Interpretation ID: aiam3757
Manager
Safety & Emission Control Engineering
BMW of North America
Inc.
Montvale
NJ 07645;
Dear Mr. Ziwicka: This is in reply to your letter of August 4, 1983, to Mr. Vinson o this office asking for reconsideration of our December 8, 1982, letter in which we stated that Motor Vehicle Safety Standard No. 108 prohibits the use of glass or plastic shields in front of motorcycle headlamps. You have pointed out that this appears to reverse a previous interpretation issued by this office on March 15, 1978, in which we concluded that such covers were not precluded.; As is well known, SAE Standard J580 *Sealed Beam Headlamp Assembly precludes the use of covers in front of headlamps in use. Because Standard No. 108 allows installation on motorcycles of half of a passenger car sealed beam headlighting system (principally because SAE J584 allows use of headlamps meeting SAE J579 *Sealed Beam Headlamp Units*), the 1982 interpretation applied the prohibition against covers to all sealed beam headlamps, even those used on motorcycles. With respect to unsealed lamps, the agency cited paragraph S4.1.3, the prohibition against installation of additional equipment impairing the effectiveness of required lighting equipment, and concluded that the possibility of deterioration of light output through cracked or discolored covers precluded covers over nonsealed lamps. On the other hand, the 1978 interpretation concluded that, since the cross referenced J579 did not itself reference J580, the prohibition did not apply.; We have reviewed this matter and have concluded that headlamp cover for motorcycles are not *per se* prohibited by Standard No. 108. As the 1978 interpretation implies, and as you make explicit, the only standard Table III directly incorporates for motorcycles headlamps is J584, whereas J580 is one of several standards directly incorporated for headlamps on four-wheeled vehicles. Nevertheless, we still conclude that these covers are prohibited if they impair the effectiveness of the headlamp.; If, for example, the angle of the cover is so extreme that headlam 'effectiveness' is 'impaired' because of deterioration of the beam, then the manufacturer may wish to remove the shield or redesign it. If, as another example, a plastic cover is intended and a manufacturer has knowledge that it is susceptible to accelerated hazing or cracking, that manufacturer should not use a cover manufactured of this plastic.; In summary, this letter modifies both our 1978 and 1982 opinions b concluding that headlamp covers for motorcycles are permissible if they will not impair the effectiveness of the headlamp.; The agency is reviewing this subject to determine if rulemaking i advisable to prohibit covers of any sort over motorcycle headlamps, similar to the prohibition against such covers on four-wheeled motor vehicles.; Sincerely, Frank Berndt, Chief Counsel