WINCHESTER — A warning letter about “significant violations” of the federal Food, Drug and Cosmetic Act at its Frederick County rendering plant was sent to Valley Proteins Inc. on Nov. 18 by the FDA.

The plant, located at 1635 Indian Hollow Road, produces animal food ingredients distributed to animal food manufacturers.

According to the letter, the Food and Drug Administration discovered pentobarbital — a drug approved to anesthetize and euthanize animals — in a sample of finished animal fat products taken from the rendering plant Nov. 14, 2018.

“The presence of pentobaritbal in your animal fat products causes these products to be adulterated because the animal food contains an unsafe new animal drug,” the letter states.

An investigation revealed that Valley Proteins became aware of the pentobarbital contamination on Dec. 18, 2018, but did not take immediate action to notify customers or recall the product, the letter states. Valley Proteins told the FDA it did not plan to issue a recall and did not provide the FDA with requested information regarding the amount of potentially affected product that was distributed.

FDA District Director Evelyn Bonnin said in the letter that Valley Proteins asserted that pentobarbital is an “unavoidable contaminant not known to present a health hazard.” She wrote that Valley Proteins “failed to adequately address this problem” and disputed the assertion that adulteration of animal food with pentobarbital is unavoidable.

In response to being notified of the objectionable conditions, Valley Proteins stated it doesn’t believe there are any legal requirements for it to issue a voluntary recall. However, the FDA says, “It is important to notify affected customers and remove all adulterated animal food from the marketplace.”

Valley Proteins President and CEO Gerald F. Smith Jr. told The Star in a phone interview that he would not disclose the customers that might have received contaminated products, but he said the Indian Hollow Road plant “does not sell products to the pet food industry.”

“To be honest with you, the main thing that we believe the contamination came from was a few euthanized horses that we received at the Winchester facility,” Smith said.

Valley Proteins stopped processing dead horses last January, though it continued to collect and dispose of them for a few months after that “to not leave our farmers high and dry,” Smith said. In May, that service was discontinued.

Smith said Valley Proteins has addressed most of the FDA’s complaints and that the pentobarbital is a “very, very small” contamination that won’t impact animals, so there are still no plans to issue a recall, he said.

According to the letter, Valley Proteins has been conducting pentobarital testing since January 2019. It also no longer accepts or processes “dead stock,” which includes all euthanized animals.

The FDA told Valley Proteins it is “responsible for investigating and determining the causes of the violations” and preventing their recurrence.

“Failure to do so may result in regulatory action without further notice such as seizure and/or injunction,” the letter stated.

Valley Proteins provides rendering and recycling of animal by-products, according to online information. It offers animal fats and oils, feed fat, yellow grease, poultry fat, biofuel fat, protein meals, and pet food ingredients. The family-owned business serves customers worldwide.