To refrigerate or not, that is the question. When it comes to eggs, it all depends on where you live. Different nations handle this food storage issue differently.
Here in the U.S., we refrigerate -- always -- while our neighbors across the ocean in the U.K. (and many other countries) don't. It's not so much a matter of custom as it is of food safety. Here's why.
In the U.S., all of our commercial eggs are power-washed before being packaged and shipped to a local grocery store near you. The reason for power washing is to rid the egg's exterior of any harmful bacteria -- salmonella is the big fear here -- by rinsing off all organic matter.
Salmonella can contaminate an egg in two ways. One, by passing from an infected hen to its egg when laid. Or two, it can get on the outside of the shell from contact with chicken feces. Power washing does away with the manure. Unfortunately, it also washes away the egg's natural protective coating called the cuticle, making it more porous and susceptible to contamination. Refrigerating the eggs helps keep potentially harmful microorganisms at bay.
In the U.K. however, eggs are not washed because it's believed that washing can transfer harmful bacteria from the outside to the inside of the egg. Instead, hens in the U.K. are vaccinated to prevent salmonella.
Both methods are effective in keeping salmonella controlled -- one is not better than the other. Just be sure to be aware of the safety regulations in whichever country you happen to be buying your eggs in.
As they say, when in Rome ...