Document Z7D7gZNk0r3g4YGqbOxVKdQd

Aht Associates, Inc. -4- December 28, 1977 Page 42 Again the illustrations are for brake drums or lining for drum type brakes. It might be well to have an illustration of someone standing and vacuuming the dust from the disc brake assembly on the car. Page 43 Again it is stated that the worst offender among brake shop operations is blowing the dust out of drums. I agree that this is a common practice that should be discontinued. However, the wording should also refer to disc brakes and my comments on page 37 still apply. There is another item on page 43 which 1 question. The draft states that brake linings also contain silica which can cause lung disease and lead which harms the nervous system. The sentence is not correct because brake linings do not necessarily contain silica or lead. While it is true that some brake linings may contain silica and some may contain lead it is most likely that the majority of brake linings commercially used today do not use either silica or lead. Page 45 The draft states: "Do not use for cleaning brake drums, surfaces, or equipment." It is referring to compressed air nozzles. Again, the specifying of '"brake drums" is not proper because mechanics not only use compressed air for blowing out disc brake assemblies but they also use it for blowing out the backing plate assemblies on drum brakes. If such a label is to be used it should read "Do not use for blovr ing out dust from brakes, drums, discs, rotors or calipers," or some other word ing to this effect. Page 47 Again the draft states: "The first thing the workers should learn is the proper way to clean out brake drums." Again, the emphasis is on brake drums which are now being superseded by disc brakes* It might also be suggested that shops could remove the dust from brake drums by taking them directly to a workbench and tapping out dust on old newspaper which could then be wrapped and put in disposable plastic bags. This would be prior to the washing out with a wet rag. Page 65 The draft states that the monitoring tests must be done at least every six months. It is my understanding that the monitoring should be done at least every six months where asbestos concentrations can be expected to exceed the 2 fibers per cc limit. If experience in earlier monitoring and in the introduction of good work practices indicates that the concentrations would not be above 2 fibers per cc, I question whether monitoring must be done "at least every six months." SPNY 004743