The story of the controversy surrounding the use of Zylon® in body armor seems to be a rather predictable tale of the obfuscations of business and government concerning public health and safety, with the expected casualties and penalizing of its whistle-blowers. One of the differences and the many others that have emerged concerning product safety in this post-atomic age is that in this case it has only taken a single death for the biggest name in business to immediately recant and actively pursue some kind of resolution, even if it might not be what its customers would find perfectly ideal.
Zylon® is a fiber filament manufactured by Toyobo, a Japanese firm. It is used in the majority of the most popular bulletproof body armor types, and also in other commercial projects, including flame resistant clothing and equipment. Among the companies using Zylon® is Second Chance, which manufacturers body armor and at least until recently had the lion's share of the market. However, after a police officer on duty suffered a serious gunshot injury while wearing one of Second Chance's Zylon® vests, the company recalled their popular Zylon® lines, citing new research which might show vests were compromised.
Tests performed by Second Chance suggested that Zylon® vests degenerate at an accelerated rate in some cases, and may be no long 100% effective when they reach a slightly more advanced age (over one year). Tests by Toyobo country also show that degeneration does happen, however they claim it is only likely in extreme conditions of heat and humidity, and that body armor companies should be able to design vests so as to escape this flaw. Both Toyobo and other manufacturing companies suggest that their product is not innately flawed, and should be continued in production. So far, Second Chance has been the only company to offer any sort of recall or to discontinue making the vests.
It is difficult to say with certainty what the truth of the matter is regarding the safety of Zylon®. On the one hand, there has only been one failure of a safety vest, and over 2,500 or so instances of vests saving an officers' life. Both Toyobo and the other armor manufacturers seem to have a legitimate set of arguments as to why Zylon® is a dependable ingredient in bulletproof vests. It seems possible that Second Chance is either overreacting to the data they have found regarding Zylon® or that the problem is limited to their methods of using Zylon® and does not lie with the material itself. On the other hand, just one failure does seem to indicate a greater problem, and combining Zylon®'s admitted degeneration issues with the practical evidence Second Chance claims to have gathered does seem to indicate that a serious problem exists. It seems improbable that the leading manufacturer of personal body armor would have the worst and most unsafe design and that its competitors (who do not appear to even be testing their used vests) would not be prone to the same mistakes in construction.
Currently, Second Chance is offering to upgrade all its Zylon® vests for free, or replace them for a sharp discount which varies according to age. (The average life span cited for vests is between five and ten years, so a one-month-old vest is obviously worth more for credit than a five-year-old vest which probably needs to be thrown away anyway) This has not satisfied everyone, and Second chance is currently bound up in a number of lawsuits claiming that they committed fraud by releasing unsafe jackets. On this issue, at least, the reality seems rather cut and dry. Unlike other vest manufacturers, Second Chance is the only one that is admitted there is a problem with their Zylon® vests and offers to replace or repair them. This sort of responsibility is actually uncommon to companies whose products have an occasional failure, and it would be far more typical to deny the accusations and continue selling the vests. The fact that Second Chance has not taken this opportunity to continue releasing killer products is not something they should be punished for, nor does it make sense to penalize them because they were willing to undertake research on product safety and took some time to draw conclusions and present their findings and so forth before withdrawing the vests. Such research is still a step beyond other companies, even if its implications took a month or two to make their way up the chain of command. In short, while it is difficult to say if Second Chance is right that the vests are dangerous, it is easy to say that at the least they should not be penalized for this admission.
Body armor has a long history of trial-and-error development, and throughout time designers of armor have struggled to keep up with those who created weapons designed to pierce it. Somewhat amusingly, the first recorded armor was made of light and flexible materials not unlike those used today, if overwhelmingly more low-tech. Body armor and shields were both made from animal skins. However, advanced in technology led to wooden and metal shields and body protection of various sorts. Metal breastplates were common in very early history, and by the Middle Ages full "suits" of armor were created that sheathed every part of the wearer's body in protective metal. While crossbows and longbows that could penetrate armor presented a danger to those wearing full body armor, it was the coming of firearms that finally made metal armor completely outdated. Bullets could easily pierce even strong metal shells. Meanwhile, in Japan soft body armor was being developed that might be considered a direct ancestor of today's bullet proof vests. Using silk, which was significantly stronger than most other natural fibers, medieval Japanese armor makers could create tough garments that would help turn blades.
So when the American military began researching the possibility of creating some sort of body armor that would stop bullets, silk became one of the primary candidates. There was some limited success with this, and silk body armor could stop low-velocity bullets. However, it did nothing against more advanced high-velocity ammunition. Many other forms of body armor were suggested, but none proved to be particularly feasible. The next best thing came about during World War II with the invention of the "flak jacket" which was comprised of a ballistic nylon, and provided some protection against flak and other munitions fragments, though not particular useful against pistols and rifles. Flak jackets certainly saved lives during the war, but they were not a legitimate option for peace time officers.
But in the 1960s, new forms of synthetic fibers made the manufacture of body armor a reality. After extensive research by the National Institute of Justice's Bureau of Standards', it was discovered that the Dupont corporations' material called Kevlar would work remarkably well as ballistic fiber. "Ironically, the fabric was originally intended to replace steel belting in vehicle tires." (NIJ) According to Lester Shubin, how managed the project, "The Army notified me that DuPont had a new fabric to replace steel belting for high-speed tires. When I saw it, I realized it might be a great improvement over nylon for personal armor....and I took a piece of Kevlar to a gun range. The bullets didn't go through." (NIJ)
So Kevlar became the standard for body armor for many years to come. Much of the work on its development was done by government agencies such and the FBI, Secret Service, and the National Bureau of Standards. The government also funded private contractors such as The Aerospace Corporation and MITRE Corporation. Of course the U.S. Army also got involved in research. To some degree this intense study of the nature of Kevlar is different than the work that went into Zylon® as a material, which was primarily explored by independent companies. Kevlar was tested both against a wide range of bullets, and the vest design was finalized. Medical testing oversaw what level of protection was necessary in the regular line of duty, because of concerns about the blunt trauma inflicted by a non-penetrating bullets.
Like Zylon® today, researchers found that Kevlar degraded under less-than ideal circumstances. For example, sunlight, cleaning agents including bleach, repeated washing, and moisture were all listed as potential threats to the integrity of the body armor. One important fact to remember from this era is that this early armor made by the government itself "was designed to ensure a 95% probability of survival after being hit with a.38 caliber bullet at a velocity of 800 ft/s. Furthermore, the probability of requiring surgery if hit by a projectile was to be 10% or less." (NIJ) In short, back in the day when Kevlar was the standard, a 5% fatality rate when wearing the jacket was considered to be acceptable causalities. This is significant to keep in mind when one approaches the story of how a single bulletproof vest failed…