Document 8dGzqMnxXvGbevKZKRZDrznB

AIA-120 \ / ( COBRA High Friction Composition Brake Shoes _________ 'Environments! Safety This is in response to your request for information concerning possible . environmental hazards that could result from the use of COBRA Cooposition Brake Shoes. Investigations we have conducted offer reasonable assurance chat COBRA brake ahoes do not pose an environmental hazard to aicher personnol handling them or personnel in close proximity to the point where they are utilized during braking operations. Specific actions that we have taken to insure the environmental safety of COBRA brake shoes are as follows: . . 1. A certain amount of asbestos fiber is included in Che composition materiel end becking stock of each COBRA brake shoe. During the manufacturing process, the asbestos and other materials are molded into a hard block of friction material which la bonded to a steel backing place. AC this point, the asbestos is effectively contained within the friction material. As a further protection, the entice brake shoe is dipped in a saalant which will prevent any loose asbestos particles becoming airborne during handling of the brake shoes. The sealant also restricts rusting of the backing plate dur ing outside storage and provides Che distinctive "red" shoe color. 2. We have been questioned by various gtoups and individuals concerning the amount of asbestos fiber released by COBRA brake shoes during braking action. To be able to answer these questions, we ran an elaborate series of dynamometer tests in 1971 during which all the wear dust from various types of braking cycles was collected and analyzad. The results of these tests show that almost all of the asbestos fiber is decomposed during brake applications. Less than one percent of the original asbestos fiber in the shoe remains as fiber in the wear dust and less than one tenth of that becomes airborne. Since each stop WllTINGMOUJl AIK IRAKI COUfAMX m J**fcaaf JOHN:l*MAV!LU COA P-0* AIA-120 wear* only a very small amount of material from each shoe, and since each shoe contains only a very small percentage of asbestos fiber, it can be seen that the amount of asbestos fiber that becomes air borne with each stop is not significant. 3. During the same period of investigation covered in 2 above, possible toxicity of gases liberated by COBRA9 brake shoes during braking was also given attention. Scop and drag tests were performed and samples of gases given off during braking were collected by a technician from an independent testing laboratory. The samples were subsequently analyzed and the results reported. Results showed that the COBRA9 brake shoes gave off no extremely toxic materials, and only small amounts of hydrocarbon gases. It was concluded that no amounts of harmful gases sufficient to be injurious to health were liberated. . . *- 4. The original COBRA9 brake shoe composition also contained lead. All shoes manufactured since November'1975 have utilised a lead-free com position. The primary reason for this change was to eliminate lead from our plant environment for the protection of. manufacturing employees exposed to the raw material. . 5. In early 1977, WABCO, in cooperation with Johns-Hsnville research persannell, conducted a series of eir sample tests in the Boston Svibway in an offort to capture chrysotlle fiber during train operations. Samples were taken between Che cars near Che Crack level, in Cha passenger and mocorman's area, and on the platforms over a 10 hour period of highest density operation. No significant fiber counts were seen on any of the filters. 6. In 1978-79, we developed and have in locomotive and mass transit ser vice a COBRA9 Composition Brake Shoe which contains neither asbestos or lead in the friction material. We trust the above information will provide answers to questions that may Arise as to the environmental characteristics of COBRA9, brake shoes. Please let us know If any additional information is required. Sincerely yours. EVK/J E. W. Kojsza J \ Manager-COBRA9 Shoe Sales