Interpretation ID: aiam0244
Director
Automotive Safety Engineering
General Motors Corporation
General Motors Technical Center
Warren
MI 48090;
Dear Mr. Lundstrom: This is in reply to your letter of June 26, 1970, to Mr. Douglas W Toms, Director, National Highway Safety Bureau, concerning plastic materials for reflex reflectors.; The contents of your letter, including the technical data an information enclosed therewith, have been carefully reviewed by interested members of this Bureau. As a result of this review and evaluation, and also considering the nature and intent of the requirements in question, we concur, basically, with your interpretation of the requirements of SAE J576b, as subreferenced in Federal Motor Vehicle Safety Standard No. 108. Your interpretation of the requirements of paragraphs 3.4 and 4.2 of SAE J576b, as quoted from your letter, is as follows:; >>>'A plastic material used in a lamp or reflector assembly so that i is covered by other material and is not directly exposed to sunlight meets the requirements of SAE J576b if, when so covered, it satisfies the requirements of paragraphs 3.4 and 4.2.'<<<; We would fully concur with this interpretation if it is rephrased t read as follows:; >>>'A plastic material used in a lamp or reflector assembly so that i is covered by other material and is not directly exposed to sunlight meets the requirements of paragraphs 3.4 and 4.2 of SAE J576b if, when so covered, it satisfies the requirements of those paragraphs.'<<<; To test for compliance, using this interpretation, the test sampl discs, as specified in SAE 576b, would be exposed to the outdoor exposure test (paragraph 3.4) while covered with the actual lens material used in production lamp assemblies. In your particular case, the discs would be the polycarbonate ('Lexan') material and the 'covering material' would be the red taillamp lens molded for production use.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs;