The USA has filed a False Claims Act lawsuit against Toyobo Co. Ltd. of Japan and its American subsidiary, Toyobo America Inc., concerning the manufacture and sale of defective Zylon bullet-proof vests to law enforcement agencies.

From 1999 to 2005, Toyobo manufactured and marketed Zylon, a high-tensile strength polymer fibre, for use in ballistic applications; however, Toyobo was aware of significant manufacturing and degradation problems that were inherent in both its fibre and in its manufacturing process. The government's complaint alleges that Toyobo never had control of its manufacturing process, was manufacturing Zylon with serious defects that resulted in lower fibre strength, and knew that Zylon degraded much faster than was disclosed.

"The knowing provision of defective material for use in the bullet-proof vests worn by our federal agents and other law enforcement officers is more than just a fraud on the US Treasury," stated Peter Keisler, assistant attorney general for the Civil Division. "Toyobo's conduct here put the lives of hundreds of thousands of law enforcement officers at risk."