When a chicken lays an egg the shell is covered with a protein outer covering known as the "bloom". The bloom quickly dries and seals the egg from pathogens from the outside world. This is a good thing especially if the egg is going to be incubated or remain fresh. Because the egg is sealed nothing penetrates the shell and gets into the inner part. However, before you sell them you must wash the bloom off.
The logical question that comes to mind is why do we have to wash the egg's protection off creating a permeable shell? If the bloom keeps pathogens out of the albumen (white) and yolk why would we remove that protected coating? Not only does it keep things out it also does not allow the inside to dry out, keeping the egg fresher longer. A commercial egg left in the refrigerator will slowly dry from the inside. It will also absorb the odors that are in the ice box too.
An egg that has not been washed can remain unrefrigerated for up to three months. Wash the bloom off and the egg cannot last a day with temperatures above 45 degrees before it starts to develop salmonella and other bacteria harmful to the digestive tract.
There has been a fight to get egg producers to date stamp individual eggs, this is required in the UK but not herein the US. I saw a news show awhile back that did an expose on egg producers recycling old unsold eggs back into the food chain. If you've ever bought a carton of eggs and get them home and crack one open and the white is very cloudy you've probably gotten one.
When you buy a fresh egg the albumen should be clear with the exception of the chalaza. The chalaza is the strand that anchors the egg to the shell. This strand will be solid white. The yolk should be standing tall and proud. The yolk color from a free range or organic egg will be dark orange, hence the high beta carotene content. Its commercial counter part will look yellow to pale yellow if it has been recycled. Because the shell is permeable the egg white can be smaller do to shrinkage and the egg can take on the properties of what it has absorbed.
If eggs were individually date stamped then they couldn't get recycled the way they are doing now, creating a safer egg supply. Let’s get this straight; people get sick because of bad food in the industrial food supply. Other people point this out, document the abuses and lobby their leaders for change. What happens is people with more money hire insiders or just give money directly to campaigns and our leaders end up doing nothing. Sure there are counter arguments that they will point to and the will of the people is of utmost consideration, they'll say. Yet this is the same group that says we must wash eggs before we sell them.
Why? Because we as consumers can't be trusted to safely handle the eggs and we'll contaminate ourselves. In the interest of objectivity an egg does come from the chicken's vent. The vent is used to expel everything from the chicken. So the outer shell of the egg is contaminated when it comes out. This is important to note, the outer shell is contaminated not the inner shell or the albumen or the yolk.
Sometimes our eggs do have particulate matter on them but because of the bloom it does not come in contact with the inside of the egg. Can an unwashed egg make some one sick if not handled correctly? YES, it can. Will it make us sick if it is handled properly, NO. Is it hard to safely handle an unwashed egg, no. Wash the egg and your hands before use and your fine. Chicken itself can cause more cross contamination and illness than a dirty egg but I digress.
I'm sure I'll wrap my head around this someday but until then I'll keep raising chickens for their eggs. For the record we are a registered egg producer and all the eggs we sell are washed per regulations. The eggs we keep for ourselves are not.
Eat safe fresh vegetables purchased from a local farmer, not a chain hard selling that fact.