Are Organic Eggs Safer?

Federal officials matched the Salmonella bacteria responsible for the current egg recalls to bacteria found in barns and chicken feed at two major Iowa egg producing facilities yesterday. The wave of recalls has hatched a debate over whether eggs from smaller, organic farms are safer.

For grocery shoppers, there's an overwhelming variety of labels placed on eggs, including "cage-free," "organic," "Kosher," "free-range" and "natural."

While there are many claims being made about organic eggs being the "safe" eggs to buy during the current Salmonella scare, consumers should keep in mind that Salmonella bacteria affect chickens of every quality, and there is no valid scientific evidence to show that certain types of eggs contain more or less of the bacteria, according to the Food Safety and Inspection Service (FSIS).

The debate stems from how the chickens are raised. The U.S. Department of Agriculture requires farmers who want to label their eggs as "USDA Certified Organic" to prove their chickens have access to the outdoors.

Some large, non-organic farming businesses argue that outdoor access increases the threat of Salmonella infection, because it makes it possible for chickens to come in contact with wild animals, such as rats (or their feces), that may harbor the pathogen. However, there haven't been any studies to show that this is the case.

On the other hand, organic farmers argue that the conditions under which large farming businesses house their chickens – often in cages that are stacked closely next to and on top of each other – create an environment where bacteria can spread more easily among chickens.

"The smaller the farm is, the lower the likeliness of Salmonella," said infectious disease specialist William Schaffner, chair of the department of preventive medicine at Vanderbilt University School of Medicine in Nashville, Tenn. "The general thinking is that larger chicken farms are much more difficult to keep clean, and this makes it easier to transmit Salmonella."

However, Schaffner said that even in the case of organic eggs from small farms where chickens are allowed outdoor access, the Salmonella risk is not zero.

For example, in March 2009, Kirkland Signature organic brown eggs were recalled after internal testing for Salmonella gave positive results, according to the California Department of Public Health. The eggs were produced by den Dulk Poultry Farms in Ripon, Calif.

Whichever type of eggs you buy, the only definite way to lower your risk of Salmonella infection is to follow this advice, according to the FDA:

  • Always purchase eggs from a refrigerated case. Choose eggs with clean, uncracked shells.
  • Look for the USDA grade shield or mark on the egg carton. While the color of an egg's shell doesn't reflect its quality or taste, all USDA graded eggs must meet standards for quality and size, including having uncracked shells.
  • Since a cold egg left out at room temperature can sweat, facilitating the growth of bacteria, refrigerated eggs should not be left out for more than 2 hours.
  • All egg dishes should be heated up to an internal temperature of at least 160 degrees Fahrenheit (71 degrees Celsius), and should be thoroughly cooked all the way through so that no part of the eggs is "runny."
  • Cooked eggs and dishes containing eggs should be served immediately after cooking, or place in shallow containers for quick cooling and refrigerate at once for later use. Dishes should be used within 3 to 4 days.

This article was provided by Life's Little Mysteries, a sister site to LiveScience. 

Remy Melina was a staff writer for Live Science from 2010 to 2012. She holds a bachelor’s degree in Communication from Hofstra University where she graduated with honors.