Takata Air Bag Disaster: Passive-Aggressive Safety

We interrupt our regular programming to bring you a public service announcement.  If your car or truck was built in this century and is one of the following makes, it may have an air bag made by Takata that is the subject of an urgent recall.  These bags may explode in low-speed collisions or even in a sudden stop, spraying the occupants of the car with shrapnel.  The June 6, 2016 issue of Bloomberg Businessweek characterized the recalled air bags as "60 million car bombs."  That was in June; the recall has now encompassed some 70 million cars.  The following makes have been involved:  Acura, Audi, BMW, Chevrolet, Chrysler, Dodge, Fisker, Ferrari, Ford, GMC, Honda, Infiniti, Jaguar, Jeep, Land Rover, Lexus, Lincoln, Mazda, Mitsubishi, Mercedes-Benz, Nissan, Pontiac, Saab, Saturn, Subaru, Tesla, Toyota and Volkswagen.  As the recall has expanded and the scandal surrounding it deepened, the NHTSA website has updated their list of makes, models and years affected.  You can go to "NHTSA / Recalls Spotlight:  Takata Air Bags Recalls" to see if your car is on the list…

The feature unique to Takata air bags, and to their failure, is the use of ammonium nitrate (the explosive used in the 1995 Oklahoma City bombing) as a propellant.  Prior to releasing air bag inflators in 2001 using this propellant, Takata used a tetrazole-based propellant called Envirosure. But tetrazole was expensive, and Takata apparently switched to ammonium nitrate for cost reasons.  Takata was the only air bag maker to take this path*.  Takata's own engineers warned about the instability of this material, especially as it takes on moisture and deteriorates over time, but engineers who left the company claim they were ignored.  Bloomberg Businessweek reported that when an engineer wanted to investigate the cause of a test rupture in 2000, he was "reassigned."  In late 2000, a Takata engineer complained that a report on Honda airbags was based on incorrect or invalid data, and in some cases nonexistent data.  The first U.S. case of injury caused by an explosive rupture was in Alabama in 2004.  In 2005, a Takata engineer in the U.S. complained that devices sold to Honda were being supported by data from nonexistent tests. In 2006, the Takata assembly plant in Mexico was rocked by 3 large explosions, which the company blamed on improper disposal practices.  The polite term "air bag rupture" does not hint at the kinds of injuries explosive-driven metal shards can cause.  Victims of air bag ruptures have suffered, and not always survived, severed arteries and in at least one case a severed spinal column. 

Air bags have been required on all cars sold in the U.S since 1989.  Long before the first airbags appeared on cars in the 1980s, there was a spirited debate about the virtues of passive versus active safety in car design.  The deepening disaster of the Takata air bag scandal has revived some of that discussion.  Fans of active safety features argued for across-the-board adoption of disc brakes, for example.  When antilock brakes came along  (earlier than you think, on the Jensen FF in 1966) we wanted those too.  We suggested that cars could adapt better to severe weather with wider adoption of front-wheel drive or torque-sensing all-wheel drive (another feature of the Jensen FF and later on the Audi Quattro, even before air bags were required). Perhaps even more important as part of the active approach, we suggested that adopting mandatory and comprehensive driver education programs in public schools would result in a bigger reduction in the accident injury and fatality rate than adopting air bags.   It made more sense, we thought, to design our driver education and also our vehicles around the idea of avoiding accidents, rather than to simply assume that drivers couldn't help passively blundering into mishaps, and mandating the provision of cars which were massive, inefficient, overweight crash tanks…complete with air bags which, it turns out, can act like grenades. 

The air bag industry claims that its products save around 2,500 lives in an average year.  But there were around 10,000 drunk driving deaths in the U.S. in each of the past two years, and there were roughly 3,300 fatalities caused by texting or cell phone use last year.  Law enforcement figures quoted on the Huffington Post indicate that cell phone use is a factor in 25% of accidents. It would seem that spending more money on driver education and law enforcement, as well as stiffening the penalties for drunk or distracted driving in the justice system, might still be a better investment than perfecting kinder and gentler explosive devices for our car interiors.

Epilogue:    As of this writing, 13 people have died as a result of exploding Takata air bags.  In mid-June, Honda had confirmed over 100 injuries due to these air bags in its own cars.  There is no Federal test procedure for air bags.  I ordered a new passenger air bag for my Subaru in April; the Boulder dealership is just getting around to installing air bags ordered in February.  The dealer turned the passenger bag off, but stated that they could not remove it, as this action was illegal and might result in a lawsuit.  And of course, I wonder about the air bag in my steering wheel. Like the passenger one, it uses ammonium nitrate as a propellant, and I'm guessing it takes on moisture and degrades at the same rate.  Subaru claims that there's no problem with the driver's air bag.  Maybe they're taking Takata's word for it.  They're the same people who, 13 lives and a hundred plus injuries ago, were saying there were no problems with any of their products.

*Footnote:  TRW tried ammonium nitrate, but applied a freeze-drying technique to deal with the moisture threat, and special welding protocols to strengthen the inflator mechanism.  Takata took none of these precautions; owing to their high cost, TRW abandoned ammonium nitrate for more stable propellants in 2006.

Photo credit:  cargurus.com