I believe it is the gas in the triggerring cannisters that becomes weak. The bag will deploy, but with not enough acceleration to protect you from the crash. The nitrogen gas becomes more inert over time.

__________________
1987 300SDL (324000)

1986 Porsche 951 (944 Turbo) (166000)

1978 Porsche 924 (99000)

1996 Nissan Pathfinder R50 (201000)

Good. The slower the acceleration of the bag, the better. Make sure the seatbelts are functioning properly and forget the FRONT airbags. If you wear your seatbelt you don't need the front airbags. I've known a lot of people that have had them deploy in accidents and they say it's like getting jerked forward and then punched in the face. Not something I need in an accident.

I'm not totally anti airbag, side airbags have a useful purpose. If it weren't against the law I'd remove my fronts and sell them on ebay.

heck i've had my airbag for 26 years and she is as good as the day i meet her.

I was looking to replace the bag in my 87 16v and they wanted $2,400 for the thing. Ummmmm let me think about that one for a sec .....NO, Hell NO!!!

I'll take my chances with the belts and hope the bag gooes poof when it is supposed to.

__________________
Sent from an agnostic abacus

2014 C250 21,XXX my new DD ** 2013 GLK 350 18,000 Wife's new DD**

- With out god, life is everything.
- God is an ever receding pocket of scientific ignorance that's getting smaller and smaller as time moves on..." Neil DeGrasse Tyson
- You can pray for me, I'll think for you.
- When you understand why you dismiss all the other possible gods, you will understand why I dismiss yours.

Hopefully, I can clear up some confusion about air bag operation...
There is no "cannister" system that contains nitrogen in your car (at least not in the air bags)...
The bag(s) are inflated with a solid propellent gas generator that operates identically to a solid rocket motor... in fact, these air bag generators are built by well know defense contractors that build missile motors. The generators "burn" extremely fast; and produce a large quantity of gases that inflate the bag.
The rub is that there's a huge liability issue for car manufacturers related to air bags... consumers expect safety systems to work reliability and perfectly all the time... no matter how old. From and engineering perspective, this is impossible... so the companies get sued.
On top of that, anyone familiar with solid rocket motors/missiles will tell you that propellents don't "age" well... the propellents crack, weep, and generally become unstable after a number of years. The military has a regular maintenance program that inspects/maintains rocket motors of all types. The worst effects seem to result from external heat and vibration.
Generally, when propellent ages, it doesn't "slow down", it speeds up. The flame path works into all the cracks (especially the space between the fuel and the case) exposing ever more surface area to burn... in worst case scenarios, the motor explodes rather than burns... not a good thing.
(anybody ready to guess what I do for a living?) :-)
As for the seat belts; they too age and lose strength over time...
The key here is that the restraint system in your car is a system. Its not just the air bags, or the belts, or the construction of the car... its the combination. Betting that one part alone will save your bacon as well as all together is not sound engineering.
Its a personal choice I guess, but $2400 won't pay for a day of intensive care, much less the cost of putting your face back together...
Just my 2 cents.
KenP

__________________
KenP

1996 S500 W140 Coupe

finally, some folks have decided to ventilate on this issue. i have put up several posts on the subject, but i don't think i ever got a response.

here is my interest in the subject....

i have a 1986 560sel and a 1987 560sec. both of the steering wheel plastic[vinyl] bag covers have cracked out in the same area, vertically along the driver's right side molded depression.

now, i think that the propellant in these bags is sodium azide. and sodium azide is well-known as a carcinogenic, teratogenic[sic] compound. what i want to try to find out is it leaking sodium azide that has cracked the bag's steering wheel cover?

if ithe fissure hasn't been caused by sodium azide, what would cause this crack - in both cars the fracture is identical. and it would be my guess that others out there with 1986-1987 w126's have the same crack in the same place. a poll?

more importantly, i have often wondered if this crack would be an indication that the bag will inflate assymetrically, thus dysfunctionally.

i also wonder if this crack would allow for the escape of the toxic sodium azide into the passenger compartment.

any knowledge out there concerning these issues?

both of these cracks showed up within 5-10 years. i once asked a mb zone man about it, thinking it to be some kind of a warranty issue. he did not want to discuss the matter personally. eventually he answered me via my dealer's service manager. advice: "replace the bag and the cover."

lastly, i think that someone mentioned that it is against the law to remove a sodium azide bag and then operate the vehicle. could you cite the law, please.

i have removed the passenger sodium azide bag from my e320cab and replaced it with a real glovebox, recovering my center console for my coffee cup, driving gloves, etc.

all ears.

Sorry Albert, no clue as to the breakdown/interaction characteristics of Sodium Azide... or, for that matter, whether MB even uses it... many car companies do. My comments were meant to be general.
If your air bag covers are broken open, why not put your mind at ease and replace them?
Personally, I would replace any part of the car's restraint system that I suspected of being faulty.
KenP

__________________
KenP

1996 S500 W140 Coupe

thnx yr response.

a question, though. do you know of any bags that do not use sodium azide?

i don't.

i didn't even know that there was an alternative. tell me, please what that alternative[s] would be. and do you know what manufacturer[s] uses this[these] [alternative[s].

and i guess my concluding remark would be, can the driver's bag be removed and the steering wheel successfully recovered so that the wheel appears as if new?

there really is no need for these bags, i think. my seat belts are in perfect condition. and the way i drive, which is in the classical manner, not the sodium azide bag truck driver style, were a bag to inflate in one of my cars while i was performing a steering manuever, surely i would have both of my wrists broken.

still all ears

and after a preliminary surfing of the web, here is the first thing that i found concerning sodium azide...i am sure more can be found.

does anyone else find it less than amusing that the nhtsa, dot[i.e., the feds] forced these gadgets upon us by labelling them as "air"bags? a monstrous bit of public relations' chicanery and cant.

att:



Sodium azide in car airbags poses a growing environmental hazard

provided by University of Arizona

utomobile airbags use a chemical compound that is so toxic that even small amounts can kill. Yet trucks loaded with hundreds of pounds of sodium azide routinely travel the nation's highways, and discarded airbags sit like environmental time bombs in the nation's auto junkyards, a University of Arizona scientist says.

Scientists really don't know where or how all this sodium azide will wreak greatest environmental havoc, UA atmospheric scientist Eric A. Betterton said March 26 at a national meeting of the American Chemical Society in San Francisco.

For the past few years, he and his undergraduate studentshave been doing laboratory experiments to find out.

Although sodium azide has long been used in many industrial products, such as broad-spectrum biocides, explosives detonators, anticorrosion solutions, and airline safety chutes, a much larger threat emerged with the advent of the automobile airbag, Betterton said.

"As the demand for airbags increases, and as vehicle fleets age over the next few decades, the amount of sodium azide that could potentially be released to the environment will greatly exceed the approximately 5 million kilograms (11 million pounds) that has already been incorporated into inflators in the United States alone," Betterton said. "Given the huge surge in production, there exists a greatly increased potential for significant accidental spills and subsequent human exposure to this material."

Sodium azide (NaN3) looks like common table salt. But it kills everything from bacteria and fungi to mammals - including humans. It is as powerful a poison as sodium cyanide.

As a graduate student, Betterton learned firsthand that even a whiff of hydrazoic acid (HN3) sodium azide's conjugate acid can be dangerous. While conducting a laboratory experiment with the dangerous compound, he suddenly felt dizzy, his blood pressure dropped, his heart raced and his eyes flushed bloodshot red.

Eating as little as 50 milligrams (less than two-thousandths of an ounce) of sodium azide can lead to collapse and a coma-like state within five minutes as blood pressure plummets and heart rate skyrockets. Ingest a few grams, and death occurs within 40 minutes.

Studies done in the 1970s show that, at 10 parts per million in the soil, sodium azide kills or degrades the seeds of many plants, Betterton noted. At 200 ppm, sodium azide not only sterilizes the soil - killing soil bacteria and fungi but also changes soil chemistry.

Just how sodium azide is metabolized is unclear. "Practically nothing is known about the environmental chemistry or biology of azide," Betterton said.

What is known is that sodium azide is water-soluble. "Spills therefore could potentially migrate into sewers, streams, lakes, and groundwater systems," Betterton said. The compound easily pronates (adds a proton) when wet, becoming volatile hydrazoic acid, a potential threat to sanitation workers, for example, he added.

Azide spills are not just "possible." They already have happened. In December 1996, a tanker truck hauling 80 fifty-five-gallon drums of sodium azide overturned and burst into flame 65 miles south of Salt Lake City. Rain intensified the giant toxic vapor plume released by the burning chemical. When the plume blew toward Mona, Utah, the town's nearly 2,000 residents were evacuated.

In Arizona, millions of pounds of sodium azide are shipped on Interstate 10 for airbag manufacture in Mesa, Betterton noted. A Utah-sized spill could be disastrous in population-dense Phoenix, he said.

Sodium azide tablets are stacked like small hockey pucks in two-inch-diameter metal canisters inside airbags. The driver-side airbag can is about 1 and 1/2 inches long and holds about 50 grams of sodium azide. The passenger-side airbag can is about six inches long and holds about 200 grams to inflate a bag big enough to fill the front-seat passenger area.

On impact, an electromechanical trigger heats sodium azide to explosively decompose, forming nitrogen gas - the main constituent of the air we breathe and metallic sodium. Additives like silica or iron oxide sometimes are used to scavenge the metallic sodium, which could cause burns.

There are no regulations requiring the detonation of airbags when cars are scrapped - "a smart way, I think, to get rid of this stuff," Betterton said. Scrap yard operators can remove car airbags and set them aside to accumulate in junk yards. Or, they are left in cars as they rot on the lot. Even worse, they are sent along with cars through crushers, and worst of all, wet crushers. The airbag canisters could be smashed, spilling sodium azide over the ground and generating sodium azide dust.

In laboratory experiments at the University of Arizona, Betterton and his students tested how readily sodium azide oxidizes (combines with oxygen) when exposed to some environmental oxidants that may be found in water, such as hydrogen peroxide, an ingredient in natural rainwater, and ozone, a very powerful oxidant in the atmosphere.

Oxidation is one way sodium azide degrades in the environment, just as the burning (oxidizing) truckload of sodium azide spewed up the spectacular toxic plume in Utah.

Betterton and his students found that only ozone is a potential oxidant for sodium azide.

However, sodium azide combines with water to form the highly volatile hydrazoic acid. Betterton and his students determined the "Henry's Law constant" for hydrazoic acid, or the ratio of how much hydrazoic acid in water will remain in solution and how much will be released as gas into the atmosphere. The Henry's Law constant number is very low. That is, much more of the acid is released as gas into the atmosphere than remains in water.

"I don't know - no one knows what the lifetime of azide is in the atmosphere," Betterton said.

Currently, Betterton and a student are running experiments to determine how sodium azide might migrate through wet soil where there has been an azide spill.
Students who work on this project are funded through the Arizona/NASA Space Grant Program. Contact: Eric A. Betterton, University of Arizona, 520-621-2050; betteratmo.arizona.edu.

and the latest from the CDC....

What sodium azide is

* Sodium azide is a rapidly acting, potentially deadly chemical that exists as an odorless white solid.
* When it is mixed with water or an acid, sodium azide changes rapidly to a toxic gas with a pungent (sharp) odor. It also changes into a toxic gas when it comes in contact with solid metals (for example, when it is poured into a drain pipe containing lead or copper).
* The odor of the gas may not be sharp enough, however, to give people sufficient warning of the danger.


Where sodium azide is found and how it is used

* Sodium azide is best known as the chemical found in automobile airbags. An electrical charge triggered by automobile impact causes sodium azide to explode and release nitrogen gas inside the airbag.
* Sodium azide is used as a chemical preservative in hospitals and laboratories. Accidents have occurred in these settings. In one case, sodium azide was poured into a drain, where it exploded and the toxic gas was inhaled (breathed in).
* Sodium azide is used in agriculture (farming) for pest control.
* Sodium azide is also used in detonators and other explosives.


How you could be exposed to sodium azide

* Following release of sodium azide into water, you could be exposed to sodium azide by drinking the contaminated water.
* Following contamination of food with sodium azide, you could be exposed to sodium azide by eating the contaminated food.
* Following release of sodium azide into the air, you could be exposed by breathing in the dust or the gas that is formed.
* Sodium azide can also enter the body and cause symptoms through skin contact.
* An explosion involving sodium azide may cause burn injury as well as expose people to the toxic gas, hydrozoic acid.
* CDC has received no reports of sodium azide exposure following automobile airbag deployment.


How sodium azide works

* The seriousness of poisoning caused by sodium azide depends on the amount, route, and length of time of exposure, as well as the age and preexisting medical condition of the person exposed.
* Breathing the gas that is formed from sodium azide causes the most harm, but ingesting (swallowing) sodium azide can be toxic as well.
* The gas formed from sodium azide is most dangerous in enclosed places where the gas will be trapped. The toxic gas quickly disperses in open spaces, making it less harmful outdoors.
* The gas formed from sodium azide is less dense (lighter) than air, so it will rise.
* Sodium azide prevents the cells of the body from using oxygen. When this happens, the cells die.
* Sodium azide is more harmful to the heart and the brain than to other organs, because the heart and the brain use a lot of oxygen.


Immediate signs and symptoms of sodium azide exposure

* People exposed to a small amount of sodium azide by breathing it, absorbing it through their skin, or eating foods that contain it may have some or all of the following symptoms within minutes:
* Rapid breathing
* Restlessness
* Dizziness
* Weakness
* Headache
* Nausea and vomiting
* Rapid heart rate
* Red eyes (gas or dust exposure)
* Clear drainage from the nose (gas or dust exposure)
* Cough (gas or dust exposure)
* Skin burns and blisters (explosion or direct skin contact)


* Exposure to a large amount of sodium azide by any route may cause these other health effects as well:
* Convulsions
* Low blood pressure
* Slow heart rate
* Loss of consciousness
* Lung injury
* Respiratory failure leading to death


* Showing these signs and symptoms does not necessarily mean that a person has been exposed to sodium azide.


What the long-term health effects may be

Survivors of serious sodium azide poisoning may have heart and brain damage.

How people can protect themselves and what they should do if they are exposed to sodium azide

* First, get fresh air by leaving the area where the sodium azide was released. Moving to an area with fresh air is a good way to reduce the possibility of death from exposure to sodium azide.
* If the sodium azide release was outside, move away from the area where the sodium azide was released.
* If the sodium azide release was indoors, get out of the building.
* If leaving the area that was exposed to sodium azide is not an option, stay as low to the ground as possible, because sodium azide fumes rise.
* If you are near a release of sodium azide, emergency coordinators may tell you to either evacuate the area or to “shelter in place” inside a building to avoid being exposed to the chemical. For more information on evacuation during a chemical emergency, see “Facts About Evacuation”. For more information on sheltering in place during a chemical emergency, see “Facts About Sheltering in Place”.
* If you think you may have been exposed to sodium azide, you should remove your clothing, rapidly wash your entire body with soap and water, and get medical care as quickly as possible.


* Removing your clothing:
* Quickly take off clothing that may have sodium azide on it. Any clothing that has to be pulled over the head should be cut off the body instead of pulled over the head.
* If you are helping other people remove their clothing, try to avoid touching any contaminated areas, and remove the clothing as quickly as possible.


* Washing yourself:
* As quickly as possible, wash any sodium azide from your skin with large amounts of soap and water. Washing with soap and water will help protect people from any chemicals on their bodies.
* If your eyes are burning or your vision is blurred, rinse your eyes with plain water for 10 to 15 minutes. If you wear contacts, remove them and put them with the contaminated clothing. Do not put the contacts back in your eyes (even if they are not disposable contacts). If you wear eyeglasses, wash them with soap and water. You can put your eyeglasses back on after you wash them.


* Disposing of your clothes:

* After you have washed yourself, place your clothing inside a plastic bag. Avoid touching contaminated areas of the clothing. If you can't avoid touching contaminated areas, or you aren't sure where the contaminated areas are, wear rubber gloves or put the clothing in the bag using tongs, tool handles, sticks, or similar objects. Anything that touches the contaminated clothing should also be placed in the bag. If you wear contacts, put them in the plastic bag, too.
* Seal the bag, and then seal that bag inside another plastic bag. Disposing of your clothing in this way will help protect you and other people from any chemicals that might be on your clothes.
* When the local or state health department or emergency personnel arrive, tell them what you did with your clothes. The health department or emergency personnel will arrange for further disposal. Do not handle the plastic bags yourself.
* For more information about cleaning your body and disposing of your clothes after a chemical release, see “Chemical Agents: Facts About Personal Cleaning and Disposal of Contaminated Clothing”.
* If someone has ingested sodium azide, do not induce vomiting or give fluids to drink. Also, if you are sure the person has ingested sodium azide, do not attempt CPR. Performing CPR on someone who has ingested sodium azide could expose you to the chemical.
* When sodium azide is ingested, it mixes with stomach acid and forms the toxic gas, hydrozoic acid. If a person who has ingested sodium azide is vomiting, isolate and stay away from the stomach contents (vomit) to avoid exposure to the toxic gas.
* Do not pour substances containing sodium azide (such as food, water, or vomit) in the drain, because the drain can explode and cause serious harm.

* Seek medical attention right away. Dial 911 and explain what has happened.


How sodium azide poisoning is treated

Sodium azide poisoning is treated with supportive medical care in a hospital setting. No specific antidote exists for sodium azide poisoning. The most important thing is for victims to seek medical treatment as soon as possible.

How you can get more information about sodium azide

You can contact one of the following:

* Regional poison control center (1-800-222-1222)
* Centers for Disease Control and Prevention
* Public Response Hotline (CDC)
* English (888) 246-2675
* Español (888) 246-2857
* TTY (866) 874-2646


* Emergency Preparedness and Response Web site
* E-mail inquiries: cdcresponse@ashastd.org
* Mail inquiries:
Public Inquiry c/o BPRP
Bioterrorism Preparedness and Response Planning
Centers for Disease Control and Prevention
Mailstop C-18
1600 Clifton Road
Atlanta, GA 30333


* Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Pocket Guide to Chemical Hazards.


This fact sheet is based on CDC’s best current information. It may be updated as new information becomes available.

Last reviewed on 05/09/03

The Centers for Disease Control and Prevention (CDC) protects people’s health and safety by preventing and controlling diseases and injuries; enhances health decisions by providing credible information on critical health issues; and promotes healthy living through strong partnerships with local, national, and international organizations.


Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30333, U.S.A
Tel: 404-639-3311 | Public Inquiries: 888-246-2675 • español 888-246-2857 • TTY 866-874-2646 Department of Health
and Human Services

That report is frightening. Do all cars use this to inflate airbags?
Any known deaths from the airbag gases?

to the best of my knowledge, all automobile manufacturers use bags that employ sodium azide as the propellant. and have always used this compound since "air" bags were first introduced.

for all of us hoi polloi, this issue about the implementation of sodium azide as the propellant was adroitly managed so as to keep it out of the public's view. that is how the bags came to be identified as "air"bags. as opposed to sodium azide bags.

it is sort of like the current story that prions cause bovine spongiform encephalopathy[bse, aka mad cow disease]. as you can discover on your own, prions have never been found, they are notional. what is not notional is that cattle are treated with large amounts of neurotoxins[aka pesticides]. the international chemical industry would love for us to ignore the organophosphate, organochloride neurotoxins that are applied to cattle in a thorougly uncontrolled manner.

my guess is that if you looked, you would find that the sodium azide that is supplied to the "air"bag suppliers is manufactured by the same entities.

you know, safety can be a double-edged sword. companies looking for a market for their toxic sodium azide might have created the "air"bag market by the adroit and concentrated usage of public relations and congressional lobbying that resulted in the federal mandate for "air"bags.

something to think about.

for those of you with statistical inclinations, consider injuries, deaths, per vehicle mile travelled prior to sodium azide bag incorporation into automobiles and afterwards.

i haven't crunched the numbers, but my guess would be that there hasn't been a statistically noticeable improvement.

may i reintroduce you to the federal government for sale to the highest bidder? the name is madam.

Okay, it's getting near the end of 2005, so if you have an airbag equipped Mercedes built BEFORE 1990, your airbag is probably "expired." NHTSA, the DOT and your local state regulations all have something to say about the condition of your car's safety systems, so it might be a good idea to check.

as off 11/1/05 www.germancarfans.com had a cover story on Mercedes' history with airbags

"Legal Disclaimer" I would think that the manufacturers and the legislators haggled at great length over the details regarding "product liabilty." After 15 years how could anyone respectivley hold the manufacturer liable for an incident which resulted in death because the accelerant used to deploy the bag degraded over time.

"Useful service life" I need to stop before I get started.....