Skip to Content


NHTSA's Activities Under the United Nations Economic Commission for Europe 1998 Global Agreement: Glazing

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


National Highway Traffic Safety Administration (NHTSA), DOT.


Request for comments.


NHTSA is publishing this notice to inform the public that there may be a vote to adopt the Global Technical Regulation (GTR) on Glazing at the March 2008 session of the World Forum for Harmonization of Vehicle Regulations (WP.29). In anticipation of this vote, NHTSA is requesting comments on this GTR to inform its decision for the vote. Publication of this information is in accordance with NHTSA's Statement of Policy regarding Agency Policy Goals and Public Participation in the Implementation of the 1998 Global Agreement on Global Technical Regulations.


Written comments may be submitted to this agency by March 6, 2008.


You may submit comments [identified by DOT Docket No. NHTSA-2008-0008, Notice 1] by any of the following methods:

  • Federal eRulemaking Portal: Go to Follow the online instructions for submitting comments.
  • Mail: Docket Management Facility: U.S. Department of Transportation, 1200 New Jersey Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC, 20590-0001.
  • Hand Delivery or Courier: West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue S.E., between 9 a.m. and 5 p.m. ET, Monday through Friday, except Federal holidays. Telephone: 1-800-647-5527.
  • Fax: 202-493-2251

Instructions: All submissions must include the agency name and docket number for this proposed collection of information. Note that all comments received will be posted without change to including any personal information provided. Please see the Privacy Act heading below.

Privacy Act: Anyone is able to search the electronic form of all comments received into any of our dockets by the name of the individual submitting the comment (or signing the comment, if submitted on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit

Docket: For access to the docket to read background documents or comments received, go to and follow the online instructions, or visit the Docket Management Facility at the street address listed above.

Start Further Info


Mr. Ezana Wondimneh, Division Chief, International Policy and Harmonization (NVS-133), National Highway Traffic Safety Administration, 1200 New Jersey Avenue, SE., Washington, DC, 20590-0001; Phone (202) 366-0846, Fax (202) 493-2280.

End Further Info End Preamble Start Supplemental Information


At the March 2004 session of WP.29 the formal proposal to develop a GTR on safety glazing, sponsored by Germany, was adopted with a modification to restrict the scope of the GTR to glass-based safety glazing. An informal working group chaired by Germany was subsequently established to develop the GTR. In October 2004, NHTSA docketed the draft GTR proposed by Germany (69 FR 60460, 60462; October 8, 2004), but received no comments. At the November 2005 session of WP.29 AC.3 further agreed that the GTR would not include installation provisions and that the informal working group could consider possible approaches to including certification markings in the GTR. However, it was later decided by WP.29 that a separate informal working group would be tasked with examining the issue of markings for all GTRs. Therefore, the glazing GTR only specifies the required markings to identify the type of glazing material without reference to certification type markings. Contracting parties to the 1998 Agreement will be able to require additional markings for identification of manufacturer and the regulation(s) the glazing is manufactured to comply with.

On October 10, 2006, NHTSA published a new notice that described the progress made on the agency's GTR activities including the glazing GTR (docket number NHTSA-2003-14395). The notice included the draft GTR, provided discussions on several key issues, and requested public comments. A comment with regard to the GTR was submitted by Pilkington North America that sought to clarify an incorrect citing of the test procedures concerning light transmittance and optical distortion, which has since been addressed.

The latest draft of the GTR specifies performance requirements for various types of glazing (i.e., laminated and toughened glass) intended for installation in Category 1 and 2 vehicles as defined in Special Resolution No. 1. The requirements apply to glazing as an item of equipment, and do not include installation requirements for vehicles. Performance requirements for some of the materials vary depending on whether the material is intended for installation as a windscreen or a pane. The draft includes requirements and tests to ensure the mechanical strength, optical qualities and environmental resistance of glazing.

Four sets of tests and requirements for mechanical properties are under consideration in the GTR: a fragmentation test, a 227g steel ball impact test, a 2.26kg steel ball impact test and a 10kg headform impact test. Each of the first three of these tests was adopted from widely used procedures currently in effect, with small differences, in all three national regulations examined for this GTR (European, Japanese and U.S. safety regulations). The fragmentation test proposed in the draft GTR is based on the current European approach, except that it was modified to use two different impact forces depending on the design of glazing being evaluated. The 227g and 2.26kg steel ball impact tests are also very similar to the existing national regulations examined—with the exception of the drop height for the small ball test. Based upon analysis conducted by Japan, which determined that the force from a drop height of 2.0m replicated the force of a typical object that impacts a pane, it was decided that a drop height of 2.0m could be specified. The headform test (which is currently in the European and Japanese national regulations, but not in the U.S.) under consideration for the GTR specifies one drop height (1.5m), instead of retaining the two separate drop heights currently found in the European and Japanese regulations because the purpose of the second height drop was already addressed in other tests specified in the GTR. Also, the headform test is an optional requirement in the GTR. Each contracting party to the 1998 Agreement can decide whether or not to apply this provision in national/regional law.

Three types of optical qualities are addressed in the GTR: light transmission, optical distortion and double imaging. The minimum light transmittance level for glazing requisite Start Printed Page 7804for the driver's forward field of vision is 70 percent, per U.S. and Japanese regulations, rather than 75 percent required in European regulations. This is supported through a cost-benefit analysis, which shows no perceptible difference in light transmission and savings in energy usage. The light transmission test procedure used in the GTR was adopted from the European and Japanese test procedures, because they are based on the driver's field of view and thus better approximate normal driving conditions. For the other optical quality tests, the main differences between the standards and regulations examined were not the requirements but just the test procedures. These differences were resolved by selecting the European and Japanese test procedures for the same reasons mentioned above.

The GTR also includes environmental resistance requirements related to temperature change, fire, chemical resistance, abrasion, radiation, high temperature and humidity. The first four of these were common to all the examined regulations. The remaining three requirements had minor differences, which the GTR resolved by selecting the best alternatives. For example, in the case of resistance to radiation, the major difference between the American and European approaches is that the former specifies 100 hours exposure, using a specified radiation source, while the later specifies 100 hours of exposure at 1400 W/m2. Since the European procedure ensures a constant level of exposure and allows for alternative sources of UV radiation during testing, it was deemed more flexible and was thus selected for the GTR.

In July 2007, NHTSA received comments on the draft GTR from the Society of Automotive Engineers (SAE) Glazing Committee. In October, the agency made recommendations to the informal working group to implement some of the SAE comments into the GTR. The comments accepted in the GTR included editorial corrections, clarifications to Part A of the draft GTR (the technical rationale and justifications section), adding a definition for “Uniformly toughened-glass”, and clarifying what would be considered a sharp edge for the fragmentation test. Several other points were not incorporated since they fell outside the scope of the GTR, were not relevant or already addressed in previous notices, or could not reasonably be pursued without conducting lengthy additional research and validation testing that is not supported by the majority of the Contracting Parties to the 1998 Agreement. SAE's comments can be found in the docket of this notice.

The informal working group submitted the draft GTR to the Working Party on General Safety Provisions (GRSG) for consideration at the October 2007 session. The October 2007 session of GRSG voted to recommend the GTR to WP.29. The GTR is expected to be voted on at the March 2008 session of WP.29. In anticipation of this vote, NHTSA requests comments on the draft GTR. The draft GTR that will be considered can be found in the docket for this notice.

Once the GTR is established through consensus voting at WP.29, NHTSA will initiate domestic rulemaking to amend its existing FMVSS to incorporate approved provisions of the GTR. This will allow for further opportunity to consider comments from interested parties through the usual rulemaking process. If NHTSA's rulemaking process leads it to either not adopt or to modify aspects of the GTR, the agency will seek to amend the GTR in accordance with established procedures under the 1998 Global Agreement and WP.29, as it recently did with the door lock GTR.

Start Signature

Issued on: February 5, 2008.

Stephen R. Kratzke,

Associate Administrator for Rulemaking.

End Signature End Supplemental Information

[FR Doc. E8-2474 Filed 2-8-08; 8:45 am]