Animal lungs have been banned from human food in the United States since 1971, when the USDA ruled them unfit for consumption. The regulation, codified in federal law as 9 CFR 310.16, is straightforward: “Livestock lungs shall not be saved for use as human food.” The ban applies to lungs from all livestock species, and it remains in effect today with no scheduled changes.
What the Law Actually Says
The federal regulation draws a hard line. Healthy lungs can be used in pet food, sold to pharmaceutical manufacturers, or discarded, but they cannot enter the human food supply under any circumstances. Lungs found to be diseased or contaminated with chemical or biological residues are condemned entirely and cannot even be used for pet food. They must be labeled “U.S. Inspected and Condemned” and destroyed.
This isn’t a guideline or recommendation. It’s an enforceable rule under the USDA’s Food Safety and Inspection Service, and any slaughterhouse or meat processor that violates it risks losing its federal inspection status.
Why Lungs Are Considered Unsafe
Lungs are uniquely vulnerable organs. Unlike muscle meat or even other offal like liver or kidneys, lungs are directly exposed to the outside environment through the airway. Every breath an animal takes pulls air, dust, bacteria, and other particles deep into the lung tissue. This makes lungs far more likely to harbor contaminants than other organs.
During slaughter, the risk compounds. Stomach contents can reflux into the airway, flooding the lung tissue with gastric fluids and partially digested food. This aspiration is difficult to detect visually and nearly impossible to clean. Foreign material that reaches the lungs can trigger inflammatory responses, fluid buildup (pulmonary edema), and granulomas, which are clusters of immune cells that wall off irritants. These changes happen at a microscopic level, meaning a lung can look normal on the outside while containing pockets of contaminated or inflamed tissue inside.
Livestock lungs also carry a heavy burden of respiratory pathogens picked up during the animal’s life. Pigs, for example, commonly harbor bacteria like Mycoplasma hyopneumoniae, Pasteurella multocida, and Actinobacillus pleuropneumoniae, all of which cause chronic pneumonia that may leave scarring and lesions throughout the lung tissue. These infections are so common in finishing herds that lung lesion scoring at slaughter is used as a standard measure of herd health. Cattle and sheep face their own set of respiratory infections. The result is that a significant percentage of livestock lungs arriving at slaughter already show signs of disease, even if the animal appeared healthy.
Why Lungs Are Harder to Inspect
The USDA’s inspection system is built around the idea that inspectors can evaluate meat for safety before it reaches consumers. Lungs make this unusually difficult. Their spongy, air-filled structure means contaminants can be distributed throughout the tissue in ways that aren’t visible on the surface. A liver or heart can be cut open and examined with reasonable confidence. A lung’s millions of tiny air sacs create countless hiding places for bacteria, fluid, and foreign material.
This is the practical core of the ban. It’s not that every animal lung is dangerous. It’s that there’s no reliable, scalable way to ensure the ones reaching consumers are safe. The USDA concluded that the inspection burden was too high and the contamination risk too unpredictable to allow lungs into the food supply.
The Haggis Problem
The most visible consequence of the lung ban has nothing to do with American cuisine. Traditional Scottish haggis, a dish made from sheep’s heart, liver, and lungs mixed with oatmeal and spices inside a stomach casing, has been effectively illegal in the United States since the 1971 ruling. The dish cannot be imported from Scotland, and it cannot be made authentically by American producers.
This has created a decades-long frustration for Scottish Americans and haggis enthusiasts, particularly around Burns Night each January, when the dish is traditionally served. American-made “haggis” substitutes exist, but they replace the lung with other offal or meat, which changes the texture and flavor profile considerably.
Scotland’s largest haggis producer, Macsween of Edinburgh, has been working on a reformulated recipe that omits sheep lung entirely, aiming to legally enter the U.S. market of 335 million potential customers. The company has suggested a lung-free version could be available in the U.S. by 2026, though it raises the obvious question of whether haggis without lung is still really haggis.
Other Countries Allow Lung Consumption
The U.S. ban is not universal. Lungs are eaten in many countries across Europe, Asia, and Africa. The United Kingdom, where haggis originated, permits the sale and consumption of animal lungs under its own food safety framework. So do most EU member states, where offal including lungs is sold in butcher shops and used in traditional recipes.
These countries rely on their own inspection protocols to manage the risks rather than imposing an outright ban. The difference reflects a regulatory philosophy: the USDA chose to eliminate the risk entirely by removing lungs from the food supply, while other nations chose to manage it through inspection and processing standards. Neither approach has produced a notable food safety crisis, which is part of why the ban strikes some people as overly cautious and others as appropriately conservative.
Healthy lungs that pass initial inspection in U.S. slaughterhouses don’t go to waste. They’re routed into pet food production or sold to pharmaceutical companies, where they’re labeled “Inedible [Species] Lungs” and used to extract biological compounds. The infrastructure for handling lungs already exists; the line is simply drawn at human plates.