OSHA Hazard Information Bulletins
Automobile Air Bag Safety
August 30, 1990
- LEO CAREY
- Office of Field Programs
- THOMAS J. SHEPICH
- Directorate of Technical Support
- Safety Hazard Information Bulletin on Automobile Air Bag Safety
The Directorate of Technical Support issues Hazard Information Bulletins (HIBs) in accordance with OSHA Instruction CPL 2.65 to provide relevant information regarding unrecognized or misunderstood safety and health hazards, and/or inadequacies of materials, devices, techniques and engineering controls. HIBs are initiated based on information provided by the field staff, studies, reports and concerns expressed by safety and health professionals, employers and the public. Information is compiled based on a comprehensive evaluation of available facts, literature and in coordination with appropriate parties. HIBs do not necessarily reflect OSHA policy.
The OSHA Health Response Team has brought to our attention a potential hazard for rescue personnel pertaining to collisions involving vehicles equipped with air bags. A local safety alert has been distributed in New Jersey on this subject. The alert overstates the potential hazards to rescue personnel by advising them to wait for 10 to 20 minutes before approaching deployed airbags and also warning of excessive steering column temperatures. These problems and others are explained in the enclosed Emergency Rescue Guidelines for Air Bag - Equipped Cars published by the National Highway Traffic Safety Administration (NHTSA) of the Department of Transportation.
Air bags are inflated by nitrogen gas which is produced by the highly toxic chemical, sodium azide. However, the sodium azide is completely consumed by this reaction. After deflation of the bag some irritant dusts (including sodium hydroxide) are released. NHTSA advises that rescue personnel wear gloves and eye protection for this situation. However, there is no need to wait for 10 to 20 minutes for vehicle ventilation. Moreover, there is no evidence of excessive steering wheel temperature due to air bag deployment.
NHTSA does discuss a situation that could rescue personnel although it would be a rare occurrence. An undeployed air bag is not likely to deploy after a crash. Moreover, most incidents will not require rescue workers to work in what would be the deployment path of the air bag; so, rescue operations could begin without delay. When someone is pinned directly behind an air bag, special procedures should be followed.
To defeat electrically activated systems the battery cables must be cut. This begins the deactivation period for backup power systems. For some vehicles deactivation will occur in a matter of seconds, others take a few minutes. Until deactivation is complete, the steering wheel should not be displaced or cut. Moreover, heat should not be applied in the steering wheel hub area and the air bag module itself should not be cut.
Please distribute this bulletin to all Area Offices, State Plan States, and Consultation Projects.
EMERGENCY RESCUE GUIDELINES FOR AIR BAG-EQUIPPED CARS*
Incident with a Fire First use normal fire extinguishing procedures, then follow the rescue guidelines below.
Incident with a Deployed Air Bag
Use normal rescue procedures and equipment. Do not delay medical attention. DEPLOYED AIR BAGS ARE NOT DANGEROUS.
However, they do produce a dust that may cause minor skin or eye irritation which can be prevented by:
- Wearing gloves and eye protection
- Keeping the dust away from the patient's eyes and wounds
- Removing gloves and washing hands after exposure to the dust
Incident with and Undeployed Air Bag
An undeployed air bag is unlikely to deploy after a crash. Most incidents will not require rescuers to work in what would be the deployment path of the air bag; therefore, rescue operation can begin without delay.
IN THOSE RARE INSTANCES WHEN SOMEONE IS PINNED DIRECTLY BEHIND AN UNDEPLOYED AIR BAG, SPECIAL PROCEDURES SHOULD BE FOLLOWED:
- Disconnect or cut both battery cables safely
- Avoid placing your body or objects against the air bag module, or in what would be the deployment path of the air bag
- Do not mechanically displace or cut through the steering column, until after the system has been fully deactivated
- Do not cut or drill into the air bag module
- Do not apply heat in the area of the steering wheel hub
If your questions are not answered below, please contact the NHTSA Office of Occupant Protection, NTS-13, Washington, DC, 20590, or USFA Office of Firefighter Health and Safety, NETC, Emmitsburg, MD 21727.
AIR BAG-EQUIPPED CAR EMERGENCY RESCUE QUESTIONS AND ANSWERS
Q1 How does an air bag work:
Because air bags are designed to deploy only in frontal or near-frontal crashes-not in side, rear, or rollover crashes-it is possible that you will be involved in rescuing someone from a car with an air bag that did not deploy.
- Most Air bag-equipped cars on the road today have a driver-side air bag. A few makes, Lincoln, Mercedes and Porsche, have both drive and passenger-side air bags as standard or optional equipment. The air bag is designed to supplement the protection offered by safety belts. In a frontal impact of sufficient severity (comparable to a collision into a solid wall at 10-14 mph or above), sensors in the vehicle detect the sudden deceleration and trigger the inflator module. This causes the solid chemical propellent sealed inside the inflater, principally sodium azide, to undergo a rapid chemical reaction. This reaction produces primarily nitrogen gas, the same gas that makes up 80 percent of the air we breathe. The gas inflates a woven nylon bag packed inside the steering wheel hub or the instrument panel for the front seat passenger. The bag inflates in less than one-twentieth of a second, splitting open its protective cover, and inflating in front of the occupant. As the occupant contacts the bag, the nitrogen gas is vented through openings in the back of the bag, which helps to cushion forward movement.
Q2 How do I identify a car equipped with an air bag?
If the bag did not deploy, several methods can be used. The steering when hub is large and rectangular, (about 6" by 9"). The large hub usually will be covered with a scored, soft plastic material. The words, "Supplemental Inflatable Restraint," "Air Bag," or initials such as "S.I.R.," or "SRS," may be embossed somewhere on the surface. In most cases, the Vehicle Identification Number (VIN) can be used to determine the presence of an air bag. Exhibit 1 show the codes used by the auto manufacturers.
Some manufacturers indicate the presence of an air bag system by placing placards under the hood and on the driver side windshield pillar.
If you cannot determine whether the car is equipped with an air bag, you should assume that it has one, particularly if it's a late model car, and follow the rescue guidelines for air bag cars.
- If the bag has deployed you will be able to see it drooping from the steering wheel hub or the instrument panel on the passenger side.
Q3 Is smoke produced during deployment?
- There are three kinds of "smoke." First, many people mistake the cornstarch or talcum powder used to lubricate the bag as smoke. The substances should not be a problem for rescue workers or accident victims. Second, a sealant which is used to prolong the life of the air bag system can smoke when the air bag is deployed. This smoke dissipates rapidly and should not be a cause for concern. Lastly, during deployment small particles from inside some bag systems are vented into the passenger compartment. These airborne particles look like smoke and some are deposited as a powdery residue on and around the bag.
Q4 Is the air bag hot?
- The bag itself will not be hot. Some components within the air bag module will be hot for a short time, but they are relatively inaccessible and should pose not threat to rescue personnel or crash victims. However, personal contact with the steering wheel hub should be avoided for at least 15 minutes after deployment.
Q5 What about the powdery residue on and around the bag?
The same gloves and eye protection that rescuers would normally wear to protect themselves (from sharp metal edges, glass, or form bodily fluids) also will prevent any irritation to the skin or eyes resulting from the residue released during deployment. Thus, the potential for this type of exposure is not severe enough to warrant delaying rescue operations. Hands should be washed with mild soap and water after handling a deployed bag. Also, avoid rubbing your eyes, eating, or smoking after handling the bag until you have removed the gloves and washed your hands. Rescuers also should take care to avoid introducing the residue into the eyes, or any wounds of the patient. If the residue gets into the eyes, they should be flushed with water.
- The residue is primarily corn starch or talcum powder, which is used to lubricate the bag as it deploys, and by-products of the chemical reaction that produces the nitrogen gas to inflate the air bag. This residue may contain a small amount of a potential skin irritant, sodium hydroxide.
Q6 Is there any sodium azide in the residue? Is it harmful?
- There is no detectable amount of sodium azide residue present in the passenger compartment after an air bag deployment. Sodium azide, a component of the air bag inflator propellent, converts the nitrogen gas used to inflate the air bag. Sodium azide in its solid state is toxic. But since it is hermetically sealed in a very strong metal container, which itself is located inside a protective housing within the steering hub, it is unlikely that rescue workers will be exposed.
Q7 If an undeployed air bag module is somehow ruptured, what precautions should be taken?
- In the unlikely event that the canister containing the sodium azide-based propellent will be found in a variety of pressed tablet forms. Do not touch or ingest any exposed propellent or expose it to an ignition source. As in all other rescue operations, rescuers should wear gloves and eye protection.
Q8 Is the sodium azide canister likely to explode during a car fire?
- No, The air bag is designed to inflate normally in the event that a vehicle fire causes the canister to be heated above 300 degrees F. Consequently, it is possible that the air bag will deploy in a car fire, but there should be no fragmentation of the inflator.
Q9 If there is a fire in an air bag car, can water be used to extinguish it?
- Yes, Any effective fire-fighting medium, including water may be used to extinguish a fire in an air bag-equipped car.
Q10 Is it all right to breathe the passenger compartment air after an air bag has deployed?
- Chemical analyses of deployment by- products show no reason for concern. Also, tests have been conducted with volunteers, chronic asthmatics known to be highly susceptible to airborne particles. These tests showed that the atmosphere produced by an air bag inflation posed not respiratory system hazard to the asthmatics studied.
Q11 What has been the experience of crash test personnel in dealing with air bag-equipped cars?
- NHTSA has crash tested more than 70 cars with air bags. The engineers and technicians who regularly handle deployed air bags and test dummies have reported no ill effects from their repeated exposures to the products of air bag deployments.
Q12 If the air bag did not deploy in the crash, is it likely to deploy after the crash?
In most cases, rescue operations can proceed normally and without delay. In the unlikely event that a driver or passenger is pinned behind an undeployed air bag, it will be necessary to take special precautions (See Q 15).
- No, The sensor devices used to activate the system are designed to respond only to the type of violent forces present during a crash. It is unlikely that the same type of forces will be created during rescue operations.
Q13 If the air bag(s) did not deploy in the crash, can the system be deactivated?
- The electrically activated systems used on most air bag-equipped cars can be deactivated. First, disconnect or cut both battery cables. This will begin the deactivation period for the backup power system that is part of most electrically activated systems. For some vehicle makes, deactivation will occur in a matter of seconds, others take a few minutes (see exhibit 2). Mechanically activated systems, used only on 1990 Jaguar coupes and convertibles, cannot be deactivated in the field.
Q14 Should rescuers wait for the system to be fully deactivated before proceeding with rescue operations?
- Except for the special case of someone being pinned behind an undeployed air bag, rescue operations can and should begin immediately. Rescue workers should not place themselves or any objects on the air bag module (the face of the steering wheel hub), or in what would be the deployment path of the air bag.
Q15 What if someone is pinned behind a steering wheel or instrument panel with an undeployed air bag?
If the circumstances permit wait for the system to be fully deactivated before attempting to remove the victim, (see Q. 13 for deactivation procedures).
You need not wait to provide medical attention, so long as you do not place your body or any objects on the air bag module, or in what would be the deployment path of the air bag.
If the patient must be removed at once, extrication efforts should be performed from the side of the entrapped victim, and away from the potential deployment path of the air bag. Do not place your body or objects against the air bag module. Do not mechanically displace or cut through the steering column unless the air bag system has already been fully deactivated. At no time, should anyone drill into the air bag module or apply heat (above 300 degrees F) in the area of the steering wheel hub.
In the case of the mechanically activated system currently found only on 1990 Jaguar coupes and convertibles extreme care should be taken to avoid sharp halting impacts to the steering column, particularly in a forward or rearward direction. Cutting of the steering wheel rim or the column is permissible if the previously mentioned type of impacts can be avoided.
NOTE: Crashes that result in victims being pinned behind an undeployed air bag will be rare. NHTSA has not heard of such a case among the thousands of crashes documented to date. An unusual combination of circumstances for example, a direct side impact which buckled the floor upward beneath the victim, would have to be present to trap someone without deploying the air bag.
- In the unlikely event that a driver or front seat passenger is pinned behind an undeployed air bag, special procedures should be followed.
Q16 Occasionally we use damaged cars for rescue training purposes. The cars are scrapped after we finish the training. Should we take any precautions to prevent an unwanted deployment during training?
- Before using an air bag-equipped car for training purposes, deploy the air bag. A procedure for deploying the air bag can be found in the service manual provided to each manufacturer to it dealers. Contact the car dealer for assistance.
Vehicle Identification Number Codes for Driver- and Passenger-Side Air Bags
|MAKE||SERIES||MODEL YEARS||VIN POSITION||VIN VALUE||TYPE**|
|BENTLEY||1990||8||D or O||D|
|CHRYSLER||1988-90||4||X or Y||D|
|DODGE||1988-90||4||X or Y||D|
|PALLETTE COLLECT; XJ6 SOVER.; VDP, XJS||1990||5||W||D|
|XJ6 SOVER. VDP, XJS||1990||5||X||D/P|
|LEXUS||1990||8||E OR T||D|
|MERCEDES BENZ||1985-90||8||B OR D||D|
|PLYMOUTH||1988-90||4||X OR Y||D|
|PORSCHE||(UNABLE TO IDENTIFY BY VIN)|
|ROLLS ROYCE||1990||8||D OR O||D|
|SAAB 9000S||1988-89||8-Apr||CS55d; CS58D||D|
|Supra||1990||8-Apr||MA7OM; MA7ON;MA7IM; MA7IN||D|
|Celica GT||1990||8-Apr||ST87F; ST87N||D|
**D= Driver-side air bag
**D/P= Driver-side air bag and passenger side air bag
Deactivation Times for Air Bag Back-up Power Supply
|Rolls Royce||30 Minutes|
|VW (Audi)||10 Seconds|
***MY 1985-89 = 0; MY 1990 = 15 Minutes; MY 1991 = 1 minute if positive battery cable is shorted to
*Based on information provided to the National Highway Traffic Safety Administration (NHTSA) by the automobile and air bag manufacturers, and coordinated with U.S. Fire Administration (USFA).