Interpretation ID: 20674.ztv

Mr. Vann H. Wilber
Director, Vehicle Safety and Harmonization
Alliance of Automobile Manufacturers
1401 H Street, NW - Suite 1409
Washington, DC 20005

Dear Mr. Wilber:

We are replying to your letter of September 10, 1999, with reference to marking headlamps with the symbol "DOT."

Paragraph S7.2(a) of Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices and Associated Equipment, requires the lens of each headlamp and beam contributor to be marked with the symbol "DOT" to certify its compliance with all applicable requirements. You state that "lens" can be interpreted on some contemporary headlamp designs to "include several elements on the reflector or other interior components that contribute to the photometric performance of the forward light." You ask that we interpret S7.2(a) to allow the DOT symbol to be located on internal optical elements "as long as it is visible from the front when installed on the vehicle without removal of any part."

You reference our interpretation of April 25, 1996, to Guy Dorleans "that could appear to conflict with the interpretation we are seeking here," and you seek to distinguish it "on the basis that the question addressed by the agency in that letter apparently presumed that the only 'lens' in the headlamp assembly at issue there was the 'clear lens' in the front of the headlamp housing, whereas the advanced designs we are asking you to consider here include optical elements ('lens') on the interior of the lamp." In the event we cannot distinguish it, you ask that we "reverse the conclusions in that interpretation to the extent they would preclude marking the 'DOT' symbol on interior optical elements."

I am sorry to say that we cannot distinguish your request from the Dorleans letter or reverse the conclusions to the extent that we can allow certification to be placed on interior optical elements. As you pointed out, the DOT marking requirement originated as a certification applied to the lenses of sealed beam headlamps. You are correct that Standard No. 108 does not define the word "lens." In the absence of a definition, we believe that the word "lens" has been clearly understood over the years to refer to the glass or plastic front of the headlamp housing through which light is emitted, and not to the other components of a headlamp, the reflector and the light source. Thus, whether a headlamp is sealed beam, replaceable bulb, integral beam, its lens has been clearly identifiable as such for purposes of affixing the DOT marking. We cannot interpret the word "lens" in a manner that departs from the common understanding of the word. However, we intend to address the concern of your members by rulemaking to amend Standard No. 108 to adopt a definition of "lens" broad enough to encompass interior optical elements where the certification symbol could be placed .

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:108
d.11/9/99