Those seemingly mysterious numbers aren't just there for shoppers trying to determine freshness.
Packaging codes provide important traceability information. If a particular production lot is identified as part of a food-safety recall, codes on cartons can help consumers determine whether their eggs are included.
That's one reason it's wise not to discard the carton immediately after bringing eggs home. Keeping eggs in their original carton preserves the identifying information and also makes it easier to follow storage guidance.
Freshness and Safety Are Not Exactly the Same Thing
This is perhaps the most important point to remember.
An egg can gradually lose quality as it ages. Its texture and performance in cooking may change, even when it has been properly refrigerated. But food safety depends on more than age alone.
Fresh eggs can contain Salmonella, even when their shells look clean and uncracked. The FDA therefore recommends careful refrigeration, proper handling, and thorough cooking.
In other words:
A carton date is a useful piece of information, but it isn't a substitute for safe food handling.
How to Store Eggs Properly
Once you understand the carton codes, the next step is making sure your eggs are stored correctly.
Keep Eggs Refrigerated
The FDA recommends storing eggs at 40°F (4°C) or below. After purchasing them, refrigerate them promptly rather than leaving them at room temperature for an extended period.
Keep Them in the Original Carton
The carton protects the eggs and keeps their identifying information available.
It also helps prevent odors from other foods from affecting the eggs.
Avoid the Refrigerator Door
Although many refrigerators have egg-shaped compartments in the door, the temperature there can fluctuate more frequently than in the main refrigerator compartment.
USDA recommends keeping eggs in the coldest part of the refrigerator rather than the door.
Don't Wash Eggs at Home
If you're using commercially processed eggs, washing them again at home isn't recommended. USDA explains that home washing can increase contamination risk by allowing water to move through the shell's pores.
How Long Do Eggs Usually Keep?
Under proper refrigeration, USDA says shell eggs can generally be kept in the refrigerator for three to five weeks from the day they are placed in the refrigerator.
For best quality, the FDA recommends using refrigerated eggs within about three weeks.
These recommendations assume that the eggs have been properly refrigerated and handled. If eggs have been exposed to unsafe temperatures or poor handling, the carton date cannot make them safe again.
What If the Carton Date Has Passed?
Don't automatically assume that the eggs must be thrown away simply because the printed date has passed.
Instead, consider:
- Were the eggs kept continuously refrigerated?
- Is the carton intact and identifiable?
- Are the shells cracked or damaged?
- Do the eggs show obvious signs of spoilage after cracking?
- Have the eggs been handled safely?
USDA explains that food dates generally communicate quality rather than automatically marking the point at which food becomes unsafe. However, food that has been improperly stored or shows signs of spoilage should not be eaten.
When in doubt about an egg that has been mishandled or exposed to unsafe temperatures, the safest choice is to discard it.
Safe Cooking Matters Too
Even eggs that are fresh and properly refrigerated can potentially carry Salmonella.
The FDA recommends cooking eggs until the yolk and white are firm and cooking foods containing eggs thoroughly.
For dishes containing eggs, using a food thermometer can provide an extra measure of confidence. The FDA recommends cooking egg-containing casseroles and similar dishes to 160°F (71°C).
If a recipe calls for eggs that remain raw or undercooked, such as certain homemade desserts or sauces, consider using pasteurized eggs or pasteurized egg products when appropriate.
A Quick Cheat Sheet for Egg Carton Codes
| Marking | What It Generally Tells You |
|---|---|
| 3-digit number | Pack date expressed as the day of the year |
| Sell By | Retail inventory/stock-rotation date |
| Best By / Best Before | Expected quality period |
| Use By | Recommended quality-use date |
| P-#### | Egg-processing plant identification number |
The exact labeling requirements can vary by jurisdiction, so treat this as a practical guide rather than assuming every carton will use identical markings.
Frequently Asked Questions
Does the three-digit number tell me when the eggs expire?
No. The three-digit number on USDA-graded cartons represents the packing date, expressed as the day of the year. It is not simply an expiration date.
Are eggs automatically bad after the sell-by date?
Not necessarily. A sell-by date primarily helps retailers manage inventory and does not automatically mean the eggs are unsafe immediately afterward. Proper refrigeration and handling are essential.
Should eggs be stored in the refrigerator door?
It's better to keep them in the main refrigerator compartment, where temperatures are generally more stable. Keep them in their original carton.
Why is there a “P” followed by numbers on my carton?
That is generally the plant identification number, which helps identify the facility associated with processing or packing the eggs.
Can eggs still be unsafe even when the carton date hasn't passed?
Yes. Fresh eggs can contain Salmonella, and improper storage or handling can increase food-safety risks. The date alone cannot guarantee safety.
The Bottom Line
Egg carton codes may look mysterious, but they're really there to provide useful information about when eggs were packed, where they came from, and how their quality dates should be interpreted.
The most useful habit is to look at the entire picture rather than relying on one number. Keep eggs refrigerated at 40°F (4°C) or below, store them in their original carton, handle them carefully, and cook them thoroughly.
Once you know what the three-digit pack date, sell-by date, and plant code mean, reading an egg carton becomes much less confusing—and you can make more informed decisions about freshness, quality, and food safety.