Document JrB38qrZ2N1oapzxGVBqydwvv

ing those tosis Re* lg on the 2 devoted & Parkes n formed ustomers id service \ists and, i premises .'S, by the own Gust surement. to be eniiitenance. determine :: .of dustaring two h will- be ee of bulk to those r is for the to remind .'commend nieve what stosis Re safe level, trol over a d types of the health T surfaceff in hand- he country i w ith, and . in service i-'ible with Asbestosis i X Ann. Oceup. Hyg. Vol. 13. pp. 33-36. Pcrgamon Pres* 1970. Printed in Great Britain REMOVING DUSTS FROM BRAKE ASSEMBLIES DURING VEHICLE SERVICING- ALTERNATIVE CLEANING METHODS* G. L. Lee British Leyland, Longbridge, Birmingham PRELIMINARY CONSIDERATIONS Whatever the criticisms may be from an occupational health point of view, few would deny that the operation of removing brake dusts with an air line is efficient in that the total time to perform the task is extremely short. The time required to perform an operation is of vital importance in industry and any process changes will always be judged relative to the time scale. In addition, the effort required from an operative in using the method should be minimal and it is easy to see that the chances of de veloping a technique of cleaning which will reduce dust emissions but at the same time require no more time and effort are extremely slim. Quite clearly, we must concede from the very beginning that some increase in time and effort involved is inevitable. When viewed under normal lighting conditions, the result of applying a com pressed-air line to remove brake dusts is very dramatic. Unfortunately, mere dramati sation alone is not adequate to describe the emission of dust from a process; more objective methods are needed. The conventional method of evaluating an environ mental condition is the measurement of the appropriate parameter (in this case-- fibre counts), referring the results to hygiene standards. In experimental work to evaluate dust control methods, simpler, "relative" techniques of measurement have considerable advantages and part of this work is concerned with applying a fairly simple method to define certain environmental conditions which prevail when brake dusts are removed by blowing out with a compressed air line and comparing these with the conditions obtained when a dust control technique is applied. Because the method is a relative one, care Co prevent errors from extraneous sources of variation is important. These sources of error are discussed later. METHODS USED TO EXAMINE ENVIRONMENTAL CONDITIONS When dusts are released in relatively small quantities it is often impossible to see the clouds under normal lighting conditions. They can be made visible using the Tyndall Beam effect and this has been employed extensively during the experimental work. This paper was originally presented at a Conference on Exposure to Asbestos during Brake and Clutch Maintenance, held at Brentwood, Essex, March, 1969. 33 0*