At what point is food considered unsafe for consumption concerning its “use by” date?

Food is considered unsafe for consumption when the "use by" date has passed because this date indicates the last day that the food is guaranteed to retain its intended quality and safety. After this date, there is a risk that harmful bacteria may have developed, or the food may no longer be suitable for consumption. The "use by" date is critical for items that are highly perishable, such as meat, dairy, and some prepared foods, which can pose health risks if consumed after this point.

In contrast, simply being unopened does not guarantee safety past the "use by" date, as the integrity of the food can still degrade over time. Storage at room temperature can increase the likelihood of spoilage, but if the item is still within its "use by" date, it may still be safe to consume, provided it has been handled well prior to that point. The concept of being "out of sight" doesn't impact the safety of the food either; visibility does not correlate with safety. Therefore, passing the "use by" date is the definitive indicator for food safety concerns.