Interpretation ID: 22310.ztv

Mr. Paul DeStefano
Optical Engineering Supervisor
Valeo Sylvania L.L.C.
1231 'A' Avenue North
Seymour, IN 47274

Dear Mr. DeStefano:

This is in reply to your letter of October 15, 2000, asking for an interpretation of S7.5(g) of Federal Motor Vehicle Safety Standard No. 108.

Paragraph S7.5(g) requires in pertinent part that the lens of a replaceable bulb headlamp be marked with the bulb marking designation provided in compliance with 49 CFR Part 564. In the hypothetical you present, the same headlamp lens would be used for two similar headlamp systems. The lower beam of one system would include a type H7 halogen bulb. The other system's lower beam includes a high intensity discharge (HID) D2S light source. You would like to mark the lens in front of the lower beam with both "H7" and "D2S," either one positioned above the other, or side by side. In a third variant, the marking could read "H7 or D2S." You state that it would not be possible to interchange the H7 and D2S light sources due to the different mechanical designs and electrical connections. You ask that we concur in your belief that this dual marking satisfies the intent of Standard No. 108.

We cannot concur. The lens marking must indicate only the light source that is behind the lens. The purpose of the marking is to ensure that there is a proper replacement for the light source if required. The aftermarket has begun to offer equipment that can convert filament lamps into HID lamps. This results in significant increases in intensity to the extent that the headlamps may no longer comply with the maximum candela restrictions of Standard No. 108. Dual marking of the lens could be interpreted as countenancing the replacement of an H7 filament type light source with a D2S HID type light source. In addition, local law enforcement officers are aware of the importance of complying lighting equipment to safety in their jurisdictions, and depend upon unambiguous lens marking to assist them in enforcing local lighting laws.

If you have any questions, you may phone Taylor Vinson of this office (202-366-5263).

Sincerely,

Frank Seales, Jr.
Chief Counsel

ref:108
d.1/19/01