Breakage of the oxazole ring correlates with degradation of the mechanical properties of Zylon fibers.
The Department is issuing a Body Armor Standard Advisory Notice to alert law enforcement to the potential risks associated with the use of Zylon in body armor, and will adopt new interim requirements for its body armor compliance testing program.
This program is designed to provide critical resources to state, local, and tribal jurisdictions for the sole purpose of purchasing bullet-resistant body armor for sworn law enforcement officers.
(BJA) Body Armor: A survey of 782 agencies nationwide, conducted by the Police Executive Research Forum (PERF) and the Justice Department's Bureau of Justice Assistance indicates that, while nearly all law enforcement agencies (99%) provide body armor for officers, only 59% require it to be worn at some time, and of those, only half had a written policy concerning its use. "More than 3,000 police officers' lives have been saved by body armor since the mid-1970s when NIJ began testing and developing body armor and performance standards for ballistic and stab resistance.
Mesloh, 9 (1) Law Enforcement Executive Forum 121-128 (2009).
A baton that is too light or too small may cause an officer to strike a subject repeatedly to effectively control a suspect, which is perceived badly by both the media and the public.
Only four used armor vests tested met all performance criteria under NIJ's body armor standard for new body armor.
In the tests, age and appearance of used Zylon-based vests were ineffective predictors of potential ballistic performance.
The National Institute of Justice (NIJ), the research, development, and evaluation arm of DOJ, conducted extensive testing on used Zylon-based body armor.
The testing was carried out as part of the Attorney General's Body Armor Safety Initiative, which began in November 2003.
NIJ's research also showed that ballistic-resistant material, including Zylon, can degrade as a result of exposure to environmental conditions, such as moisture and light.
It is likely that the ballistic performance degradation in Zylon-containing armor is closely related to the chemical changes found in what is known as the oxazole ring.
As a result, body armor models that contain Zylon will not be compliant, unless their manufacturers provide satisfactory evidence to NIJ that the models will maintain their ballistic performance over their declared warranty period.