The lifespan of COVID-19 on hard surfaces depends on many variables, such as moisture content and other unknown factors, so the guidance on lifespan varies depending on each situation. The best defense against the spread of germs, including COVID-19, is to have employees/volunteers practice good hygiene and to educate the end user about good hygiene.
Here is a quick three minute video about what should you know before sanitizing your groceries. Sanitizing food surfaces and washing produce is an extra measure that may be taken once food is at home. It is a good idea to clean and sanitize surfaces, not only after bringing in boxes or bags, but to make this a habit a few times a day. But the best defense against viral transmission is washing your hands before and after handling food packaging.