Sodium chloride, also known as common salt, is not considered a stale compound. It is quite the opposite—it's a stable compound at room temperature and pressure. It doesn't undergo decomposition reactions or react with air and remains unchanged over time.

The idea of staleness is usually associated with perishable food items that deteriorate. In contrast, sodium chloride serves as a preserving agent due to its anti-microbial properties, preventing food from spoiling for a longer duration.

Therefore, it's incorrect to label sodium chloride as a stale compound.