Opened containers of sour cream, chives, and butter should be discarded after a customer has used them to ensure food safety and prevent cross-contamination. Once such items have been exposed to the environment or handled by customers, they can become contaminated with bacteria or other pathogens.
Food safety regulations often specify that anything exposed to the public should not be reused, as this helps to mitigate the risk of foodborne illnesses. This practice is especially important in a food handling context where maintaining hygiene and the safety of consumables is a priority.
While some items can be refrigerated or reused under certain conditions, opened condiments and spreads intended for individual servings are typically not safe to keep after being exposed for public use.