How did they get into food? What’s known about the risks? And what can be done to keep these drugs off your plate?

Ketamine, a hallucinogenic party drug and experimental antidepressant. Phenylbutazone, an anti-inflammatory deemed too risky for human use. Chloramphenicol, a powerful antibiotic linked to potentially deadly anemia.

All these drugs are prohibited in beef, poultry, and pork consumed in the U.S. Yet government data obtained by Consumer Reports suggest that trace amounts of these and other banned or severely restricted drugs may appear in the U.S. meat supply more often than was previously known.

The data—as well as Consumer Reports’ review of other government documents and interviews with farmers, industry experts, government officials, and medical professionals—raise serious concerns about the safeguards put in place to protect the U.S. meat supply.

These concerns start with how poultry, cattle, and pigs are raised in this country. And they include questions about how the federal government tests meat from these animals, and how it investigates and enforces potential violations.