Legal Analysis of Takata Patents as a Roadmap to Discovery


Recent reports of airbag ruptures shooting shrapnel at vehicle occupants are terrifying millions of Americans and vehicle occupants abroad. As a Victim's Rights Attorney, who handled airbag cases long before the 2014 recall, my goal, on behalf of my clients and other potential victims, is to ascertain answers as to why airbags are rupturing or malfunctioning, and help figure out a way to prevent future injuries or death. In addition to representing numerous victims of airbag injuries, I've handled more than 5,500 accident and injury cases on behalf of victims injured or killed as a result of negligence and gross misconduct.

To understand the cause of the reported airbag ruptures and defects, I analyzed several patent filings with the United States Patent and Trademark Office. The thorough patent search, coupled with my experience in reconstructing accidents and in handling several other airbag rupture accidents, serves as a base and guide for further research and analysis.


The 2006 Dodge Charger Claim

By way of background, I was retained in September 2013 by a victim of a car accident whose leg was stabbed by a 4 inch piece of metal that shot out of his airbag in the 2006 Dodge Charger.
 
My initial instinct was to notify Chrysler of the airbag incident. My goal was to discover the cause of the explosion to determine if Chrysler or Takata were legally liable. I thought at the time that the opportunity to dissect the internal components of an airbag, a life-saving device that one hopes remains ensconced in the steering wheel component, was a once in a lifetime experience. As a bit of a technology and science aficionado, and being married to a biomedical engineer, I was fascinated by the airbag's mechanics and the opportunity to explore the inner workings of an airbag.

The inside of the deployed 2006 Dodge Charger airbag looked like a mix of small paper clips put through a paper shredder, with an orange rust-colored dust throughout. There was a 5 inch or so hole in the airbag with singed edges around the hole. They looked like burn marks. Underneath the airbag was a metallic container which housed the inflator. It also looked like it exploded. Inside the housing was more orange dust and more metal fragments. Both the outside metal container and inside areas showed signs of rust or corrosion.

I also got to touch and feel the piece of metal that shot through the airbag and into my client's thigh. It was, as I learned, a piece of coil that sits inside the airbag unit. It was composed of hard metal strips that were similar to a small paper clip extended to its full length, and interwined with 20 other extended paper clips. Imagine this shooting out at you at 100 MPH with an unknown trajectory. The difference between injury and death in an accident with exploding shrapnel is luck.

I wondered how the container could have been rusted or corroded. I don't know if Takata or Chrysler ever tested the airbag unit or swabbed the chemical reaction particle residue to reverse engineer it. Perhaps that could tell them exactly what compounds were present post-explosion to see if it was inconsistent with prior testing. Neither Chrysler, nor Takata, advised me of any test results after they received the unit and I am unaware if any testing was completed.

The First 2001 Honda Civic Claim

Shortly after resolving the legal claim made against Takata and Chrysler for the 2006 Dodge Charger incident, I was retained by another victim of an airbag shrapnel injury. This time, the victim was driving a 2001 Honda Civic when she struck another vehicle at moderate speed. Her driver's side airbag deployed and a piece of thick metal, approximately 2 in. x 1 in., flew through her airbag and struck her in the forehead just an inch above her eye, fracturing her sinus cavity and causing other serious injuries to her face.

Like the prior case, I was able to analyze the airbag unit on the 2001 Honda Civic post-accident. This airbag also had a hole in it with burn marks around the area where the piece apparently tore through before striking our client. The piece of metal that struck our client displayed signs of corrosion, which appeared to be rust on both sides. After examining the airbag container, there was an obvious hole on top. It was  apparent that the metal projectile that struck my client was the missing piece of the airbag inflator's container. 

Another 2001 Honda Civic Airbag Rupture Claim

I also represent another victim injured by shrapnel when she was driving a 2001 Honda Civic and was involved in a t-bone type of accident. Upon impact, her passenger-side airbag exploded. A piece of the airbag caught fire and landed on her body. The actual airbag unit detached from the dashboard, flew through past the front seat of the car and landed in the backseat. Like the other, it showed signs of burn marks, and the car had a melted dashboard and seat handle where the burning shrapnel touched.

In addition to the aforementioned cases, I am presently representing other airbag injury victims, including those involving injuries allegedly caused when the airbags did not deploy, where the airbag deployed without any accident, and where the airbag deployed with greater force than necessary and allegedly caused significant injuries. Therefore, understanding the root cause of these airbag ruptures or malfunctions is essential to providing my clients and the public with answers, and preventing an essential safety component of modern vehicles from turning into a weapon.

So what is the root cause of these airbag ruptures or malfunctions? Did Takata know about dangers in the airbags for years? How long have airbags been exploding this way?

To begin the analysis, we start (and maybe end) with ammonium nitrate. Takata reportedly used a chemical called ammonium nitrate as an explosive propellant in the affected airbag inflators.

What is Ammonium Nitrate?

According to the United States Environment Protection Agency (EPA), ammonium nitrate is produced by neutralizing nitric acid with ammonia. It is often found in fertilizer and explosives. Yes, explosives. The Western Fertilizer Handbook notes that ammonium nitrate has a critical relative humidity of 59.4%, above which it will absorb moisture from the atmosphere. Therefore, it is important to store ammonium nitrate in a tightly sealed container according to the handbook. Otherwise, it can coalesce into a large, solid mass.

On March 4, 1959, Inventor Paul Martin, Jr. patented what he called an anticaking-agent for ammonium nitrate, Patent No. US2879133. Mr. Martin identified that "in the presence of atmospheric humidity, particulate ammonium nitrate takes up moisture and the individual particles tend to agglomerate to form lumps; under conditions of high humidity the ammonium nitrate particles tend to form a solid mass."

The manufacturing plant where the ammonium nitrate used in Takata airbags is located, according to reports, is in Ciudad Frontera, Mexico. The humidity level in Ciudad Frontera, Mexico as I write this article is 65%, according to a Miami Herald weather report. This exceeds the level of relative humidity of ammonium nitrate cited by the Western Fertilizer Handbook. If the temperature in the factory was not controlled, or if the factory experienced a period without air conditioning or proper humidity control, and if the ammonium nitrate was not adequately shielded from the humidity during receipt, storage or manufacture, it seems plausible that atmospheric humidity could get into the plant and contact the ammonium nitrate, causing it to be compromised. If these inflators were defective, it could be like having hand grenades sitting inches from every driver in an affected vehicle.

Even if the airbag inflator was manufactured properly, if not sealed correctly or if the sealant broke down over time, then the ammonium nitrate may have been exposed to humidity. If, as Mr. Martin notes in his patent, the humidity contacted the ammonium nitrate in higher humidity conditions, the ammonium nitrate could have transformed into a solid mass.

Regardless of whether there was a breakdown in the inflator chemicals before it left the factory, or whether the integrity of the inflator or airbag module became compromised sometime thereafter, these concerns appeared to be considered throughout Takata's patent applications for many years, and recognized by their competitors.
 
Based on my observations and investigations of the airbag malfunction cases I have handled, there was an apparent breakdown of the integrity of the airbag units in the 2001 Honda Civics and the 2006 Dodge Charger, and what appeared to be signs of corrosion or rust. This is evidence that the airbags degraded over time. Moreover, if the ammonium nitrate in the inflators were exposed to humidity at any time, whether in the manufacturing facility or while in the affected vehicles, the airbags may have been ticking time bombs. The safety device that should protect the occupant may ultimately be the object that hurts or kills them.

The U.S. Patent Filings

Patent applications reveal long-known concerns of shrapnel caused by exploding airbag units.  The first known published patent application considering airbag containers rupturing and shooting shrapnel at vehicle occupants dates back to at least 1985.

In 1985, Patent No. 4561675 was issued and discussed a situation in which temperatures of a certain range may degrade the airbag housing, causing it to "rupture or burst, sending pieces and fragments flying in all directions." While it is unknown if the housings in the presently affected vehicles were made up of the same or similar compounds, or what specific temperatures were reached by the ignition of the explosive, the possibility of airbag housing ruptures have been considered by airbag inventors for nearly 30 years.

Granted in 1989, Patent No. 4858951A notes a situation where "the igniter and gas generating material are supported in an aluminum housing having a mechanical strength which degrades when heated to an elevated temperature. If the gas generating material is ignited when the aluminum housing is at a temperature of about 650° F, the housing may burst and pieces of the housing may fly in all directions."

Contrary to these findings, Takata's executive recently testified at a Senate hearing that Takata was not aware of airbag rupturing problems involving its airbags until 2004 or 2005. However, there was a known risk of airbag housing rupturing, according to the 1985 and 1989 patents. We do not know yet if Takata ever considered airbag rupturing when they manufactured the affected airbags. However, this data was readily accessible through the United States Patent and Trademark Office.

Filed in 1995, inventor Christopher Ludwig, who according to his profile online worked for Talley Defense Systems, noted in Patent No. US5551725 regarding a vehicle inflator that “the vehicle airbag inflator must be stable and safe in its pre-stored, pre-deployed state. This pre-deployed state may be quite prolonged, typically lasting one to several years, and often up to 20 years. During this pre-deployed period, the inflators routinely must endure a wide range of ambient temperatures, humidities, vibrational modes, and other harsh conditions. When called upon, the inflator must perform to specifications with high reliably.” This patent recognizes that long term performance of the airbag inflators must be reliable. 

Given the high susceptibility for ammonium nitrate to absorb moisture when subjected to certain levels of humidity, and humidity as a factor considered when developing airbag inflators, special care should be made to protect the integrity of the ammonium nitrate not just during manufacture, but throughout the lifespan of the airbag’s use in a vehicle.

Takata employees reportedly knew of deficits with using ammonium nitrate in airbags dating back to at least 1995. In a 1995 patent application filed by Paresh S. Khandhadia, filed under Patent No. 5460671, Mr. Khandhadia recognized the risk of airbag housing ruptures and the need to prevent this from happening. He wrote, “One test that vehicle occupant restraint inflator systems must pass is exposure to fire whereupon the gas generating material of the inflator is expected to ignite and burn, but the inflator pressure vessel must not rupture or throw fragments.” According to his LinkedIn profile, Paresh S. Khandhadia is Vice President of Inflator Organization at Takata.

Mr. Khandhadia further recognized the need for an inflator system that could withstand long term storage in an occupant vehicle. He stated that “Vehicle occupant restraint inflator systems must pass ageing requirements in order to ensure reliable ignition despite exposure to a wide range of temperatures over the life of the vehicle.”

A 1996 patent application, Patent No. 5872329, was filed by Sean P. Burns and Paresh S. Khandhadia regarding the use of nonazide gas generant compositions, including ammonium nitrate. The inventors discussed issues with using ammonium nitrate or certain compounds containing ammonium nitrate, which included “poor ignitability, delayed burn rates, and significant performance variability.” According to his LinkedIn profile, Sean P. Burns is Director of Research and Development at Takata.

In 1997, Patent No. 6306232 was filed by Sean P. Burns and Paresh S. Khandhadia regarding smokeless gas generators in airbags. inventors noted that "often, gas generant compositions incorporating phase stabilized or pure ammonium nitrate exhibit poor thermal stability, and produce unacceptably high levels of toxic gases, CO and NOx for example, depending on the composition of the associated additives such as plasticizers and binders. In addition, ammonium nitrate contributes to poor ignitability, lower burn rates, and performance variability."
 
Takata’s own employees identified performance variability and poor thermal stability of ammonium nitrate in at least 1997, yet for years to come Takata continued to use ammonium nitrate or a compound using ammonium nitrate in its airbag inflator, according to testimony a Takata executive gave before the Senate.

In 2003, then AutoLiv Senior Scientist Brian Hamilton, filed Patent Application No. 20040149363 pertaining to phase-stabilized ammonium nitrate. He recognized that "the incorporation and use of ammonium nitrate in pyrotechnic gas generant formulations has generally been subject to certain difficulties or limitations." Noted "shortcomings" included "low burn rates, burn rates exhibiting a high sensitivity to pressure, as well as to phase or other changes in crystalline structure such as may be associated with volumetric expansion such as may occur during temperature cycling over the normally expected or anticipated range of storage conditions, e.g., temperatures of about −40°C to about 110°C."

Mr. Hamilton teaches that ammonium nitrate typically goes through five phases. "In particular, ammonium nitrate is known to undergo temperature-dependent changes through five phase changes, i.e., from Phase I through Phase V, with an especially significant volume change of ammonium nitrate associated with the reversible Phase IV to Phase III transition." Most concerning, in the report of Mr. Hamilton's patent application is his findings that, "such changes, even when relatively minute, can strongly influence the physical properties of a corresponding gas generant material and, in turn, strongly affect the burn rate of the generant material. Unless checked, such changes in ammonium nitrate structure may result in such performance variations in the gas generant materials incorporating such ammonium nitrate as to render such gas generant materials unacceptable for typical inflatable restraint system applications." According to Mr. Hamilton, any change to ammonium nitrate's structure can make it unacceptable for typical airbag systems.

In 2005, a patent for autoignition compositions, a provisional patent which was converted into Patent Application No. 20070113940, was filed by Takata employees discussing moisture issues with certain compositions. In their application, the inventors note that certain specified compositions "sometimes decompose given their hygroscopicity or tendency to absorb moisture. Unsuccessful attempts have been made to inhibit moisture retention or uptake within these compositions without adversely affecting the desired autoignition temperature." It is unclear whether ammonium nitrate was a tested composition and what the tests revealed if it was studied.

Another patent was filed in 2005 by Takata employee Deborah Hordos regarding gas generators used in airbags, under a provisional patent which was converted into Patent Application No. 20060220362. Ms. Hordos noted that "certain propellants may be hygroscopic wherein the absorption of humidity and/or water may inhibit expected burn characteristics and therefore may result in performance variability of an associated airbag cushion during a crash event." It is unclear whether she is referring to Takata's use of ammonium nitrate, though her statement suggests some knowledge on her part of performance inconsistency and propellants absorbing humidity.

In 2006, Takata engineers filed another patent concerning phase-stabilized ammonium nitrate, under Patent Application No. 20070084532. They found that a concern with phase-stabilized ammonium nitrate-containing propellants is that "they exhibit significant aggressive behavior with regard to ballistic properties." They further noted that extreme tests including high temperature heat aging, thermal aging, thermal cycling, thermal shock, and humidity cycling "can cause many problems, ranging from failure to inflate the airbag to over-pressurization of the inflator leading to rupture." In this 2006 patent application, Takata employees found that, "it is therefore desirable to have a gas generant and inflator system that performs the same regardless of conditioning."

From the language in the patent application, it seems like Takata may have performed extreme tests on ammonium nitrate-containing airbag inflators and learned of inflator ruptures in at least 2006. The patent application suggests a need for stability and consistency in the performance of the airbag inflators, something there would generally be no need for unless there were problems identified.

In 2008, a team of Takata engineers again filed a patent proposing a new formula for the airbag inflators, under Patent Application No. 20090008003. They found, "moisture or volatile contaminants can be introduced to gas generating systems in many ways. A few examples include: improperly processed gas generants that contain excess moisture; moisture introduced to the system via humidity during assembly; moisture introduced to the system during environmental conditioning such as high humidity cycling or salt spray; moisture introduced to the system via decomposition of materials within the system such as auto-ignition materials, seals, gaskets, greases, and other gas generator constituents."

The patent application from 2008 suggests more than one potential root cause in Takata's airbag ruptures, including decomposition of materials and components, moisture during manufacturing, improper processing of ammonium nitrate, and others.  It also suggests that Takata's employees were aware of these potential problems, as they cited them in their patent filing. It is unclear yet how, if so, they became aware of the problems.

Again in 2008, Takata employee Deborah Hordos, filed a patent for a change in the gas generator, Patent Application No. 20090102171. An object of the proposed invention "is  to provide a gas generator having a propellant cushion that prevents movement of the propellant tablets or grains by providing a bias thereagainst. Furthermore, the cushion is formed from a desiccating material thereby removing moisture and inhibiting moisture uptake by the propellant both during manufacture, and during its normal shelf-life within a vehicle interior."

From the language in the invention in 2008, Takata's employee may have known of a concern of moisture presence in the gas generator, moisture exposure during manufacture, and even moisture exposure while in consumer vehicles.

In 2010, Takata employees were again listed as inventors on a provisional patent application for a gas generant manufacturing method, converted into Patent Application No. 20130068354. They state, "USCAR requirements include thermal testing by holding compositions at about 107C for about 400 hours without thermal decomposition of the compositions. Certain compositions containing phase stabilized ammonium nitrate, for example, oftentimes present concerns with regard to thermal stability."

In 2012, Takata engineer Jun Nishimura filed for a patent related to the inflator, under Patent Application No. 20140290523. Takata's employee notes, "According to test results carried out by the applicant, it has been confirmed that output increases by approximately 25% in the case of an inflator operating at high temperature (approximately 80° C. to 85° C.) compared to normal temperature (23° C.)."

The employee goes further, "For this reason, when an inflator operates at high temperature with a conventional side airbag, curtain airbag, knee airbag, or the like, gas of higher pressure than at normal temperature is introduced into the airbag. For this reason, in order to ensure reliability during airbag inflation, it has been necessary to reinforce the airbag sewing, use high-strength sewing threads in the airbag, partially add seal reinforcing material to the airbag, and the like. In this case, increases in material costs due to using reinforcing members, seal members, special thread, and the like, increases in manufacturing costs due to additional processing steps, and the like become problematic."

From this patent application in 2012, we learn that in at least as early as 2012, Takata confirmed a problem with the airbag materials used, but also found that the material costs to reinforce the airbags was "problematic."

In 2013, Takata employees Deborah Hordos and Research and Development Specialist Scott Rambow filed a patent application for self-healing additive technology, under Patent Application No. 20140150935. Takata's employees recognized that, "during temperature cycling inside of an inflator, tablets or wafers of gas generating compositions containing phase-stabilized ammonium nitrate or PSAN (e.g. PSAN containing about 85 to 90 weight percent ammonium nitrate coprecipitated with about 10-15 weight percent of a potassium salt such as potassium nitrate), may lose density especially in the presence of moisture or humidity. It is believed that in some circumstances, the density loss may lead to less predictable performance criteria."

As evidenced in the patents filed by Takata's own employees, concerns over humidity, thermal stability, poor ignition, and performance variability were known risks to Takata for many years. Previous patents filed by independent scientists were easily accessible through a rudimentary patent search. Despite all of the research that supported the patent applications from Takata employees and other inventors making material changes to the airbag systems, those driving vehicles with prior versions were never told about potential dangers. They were never advised to have their airbags replaced or inspected to our knowledge.

Additionally, there has yet to be full public disclosure of which vehicles contain which version or variation of the inflator or airbag unit. Presumably, one would be safer in a vehicle with an airbag using one of the more recent inventions than a vehicle containing an airbag from the 1999 patent. If safer alternatives are available, the airbag manufacturers should provide an option for vehicle owners to have their airbags upgraded or replaced in a timely manner.

Possible Causes of Airbag Ruptures

There are a myriad of causes contributing to airbag ruptures as reported. The ruptures might have been caused by humidity coming into contact with the ammonium nitrate while stored in the manufacturing plant, rendering it unfit for use. Humidity may have contacted the ammonium nitrate during the production phase of the inflators. The sealant on the inflators may have broken down over time or were not sealed properly, allowing humidity to enter the container and compromise the ammonium nitrate. The ammonium nitrate may have become unstable over time and decomposed or degenerated. The ammonium nitrate may have burned at too high a temperature, leading to an explosion and causing the container to rupture. Humidity may have entered the airbag console and corroded or rusted the exterior or interior of the container housing, compromising the integrity of the unit. Performance variability of ammonium nitrate may have created inconsistent deployment results, with some airbags deploying properly and some not.

Whether there is one root cause or several, the consistent theme is that there is an apparent problem with certain airbag units which may still be on the roads. These drivers and passengers may not be aware that their vehicle's integral safety feature might actually be an explosive sitting directly in front of them.

Moving Forward

More oversight and controls may be needed over manufacturing and use of airbag units. A plethora of potential issues exist which could lead to the compromised integrity of the airbag units. While it is unknown whether the prior shrapnel incidents were caused by one or several factors, patent applications reveal that Takata considered safer alternatives over the more recent years. Reporting potentially dangerous issues is critical to keeping the public safe.

Perhaps we can conclude that regardless of the compounds and structures encased within the airbag component, airbags may have a lifespan. Like other automotive parts, airbags may need to be replaced after a period of time. Oil needs to be changed every certain number of months or years, tires only last a certain number of miles before they start to bald, windshield wipers often need replacement, and even engines sometimes need replacement. Maybe in the coming months or years, we will change our thinking to have routine airbag safety swaps and airbags added to vehicle warranties.

Perhaps too product manufacturers should be required to notify or warn their customers whenever they find a danger with a product already in the marketplace. We certainly want manufacturers to constantly strive to make a product better. We should require, however, that if a product manufacturer finds a defect or something potentially dangerous with a prior version of its product that it let its customers know so they could replace the product for a safer alternative if they choose.

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Airbag attorney Jason Turchin has appeared on CBS Evening News, CBS This Morning, WSVN/Fox Miami, Telemundo, NBC6, CBS4, and other media outlets as one of the leading airbag attorneys in the US. For more information on Jason Turchin or to contact him, call 800-337-7755.