Mr. Bruce M. Gates
Gates Brothers Glass Shops
P.O. Box 657
Bellefontaine, OH 43311

Dear Mr. Gates:

This responds to your May 22 and May 23, 1996, e-mails concerning the practice of some auto glass replacement companies of replacing windshields in used vehicles using a butyl tape. You believe that this practice is unsafe because the butyl tape withstands less pressure than the primers and urethane that your company uses, and that you say the vehicle manufacturers specify in their installation procedures.

A provision in our statute (49 USC, Chapter 301) prohibits motor vehicle repair businesses from "knowingly mak[ing] inoperative any part of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with a motor vehicle standard . . . ." (30122(b)). You appear to be aware of that provision and that the National Highway Traffic Safety Administration (NHTSA) has a longstanding position that the replacement of a damaged windshield is not a "making inoperative" with respect to the windshield mounting standard (Standard 212), regardless of the method used to maintain the integrity of the windshield. (See, e.g., enclosed October 5, 1983 letter to Mr. Anthony M. Peterson.) Section 30122(b) would not apply because the windshield mounting was already "inoperative" when it was brought to the repair shop.

You ask us to reconsider this position, believing that vehicles have changed dramatically in the last decade, such as by having "air bags that deploy off the windshield and so many vehicles relying on Urethane to provide the necessary support to the roof structure . . . ."

We are unable to agree that the "make inoperative" provision could require a replacement windshield to be installed as though it were new. The provision does not require repair businesses to ensure that damaged (or worn) systems brought in for repair perform better after repair than they did before repair. Assuming that the original urethane sealant was an element of design necessary to comply with the air bag or roof crush requirements, the element of design was already "made inoperative" when the vehicle was brought to the repair shop.

While NHTSA does not currently regulate the use of butyl tape in windshield replacement, we want to find out more about the safety implications of the practice. Accordingly, we have forwarded your e-mail to our safety engineers for further consideration.

Please call Paul Atelsek of my staff at (202) 366-2992 if you have any further questions.


Samuel J. Dubbin

Chief Counsel