ANIMAL CARE LABELS Four main terms indicate the level of care hens received.

For eggs from chickens that live in the sort of utopia conveyed by the images on most egg cartons, look for “animal welfare approved.” Available in limited markets, it is a new label by the Animal Welfare Institute that is given only to independent family farmers. Flocks can have no more than 500 birds, and chickens over 4 weeks old must be able to spend all their time outside on pesticide-free pasture with a variety of vegetation. They must have access to dust baths and cannot have their beaks trimmed (a practice on crowded egg farms) or be fed animal byproducts.

Image WHATS IN AN EGG? The array of labels on egg cartons can be bewildering. Some provide reliable information about audited claims (like U.S.D.A. organic and certified humane raised and handled). Others are unregulated and unverified. Credit... Hiroko Masuike for The New York Times

“Certified humane raised and handled” hens and “American humane certified” hens are kept cage free, though not necessarily outdoors.

“Certified humane raised and handled” is administered by Humane Farm Animal Care, the only animal welfare program audited each year for reliability by the Department of Agriculture. It is endorsed by many animal welfare organizations. It has requirements for, among other things, ventilation, density and the number of perches and nesting boxes that must be provided. It requires that each hen have at least 1.5 square feet of space (324 square inches).

The “American humane certified” label was created by the American Humane Association. Its standards, similar to those of “certified humane raised and handled,” prohibit forced molting (reducing feed to increase egg production) and require that hens have at least 1.25 square feet of space (225 square inches).

“United Egg Producers Certified,” formerly “Animal care certified,” is presented by the United Egg Producers, America’s leading trade association for egg farmers, which has standards for caged and cage-free layers. The group adopted the new name under pressure from the Federal Trade Commission and the Better Business Bureau, which agreed with complaints they had received that “Animal care certified” misled consumers by implying more humane treatment than the hens were getting. Even with the new title, many animal welfare advocates say those standards are too low. The standards permit hens to have as little as 67 square inches of space, less than a letter-size sheet of paper, which is 93.5 square inches.

What Birds Are Fed

ORGANIC Any product with the “U.S.D.A. organic” emblem must meet the standards of the agriculture department’s National Organic Program. Among the program’s requirements: birds must be kept cage free with outdoor access (though the time and the type of access are not defined), they cannot be given antibiotics (even if ill) and their food must be free from animal byproducts and made from crops grown without chemical pesticides, fertilizers, irradiation, genetic engineering or sewage sludge. If organic eggs do not have the program’s emblem, they may be part of an independent or state-run program, and it may take some research to determine the program’s standards.