The Department of Justice has sued Honeywell International to recover damages from the sale of laminated fiber materials supplied to bulletproof-vest makers. DOJ charges that Honeywell knew and did not inform the government that the laminate was made with a defective fiber, known as Zylon, manufactured by Japan's Toyobo. The government alleges that Zylon quickly lost strength in hot and humid conditions. In at least one instance, in 2003, a vest made with Zylon fiber failed to protect a Pennsylvania police officer from serious injury. Developed by the Air Force in the 1980s, Zylon consists of rigid-rod chain molecules of poly(p-phenylene-2,6-benzobisoxazole). A Honeywell spokesman says the firm did not make the fiber, did not manufacture vests sold to military and law enforcement agencies, and was unaware of any instances in which vests containing the laminate failed. He says Honeywell intends to vigorously defend itself. Last October, Hexcel agreed to pay $15 million to settle DOJ charges that it too knew Zylon fiber was defective but still sold woven Zylon fabric for use in bulletproof vests. DOJ has also filed suit against Toyobo and vest makers.