The U.S. Food and Drug Administration has yanked approval of a drug to treat diseases in pigs because it would potentially leave a residue that could cause cancer in humans.

Carbadox, made by Phibro Animal Health, is used to cure dysentery and bacterial enteritis in pigs, was approved all the way back in 1972. However, the agency said in a statement that potential cancer risks from consuming pork liver or other pork products can be dangerous for humans because carbadox leaves behind a residue that can lead to cancer.

The FDA didn’t say people should avoid pork products, as potential cancer risks are based on a lifetime of eating pork liver or other pork products that have carbadox residues. However, the agency felt it was best for the overall safety of the population to remove carbadox from the market.

Phibro officials have said the product is safe and they disagree with the decision, arguing that the drug has been sold for more than 40 years and has been widely used to control bacterial diseases.

“The manufacturer of carbadox has failed to provide sufficient scientific data to demonstrate the safety of this drug given evidence that carbadox may result in carcinogenic residues,” Michael R. Taylor, FDA deputy commissioner for foods and veterinary medicine, said in the statement. “As a result, FDA’s Center for Veterinary Medicine is taking legal action to remove this product from the marketplace.”

The statement adds: “To remove its approval, CVM must first file a Notice of Opportunity for Hearing, which it issued today. The notice provides the manufacturer of carbadox with an opportunity to request a hearing on whether the approval should be withdrawn. The company has 30 days to request a hearing. If the company does not request a hearing, the agency can proceed with removing the animal drug from the market.”