Are laminated door glasses a safety device or a performance feature? Good question. It seems that some ARG glass manufacturers believe that these laminated sidelites are performance features. They produce an aftermarket tempered part for replacement of the laminated part found in the original vehicle. That seems to suggest that laminating a part has primarily acoustical purposes, and the tempering of the part satisfies any safety requirements. This was curious to me so I thought I would look into it.

I was taught that laminated glass is installed to protect against occupant ejection during a rollover accident. I was also told that the laminated part acted as a “back stop” for air curtains for side impact protection. Both of these uses seemed to me to be safety related.

If that is the case, according to the National Safety Act of 1966, “a safety device cannot be rendered inoperable” so a laminated door glass would have to be re-installed or the glass company would be rendering a safety device inoperable. Safety takes precedence over performance. Replacing a laminated glass with a tempered part only satisfies a portion of the total safety delivered by the automotive glass part.

I remember a case in 2005, in which a plaintive sued Ford for installing tempered glass in a vehicle when the vehicle manufacturer knew that a laminated part would be safer. Was it? The jury seemed to think so. They awarded the plaintiff more than $30 million.

Even though in that case, the verdict sided with the plaintiff, the debate rages on. On one side you have those who advise that the laminated part should be considered a safety device to prevent occupant ejection from the vehicle. The other side the argument is that laminated glass restricts escape in case of vehicle submersion.

Who is right? According to National Highway Traffic Safety Administration (NHTSA), both are. NHTSA declined to rule on the issue because both arguments are correct and proper so they refused to get involved and failed to make a definitive decision.

So, where should the automotive glass industry stand on this issue? I think we approach the question the same way we approach other issues where there is not clear guidance; we defer to the vehicle designers. Car manufacturers (for better or worse) are responsible for the safety designed into every vehicle made.  If a vehicle was designed with laminated door windows, should those of us in the aftermarket question the intent? I believe that putting a tempered part where a laminated part was originally, has the potential of opening up large liability issues. I doubt that many of us want to be involved in that.