### How to Read the Codes on Egg Cartons

Egg cartons can display several dates and numbers, which can be confusing at first. On many U.S. cartons, the three-digit number is a **pack date**, showing the day of the year when the eggs were processed and packaged. The code runs from **001 for January 1 through 365 for December 31**, making it easier to compare cartons and use older eggs first.

Other markings serve different purposes. A code beginning with **“P”** identifies the processing or grading facility, while **“Sell By”** dates mainly help stores manage inventory and **“Best By”** dates are more related to quality. Proper refrigeration is also important, with USDA guidance indicating that raw shell eggs generally keep for about **three to five weeks** when stored at **40°F (4°C) or below**, preferably in their original carton on an interior refrigerator shelf.

Freshness and safety are not the same thing. An egg may look and smell normal while still carrying harmful bacteria such as Salmonella, so the popular water-float test cannot determine whether an egg is safe to eat. To reduce risk, avoid cracked or heavily contaminated eggs, wash your hands and surfaces after handling raw eggs, and cook eggs until both the whites and yolks are firm.

Cooked egg dishes generally last about **three to four days** in the refrigerator, while hard-cooked eggs can be kept for about **one week**. The carton codes are useful clues, but they are not a complete safety test. Keeping eggs properly refrigerated, preventing cross-contamination, cooking them thoroughly, and promptly refrigerating leftovers are the key steps for safer egg storage and preparation.