FDA officials also said that the contaminant has now been found in supplies of the drug heparin shipped from 12 different Chinese factories to 11 countries.
The agency sent a warning letter Monday to Changzhou SPL, the company identified as the source of the contaminated heparin. In the letter the FDA said the plant used unclean tanks to make the drug, accepted raw materials from unacceptable vendors and had no way to remove impurities, according to The New York Times.
Heparin, which is given to heart surgery and dialysis patients, is made from mucous membranes from the intestines of slaughtered pigs that are often cooked in unregulated family workshops in China, according to the paper.
FDA officials have said that they don't know for sure how the contaminant -- a cheaper compound called over-sulfated chondroitin sulfate -- entered the drug supply chain.
But they do know that the compound, when administered quickly, could cause the allergic-type reactions that led to the 81 heparin-related deaths recorded between November 2007 and February, Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, said in a press conference.
Chinese officials disputed that claim.
Jin Shaohang, a top official at the Chinese National Institute for the Control of Pharmaceutical and Biological Products, told the Washington Post that some of the heparin associated with the allergic reactions did not contain chondroitin, and that none of the other countries where the contaminant has been found have experienced an increase in severe allergic reactions.
The contaminated heparin is the latest in a string of toxic exports that have worried U.S. officials -- and the public -- in the past year, including lead-painted toys, tainted pet food and contaminated toothpaste.
The FDA announced plans to open offices in three Chinese cities, according to the Times, but has yet to secure permission from the Chinese government.
"Will the U.S. government accept the Chinese FDA to set up in the United States?" Ning Chen, second secretary at the Chinese embassy, told the paper.
Meanwhile, in a House hearing Tuesday, the U.S. Government Accountability Office released a report finding that the FDA's budget for foreign inspections is far too small.
The review found that the agency inspected 11 percent of the more than 3,200 registered foreign drug ingredient makers in 2007. The GAO estimated that it would cost more than $67 million to inspect each of those factories every two years; right now, FDA has budgeted about $11 for the task in 2008.
"FDA will need to devote considerable resources to this area if it is to increase the rate of inspections," GAO health care director Marcia Cross said at the hearing, according to Reuters. "However, FDA's plans currently call for incremental increases that will have little impact in the near future."