Disinfection? How Many Times?. ACS nano, acsnano.0c03597.
A hair dryer at 70°C for 30 minutes inactivates the influenza virus, while a conventional oven at 56°C for 30 minutes only partially inactivates it. Warning: the use of the hair dryer is strongly discouraged, because the risk of aerosolization of viral particles and, therefore, contamination is high.Song, W., Pan, B., Kan, H., Xu, Y., & Yi, Z. (2020). Evaluation of heat inactivation of virus contamination on medical mask. Journal of Microbes and Infections 15(1), 31-35.
Comparison of the effectiveness of N95 surgical gauze ("gauze masks") and non-woven ("spunlace masks") masks after decontamination using dry heat (rice cooker), wet heat (autoclave), bleach, isopropanol, or ethanol.Lin, T. H., Chen, C. C., Huang, S. H., Kuo, C. W., Lai, C. Y., & Lin, W. Y. (2017). Filter quality of electret masks in filtering 14.6-594 nm aerosol particles: Effects of five decontamination methods. PloS one, 12(10).