Use of nitrofuran in food animals was largely banned world-wide by 2002.    From Wordnik.com.  [U.S., Canada Split Over Chinese Shrimp] Reference

Canada said it started inspecting all shipments of Chinese shrimp for the antibiotic nitrofuran in September 2006, and the first three shipments from Guolian passed inspection.    From Wordnik.com.  [U.S., Canada Split Over Chinese Shrimp] Reference

Specifically, through targeted sampling from October 2006 through May 2007, the FDA repeatedly found that farm-raised seafood from China contained antimicrobial agents not approved for use here: nitrofuran, malachite green, gentian violet and fluoroquinolone.    From Wordnik.com.  [FDA warning on Chinese fish highlights problems with inspections] Reference

They include many human antibiotics, penicillins and some names I recognise from the bad days of the European fish-farming industry -- nitrofuran, chloramphenicol and organophosphate pesticides.    From Wordnik.com.  [Chinalyst - China blogs in English] Reference