The BfR is not yet aware of this kind of infection chain. According to the state of knowledge, the oral/alimentary transmission route (via the oesophagus and stomach) does not play a role in the current outbreak of SARS-CoV-2. Transmission primarily occurs via droplets resulting from coughing and sneezing and are absorbed by other people via the mucous membranes of the respiratory tract. Furthermore, transmission via contact or smear infections cannot be ruled out in which the pathogens reach the mucous membranes of the nose or eye directly, where they can lead to infection.
A virus contamination from drinking vessels, such as drinking glasses, in restaurants would occur as a result of use by an infected person, whereby the virus is transmitted to the glass via the hands or saliva. Transmission to another person through mucous membrane contact with the glass may then occur if this vessel has not been sufficiently cleaned in the meantime. Certainly, infections with SARS-CoV-2 via this transmission method have not yet been detected.
As enveloped viruses, the genetic material of which is coated by a layer of fat (lipid layer), coronaviruses react sensitively to substances that dissolve fat, such as alcohols or surface-active agents, which are contained in soaps and dish washing detergents as grease removers. Although specific data is not yet available for SARS-CoV-2, it is likely that these substances damage the virus surface and render the virus inactive.
A current research project at the BfR using the human coronavirus 229E, which is related to SARS-CoV-2, shows that coronaviruses are relatively stable on glass and can remain infectious for days to weeks after drying on glass. The effect of light is a major influencing factor. Infectious coronaviruses could be detected for up to seven days when stored in daylight and up to 21 days in the dark. It’s therefore important that drinking glasses are cleaned sufficiently. The investigations of the BfR demonstrated that most commercially available dish washing detergents are sufficient to inactivate coronaviruses in dish washing water within 15 seconds at a temperature of 23 °C. A higher temperature of 43 °C and a longer exposure time of 60 seconds was only necessary for a detergent with a lower total surfactant content. Using a DIN 6653-3 compliant manual glass washer, coronaviruses could be efficiently removed from glasses even when using cold water.
The study was published on April 6, 2022 in the scientific journal Food Microbiology: https://doi.org/10.1016/j.fm.2022.104036
For the related SARS-CoV, a laboratory study showed that treatment with a commercially available dish washing liquid for 5 minutes at room temperature led to complete virus inactivation (https://academic.oup.com/cid/article/41/7/e67/310340 ). Longer periods and higher temperatures could increase the efficiency of virus deactivation. Cleaning drinking vessels in dishwashers or glass washing machines at 60 degrees Celsius or a higher temperature is, therefore, particularly efficient. If this is not possible, water that is as hot as possible (> 45 °C, but no higher than 50 °C, in order to protect the hands), along with detergent, should be used in manual cleaning processes. When using colder water, particular care must be taken to ensure that there is a sufficient amount of detergent, that glasses are left in the sink for longer time, and that glasses are carefully cleaned mechanically, then dried.
Further information can be found in the BfR opinion 'Hygienic efficiency of dishwashers for drinking glasses in the food service sec tor' :
The BfR is not yet aware of this kind of infection chain. According to the state of knowledge, the oral/alimentary transmission route (via the oesophagus and stomach) does not play a role in the current outbreak of SARS-CoV-2. Transmission primarily occurs via droplets resulting from coughing and sneezing and are absorbed by other people via the mucous membranes of the respiratory tract. Furthermore, transmission via contact or smear infections cannot be ruled out in which the pathogens reach the mucous membranes of the nose or eye directly, where they can lead to infection.
A virus contamination from drinking vessels, such as drinking glasses, in restaurants would occur as a result of use by an infected person, whereby the virus is transmitted to the glass via the hands or saliva. Transmission to another person through mucous membrane contact with the glass may then occur if this vessel has not been sufficiently cleaned in the meantime. Certainly, infections with SARS-CoV-2 via this transmission method have not yet been detected.
As enveloped viruses, the genetic material of which is coated by a layer of fat (lipid layer), coronaviruses react sensitively to substances that dissolve fat, such as alcohols or surface-active agents, which are contained in soaps and dish washing detergents as grease removers. Although specific data is not yet available for SARS-CoV-2, it is likely that these substances damage the virus surface and render the virus inactive.
A current research project at the BfR using the human coronavirus 229E, which is related to SARS-CoV-2, shows that coronaviruses are relatively stable on glass and can remain infectious for days to weeks after drying on glass. The effect of light is a major influencing factor. Infectious coronaviruses could be detected for up to seven days when stored in daylight and up to 21 days in the dark. It’s therefore important that drinking glasses are cleaned sufficiently. The investigations of the BfR demonstrated that most commercially available dish washing detergents are sufficient to inactivate coronaviruses in dish washing water within 15 seconds at a temperature of 23 °C. A higher temperature of 43 °C and a longer exposure time of 60 seconds was only necessary for a detergent with a lower total surfactant content. Using a DIN 6653-3 compliant manual glass washer, coronaviruses could be efficiently removed from glasses even when using cold water.
The study was published on April 6, 2022 in the scientific journal Food Microbiology: https://doi.org/10.1016/j.fm.2022.104036
For the related SARS-CoV, a laboratory study showed that treatment with a commercially available dish washing liquid for 5 minutes at room temperature led to complete virus inactivation (https://academic.oup.com/cid/article/41/7/e67/310340 ). Longer periods and higher temperatures could increase the efficiency of virus deactivation. Cleaning drinking vessels in dishwashers or glass washing machines at 60 degrees Celsius or a higher temperature is, therefore, particularly efficient. If this is not possible, water that is as hot as possible (> 45 °C, but no higher than 50 °C, in order to protect the hands), along with detergent, should be used in manual cleaning processes. When using colder water, particular care must be taken to ensure that there is a sufficient amount of detergent, that glasses are left in the sink for longer time, and that glasses are carefully cleaned mechanically, then dried.
Further information can be found in the BfR opinion 'Hygienic efficiency of dishwashers for drinking glasses in the food service sec tor' :