Why is it important to count penicillin and sulfa on a designated counting tray?

Counting penicillin and sulfa on a designated counting tray is crucial to avoid cross-contamination, as both antibiotics can cause severe allergic reactions in sensitive individuals. Using separate trays ensures accurate counting and prevents the mixing of different medications, which is vital for patient safety. Additionally, it helps maintain the integrity of the medications and supports proper inventory management in a pharmacy setting.