Takata Airbag Recalls Widen To Potentially Affect Other Types Of Airbag

The Takata airbag case has become the largest product recall in history, caused over 20 deaths, and cost many billions of dollars. Replacement efforts are still ongoing, and sadly, the body count continues to rise.  Against this backdrop, further recalls have been announced affecting another type of Takata airbag.

The recall affects BMW 3 Series vehicles, produced between 1997 and 2000. Notably, it appears these cars may have been built before Takata’s fateful decision to produce airbag inflators using ammonium nitrate propellants, known for their instability. Instead, these vehicles likely used Takata’s proprietary tetrazole propellant, or Non-Azide Driver Inflators (NADI). These were developed in the 1990s, and considered a great engineering feat at the time. They were eventually phased out around 2001 for cost reasons, leading to the scandal that rolls on to this day.

As these airbags were produced before the switch to ammonium nitrate, they have thus far escaped scrutiny as part of existing recalls. Two recent incidents of airbag misdeployments in Australia led to the recall, causing a death and a serious injury. BMW Australia have advised owners not to drive affected vehicles, and are offering loan or hire cars to affected vehicles. Given the age of the affected vehicles, the company is considering a buyback program in the event that suitable replacement parts cannot be made available.

This development is foreboding, as it suggests yet more cars, originally considered safe, are now at risk of injuring or killing occupants in the event of a crash. It’s not yet clear exactly which makes are effected by this recall, but expect the numbers of vehicles to continue to climb.

[via Sydney Morning Herald]

55 thoughts on “Takata Airbag Recalls Widen To Potentially Affect Other Types Of Airbag

  1. ” BMW Australia have advised owners not to drive affected vehicles, and are offering loan or hire cars to affected vehicles.”

    LOL, does anyone remember when we drove our cars before airbags ?

        1. One of the first to die was in Orlando. The cops thought someone shot her in the neck and that caused the accident. They were looking for a killer until it was found to be shrapnel from the air bag deploying! What about the seatbelt locks on some cars, are those not made with the same explosive? A thrift shop near me has one on their shelf, I told them you guys do know that’s an explosive seat belt lock. They didn’t care, wonder what the chance is of someone setting it off with static picking it up to look at it?! I wouldn’t mess with it lol!

    1. you have obviously never had an airbag go off on you before. I have, and I was braced and expecting it, and holy shit was it unplesant and I had nice powder burns up my arms to show for it, if that happened to you while you were just driving along, you will crash, no doubt about it, assuming you dont suffer a direct injury from shrapnel first.

        1. Sorry that reads like apples to oranges theatrics to me, not relative facts. The questions are. How much energy does is take to launch that relatively lightweight Item? In terms of PSI ( sorry world I live in the USA) how much force is imparted to a human body in an accident? When I learned to drive we where taught the proper hand wheel position was at 2 and 10, now I see, it’s 3 and 9. I have come to learn a possible reason for that may, to keep forearms out of an airbag’s path.

      1. denis: Just so you know, the explosions and subsequent shrapnel happen during intentional airbag activation. The problem isn’t unintentional inflation, but too fast a burn rate of the explosive.

        1. The popular concept is too rapid a burn, but ammonium nitrate absorbs water and becomes less energetic over time. From high speed photography the real failure mode is that incomplete combustion allows plugs of solid material to block the gas vent holes, turning the inflater into a tiny pipe bomb from overpressure. Had they been built with an over-pressure relief score in the metal tube that would allow it to simply split instead of becoming a fragmenting grenade the result might have just been partial inflation and not lacerations.

          1. That’s a reasonable theory considering the scarcity of detailed information available that explains how humidity temperature cycles attribute to the failure in simple terms. It really is pretty simple once you understand a few basic principles. Don’t think about the burn rate alone as being too rapid, instead think about the ‘gas generation rate’ being too rapid. The inflators explode when gas is generated inside the inflator faster than it can exit. Gas generation rate is set by two things:
            1) the surface area of propellant that’s burning
            2) the burn rate of the propellant
            Most people don’t realize that the burn rate of all propellents increases with pressure. It’s a property of the propellent called the “pressure exponent”. A good stable burning propellant has a low pressure exponent and a fast burn rate. Meaning the rate at which it burns doesn’t increase much with pressure. A propellant with a high pressure exponent will burn very slow at low pressure but exceedingly fast at high pressure. Ammonium Nitrate based propellants, like takata’s PSAN, have a high pressure exponent. So any increase in chamber pressure causes a relatively significant increase in burn rate, compounding the increase in gas generation rate. If propellant wafers break, more surface area burns, attributing to greater gas generation rate. This is why it’s critical that the surface area of propellant be controlled throughout the entire combustion cycle. Here’s where humidity and temperature come in.

            Ammonium Nitrate based propellants exhibit what propellant chemists refer to as “solid-solid phase changes” at certain specific temperatures. These phase changes are really like the crystalline lattice structure changes that occur in water when it freezes. Water floats when it freezes because it’s volume increases. It’s volume increased because it’s hydrogen and oxygen molecules form a lattice structure that takes up more space than when it’s liquid. The molecular structure of Ammonium nitrate (AN) does the same thing at certain temperatures. It swells or contracts depending on what temperature it’s at. Militaries and explosives experts around the world have known about the phase stability problems of AN since the 1950’s. AN is also very water soluble and hygroscopic (it absorbs water from the air). When Takata introduced their PSAN inflators they claimed they had created a ‘phase stabilized’ formation of AN propellant. They even patented it. They were granted Multiple patents. Many people were skeptical because very smart chemists all around the world had been trying to do that for more than half a century before Takata made that claim. The swelling and contracting of AN, as it goes through the phase changes causes the propellent to get micro cracks which weaken the wafer. It basically breaks apart or crumbles when it burns after so many phase change cycles of swelling and contracting over time.

            And very small amounts of water exacerbate the phase changes. AN is a cheap explosive and good if you just want to blast something. But airbag inflators are thrust neutral rockets. AN is not a good choice if you want to control the explosion, like rockets and airbags require.

    2. So airbags weren’t safe after all …

      Still remember some “crazy, irresponsible car owners” forcing dealerships to install a main switch disabling airbags …

      How ironic AND HOW RIGHT THEY WERE !!!!!

  2. When I took my Toyota in for oil change, I asked when the airbag would be changed.
    Dealer said, “Oh, we did that last time”.
    I have zero confidence that he spoke the truth.
    And, I have no way to check.

    1. Phone any dealer with your VIN code, they should be able to lookup the vehicle and confirm whether or not the airbag(s) have been replaced as part of the recall, and if they cannot find any confirmation you can ask them to do it. (for free)

      Worst case scenario they open the compartment to take a look, see it was already changed, and then put it all back together and update the database.

      Personally I would avoid opening an airbag compartment if you are not sure that the recall has been done as it takes a long time to properly discharge the system and it can take a long time to find the stupid harness to unplug the airbag you want to look at.
      Also, if you haven’t had the ‘pleasure’ of working with the electrical connectors in airbag systems, they are a wonder of engineered failsafe latches and security plugs to prevent any possible unintentional disconnection.
      The ones in my Nissan had no less than 3 stages to unplug the connector.

  3. I don’t understand why this is called “airbag recall” at this point. It looks like a simple fact of explosive charges having shelf life being neglected of cares by car manufacturers.

    1. Sung to the tune of “Born Free”:

      M G
      I live just to touch you
      When I double clutch you
      MG, it gives me a thrill

      M G
      I love your ignition
      Your four speed transmission
      Your points your plugs and your grill

      M G
      I’ll wash you and wax you
      If some Chevy smacks you
      I’ll die, M G

      -Mad Magazine #119 (June 1967)

  4. “safe” is not an absolute, it’s relative. Airbags are there to make cars “safer” not “safe”. There is no such thing as completely safe, except for chosing not to do an activity. In this case, it seems there’s a limited life on s component, just like most other parts of the car (brakes, oil, transmission,etc.). Another fact is some safety features can cause their own hazards impacting overall safety (seatbelts preventing people from escaping).

    Maybe someday people will realize that humans can’t predict the future and stop feeding the lawyers.

    1. Then again airbags aren’t expendable items in the nature of the items you mention. Those mentioned to give a driver an indication that not all is well. While it probably wont happen at mostbargain basement “service center’, a trained service person can reliably notice potential problems with the metal lines, and hoses in the brake system, as well as leaking calipers and brake cylinders.. Yea I never undertook the auto industry moving away from aircraft belt buckle that easily can be released under tension Where it’s the insurance industry that use facts to drive regulation, I assume the facts don’t support current car seat belt design doesn’t lead to more deaths and injuries, affecting the profit margin.

      1. Can you provide an example of a car seatbelt made in the last few decades that _doesn’t_ release under tension? I’ve driven in many different countries and never seen a seatbelt that doesn’t release when you press the button, even if the belt is very tight.

      2. If there would be a significant advantage and no disadvantage changing belt buckle design it would already be enforced by law, just as most safety features were forced on the industry (with some exception like Volvo where safety have been part of the corporate image).

        1. “just as most safety features were forced on the industry”

          Do you mean like how every new car had a seatbelt when it was finally required? Regulations follow innovation, they don’t precede it.

    2. Takata knew this would kill people and specifically chose to hide that fact from regulators. There isn’t anything necessary to the operation of the inflater that must kill people; a simple steel shield could have been added to deflect the fragments at a few cents of cost. Takata saved that cost, which is far less overall than the damage they did by hiding the defect.

      1. “Takata knew this would kill people”

        You are arguing they committed murder, which has no basis on reality. They thought they could get the same performance with a different design.

        Engineers aren’t God, quit trying to claim they can think of everything and prevent it.

  5. With all these recalls I’m getting somewhat nervous as my SAAB is yet to be on a list but should it occur I can’t see GM covering the recall.

    Will just have go back to driving my 1970’s VW KOMBI again – no air bags to worry about there

    1. And therein lies the rub: today, it is still easy enough to find and buy an old car that be made to run, that doesn’t have airbags. But the number of pre-airbag vehicles is an continually diminishing, and the earliest airbags are still out there, getting older by the day. I don’t think that Takata airbags are the only ones that get more and more hazardous as they age; theirs are just the youngest ones to have degraded enough to kill people frequently enough to be noticed. The industry has decided that old cars aren’t a problem because they USUALLY get taken out of circulation before they become killers. But every one of them is a ticking bomb.

          1. But, one could buy a containment device that EMT’s use to prevent an airbag from fully deploying, should it deploy while they are trying to remove the driver from the vehicle.
            it would be a bit bulky on the steering wheel, but, I imagine one would get used to it being there.

  6. Keep in mind that airbags are a SUPPLEMENTAL restraint system. Their reason for existing is so that if people choose not to wear a seat belt will still be protected from some injuries in a collision, and those of us who wear seat belts without fail, are subjected to an additional hazard (actually, more than one, since even perfectly functioning airbags can still cause injuries) without our consent.

    My suggestion (go ahead, try to sue me) is that anybody who wears seat belts (and requires their passengers to do so) take charge of their own safety, by deactivating and removing their airbags. Of course the SRS computer may then prevent you from starting the car. But the explosive charges are set off by resistive devices, and the SRS computer can’t tell the difference between the resistor in an airbag and a resistor of the same value without an airbag.

    Where is the proof that ALL airbags don’t have similar problems, once some amount of time has passed? Takata claims that their “inflators” are safer than those using ammonium nitrate, but that just begs the question, what vehicles are on the road today with unsafe ammonium nitrate inflators?

    1. First – look up what “begs the question” means, because your sentence makes no sense using it.
      Second, Takata is the company that used the cheaper ammonium nitrate. AFAIK no one else was that stupid. Ammonium Nitrate becomes less combustible when it becomes saturated with moisture. AFIAK this contaminated material doesn’t burn completely and blocks the gas discharge vents, turning the inflater into a tiny pipe bomb. Takata could have added a shield or added a pressure-relief groove to rupture below the point of explosion. They did not.

  7. It’s about 60L ( the size of a kitchen garbage bag or large camping backpack) of nitrogen generated in 30-50ms for a standard steering wheel / front passenger airbag. I’ll leave force calculations as an exercise for the reader.
    Without modern 3-point seat belts airbags inflate with enough force to break your neck and associated bones.

  8. Just apply precaution while driving an do it responsibly, be an example and others will follow.
    Then no airbag needs to deploy.
    Yes, this will take decades do creep down to the bottom of our society of… unqualified drivers. Shame on unqualified drivers.

    For US residents: use your firearm against the bomb in your steering wheel.

  9. @BrightBlueJim
    >Keep in mind that airbags are a SUPPLEMENTAL restraint system. Their reason for existing is so that if people choose not to wear a seat belt will still be protected from some injuries in a collision, and those of us who wear seat belts without fail, are subjected to an additional hazard (actually, more than one, since even perfectly functioning airbags can still cause injuries) without our consent.

    It’s called a SUPPLEMENTAL restraint system because the airbags supplement and don’t replace the use of seat belts. You have to be wearing your seat belt for the airbags to work as intended. They help slow you down so the airbag has time to open, as well as aim you at the airbag properly. If the airbag helped you survive a crash without wearing your seat belt, it’s coincidental.

  10. I’m glad you covered this Lewin. This is obviously interesting, as you point out, because the NADI inflator design doesn’t have the inherent flaws that the PSAN inflators have. Takata made many millions of Non Azide inflators, until now I’ve never known of a defect prompting a “do not drive” order on any. It makes me wonder if all the visibility of the PSAN inflators has allowed accident investigators to more quickly confirm inflator ruptures now, when it was missed in the passed because nobody knew to look for it. And maybe if there have been small inflator recalls, only affecting ~12k cars nobody but the vehicle owners ever knew because it didn’t make international news. Before Takata’s PSAN inflator’s few people knew the truth about what’s in airbags so it wasn’t on the global-public’s radar. Your closing statement is spot on. The numbers will climb. Especially if public awareness is a driving factor in this one.

    I never worked directly on NADI inflator designs, but I’m familiar with them. When I saw the news about this recall, I was surprised. There are only a handful of things that can cause an inflator to rupture. The defect has to be related to something that decreased the housing strength, such as a flawed weld. Or something that increased the combustion pressure, such as a blocked nozzle or excessive propellant surface area. Or, however unlikely, some combination of both. After mulling over what manufacturing defect could cause the problem to first manifest itself 20 years later, there’s only one thing that really jumps out at me. And it would have been annoying owners of the effected vehicles for years. Propellant rattle. It would be interesting to know if anyone who had a BMW 3 series affected by this NADI recall could hear what might sound like a bottle of aspirin tablets rattling in their steering wheel.

    All inflators have a design feature or component that prevents propellant from rattling, usually a spring or lofty cushion. Like the cotton you find in aspirin bottles. The cotton is there so the tablets don’t rattle around and break over time. If a specific medication dose is critical and all the tablets are broken, it might take some extra effort to get the dose right. The propellant geometry in NADI inflators is in the form of tablets. And since propellant surface area is critical, it’s important tables dont break. You can imagine what a bottle of tablets might look like if you took the cotton out, taped it to a steering wheel and let them rattled around for 20 years. A defect such as a missing or faulty cushion that allowed propellent to rattle to the extent that surface area increased significantly over time, could explain this one. It’s just a theory until proven otherwise.

    Hopefully people with BMWs under this recall will see this and let us know if they could ever hear rattling in the airbag module. It wouldn’t prove the theory, but it would be some evidence to support or refute it, for whatever that’s worth.

    In a comment to your June article I referenced purchasing over 150 PSAN inflators for testing. When I bought those PSAN inflators I also bought a few BMW airbag modules with Non Azide inflators. None of them are NADIs but I’m tempted to do a live direction on one of the passenger configurations (PNAPI) just to see if the there’s any indication of propellant breakage after 20-years of road vibration.

    If you look close at what Takata still doesn’t want you to know about the PSAN inflator flaws, you’ll notice surface area is a common theme there too. PSAN inflators fragment because propellant surface area gets jacked up on ignition. The ignition energy itself fractures PSAN wafers like fine china, it just “crumbles” more after environmental exposure. At least NADI doesn’t have that “controlled ignition fracturing” problem, that Takata wants you to believe is an intentional design feature.

    1. All good points..
      As I travel back through time, I recall major kerfuffles that, (Like the airbags) never actually were properly explained to the public.
      But, that’s just the way of it.
      All the different “Root Cause” scenarios proffered so far are nebulous and you could even say, “Smoke and Mirrors”.

      The San Onofre shutdown for one. Nobody will see jail time for the change in design of the “Super Heater Tubes”, and nobody will explain who or how that actually happened. Not unusual, as any Engineering led group seldom points fingers at their own. Who pays? The public.

      My engineer changed the alloy on our super heater tubes to save money. (Sound familiar?) 3 months later, boom, steam leak in the SH tubes. Right in the middle of peak earnings time. The result was, $1000 per hour earnings gone for 20 days. And, nobody was pointed out as the culprit.

      Boeing is having engineer issue these days.. Who knew? (FAA?)

      So airbags? Piss poor design from the git go..

      1. Great example, and perspective. So true. There are multiple levels of smoke and mirrors in this case.

        I believe airbags in general are a very good technology. The problem is that Takata’s recalled inflators are not good. The quality triangle says you can only pick two of the following three: 1) good, 2) fast, or 3) cheap. When Takata launched PSAN inflators into the market, they picked #s 2 and 3. Most inflator manufacturers at least pick #1.

        The “smoke and mirrors” has kept people from understanding the risk and that has arguably prevented some people from avoiding it. I want to teach people how to identify a Takata PSAN inflator in an airbag. Especially all the people selling them as replacement parts on ebay. There are hundreds if not thousands for sale on ebay right now. Some of them are the “alpha” inflator configuration. It really bothers me, and Takata is responsible for the general lack of awareness.

        When the problem first began to manifest itself, Takata downplayed the danger with statements like “the inflator can explode with too much force, throwing metal and plastic shards at the occupant”. There’s no plastic to speak of in the inflator. Then finally, years later, after the May 2016 NHTSA mandated recall of all ~70 million non-desiccated PSAN inflators in the US, we began to hear different descriptions like “ticking time bomb” and “hand grenade”.

        Last year I purchased more than 150 recalled PSAN inflators that were sold to me from salvaged vehicles, to have them formally tested. I purchased them all from large scale salvage vendors. In that process I characterized many of Takata’s PSAN inflator variations. I submitted the test results to the DOT, and five months later the EPA issued this ruling regarding the hazardous waste problems the recall created.

        The ruling did address one major problem. I believe it was effective at stopping the large scale salvage vendors from selling recalled inflators as replacement parts. People had already died from that problem when I bought the inflators for testing. In Spring of last year I purchased 40 recalled Takata PSAN inflators from one store on one day. I purchased 28 the very next day at a different store, then 24 at another store the day after that. A total of 92 recalled Takata inflators in three days. The ruling has seemed to stop that problem. But other aspects of the EPA’s ruling were “smoke and mirrors”, so I submitted formal comments. They can be found here: https://www.regulations.gov/document?D=EPA-HQ-OLEM-2018-0646-0034

        One of my general comment topics was regarding the need for clarification on a shipping container that addressed the hazard the recalled PSAN inflators pose in a fire. The “answer” (presumably inspired by our federal court system) to that comment showed up in the form PHMSA’s Special Permit 20495, issued to Takata, now going by the name “Tk Servises”. SP 20495 can be found here: https://www.phmsa.dot.gov/approvals-and-permits/hazmat/file-serve/offer/SP20495.pdf/offerserver/SP20495

        The original revision of SP20495 was dated September 12, 2019, about two weeks ago it was revised to the current “1st revision” dated October 23, 2019. As far a special permits allowing shipment of explosive hazardous materials go, SP20495 is almost entirely smoke and mirrors. For example, I don’t believe the first two container embodiments described in SP20495 will address the hazard. Specifically, because a 20 gauge steel drum is only 0.9mm thick. Slow-cook-off testing in the supporting detail of my comments to the EPA ruling suggests the shrapnel from inflator ruptures will go through that like its warm butter. So why would Takata want to use 20-guage steel? In my opinion, its not good for the application. I guess because its cheep.

        Once you see through the smoke, you can start to predict things. Based on the most recent revision to SP20495, I predict the EPA will soon make a formal statement clarifying that the specific containers which address the shipping hazard Takata inflators pose in fire, are the exact containers described in SP20495. Its just a theory at this point. If it turn out to be true, perhaps I’ll need to buy several hundred recalled inflators to fill one of the poorly designed container embodiment and subject it to formal testing. Afteral that will be the only way I know thats been proven to stop the sale of them. It worked in 2018 to get them out of the big stores. Perhaps that’s what it will take to get them off of ebay.

  11. The original airbag design may have been compromised by engineers watching to many Bruce Willis movies.

    You see him outrunning explosions all the time.

    However, that’s “Movie Magic”, as explosions propagate at 700 mph.

  12. This NADI recall just hit the US. Here’s a link to the NADI Recall report on NHTSA’s website.


    Notice “vibration” is listed under the ‘Description of cause’ heading. Vibration in combination with freeze/thaw cycles after moisture ingress, could creat the following scenario.
    1) moisture ingresses into the propellant
    2) the water in the propellant freezes (ice expands) breaking or weakening the bonds that hold the propellent grain geometry together as a solid structure (i.e. wafer, tablet, batwing, etc…).
    3) vibration causes the propellant geometry to break (crumble, crack, fracture, whatever Takata wants to call it). Regardless of what they call it, the propellant surface area increases, when the geometry (tablets in this case) breaks.

    If the seal is compromised, moisture will exit the inflator the same way it entered leaving the propellant dry. So if the crash occurs (inflator deploys) when the ambient outside temp is hot and dry, the fractured propellent will be dry and deploy aggressively because propellent surface area is excessive. If the inflator happens to deploy at a time when the propellant is still damp, because the climate conditions have not driven moisture out, the operating pressure will be low because damp ‘Non Azide’ propellant burns slower when it’s holding moisture.

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