NIJ Report Says Failed Vest Was Weaker
by Dave Workman
Senior Editor
A preliminary report from the National Institute of Justice (NIJ) on the condition of a bullet-resistant vest worn by a Pennsylvania police officer shot on duty in June 2003 said fibers in the vest may have lost up to 30% of their strength.
However, the report hedged on the fibers, noting that “the preliminary test results indicate that there may be degradation occurring in the ballistic performance of used Zylon-based (vests).” Further testing is underway.
“At this point,” the report states, “it cannot be stated conclusively that the weakened condition of the fabric was the exclusive or predominant cause of the failure.”
The June 23, 2003 shooting of Forest Hills, PA, Officer Ed Limbacher, and subsequent concerns over the failure potential of vests made with a lightweight fiber called Zylon touched off an investigation by the Department of Justice, and the on-going test of vests made with Zylon.
Second Chance Body Armor had been using Zylon—a fiber produced by a Japanese firm called Toyobo—in the production of its Ultima vest. That model has been discontinued.
Gun Week obtained a copy of the preliminary report to Attorney General John Ashcroft in which the NIJ confirms that the Zylon fibers in Limbacher’s vest had lost up to 30% of their tensile strength.
Limbacher was shot in the abdomen by an assailant using a .40-caliber handgun. One bullet penetrated the vest and remains in Limbacher’s abdomen. Another round struck Limbacher in the arm. The NIJ study is looking at the possibility that the angle of trajectory may have had some influence on vest penetration.
The NIJ report stressed that the Limbacher shooting is the first case reported in which an NIJ-compliant body armor appears to have failed. NIJ sets body armor standards.
Toyobo has acknowledged that Zylon’s strength decreases due to exposure to certain environmental conditions including high temperature and humidity, and exposure to ultra violet and visible light. It initially announced that the vests might deteriorate due to certain environmental conditions in July 2001. Second Chance subsequently did its own tests.
Late last year, Gun Week actually participated in an unscientific test of a used Second Chance Ultima vest, firing rounds from a 9mm, .357 Magnum, .40 S&W and .45 ACP into the vest. Rounds from the 9mm and .40 S&W penetrated the vest, while the .45 and .357 Magnum did not.
Last year, Second Chance took the unusual step of announcing publicly that there might be a problem with the Zylon-based vests. It immediately began offering “upgrade” panels that add layers of bullet-resistant material to the vests, or offering low-cost replacement of the Ultima models with the company’s Monarch vest model, which is made with a different ballistic material.
There are, the report said, nearly 240 different models of Zylon-based ballistic vests on the market, produced by 16 different manufacturers.
During the initial testing, the front panel of each body armor sample was shot, with two different caliber handguns, three shots each. At least one of each caliber bullet was fired into the vest at a 30-degree angle. Half of the vests were penetrated by at least one round, the .357 Magnum in all but one case.
Test vests were retrieved from law enforcement agencies all over the country, and they ranged in age from eight months to more than five years. There were models from four different manufacturers.
According to the report, “Preliminary test results are consistent with the working theory that there may be degradation occurring in the ballistic performance of used Zylon-based armors.”
The second phase of testing will involve about 500 vests, randomly selected from five different climactic regions, five different age classes and four different brands.
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