Hello,
Thank you for your query at DoctorSpring.com
I understand your concern.
Please do not worry. Viral infections can't be spread that way, and moreover no virus survives outside the human body for more than 30 seconds to 1 minute. So, that brownish substance does not pose any threat.
Please feel free to discuss further,
Regards.
Patient replied :
Thank you for your response.
Is there any risk if I touched the substance less than 30 seconds after it got on the shopping cart?
Thanks.
No, there is really no risk here.
You can completely relax.