Late last week the Food and Drug Administration (FDA) urged consumers to stop using Children's Tylenol and other over-the-counter products made by McNeil Consumer Healthcare. This week the agency explained why.

FDA said its inspectors encountered thick dust and contaminated ingredients at the Fort Washington, Pa., plant producing the products. Some equipment was covered with grime, there was a hole in the ceiling in one room and pipes were patched with duct tape.

On closer inspection, FDA said it found raw ingredients contaminated by an unspecified bacteria, a lack of quality control procedures and poor handling of complaints. Among the complaints, the agency said, were 46 reports of "dark material" in the liquid products between June 2009 and April 2010. While bacteria were present in the plant, FDA said its tests failed to detect it in any finished product.

Johnson & Johnson, which owns McNeil Consumer Healthcare, has suspended production at the Pennsylvania plant and promised to do better.

"The quality issues that the FDA has observed, many of which we had recently identified in our own quality reviews and communicated to the FDA, are unacceptable to us, and not indicative of how McNeil Consumer Healthcare intends to operate," the company said in a statement. "While the chance of serious adverse medical reaction is remote, we apologize to those who rely on our medicines for the concern and inconvenience this recall may have caused. We will provide a detailed response to the FDA on their observations, and work diligently to ensure that they are addressed."

The company said it would not restart operations until it has taken the necessary corrective actions and can assure the quality of products made there.

FDA has urged parents to select private label alternatives for the over-the-counter medications and said it was considering possible further regulatory action.

Meanwhile, Congress is getting into the act. Both the chairman and ranking Republican on the House Committee on Oversight and Government Reform issued a joint statement saying they are "deeply concerned" about the recall.

Chairman Edolphus "Ed" Towns (D-NY) and Ranking Member Darrell Issa (R-CA) have announced that the committee has opened an investigation into the circumstances surrounding a major recall of children's medication.