Monday, October 27, 2014

Do Not Sit Here: The Exploding Airbag Recall

Airbags are a required safety feature on cars sold in the U. S. since at least 1998.  They have undoubtedly saved lives, especially in situations where the driver or passengers neglected to use seatbelts.  So whatever else we say about them, we should bear in mind that overall, cars are probably safer with airbags than without them.  But only if the airbags themselves are safe.  And lately, some drivers have found that the airbag cure was much worse than the accident disease.

Over a hundred injuries and at least two fatalities have been attributed to defective airbags made by Japanese supplier Takata.  According to the New York Times, in 2009 a 33-year-old mother of three ran into a mail truck in Richmond, Virginia, and her airbag deployed.  The injuries from the wreck itself were minor.  But a piece of shrapnel from the metal canister containing the airbag explosive shot through her neck and she allegedly bled to death as a result. 

For an airbag to be an effective cushion during a collision, it has to deploy in well under a tenth of a second.  This involves creating a large volume of high-pressure gas in a short time.  The early airbags used an explosive called sodium azide, but the residue was toxic. So in the 1990s, manufacturers began to research other chemicals that would be less noxious and also allow for a smaller propellant package. 

Takata, one of the largest airbag suppliers in the world, developed a compound based largely on good old ammonium nitrate (the same chemical involved in the West, Texas explosion on April 17, 2013), along with other components designed to moderate the tendency of this substance to detonate and to absorb moisture.  The manufacture of any product involving explosives requires rigorous adherence to procedures that maintain the integrity of the ingredients all the way from the raw materials to the finished item.  But as various documents have indicated, Takata has not always been sufficiently diligent in their manufacturing processes.

As Takata has responded to inquiries by automaker customers and regulatory agencies, it has admitted to several manufacturing errors over the years.  Again according to the Times, one set of defective airbags was attributed to workers in a Mexican assembly plant who allowed moisture-sensitive explosive ingredients to sit on the plant floor too long in a humid environment.  Other documents show rusty propellant containers and foreign objects in the propellant cans may have been responsible.  Problems with the airbags began to show up as long ago as 2004, and in a series of widening recalls in the last few months, eleven automakers have recalled over 14 million vehicles for replacement of suspect airbags made by Takata.  Many of the vehicles being recalled are in the most humid states in the U. S., which indicates that deterioration due to high humidity is the main culprit here.  Toyota has told its dealers that if the replacement airbags on a recalled vehicle are not immediately available, they should put a sticker on the dashboard next to the defective airbag.  The sticker reads "Do Not Sit Here."  Good luck with that.

This particular story comes close to home, personally.  In our Honda household we operate both a Civic and an Element.  They are very good cars, but neither has been in a major collision that set off the airbags.  For this I am grateful.  I checked their VINs (vehicle identification numbers) at a U. S. government website designed to let owners know of any recalls out on their vehicles, and hit the jackpot both times.  I don't think I'll wait for the dealer to write me.  My 89-year-old father-in-law rides in the passenger seat of the Element.  It would be a shame for a World War II U. S. Navy veteran of the Pacific theater to be cut down by a defective Japanese airbag.  But it could happen, at least until I get those airbags replaced. 

As hazards go, this one is not worth lying awake nights about, unless maybe you work for Takata or one of the affected automakers.  As long as you're not in a wreck, apparently the airbags won't spontaneously combust, and most of them appear to work properly, especially if you don't live in an area that's particularly humid (watch out, Houstonians!).  But even a few defective airbags are too many. 

We won't know for some time why it took so long to uncover the problems and do something about them.  But some contributing factors are apparent already.  First, the problem arose not in a particular automaker's design (as was the case with the GM ignition recall), but with a supplier's manufacturing process.  It is impossible to test an airbag non-destructively, so except for sample testing, which automakers may or may not do, I'm not sure how they could have caught the problem by incoming inspections of Tanaka's product. 

People can be injured even by airbags that work properly and have no design or manufacturing defects, so sorting out incidents that involve defective airbags from those that don't is not a trivial problem, except in the glaringly obvious cases when metal shards from the airbag tear it to ribbons and slice into passengers.  And while the automakers did the minimum required when they received word about the airbag injuries, which was to notify the National Highway Traffic Safety Administration (NHTSA) within five days, they don't have to give a lot of details.  And if the feds choose not to follow up the notification, the matter ends there, as it did for most of the last ten years.  Only when lawsuits and headlines began to pop up about the matter did the automakers start issuing recalls and pressured Takata to shape up.

I don't know what Takata's market share in the airbag industry is, but my guess is it's pretty high.  Companies that sell products to large OEM (original equipment manufacturer) firms often develop too-chummy relationships with their few customers, who in turn are reluctant to threaten to take their business elsewhere if problems arise.  It's the old monopoly problem, but in this case the consumer is harmed not by exploitative prices—I'm sure the automakers pressured Takata to keep their prices down—but by defective merchandise.  Unfortunately, there is no easy solution for this type of structural problem, except for buyers and regulators to be increasingly vigilant for signs that there is a manufacturing problem.

If you happen to drive one of the fourteen million vehicles affected by the recall, here's hoping you get your car to the dealer soon—and you get it back with something better than a "Do Not Sit Here" sticker.

Sources:  Car and Driver magazine's online edition carried a report on the recall that I referred to, at  I also referred to the New York Times article published online on Sept. 11, 2014 at  The U. S. NHTSA's VIN recall website is at

Monday, October 20, 2014

Handling Ebola Patients: An Engineering Problem

Two nurses who treated the late Ebola-virus victim Thomas Eric Duncan have been diagnosed with Ebola virus as well.  They treated him at the Texas Health Presbyterian Center hospital in Dallas, where he died on October 8 after traveling there from Liberia, where he acquired the virus.  Despite apparently following the protocols recommended by the U. S. Center for Disease Control (CDC) for dealing with patients with Ebola, nurses Nina Pham and Amber Joy Vinson are now being treated for the disease as well.  Their chances are grim:  the death rate from the virus can be as high as 50%. 

Besides all that, one could be excused from believing that nothing else is going on in the U. S. right now except the Ebola virus, at least judging from the media coverage in Texas.  If there is a futures market in Clorox, now's your chance.

We are used to thinking of technology only in terms of hardware, or maybe hardware and software.  But engineering designs can center around people and their behavior too.  The elaborate protocols and procedures that integrated-circuit manufacturers follow are just as essential to making their chips as the silicon is.  A roomful of advanced medical equipment is just so much scrap metal without the people and plans and procedures that can use them effectively.  And just as machines can be well or poorly designed, so can protocols.

Let's look at two protocols.  One is posted on the CDC website under the title "Infection Prevention and Control Recommendations for Hospitalized Patients with Known or Suspected Ebola Virus Disease in U.S. Hospitals."  That's pretty clear.  What do they say about personal protective equipment for the nurses and other personnel who care for Ebola patients?  It's pretty simple:  a face mask, eye protection (goggles or a face shield), gloves, and a gown ("fluid resistant or impermeable").  I don't know about you, but if I was within a few feet of a potential source of fluid that had a good chance of giving me a deadly illness, I would want to be covered by something more substantial than a "fluid-resistant" gown.

Now, let's consider another set of protocols.  In an editorial in the Oct. 16 Austin American-Statesman, critical care physician Bryan Fisk recalls the protocol he used when he was in charge of a Biosafety Level 4 Patient Isolation Suite at Ft. Detrick, Maryland.  This was a military facility designed to handle patients with diseases as dangerous as Ebola.  What kind of personal protective equipment did they use at this facility?  "[F]ully encapsulated positive-pressure protective suits with a tethered air supply."  In other words, a diving suit without the water.  Not only were they trained to do all sorts of procedures—intubation, catheterization—while wearing these undoubtedly cumbersome outfits.  Once they left the isolation unit, they underwent a complete chemical scrubdown while still wearing the suits, with the aid of other technicians.  And as long as they were treating the patient and for the length of the incubation period afterwards, they were confined to on-site quarters and not allowed to leave until there was no chance that they had acquired the virus.

There are reportedly about four of these types of isolation units in the U. S.  Understandably, they are more expensive than the standard emergency-room or intensive-care isolation units maintained by even the best public hospitals.  But in view of the fact that the CDC protocols, even if followed, fall far short of what the U. S. military does when dealing with Ebola-type situations, it's hard to resist the temptation to repeat an old consulting-engineer saying. 

The story goes that one day a consulting engineer gets a call from a factory manager where things are going haywire.  He flies out to the site, walks around a half hour or so, and then motions for the manager to come into a private office with him.  He sits down and says to the manager, "Your system is perfectly designed to give you the results you're getting."  In other words, you should not expect a badly designed protocol to deliver good results.

Fortunately, nurse Nina Pham has been transferred to a National Institutes of Allergy and Infectious Diseases isolation unit in Bethesda, Maryland.  I was unable to find any information on the protocols for protecting healthcare workers in that unit, but one hopes that it is better than the CDC's bare minimum. 

The perception of competence can be as important as actual competence.  Doctors and medical-care workers are some of the most trusted professionals in society, and when a scary thing like an Ebola case happens, the presumption is that those in charge will follow the best practices available to ensure that the disease doesn't spread.  With the failure of Texas Health Presbyterian Center to use adequate protocols, whether due to thinking that the CDC knew what it was talking about or otherwise, that trust has been severely damaged, and the word "panic" has started to show up in news items on the virus.  Professionals can be excessively reluctant to second-guess other professionals, but in this case it looks like it would have been better for someone in authority to order the Texas hospital to send Duncan to a military or equivalent-quality isolation unit the instant it became clear he was infected.  He might have died anyway, but we would have avoided any possibility that Ebola carriers were running around in public and flying in planes, which is the situation we face now.

Realistically, the risk of catching Ebola for the average person in the U. S. is virtually no higher than it was a month ago, which was approximately zero.  But already, serious damage has been done to the medical profession's reputation, and it will be some time before the fears of Ebola subside.  We can get there sooner if every organization involved with Ebola fully acknowledges the seriousness of the problem and spends the money and resources necessary to deal with it safely—or else admits they can't do it and defers to an organization that can. 

Sources:  Dr. Bryan Fisk's article "We need to send Ebola patients to U. S. disease-isolation facilities," appeared in the Oct. 16 edition of the Austin American-Statesman, p. A10.  The CDC's recommended protocol for Ebola appears at, and as of this writing was last updated Oct. 6.  The Dallas Morning News has a helpful timeline on Ebola in the U. S. at

Monday, October 13, 2014

Imagining Geoengineering

Okay, suppose some of the most extreme voices warning of global warming are right.  Suppose we really do face the inundation of much of the world's coastlines in a generation or two.  Even if, starting tomorrow, nobody ever burned a drop or a gram of fossil fuel ever again, the carbon dioxide now in the atmosphere might take hundreds of years to fall to pre-industrial levels.  So simply implementing restrictions on fossil fuels to reduce carbon-dioxide levels may not do the job fast enough.  What do we do in the meantime?  To use an automotive analogy, if you're going too fast and you see that the road ahead of you ends in a cliff, it might not be sufficient simply to take your foot off the gas.  You might actually have to apply the brakes.  David Keith says we ought to at least talk about applying the global-warming brakes.  But the question I have is, how could it ever get beyond talk?

Keith is a professor with appointments at both the Harvard Kennedy School, where he teaches public policy, and Harvard's School of Engineering and Applied Sciences.  An environmental engineer by training, Keith thinks that "geoengineering" ought to be considered along with reductions in fossil-fuel consumption as a way to reduce the effects of carbon dioxide in the atmosphere.  Geoengineering refers to intentional efforts to manipulate the climate.  So far, the only moderately successful geoengineering projects have been cloud-seeding efforts that arguably increased rainfall in some areas.  But Keith is talking about a worldwide effort to do something that will counteract global warming by artificially cooling the planet somehow.

Interviewed last March by the CBC (Keith is Canadian), he admitted that ideas such as spreading small sulfur particles in the stratosphere to reflect solar radiation as a way of countering global warming are a "brutally ugly technical fix."  But he thinks such geoengineering solutions should be on the table, rather than brushed aside scornfully, as they are by many environmental activists.

Let's try to imagine how such a geoengineering fix would work, not just technically, but politically.  Many of the geoengineering solutions that have been posed are not terribly expensive, globally speaking.  We are talking about industrial quantities of sulfur or other chemicals dispersed in the upper atmosphere, but the cost in terms of the global economy is miniscule.  There is no question that such a project could be mounted by even one well-prepared industrial nation.  The question I'd like to examine is:  could the nations of the world ever reach a consensus on what geoengineering solution to adopt?

If we examine the track record of united global action on the main cause of the carbon-dioxide increase, namely the use of fossil fuels, history is not encouraging.  The most significant effort in this direction is the Kyoto Protocol, adopted in 1997.  It is technically an extension of a 1995 UN agreement that parties signing it will reduce their emissions of greenhouse gases in accordance with certain goals spelled out in the document.  While 192 countries signed the accord, some of the most significant producers of greenhouse gases either did not participate at all (e. g. the U. S. A., China, India) or have not met their targets (e. g. New Zealand). 

The only global environmental agreement I can recall that actually worked was the way we kept chlorinated fluorocarbons (CFCs) from destroying the ozone layer.  CFCs were once used widely as refrigerant fluids (e. g. under the trademark "Freon"), but in the 1970s, scientists figured out that (a) these compounds lasted for a long time in the atmosphere and (b) they catalyzed the destruction of the important ozone layer in the stratosphere, which protects us from harmful UV radiation from the sun.  The Montreal Protocol, which went into effect in 1989, set its signatories on a path to eliminating the production of new CFCs and phasing out their use by finding alternatives.  By and large, the Montreal Protocol is a success story in international technical agreements, because most of the industrialized world signed on and actually did what they agreed to do.

Why can't we get such cooperation with the global-warming issue?  The simple answer is, it would cost more.  Telling the world economy to give up CFCs was like telling a dieter to give up the tutti-frutti milkshake he has every Shrove Tuesday.  CFCs were a minor part of the global economy compared to fossil fuels.  If we accept the most radical recommendations of those alarmed about global warming and implement restrictions as fast as they want us to, well, the point is, the world won't do it without something approaching a global police state.  Developing nations such as China and India will not willingly forego the advantages of wider use of fossil fuels to grow their economies.  It would take a world war and dictatorial economic domination by a single global-warming-prevention entity to make the world go on a fossil-fuel diet.  And that doesn't sound like a good tradeoff.

The thing that geoengineering proponents like David Keith have going for them is that many geoengineering proposals would cost a lot less than replacing fossil fuels with a sustainable alternative.  Whether geoengineering would work is another question, unfortunately even more complicated than the still-controversial question of exactly how bad climate change is going to get, and what adverse effects it will have in the future. 

Besides the technical issue of whether geoengineering would work, I think there is an esthetic or philosophical factor involved.  Many of those who advocate harsh restrictions on fossil-fuel use to avert further climate change seem to have bought into the "deep-green" assumption that humanity is really a net liability for Planet Earth.  Burning fossil fuels represents meddlesome tinkering with what Mother Nature was up to naturally, and geoengineering would be another step down that evil road of manipulating the environment.  Better we just fold our tents, globally and economically speaking, and go back to living off nuts and berries.  The trouble with that notion is that there would not be enough nuts and berries to go around unless we keep burning fossil fuels, or find an energy-equivalent alternative that won't bankrupt us.  Such an alternative is not yet at hand. 

I admire engineers like David Keith for thinking through important problems such as climate change to arrive at possible solutions that might actually work, at least technically.  Given the dismal track record of the Kyoto Protocol, the chances of arriving at a truly global accord to implement significant fossil-fuel reductions are vanishingly small.  If some of the more dire climate-change predictions come to pass, it might be easier to get international agreement on a geoengineering strategy than it would on fossil-fuel reductions, especially if the price is right.

Sources:  An article on David Keith's ideas about geoengineering appeared on March 29, 2014 on the Canadian Broadcasting Corporation's website  I also referred to Wikipedia articles on solar radiation management, the Kyoto Protocol, and chlorofluorocarbons.        

Monday, October 06, 2014

Playing with Nuclear Fire

The safety of nuclear weapons is the theme of Eric Schlosser's 2013 book Command and Control:  Nuclear Weapons, the Damascus Accident, and the Illusion of Safety.  After reading the book, my own reaction is mirrored in a quote Schlosser cites from General George Butler, who became head of the U. S. Strategic Air Command shortly before the Soviet Union came to an end in 1991.  After familiarizing himself with the secret plans for nuclear war, Butler later remarked that "we escaped the Cold War without a nuclear holocaust by some combination of skill, luck, and divine intervention, and I suspect the latter in greatest proportion."

Did you know, for example, that on March 11, 1958, a nuclear bomb landed on a playhouse belonging to the Gregg family of Mars Bluff, South Carolina?  The impact was strong enough to set off the high explosives in the bomb, destroying the playhouse, a nearby automobile, and injuring six family members.  Fortunately, the nuclear core was not inserted in the bomb.  It remained behind in a B-52 aircraft three miles above, where the navigator had entered the bomb bay to check on the status of a locking pin.  As he crawled awkwardly around the device, he grabbed the nearest object at hand for support, which happened to be the manual bomb-release lever.  The bomb fell onto the bay doors and forced them open, and the navigator narrowly avoided following it to the ground by hanging on for dear life. 

That same manual bomb-release lever was responsible for at least one other accidental loss of a nuclear bomb.  The most hair-raising accident involving nuclear weapons happened to a Titan II nuclear missile in a silo near Damascus, Arkansas, on September 18, 1980.  The Titan II was the same multistage rocket that boosted the Gemini manned spacecraft into orbit in the 1960s.  It used highly hazardous nitrogen tetroxide liquid oxidizer and an equally dangerous rocket fuel, which would explode on contact with the oxidizer.  You can imagine the challenges involved at underground missile silos all over the U. S., as Air Force personnel struggled to keep dozens of these hundred-foot-tall rockets fueled and ready for launch in minutes during the many years of the Cold War. 

Inevitably, something would go wrong.  On that fateful day in 1980, during a routine pressure check on the missile in Launch Complex 374-7, a technician dropped a heavy socket-wrench socket.  It bounced off a projection inside the underground silo, hit the thin aluminum skin of the rocket, and punctured it, allowing fuel to escape into the silo.  Over the next nine hours, things got steadily worse.  I won't give away the ending of this particular story, which reads like a Tom Clancy thriller in spots, but today the silo is filled in and the land has been returned to its previous owner.

The  Damascus accident advances in fits and starts over the entire length of the book as Schlosser digresses into the history of nuclear weapons, the evolution of nuclear-weapons policy in international relations, and attempts to make nuclear weapons safe as well as reliable.  This structure mostly works, although at times I found myself wishing for less political and military infighting and more Cold War stories about bomb accidents.  But there is plenty of both, for policy wonks interested in the finer points of Henry Kissinger's diplomatic skills and for techies wanting to know exactly how a thermonuclear weapon's electronic system functions.

The more time passes, the harder it is to believe that two of the most advanced industrial countries of the world—the U. S. A. and the Soviet Union—routinely played chicken with nuclear weapons, not just once, but dozens of times.  And most of these games were played in an era when the most advanced communications systems were either submarine cables installed as long ago as the 1860s, or shortwave radios that were essentially amateur radio sets on steroids.  During the Cuban missile crisis of 1962, generally recognized by historians as the time that the world edged closest to the nuclear brink, whenever the Soviet ambassador in Washington wanted to send urgent messages to his superiors back in the USSR, he had to call Western Union, which sent a messenger to the embassy on a bicycle and carried a piece of paper back to the telegraph office by hand.  

Because few civilians ever saw or dealt with nuclear weapons, the whole Cold War threat had an unreal quality to it, but it was frighteningly real.  Schlosser shows us that everyone living in the U. S. and the USSR, not to mention other nations with nuclear capabilities, had numerous escapes from a fiery or lingering death by nuclear holocaust during the Cold War, though most of us were unaware of them.  And of course, that threat still exists today, though now the most dangerous nations with nuclear weapons are places like North Korea and Pakistan.  As I write this, North Korea's nominal leader Kim Jong Un has not been seen in public for more than a month, so we don't really know who's in charge there.

Toward the end of the book, Schlosser quotes Langdon Winner's comment that "artifacts have politics."  That is to say, the very nature of some technologies compels the formation of certain types of political structures to deal with them.  The only way to deal with nuclear weapons, Winner concluded, is to form a secret, authoritarian system of control.  The ultimate in hazardous technology demands the ultimate in control and safety precautions.  Although nuclear-weapons powers have done pretty well at controlling the intentional use of such devices, the horror-story list of accidents that Schlosser has compiled in Command and Control leaves one with the impression that it is only a matter of time until we see an entire city or region vaporized, not because someone decided to start a war on purpose, but because some technician screwed up.  For the sake of everyone who might be endangered by it, I hope that such an accident never happens.  But unless those who decide to build nuclear weapons value safety as highly as they do reliability, the chances are that sooner or later, it will.

Sources:  Eric Schlosser's Command and Control:  Nuclear Weapons, the Damascus Accident, and the Illusion of Safety was published in 2013 by the Penguin Press.  I also referred to Wikipedia articles on Mars Bluff, SC, the Mark 6 nuclear bomb, Titan II, Langdon Winner, and the 1980 Damascus, Arkansas incident.  As of today (Oct. 6, 2014), CNN reports that Kim Jong Un has not made a public appearance since Sept. 4.