Egg cartons often contain several dates and codes, and they can be confusing at first. A “Sell By” date is mainly used by stores to manage inventory and does not automatically mean the eggs become unsafe afterward. “Best By” or “Best Before” generally refers to quality. A three-digit number usually indicates the packing date, counting the days of the year, while a code beginning with “P” identifies the processing or packing plant. These markings can also help with traceability during food-safety recalls.

Freshness and safety are not exactly the same thing. Properly refrigerated eggs can remain usable after a sell-by date, but eggs can still contain Salmonella without looking, smelling, or tasting unusual. The FDA recommends keeping eggs refrigerated at 40°F (4°C) or below and storing them in their original carton. The USDA says shell eggs can generally be refrigerated for three to five weeks when properly handled and stored.

If the date on the carton has passed, that alone does not necessarily mean the eggs should be thrown away. Consider whether they have remained properly refrigerated and whether any shells are cracked, dirty, or damaged. Eggs that have been exposed to unsafe temperatures or questionable handling should be discarded. For cooking, the FDA recommends preparing eggs until both the white and yolk are firm, while egg dishes should reach 160°F (71°C). Pasteurized eggs are a useful option for recipes that call for raw or undercooked eggs.

So, the next time you see a mysterious number on an egg carton, you’ll know what you’re looking at. The three-digit number generally indicates the packing date, “Sell By” helps retailers manage stock, “Best By” concerns quality, and “P-####” identifies the plant. Understanding these markings can help you assess freshness, but proper refrigeration, careful handling, and thorough cooking remain the most important steps for egg safety.