WASHINGTON – Animal-welfare groups and United Farm Workers of America filed a lawsuit against the Food and Drug Administration on claims the agency failed to consider the cumulative impact of ractopamine and other drugs on animal behavior, worker safety, wildlife and waterways.

The lawsuit, filed in federal district court in San Francisco, asks the court to set aside FDA's approvals of ractopamine, antibiotics and steroids while FDA performs an environmental review. Plaintiffs in the lawsuit are The Humane Society of the United States, The United Farm Workers and The Animal Legal Defense Fund.

The groups argue that new combinations of ractopamine with antibiotics and steroids remain active in animal waste; when sprayed on fields or spilled from manure lagoons, the drugs can be destructive to the environment and wildlife. The drugs also have negative outcomes for workers in agriculture, the groups claim.