Travel Reference
In-Depth Information
Exhibit 9.1
NIJ Standard for the Ballistic Resistance of Police
Body Armor
(Continued)
2.6 Type IV (Armor-Piercing Rifle)
This armor protects against 30 caliber armor-piercing bullets (U.S. military
designation APM2), with nominal masses of 10.8 g (166 gr) impacting at a
velocity of 868 m (2850 ft) per second or less. It also provides at least single
hit protection against the threats mentioned in sections 2.1 through 2.5.
2.7 Special Type
A purchaser having a special requirement for a level of protection other than
one of the above standard threat levels should specify the exact test rounds
and minimum impact velocities to be used, and indicate that this standard
shall govern in all other respects.
As you can see, a level IA vest is designed to meet a lower threat level
than a level IIA vest. For reasons unknown, the NIJ uses the designator “A”
to indicate a lower level of protection within a category. Thus, a level II vest
provides greater protection than a level IIA. Each gradation indicates effec-
tive performance against particular ballistic threats and velocities. In addi-
tion, blunt trauma, or back face deformation, is also measured and factored
in to differentiate performance between the levels. Blunt trauma is simply
the amount of crushing force that the round impacting the vest will cause
to the wearer. The standard adopted by the NIJ is that blunt trauma greater
than 44 mm, as measured in the test medium, is likely to cause death or
serious injury to the wearer even if the round does not penetrate the vest.
Often a vest prevents penetration but does not sufficiently disperse the
energy of the bullet that will be absorbed by the wearer. Excessive blunt
trauma will render a vest unacceptable against a particular ballistic threat.
Besides protecting against bullets, vests that protect against blunt trauma
can save lives in auto accidents. Many police officers have survived auto
accidents because they were wearing protective vests. Just as the armor pro-
tects against the blunt trauma associated with a bullet impact, it also pro-
vides blunt impact protection from the effects associated with a car crash.
HOW SOFT BODY ARMOR IS CERTIFIED
In the United States, the NIJ standards are well known and most police
officers, the biggest consumers of SBA, are generally aware of SBA's intended
