Document xj5m35a2GGkng8YJb3Rggy20y

FILE NAME Colonial Sugar Refinery CSR DATE 1951 Nov 2 DOC CSR164 DOCUMENT DESCRIPTION Govt Memo RE Inspection Results for Asbestos Hazard at Wittenoom Gorge Ne men ee 19 ee. ; at oat stele . PLAINTIFF'S EXHIBIT 102710 102710 es, -t State Mining Engineer Mines Department PERTH 58 KALGOORLIE 2nd November 1951 Asbestos Hazar~ Wittenoom Gorge In reply to your letter 818/51 It is of interest to know that the upper permissable limit 176 - of asbestos dust for a working atmosphere is p.p.e.a. limit It has been understood that the permissable of silica dust for a working atmosphere is 300 p.p.o.c. I imagine that this limit still holds . An average of the samples taken both in the treatment plant . and underground gives a dust count of 307 p.p.c.c. which is just over the permissable limit if the particles are all silica This high count may be accounted for by the fact that ventilating appliances were not being correctly used and that broken ore was not being watered . My report states On examination of the dust samples both from underground and the treatment plant the amount of fibre visible is very small Some samples appear to have no fibre present and an estimate of the fibre present in the _ sir would be very difficult to make I paid particular attention to the semplee examined in order to arrive at an estimate of the amount of fibre present but came to the conclusion that the greater proportion of the particles were silica However Dr. Henzell states that many long fibres may have been excluded from the count because of their reluctance to enter a machine of the Watson Konimeter type This may account for the absence of fibre in the samples but it would be advisable to take a number of samples of the air underground ~ and in the plant to determine the percentage of fibre present It may be possible to make this sample by means of the sugar tube test or a tube packed with cotton wool The Goverment Analyist should be able to advise on this matter) Or possibly the Filter Paper sampler as used for Aluminium powder concentration could be used for this purpose A sample of the air could be drawn through the Sampler and the fibre and dust retained on the filter paper which could be submitted ; for analysis There is certainly little if any boring done in the fibrous material but after the face has been fired and bogging and scraping operations are in progress much fibrous material could enter the ventilation system The enforcement of the use of plenty of water in the mine and the consequent need for a drying procese in the treatment plant is en urgent necessity