Yes, most other ballistic resistant materials are known to degrade in ballistic performance due to one reason or another. However, the current directive is to evaluate Zylon®-based body armor. Findings concerning the degradation of performance of Zylon®-based body armor may shed light on issues pertaining to other ballistic materials.
Armor manufacturers are responsible for understanding the vulnerabilities of the materials used in their designs and to consider these during the design process so that adequate safety margins are built in to the armor so that it performs acceptably over its entire ballistic-resistance warranty period. NIJ is also investing in research that may lead to the introduction of test methods and performance standards that will require body armor to successfully withstand a series of "exposure" tests during which many of the known vulnerabilities of ballistic materials will be exploited.