Factors that Impact the Effectiveness of Body Armor
New Resource from NIJ and
PoliceArmor.org offers information on how to select, purchase, wear, and care for body armor.
On this page, learn about:
Wear and Tear on Body Armor
Age is not the only factor that affects degradation of body armor. Wear and tear from normal use can also contribute to deterioration. All armor on the compliant product list must have a declared ballistic warranty period (it is up to the manufacturer to determine that period based on its test date). NIJ has taken various actions to address related issues, including:
- Producing test protocols to examine body armor performance after undergoing mechanical wear in a tumbler for 10 days while being exposed to hot and humid conditions.
- Issuing guidance that includes information about body armor life expectancy and replacement policies and that encourages agencies to inspect armor at least annually for signs of excessive wear and tear. NIJ has produced a video about inspecting armor for signs of wear and tear.
- Conducting research on how materials used in body armor change over time, how some designs may be less vulnerable to mechanical damage, and how artificial aging methods might predict service life. Learn more from the Material Measurement Laboratory, National Institute of Standards and Technology.
Care and Maintenance of Body Armor
Some substances, such as dry cleaning solvents, harsh detergents, bleach and accumulated soap residue, can damage body armor and reduce its effectiveness. Improper storage also can degrade performance. For example, storing body armor on a hanger, rather than letting the vest lie flat, can reduce the armor's effectiveness. NIJ requires that all compliant armor models include care instructions.
Law enforcement officers also should perform visual inspections to ensure that covers and armor materials are not ripped, worn through or damaged.
In 2009, NIJ funded the Police Executive Research Forum (PERF) to conduct a national survey of police officers. Among other things, the survey examined what officers knew about caring for and maintaining their body armor. The survey revealed that while most officers are knowledgeable about many body armor care and maintenance practices, a substantial number do not understand certain aspects of recommended practices or do not adhere to the practices they do understand. The researchers recommended additional training and education on body armor care and maintenance.