Windshield Replacement Could Cause Passenger Side Airbag Failure

Celeste Stewart
By now, most of us know the dangers passenger side airbags pose to young children and small adults. Many newer models offer cut off switches and sensors so that these passengers may ride in the front passenger seat without risk of being killed or injured by the passenger side airbag. However, one little known danger of passenger side airbags is often overlooked. That's the danger of airbag failure immediately following a windshield replacement or an improperly replaced windshield.

When an impact occurs, the passenger side airbag is designed to first bounce off of the windshield before bouncing back and cushioning the passenger. The problem that could happen if a windshield has just been replaced is that the adhesive used to bond the windshield to the car could fail. If the adhesive doesn't hold the windshield in place, the windshield will pop out when the passenger airbag deploys. The airbag will then continue forward and deflate on the hood of the car. The passenger's face will collide with the metal airbag box located in the dashboard rather than a soft pillow of air as expected.

Why would an adhesive fail? Most of the urethane adhesives used by windshield replacement companies are designed to pass federal motor vehicle safety standards and create a strong bond to prevent such an occurrence. However they can take up to 24 or more hours to cure sufficiently. So even if a federally approved, crash tested adhesive is used, if an accident occurs while the adhesive is still wet, the windshield could pop out causing the passenger side airbag to fail.

Most reputable auto glass replacement companies will calculate the estimated time it will take before the adhesive has cured sufficiently. This calculation is called the "safe drive away time" and is based on the temperature and humidity at the time of the windshield replacement. This is most critical for cars equipped with passenger side airbags. For those without passenger airbags, the amount of cure time before crashworthiness is restored is less. In general, automotive urethane will cure faster in warmer and wetter conditions such as a humid summer day versus cold and dry conditions such as winter time.

That's not to say the car is unusable for up to 24 hours. Many companies will explain the safe drive away time and offer to use a chemical cure or quick cure urethane instead. These adhesives are chemically activated to cure within an hour offering the car owner a one hour safe drive away time for cars equipped with passenger side airbags. While more expensive, the price of convenience often is a motivating factor. Like their slower curing counterparts, these urethanes are designed to meet or exceed all federally mandated safety standards and crash tests, they simply reach the desired crashworthiness faster.

When replacing a windshield on a car with or without passenger side airbags, it is critical to understand the safety issues and follow the recommended safe drive away schedule. Before the job is even started, ask the technician when the car will be safe to drive and if that time frame is not acceptable, ask for (and be willing to pay extra for) an upgrade to a fast cure or chemical cure adhesive.

Published by Celeste Stewart

Celeste Stewart is a freelance writer with a background in telecommunications and marketing   View profile

  • Federal Safety Standards: Federal Motor Vehicle Safety Standards 212 and 216: These standards are the performance standards the federal government dictates for windshield retention and roof support. FMVSS 212 is the head on collision barrier crash test. The test vehicle is crashed into a wall up to 30 MPH. When tested without passengers, the windshield must retain 75% adhesion on each side of the longitudinal center line. If tested with a mannequin, 50% of the windshield on each side of the longitudinal center line must remain intact. FMVSS 216 specifies the structural strength required to protect the occupants of a vehicle if there is a rollover, by preventing the roof from crushing the occupants. This test applies a force of 1.5 times the unloaded vehicle weight or 5000 pounds, whichever is less, to the “A” pillar in a downward force. The force continues until reaching a force of 1 1/2 times the unloaded vehicle weight or 5,000 pounds, whichever is less. At the end of the test, the amount of the roof’s deflection is measured. National Traffic and Motor Vehicle Safety Act of 1996 states that: No manufacturer, distributor, dealer or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard, unless such manufacturer, distributor, or repair business reasonably believes that such vehicle or item of equipment will not be used (other than for testing or similar purposes in the course of maintenance or repair) during the time such device or element of design is rendered inoperative.
  • The windshield is a safety device.
  • If the windshield fails, the passenger side airbag fails.

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