Document gD23a9G0zmDKoDyDORr2QkJ6a

I General Motors Corporation ldi Statement on EPA Proposed Asbestos Mining and Import Restrictions and Manufacturing, Importation and Processing Prohibitions July 16, 1986 Statement for Public Hearing on Asbestos Ban by Robert L. LeFevre Manager, Automotive Safety Engineering General Motors Environmental Activities Staff ' My comments today vill address General Motors concerns regarding the potential impact of the proposed rulemaking on the safety of automotive brakes and the compliance of brake systems to safety regulations. Assuring that vehicles are fitted with brake systems which fully meet the need for motor vehicle safety is a major responsibility of automotive engineers. Since 1968 the National Highway Traffic Safety Administration of the Department of Transportation has been active in establishing Federal Motor Vehicle Safety Standards which prescribe both design and performance specifications for brake systems on new vehicles. At the present time standard FMVSS 105 regulates hydraulic brakes, and FMVSS 121 addresses air brake systems. In similar ways, brake systems for vehicles which are to be sold in other countries are subject to certain national or regional regulations. As General Motors detailed in its written comments on this asbestos rulemaking, efforts are also underway to reconcile the regulatory differences by developing an internationally harmonized brake standard. Taken Individually or collectively, . these standards dictate compliance levels for a multitude of performance characteristic of brake systems and as a result have dominant influence., on brake system design decisions. Despite this number of regulations, questions as to what constitutes fully acceptable safety performance for brake systems continue to surface. General Motors and other manufacturers have repeatedly found themselves involved In discussions and debates with the NHTSA Office of Defects Investigations regarding the real-world adequacy of brake systems even though these systems fully conform with all regulatory requirements* In addition to the legal constraints, our customers have additional brake performance expectations in areas such as durability and noise. Independent of all of the safety regulations, discussions about brake system performance and customer demands, the EPA has proposed to ban asbestos, one of the few materials which has the proven ability to function and survive in the hostile environment of brake systems. This action in essence calls for a forced change in the fundamental composition of most brake friction materials. Inasmuch as there is no one-for-one substitute for asbestos, this change will require offsetting changes in brake system design. As General Motors advised in its written comments, some of its disc brake pads and virtually all of its drum brake linings are made with asbestos'' to achieve the essential blend of strength, friction stability and temperature capability. Some other materials have worked well in some applications; however, no effective substitute has been found for other applications. The elimination of asbestos from the approximately 80 systems which currently use this material would be an enormous undertaking, and total success within the timeframes cited by the agency is not certain. In light of the difficulties which have been encountered in the past in finding materials which will yield system performance meeting all regulatory, safety and customer demands, we must urge the agency to proceed with caution along the lines which we have outlined in our written comments. The composition of brake friction materials used for replacement purposes is also of serious concern to General Motors. As the EPA may be aware the performance of brake systems already operating on the public roads is not regulated, and federal regulations do not even acknowledge replacement brake friction materials. However, our experiences have taught us that replacement materials and systems which have been serviced must provide substantially the same performance as original equipment. If asbestos were to be banned as the agency has proposed and therefore were to be unavailable for use in replacements, it is probable that some applications would require that the sealed hydraulic systems be opened up to replace brake cylinders or other components to compensate for the different friction properties of the substitute materials. For example, if the substitute materials had 10Z lower friction, it might be that the best way to recover the lower system output would be by increasing the size of the wheel cylinders or to change operating pressure. Ue are convinced that customers would reject such costly part changes. To avoid causing significant changes in brake performance for cars designed to use asbestos friction materials, we urge the EPA to configure any asbestos rule so that it allows existing vehicles which are validated with asbestos linings to be serviced with asbestos linings. Ue believe that this strategy is consistent with the EPA's intent to curtail the use of asbestos, because these applications for asbestos will subside naturally as the vehicles are retired. In summary, it is essential that the EPA collaborate with the NKTSA on this rulemaking to assure that any change in brake system performance which is made necessary by an EPA rule regarding asbestos usage is consistent with motor vehicle safety needs. It is important that both the content of any rule and any Implementation schedule be responsive to both health and safety needs. Such a joint effort can assure that a potential conflict betwen NHTSA and EPA regulatory requirements will be avoided.