The coronavirus remains infectious on the pulmonary surfaces for about 5 days and on inanimate surfaces for a few hours, but this is enough time to cause one or more infections.

An efficient disinfection process should start from the well-known concept that only what is clean can be disinfected efficiently. with alcohol-based disinfectants (1). 

However, it has been shown that the type HCoV-229E, a coronavirus belonging to the alphacoronavirus (α-CoV) family and identified in 1996 (2), but rather similar to COVID-19, behaves differently depending on the surface on which it is placed.

Rapid deactivation, irreversible destruction of viral RNA and massive structural damage in coronavirus exposed to copper and copper alloy surfaces has been confirmed (3).

After exposure to the surfaces of two metal catalysts Ag/Al2O3 and Cu/Al2O3 for 5 and 20 min, SARS-CoV infectivity in Vero cells and baculovirus in Sf9 cells dropped to a very low and undetectable level, and no colony was detected using the bacterial culture method (4).

After exposure to the surfaces of two metal catalysts Ag/Al2O3 and Cu/Al2O3 for 5 and 20 min, SARS-CoV infectivity in Vero cells and baculovirus in Sf9 cells dropped to a very low and undetectable level, and no colony was detected using the bacterial culture method (4). 

It was found, using a coronavirus strain of SARS CoV-P9, that the viruses maintained their stability at 37 degrees C for at least 2 hours without significant change in the infectious capacity of the cells, but became non-infectious after 90 minutes exposure at 56 degrees C. UV irradiation of the virus for 60 minutes effectively eliminated viral infectivity (5).

Other studies have observed preventive coronavirus antiviral and contrast activity using silver-graphene nanocomposites (6), silver nanomaterials (7).

The temperature is important. In experiments on copper surfaces, cells have survived much longer on copper alloys at a temperature of 4 degrees centigrade than at a temperature of 21 degrees centigrade (8) and this should also apply to other surfaces such as copper alloys and silver alloys.

The temperature is important. In experiments on copper surfaces, cells have survived much longer on copper alloys at a temperature of 4 degrees centigrade than at a temperature of 21 degrees centigrade (8). In addition, higher humidity improves the effectiveness of antibacterial activity (9). This last two considerations also apply to other surfaces such as copper alloys and silver alloys.

References________________________________________

(1) Geller C, Varbanov M, Duval RE. Human coronaviruses: insights into environmental resistance and its influence on the development of new antiseptic strategies. Viruses. 2012;4(11):3044–3068. Published 2012 Nov 12. doi:10.3390/v4113044

(2)Hamre D, Procknow JJ.  A new virus isolated from the human respiratory tract.   Proc Soc Exp Biol Med. 1966 Jan;121(1):190-3.

(3) Warnes SL, Little ZR, Keevil CW. Human Coronavirus 229E Remains Infectious on Common Touch Surface Materials. mBio. 2015;6(6):e01697-15. Published 2015 Nov 10. doi:10.1128/mBio.01697-15

(4) Han J, Chen L, Duan SM, et al.  Efficient and Quick Inactivation of SARS Coronavirus and Other Microbes Exposed to the Surfaces of Some Metal Catalysts Biomed Environ Sci. 2005;18(3):176–180.

(5) Duan SM, Zhao XS, Wen RF, Huang JJ, Pi GH, Zhang SX, Han J, Bi SL, Ruan L, Dong XP; Stability of SARS coronavirus in human specimens and environment and its sensitivity to heating and UV irradiation.   SARS Research Team.  Biomed Environ Sci. 2003 Sep;16(3):246-55.

(6) Chen YN, Hsueh YH, Hsieh CT, Tzou DY, Chang PL. Antiviral Activity of Graphene-Silver Nanocomposites against Non-Enveloped and Enveloped Viruses. Int J Environ Res Public Health. 2016;13(4):430. Published 2016 Apr 19. doi:10.3390/ijerph13040430

(7) Lv X, Wang P, Bai R, et al. Inhibitory effect of silver nanomaterials on transmissible virus-induced host cell infections. Biomaterials. 2014;35(13):4195–4203. doi:10.1016/j.biomaterials.2014.01.054

(8) Elguindi J, Wagner J, Rensing C. Genes involved in copper resistance influence survival of Pseudomonas aeruginosa on copper surfaces J Appl Microbiol. 2009 maggio;106(5):1448-55. doi: 10.1111/j.1365-2672.2009.04148.x.

(9) Michels HT, Noyce JO, Keevil CW.  Effects of temperature and humidity on the efficacy of methicillin-resistant Staphylococcus aureus challenged antimicrobial materials containing silver and copper. Lett Appl Microbiol. 2009 Aug;49(2):191-5. doi: 10.1111/j.1472-765X.2009.02637.x.