Document KE6NzqGXozo4d8JoBrKpxVRK

FILE NAME Power Generation POW DATE 1975 DOC POW005 DOCUMENT DESCRIPTION Unpublished Conference Presentation 20047 20047 2002 JQ338 JQ338 01832-655885 01832-655885 BOBOLAR BOBOLAR MORGANFINCH MORGANFINCH MORGANFINCH Hunt Paper No. ; a2 257 ia : RIP'RISP'S XVIII INTERNATIONAL CONGRESS BRIGHTON ON OCCUPATIONAL 1975 HEALTH REVIEW OF THE CONTROL OF ASBESTOS PROCESSES IN THE CENTRAL ELECTRICITY GENERATING 50ARD J.A. Bonnell J.R. Bowker R.C. Browne J.F. Erskine R.M.P. Fernandez & P.M. Massey Contral Electricity Courtenay House 18 Warwick Lane London .C.UP .C.UP GEB Generating Board APR 15:59 01892 655085 9.5 F.02 10.0 10.0 01892-601892-6508550158920-68550585 FOBCLARK MORGANFINCH MORGANFINCH MORGANFINCH PAGE 03 The Asbestos Industry Regulations 1931 were limited in their application to specified processes in factories and workshops the so called scheduled processes as defined but it was and it was not clear whether such processes existed at electricity generationg stations assumed that they did not the Case finding in some areas of the middle 1950's suggested that there were country in cases of asbestosis amongst laggers who had been employed in the industry for long periods of time to obtain a clear assessment because It was difficult the pattern of lagging work varied not only from one to another but from one power station part of the to another country but these findings were sufficient to alert the medical services of the industry to the potential problems transient Reports of the association of slight or even exposure to asbestos with the development of mesothelioma of the pleura after a long latent interval resulted in the establishment of a scheme for careful medical surveillance of all persons who were exposed either directly or incidentally to containing lagging material Environmental surveys confirmed the desirability of such a scheme This was introduced in 1962 ard led to the discovery of further cases during the next few years Code of Practice The Dourd were advised by thair medical officers in August 1965 of the serious potential problem of asbestos exposure and they immediately ordered an enquiry into the APR 16:00 01892 655085 F.03 a 910757070065 910757070065 BOBCLARK -MUFGANFINCH -MUFGANFINCH -MUFGANFINCH vey PAGE 04 implications of discontinuing the use of asbestos and the possibility of introducing substitute materials or into other methods of thermal insulation new power stations It was recommended that a Code of Practice be prepared to prevent the formation of airborne asbestos in workplaces occupied by unprotected personnel and for improving the protection provided for personnel working with asbestos A draft code was prepared early in 1966 It was circulated for use on a trial basis during the maintenance period of 1967 and on the experience gained in these trials the Code of Practice was introduced for general use in 1958 The Code defined asbestos stated the nature of the risk to health explained the methods to be employed for protecting staff against airborne dust and outlined the policy for introducing alternative materials Adequate training of all persons was stipulated and all supervisors were to be issued with copies of the code and required to be familiar with its requirements Dust monitoring of the atmosphere was also specified Recommendations were made about working procedures including thorough wetting before stripping operations conumenced stressing the need to prevent the formation of slurry which could dry later and form an additional dust source the removal of dry dust by exhaust ventilation if wetting was not practical and the issue of approved personal protective clothing and equipment For tho removal by stripping of old legging the site of the work must be isolated and its limits defined by the placing of rope barriers together with the posting of adequate warning notices 16:00 The men working inside the roped off 01892 655085 04 BUBULARK MORGANF INCH agit PAGE 05 wns es smn 3 = Jniheybaw e e of men employed inside the roped off enclosure e a are kept to minimum It was accepted that page adoption of the code 1 would slow down the rate of working during stripping operations be required but it was stipulated that by contractual obligations contractors should to conform with its requirements Asbestos thermal insulating materials The maximum temperature to which thermal insulating materials are exposed at power stations 593 1100 A Research and Development programme was commenced to test various commercially available asbestos free thermal insulating materials in 1966 this covered the use of all thermal insulation materials from preformed sections for steam pipework to the application of sprayed mineral wools to turbine cylinders and steam chests The latter process is necessary because of the desirability to obtain evenly distributed insulation the avoidance of hot spots a process which creates a and high level of airborne dust By 1969 a sufficient number of satisfactory alternative materials had shown to be satisfactory the decision been tested and was taken to abandon the use of asbestos containing materials throughout the Board Since this time all contracts for thermal insulating materials used within the CEGB specify that these must be asbestos free The decision was reported the to Industry's National Joint Advisory Council at which the Members and Senior Officers of the Electricity Boards and the Trade Unions consult on all matters concerning health and safety in April 1969. At the APR 16:01 01892 655085 a 4007 BOBCLARK BOBCLARK MOREANF MOREANF INCH FAGE 06 " same meeting to above was . .. the use of the Code also ratified of Practice referred The alternative materials tested have included combinations of various mineral wools artificially produced mineral fibres ceramic fibres and glass fibres silicate with calcium and magnesia Problems were encountered in the early days in finding alternative materials for spraying For ease of identification the asbestos free materials are dyed in distinctive colours 30 that they can be readily recognised Medical Evidence The first case of asbestosis in the industry was reported in 1949 in a man who had been employed as a lagger for 13 years in an old power station in Manchester The pattern of lagging work varied from one power station to another and in many cases was wholly sore carried out by contractors Individual medical officers investigated the health of laggers in the London area in 1956 when 4 cases including one amongst 80 leggers investigated mesothelioma were radiographically reported A similar survey carried out in the North East in 1958 showed that 2 out of 19 laggers had evidence of asbestosis of the lungs both had been exposed for over 40 years A further survey in the Midlands in 1965-66 showed that 3 out of 77 laggors and logger mates with exposures ranging from 8 - 18 years had evidence of mild or moderate asbestosis there was in addition a further case of mesothelioma in this group Since this time there have been 45 cases of asbestosis including 3 cases of bronchogenic carcinoma APR 16:01 01892 655085 Tort otters EDBCLARK MORGANFINCH MORGANFINCH MORGANFINCH PAGE 07 07 shy asin aeynryste! op ae asbestosis amongst CEGB of the incidence of the employees disease only diagnosed after retirement nor is this a measure Many of these cases were Up until the late 1950's studies were aimed at investigating the possible occurrence of asbestosis amongst laggers and laggers mates but as the association of mesothelioma and pleural plaques with brief exposures to asbestos became evident it became clear all the trades involved in maintenance work that virtually at power stations were potentially at risk these included fitters and fitters mates riggers and eranc drivers For this reason it became necessary to establish a prospective study of all asbestos workers One of the problems that immediately arose It was eventually was the decided definition that since of an asbestos worker all work with asbestos containing lagging material should be isolated that areas should be roped off and persons who worked within the roped off area would be classed as asbestos workers They ia cane would require regular medical examination with chest radiography and their names entered in a special register at each power station Regular environmental surveys should be carried out and the air concentrations at the barriers should be kept within the limits recommended by the British Occupational Hygiene Society Standard lagging The history materials and of the control of asbestos containing asbestos related diseases in the uloctricity gonorating industry in England and Wales is an APR 16:02 01892 655085 P.07 [ot we BOBCLARK BOBCLARK BOBCLARK MORGANFINCH MORGANFINCH MORGANFINCH PAGE PAGE 08 i. example excellent excellent example of ; operation it operation operation between . services and management : research medical departments in industry The problem problem dismantling the need for stringent but there still precautions in dismantling remains stripping of old lagging material and Ei group Medical surveillance of those been people who have exposed will continue there are however a of people who having spent number many years working in power stations in various jobs may have been to asbestos dust and it is transiently exposed not possible to identify such individuals and they are not included in the under surveillance One unexpected and gratifying feature of the decision by the CEGB a major user of thermal insulating materials to abandon the use of asbestos containing & lagging materials is the stimulus given to manufacturers to search for alternative materials thus giving an impetus to the use of asbestos free lagging materials in other industries Conclusion in 1 the the The policy adopted for the protection Central Central Electricity Generating Board was of laggers based on finding of alternative asbestos thermal insulating materials and 2 the preparation and imposition of a code of practice for use at power stations where quantities of asbestos lagging materials existed and large APR 16:03 01892 655085