Safe-Food Report

Walking on Egg Shells

Keeping eggs—and hens—safe

by David Schardt, November 2010

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It’s the worst thing I’ve ever been through,” Robin Shaffer recalled. “I had no energy. The pain. You’d try to keep something in you and it just comes out.”


When Shaffer ate an enchilada, bean burrito, and chile relleno combo meal at a Mexican restaurant in Bemidji, Minnesota, in May, she had no idea that a raw egg tainted with Salmonella bacteria had contaminated her food in the kitchen. That would knock Shaffer off her feet for three weeks. “My life was literally the toilet,” she told a local TV station.


Shaffer and six other diners at the restaurant were among the first of what would become more than 1,600 documented victims of the largest outbreak of Salmonella enteritidis food poisoning since the government began compiling statistics in 1973.


The outbreak set off a national debate about how our eggs are produced. Is it cruel to cram hens into tiny cages, with no access to the outdoors, and with no room to nest or perch? Are “cage-free” eggs more humane? Are they less likely to make people sick?

Mice, Maggots, & Manure

After Robin Shaffer and restaurant-goers in at least 10 states became infected by Salmonella in May, epidemiologists in Minnesota and California were able to finger the likely source: two factory farms in Iowa that together produce more than a billion eggs a year.

But Wright County Egg and Hillandale Farms didn’t just supply restaurants. Their eggs were also sold in bulk to other companies that packaged them for resale in supermarkets under evocative brand names like Sunny Farms, Sunny Meadow, and Wholesome Farms.

When inspectors from the Food and Drug Administration finally descended on the two farms in mid-August, what they found was anything but “sunny” or “wholesome.”

Both companies’ laying houses, which each held tens of thousands of hens, were infested with flies, maggots, wild birds, and rodents. Chicken manure was piled four to eight feet high below some of the cages. Any of that might have been the source of the Salmonella.

In fact, in September, Congressional investigators discovered that Wright County Eggs had detected Salmonella on its equipment and in its barns at least 73 times during the past two years. While the companies agreed to recall a half billion of their eggs, by that point most of them had probably already been eaten.

“There is no question that these farms were not operating with the standards of practice that we consider responsible,” said FDA Commissioner Margaret Hamburg.

Yet neither egg operation had ever been inspected by the FDA. (The agency rarely checks food plants.) The FDA now says that it intends to inspect all 600 of the major U.S. egg producers.

Crowded Hens

Filth aside, is there a more humane way to produce the nation’s nearly 80 billion eggs each year? And, if so, is it less likely to turn out eggs that are tainted with Salmonella?

Too close for comfort. A typical caged hen lives in an area no bigger than this page.

More than nine out of 10 eggs are laid by hens that are confined for their lifetimes in battery cages, typically five to eight hens to a cage. (The cages are arrayed in “batteries”—rows of cages stacked one atop another.) Within each cage, every hen has about 67 square inches of floor space, less than the size of this page. That’s not enough room for them to stretch their wings or engage in other activities that are natural for hens—like nesting, perching, and rolling around on the ground (dustbathing).

It’s also not enough room for them to lay their eggs like uncaged chickens can.

“The birds suffer from extraordinary frustration on a daily basis,” says Paul Shapiro of The Humane Society of the United States.

“Chickens in nature have a very strong desire to lay their eggs in a private, dark, secluded nesting area, but battery cages don’t allow them to do that.”

A far smaller number of laying hens live in indoor “cage-free” houses, where they can walk around, spread their wings, lay their eggs in nests, and, in some facilities, perch and dust-bathe. But most cage-free hens aren’t free to wander outside.

The list of supermarkets, food processors, and restaurants that have rejected eggs from battery cages in favor of cagefree eggs is growing. In February, Walmart, the nation’s largest grocery store chain, announced that all eggs sold under its Great Value brand will be cage-free. The company joins Costco, Safeway, Trader Joe’s, Whole Foods, and other retailers in shifting to cage-free eggs.

This summer, the world’s two largest cruise companies, Carnival Cruise Lines and Royal Caribbean Cruise Lines, announced that they will begin converting to cage-free for the several million eggs they serve to passengers each year. Ben & Jerry’s, Burger King, Denny’s, Subway, and Wendy’s are shifting to cagefree eggs, as have the dining facilities at nearly 350 colleges and universities.

And the state of California has announced that it will ban the sale of eggs from batterycaged hens beginning in 2015.

Why the growing movement to cage-free production?

  • Hens. Most companies that switch to cage-free eggs cite its more humane treatment of laying hens. “It’s clear to us that cage-free farms, when certified to meet third-party standards, give hens more space to do as they please: scratch around, roost, and gossip about the henhouse,” says Ben & Jerry’s Ice Cream.
  • Eggs. Are cage-free eggs more likely to be free of Salmonella and other contaminants? It’s not clear. “The evidence suggests that cage-free facilities have significantly lower risks of Salmonella infection,” says The Humane Society’s Paul Shapiro.

    That evidence comes from Europe. In 2004 and 2005, for example, the European Food Safety Agency took samples from more than 5,300 egg-laying facilities in 24 countries.

    “Across the board, it found a higher risk of Salmonella in the caged facilities,” says Shapiro.

    But European egg facilities are smaller and are different in other ways, argue U.S. producers. Battery cages are the most effective way to separate hens and their eggs from bacteria-containing excrement, they maintain. And keeping five to eight birds in their own cage reduces the possibility of their transmitting disease to other hens in the flock.

    Who’s right? There’s not enough reliable data to tell.

    “We really don’t know if there is a big difference” between Salmonella levels in caged and cage free hens, says Jeffrey Armstrong, dean of agriculture and natural resources at Michigan State University. Armstrong chairs the Animal Welfare Advisory Committee of the United Egg Producers, an industry group.

    “Anyone who says that the evidence is clear, they’re not reading all of the scientific literature.”

The Bottom Line

  • Eggs are an inexpensive source of protein. But a typical yolk contains roughly 200 milligrams of cholesterol. That’s two-thirds of the American Heart Association’s 300 mg daily limit for healthy people.
  • Eggs are cheap enough that most people can probably afford to pay extra for cage-free or organic eggs that are more humanely produced than battery-cage eggs.

Feeling Sick?

If you become infected with Salmonella enteritidis, you’ll typically develop fever, abdominal cramps, and diarrhea beginning 12 to 72 hours after you eat a contaminated food. You’ll most likely be sick for four to seven days.

Most victims don’t require treatment other than drinking plenty of fluids. Antibiotics usually aren’t necessary. But the diarrhea can be severe, and some people require hospitalization and rehydration with intravenous fluids.

In rare cases, a Salmonella infection spreads from the intestines to the bloodstream. That can be fatal unless the person is treated promptly, cautions the Centers for Disease Control and Prevention. The elderly, infants, and those with impaired immune systems are more likely to have a more serious illness, says the CDC.

Source: CDC

Egg Tips

Salmonella in eggs is rare. Just 1 in every 20,000 eggs is contaminated. But if that egg happens to be in your next carton, the statistics don’t matter.

  • Refrigerate eggs as soon as possible in their original carton in the coldest part of the refrigerator (usually the body of the fridge, not the door). Discard cracked or dirty eggs.
  • Wash your hands, cooking utensils, and food preparation surfaces with soap and water after contact with raw eggs.
  • Cook your eggs until both the white and the yolk are firm. (Salmonella could be in either part.)
  • Use pasteurized egg whites like Egg Beaters in place of regular eggs. Or try pasteurized eggs, which look and taste like regular eggs but have been heated in the shell to kill bacteria and viruses. You can identify them by the red “P” that’s stamped on the carton or on each egg.
  • Eat cooked eggs promptly. They shouldn’t be kept warm (like in a steam table at a restaurant) or at room temperature for more than two hours.
  • Avoid dishes made with raw or undercooked eggs. That includes homemade (or restaurant-made) Hollandaise sauce or Caesar salad dressing. Commercially bottled versions are okay.

Sources: CDC and CSPI

What Does It Mean?

Don’t believe everything you read on an egg carton. Some claims mean something, while others don’t.

Here are some common claims...and some claims that we wish were more common. See the chart here.

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