< Decontamination

How do you decontaminate groceries?

Text updated on 2020-05-20

The SARS-CoV-2 coronavirus can remain infectious for several days on some surfaces. It is therefore possible to catch the coronavirus by touching your nose, eyes, or mouth after coming into contact with soiled objects. However, such cases of disease transmission through indirect contact are more difficult to detect and have not been proven with certainty.

Since transmission of the SARS-CoV-2 coronavirus is primarily via the respiratory tract through the direct interaction between individuals, it is more important to observe distancing, hand washing, and mask wearing than decontamination.

If you would like to decontaminate objects and items arriving from outside, here is our advice:

Place stable products for 3-7 days "in quarantine" in an unoccupied area. Heat accelerates the inactivation of the virus: an object in front of a sunny window will decontaminate faster than at the bottom of a cool cupboard.
Remove the cartons/packaging from yogurt and fresh products before putting them in the fridge.
Spray bags and cartons of frozen products with 70% alcohol on all sides for 30 seconds before putting them in the freezer (the survival of the virus is favoured in the cold).
Same thing for any packages/trays to be placed in the fridge, but let the alcohol evaporate (otherwise, there is a risk of fire in the fridge). To make 70% alcohol solution, add 30 ml of water to 100 ml of 90% alcohol. If necessary, use bleach diluted with 0.5% active chlorine for packaging (wear gloves and glasses, as bleach is an irritant to the skin and eyes). Wash fruits and vegetables thoroughly (place in a soapy water bath, then rinse thoroughly with clean water).

Coronavirus is not resistant to cooking temperatures, but remember to wash your hands before and after cooking, as this virus (and other germs) can be present on the skin during meal preparation.

Caution: bleach and denatured alcohol are toxic, so do not spray "naked" food. "Naked" food sprayed by mistake must be rinsed well with water before consumption .

Sources

Summary of current knowledge (20 February 2020) on the mode of transmission of the coronavirus.

Han, Q., Lin, Q., Ni, Z., & You, L. (2020). Uncertainties about the transmission routes of 2019 novel coronavirus. Influenza and Other Respiratory Viruses.

Many cases of direct contamination have taken place during a meal, work meeting, gathering, sharing a means of transport, etc. Conversely, few cases of indirect contamination have been described. In this study, several customers were contaminated in a department store even though they had not gone to the floor where the store employee with COVID-19 was working.

Wu, W. S., Li, Y. G., Wei, Z. F., Zhou, P. H., Lyu, L. K., Zhang, G. P., ... & Zhang, X. M. (2020). Investigation and analysis on characteristics of a cluster of COVID-19 associated with exposure in a department store in Tianjin. Zhonghua liu Xing Bing xue za zhi= Zhonghua Liuxingbingxue Zazhi, 41(4), 489-493.

Survival of the coronavirus on different surfaces, especially cardboard (1 day max) and plastic (3 days). Note: a duration of 7 days was observed for plastic in Chin et al. 2020 (article below). These values give the duration of stability (PCR detection) of the virus but do not provide information on the duration of virus infectivity.

Van Doremalen et al, N Engl J Med 2020; 382:1564-1567. Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1.

Measurement of the stability of the virus under different environmental conditions: the coronavirus persists for 3 hours on paper and 7 days on plastic. Alcohol at 70% (and even as little as 40%) concentration inactivates the coronavirus very quickly, in less than 3 min. Note: a stability time of 3 days was measured for plastic in Van Doremalen et al, N Engl J Med 2020 (article above).

Chin, A., Chu, J., Perera, M., Hui, K., Yen, H. L., Chan, M., ... & Poon, L. (2020). Stability of SARS-CoV-2 in different environmental conditions.

Effect of hydroalcoholic solutions on SARS-CoV-2 coronavirus.

Kratzel, A, Todt, D., V'koski, P., ... Pfazender, S. Inactivation of Severe Acute Respiratory Syndrome Coronavirus 2 by WHO-Recommended Hand Rub Formulations and Alcohols

Diluted bleach inactivates SARS-CoV-1 in 30 seconds and SARS-CoV-2 in less than 5 minutes.

Kampf, G. Todt,D, Pfaender,S., Steinmann, E. Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents.

Heat kills viruses. The SARS-CoV-2 coronavirus is highly inactivated within 20 min at 56°C (Number divided by 100,000).

Darnell, M.E.R., Subbarao, K., ... Taylor, D.R.: Inactivation of the coronavirus that induces severe acute respiratory syndrome, SARS-CoV.