Cartons of eggs are on sale at this major supermarket chain in Seoul.
A 10-digit information code is printed on the egg shells.
Plans for the new labeling system were first launched on February 23rd, and after a six-month grace period, the system is now live.
Large supermarkets have already started checking to make sure there are no problems with the labels.
Because the ink is water-soluble, it could smear during the summer. So we check the labels during the stocking process. If there are any smears, we replace the eggs.
So what does the 10-digit code indicate?
The first 4 numbers indicate the date the egg was laid, followed by a 5-digit code which indicates who the producers are.
The last number indicates the breeding environment for the chickens laying the eggs.
The number one indicates chickens raised in a paddock.
Two indicates free-range chickens.
Three and four indicate chickens raised in upgraded coops and normal coops, respectively.
But for most consumers, the first four numbers are the most important digits to look out for.
"Eggs are food, you can't eat them after they expire. So the date they were laid on is the most important thing."
Eggs have a shelf life of 30 days if stored at room temperature, and 40 to 45 days if stored in a fridge.
From Friday, if supermarkets in South Korea sell unlabeled eggs, they can be subject to a 15-day business suspension and be forced to throw away all their unlabeled eggs.
Lee Seung-jae, Arirang News.