Interpretation ID: 23918.ztv

Mr. Bing Kam
6902 Midhurst
Memphis, TN 38119

Dear Mr. Kam:

This is in reply to your letter of November 14, 2001. Because of the precautions being taken with mail addressed to Federal agencies, we did not receive it until January 16, 2002.

You have asked for an interpretation of the phrase "flashes in use" as used on the advisory sheet regarding lighting inventions which we provided you earlier. This phrase appears in the list of factors which we believe may impair the effectiveness of lighting equipment required by Federal Motor Vehicle Safety Standard No. 108 if present in supplemental lighting equipment not required by the standard. You have raised the possibility that a supplemental lamp whose cycle of flashes is more than 5 seconds might not be considered one that "flashes in use."

Standard No. 108 defines "flash" as "a cycle of activation and deactivation of a lamp by automatic means continuing until stopped either automatically or manually." The definition does not specify a time rate for a cycle. This means that any cycle of activation and deactivation is a flash, regardless of its duration.

Additionally, in our view, impairment may occur when any supplemental lamp gives the appearance of flashing, e.g., modulating in intensity or varying the illuminated area of the lens.

Sincerely,

Jacqueline Glassman
Chief Counsel

ref:108
d.4/8/02