Note: This is the first of two columns on labeling for meat and poultry. The first is on claims that tell us what is not added. The second, next week, covers claims about the rearing of livestock and healthfulness of the foods we eat.

Here's a guide to the claims — no antibiotics, no chemicals, no additives, hormone-free — and what they mean when it comes to meat and poultry.

NO ANTIBIOTICS

What it implies: That no antibiotics (drugs used to kill or inhibit the growth of bacteria in people and animals) were used in raising the animal.

What it means: There are basically two methods for using antibiotics in raising animals. The first is called "subtherapeutic," meaning that low levels of antibiotics are mixed with the feed, even if the animals are not sick. This is supposed to promote animal growth and prevent disease. In fact, according to Urvashi Rangan, an environmental scientist at the nonprofit research group Consumers Union, up to 70 percent of all antibiotics have been estimated to go into the daily feeding of animals in this country. "Some antibiotics are fed to cattle to alter the balance of bacteria in the stomach or rumen in order to favor the presence of bacteria that assist in the digestion of corn and improve animal efficiency," says Karen Killinger-Mann, a consumer food-safety specialist at Washington State University.

The other reason ("therapeutic") antibiotics are used in raising animals is if the animals are sick. Normally, if one animal gets sick, the entire herd is treated as a prophylactic measure. Organic farmers, however, can treat only that one animal and must remove it from organic production, says Rangan.

While the phrases "no antibiotics administered" and "raised without antibiotics" are allowed, the U.S. Department of Agriculture prohibits the labeling of any meat product with the term "antibiotic free." The term "no antibiotics added" may be used if sufficient documentation is provided by the producer demonstrating that the animals were raised without antibiotics.

Verification: None. The USDA technically is responsible, but there is no system in place to check the validity of such claims — so while the label is specific and, therefore, somewhat meaningful, without verification, these claims provide assurance up to a point.

The real story: Rangan says that the legally allowed amounts of antibiotic residues in meat are not the primary concern in terms of our health. The fact that farmers are boosting animal growth by giving them "low levels" of antibiotics all the time may contribute to an increase in the number of bacteria resistant to antibiotics, a serious public-health problem.

NO HORMONES

What it implies: No growth hormones (chemicals used to increase animal size) were used in raising the animal.

What it means:

Pork or poultry: The USDA does not allow hormones in their production. Therefore, the claim "no hormones added" cannot be used on labels unless it is followed by a statement that says, "Federal regulations prohibit the use of hormones." However, those regulations are not always followed. Consumers should not pay extra for pork or poultry products, including eggs, boasting this claim.

Beef: "No hormones administered" indicates that the animal was not given any added hormones over the course of its lifetime. The term may be approved for use on the labels of beef products with sufficient documentation provided to the USDA by the producer.

Verification: None.

The real story: Cattle that are not rushed to grow using hormones are often raised on pastures and live low-stress lives, thus are healthier. When you choose products from pastured animals, you are eating the food that nature intended. However, the "no hormones" claim does not guarantee that the cattle were pasture-raised.

NO ADDITIVES

What it implies: That the animal was not given any of the approximately 2,800 "food additives" (natural or artificial), including salt, sugar and corn syrup, which are by far the most widely used additives in this country, according to the USDA.

What it means: "Food additive" is defined by the Food and Drug Administration as any substance used to provide a technical effect in foods. Additives are used for flavor and appeal, food preparation and processing, freshness and safety. "No additives" means that the cut of meat or poultry itself has not been enhanced with any natural or artificial ingredients. It has nothing to do with how the animals were raised or what they ate.

Verification: None. The USDA and FDA share authority over the approval of additives in meat and poultry, but there is no verification for manufacturers using the "no additives" label.

The real story: According to Rangan, the claim may be misleading, because most people think it has to do with how the animals were raised.

NO CHEMICALS ADDED

What it implies: That the animal was raised and produced without antibiotics, additives or pesticides.

What it means: Unfortunately, no one has decided. "No chemicals added" is not a term regulated by the USDA, and no government body has proposed a solid definition. The USDA does, however, prohibit the use of the term "chemical-free" on both meat and poultry.

Verification: None.

The real story: Since there's no government definition, this label doesn't really help you. Antibiotics, pesticides and additives are not legally classified as chemicals; so, presumably, they could be added by a manufacturer using this label. According to Rangan, when the label defines what the producer means by "no chemicals" — for example, listing no antibiotics, no pesticides, no hormones — it has some level of clarity. But merely stating "no chemicals" on a label is meaningless.

Charles Stuart Platkin is a nutrition and public-health advocate, and author of "Breaking the FAT Pattern" (Plume, 2006). Sign up for the free Diet Detective newsletter at www.dietdetective.com.