Document r897mwK6DG8nNQ6GMgmdyOoG

FILE NAME: Asbestos Sacks and Bags (ASB) DATE: 1956 DOC#: ASB009 DOCUMENT DESCRIPTION: Annual Report of the Chief Inspector of Factories, Presented 1958 .fto \ r \ U 7 MINISTRY OF LABOUR & NATIONAL SERVICE I / \ ANNUAL REPORT OF THE . CHIEF INSPECTOR OF FACTORIES FOR THE YEAR 1956 s \ t i a 1 Presented to Parliament by the M inister o f Labour and National Service : kf by Command o f Her M ajesty January 1958 II LONDON HER MAJESTY'S STATIONERY OFFICE Cmnd. 329 P R I C E 9J. 6d . NET . r ip uiu' a _XrU; * wti.ch.rui Cl :DENT _ __ _____ 5TO > y * vgw ^S?i-.In-rr/pvy^e7 SET' ' ' : : ' p z * * * ^ & ^ * $ * Li-the Committee newly set up under tho Ramactive Substances A ct ttTdeal Wth the growing problem of radioactive waste disposal;' The Factoryinspector- l*lc-bas responded to appeals by various bodies for advice on tho safety of '(ibibits containing or demonstrating radioactive materials at public exhibitions. 1 During the year the plans for the first commercially built research and training -actor in this country, of the " swimming pool " type, moderated and cooled by lisht water, were submitted to and approved by the Department. The reactor is intended to be " critical " in 1957 and will employ an enriched uranium oxide fuel, containing 20 per cent Uranium 235, giving a maximum power output of j Megawatts. It is o f considerable interest to note the growing number o f well-known insurance companies (three of which consulted the Chemical Branch during ihe year) which have arranged for members of their stalls to make a special study of the problems raised by the increasing use of ionising radiations in factories ind research organisations, with a view to providing any special insurances necessary to cover accident, storage, fire and contamination risks, etc., in which ionising radiations or radioactive material may be an advene factor; these companies have supplemented their normal services to industry by giving advice on the precautions which should be taken to ensure the safety o f workers in this field. The Factory Inspectorate's advisory pamphlet, Form 342, " Precations-in the Use of Ionising Radiations in Industry " has sold-more than 3,500 copies since it was first issued in 1953, and as it has been based on the Draft Regulations, it is not expected that these, when made law, will involve industry in any un expectedly heavy burdens in complying with them. During 1956, as in previous years, a number of institutes, trade associations and private firms used Form 342 u a basis in drawing up detailed codes of practice to cover their own special requirements, and submitted these to the Inspectorate for criticism before putting them into use. I:** CHAPTER 15 i Asbestos Industry Regulations, 1931 Asbestos is used widely in industry on account o f its fire-resisting properties u d fibrous nature, and the Asbestos Industry Regulations apply in almost all factories using the material. The toxic nature o f the dust has led to a search for a less harmful but equally effective material, but it must be admitted that for most uses a suitable alternative f^ ,not been found. Fibreglass has been used in place o f asbestos for insulating "Ulkheads in ships, and a dolomite rock has been used for heat insulation, but jnese are only isolated cases, and there is no doubt that asbestos will continue `0 be used extensively in industry. m afc^c*`t'on to asbestos preparation, asbestos-textile and asbestos-cement sheet ^Hufacturing, the Regulations apply also to such processes as the making of ( cmr 8 compoun.^3>tbc "a f asbestos as fillers in paints and plastics and the i liti kir tr a d in g o f articles containing asbestos. The processes vary cont - e , y* mctbods o f complying with the Regulations take many forms* 1<*l .... 1 A . ft* / I One very hazardous process, to'which the Regulation do not always apply is the removal of old heat-insulation laggingrT he handling o f this very dr) and dusty material presents a serious health hazard, which is all the mon serious because the work is often done in confined spaces. Much o f this wortis done in premises not subject to the Factories Acts, and in any case the operation does not take long. The persons who do it arc, however, regularly engaged on it and are constantly exposed to risk. l As would be expected from the diversity of processes to which the Regulation apply, the premises concerned vary in standard from the best to the very worst. In recent years the large users of asbestos have improved their premises very much, and some smaller firms also have made improvements. There remain, however, some factories in premises where satisfactory compliance with the Regulations is almost impossible. On the whole there has been, as a result of a fuller realisation of the hazard by occupiers, a general improvement both in the premises used and in the standard of compliance with the Regulations. Mechanisation of fibre-handling, which has allowed this part o f the process to be enclosed, has played a large part in making improvements possible. For example, at one of the large asbestos works, very great care has been taken in the design of enclosed plant, which is kept under slight negative pressure. At this works, asbestos, after it has beeh through the disintegrators, is with very few exceptions handled mechanically in enclosed chutes and conveyors, and, as an example of improve ments in the enclosure of plant, recent alterations in the sectional-pipe making plant may be quoted. Loose asbestos is fed mechanically on to the lattice conveyors by which it is carried out, being subsequently damped and moulded round mandrels to form the pipes. The asbestos is still in a dry state when it is fed on to the lattice conveyors, so that this part of the machine is intended to be enclosed and under exhaust draught; the material has, however, to be levelled by hand-raking, so that sliding doors were fitted in the back o f the machine to enable this raking to be done from lime to time. Inevitably the doors were left open and dust escaped; spillage o f loose asbestos also took place, throwing dust into the atmosphere. Recently the back was enclosed by a fixed panel with perspex inspection windows ; in the panel a small hole was left, through which a rake consisting o f a bent, rod could be used with ease. No loose asbestos can now be spilt on to the floor. The opening through which dust might escape is limited to the small hole through which the rod is inserted, and this opening has been shrouded with rubber, thus making the back o f the machine virtually I dust-proof. Occupiers generally are far more aware than formerly of the risk associated with the use of asbestos, as is shown by the large numbers arranging for voluntary medical examination o f their employees. All employees in the industry are, of course, medically examined at regular intervals under the Pneumoconiosis and Byssinosis Board Scheme operated by the Ministry of Pensions and National Insurance, but occupiers like to have reports on their employees at more frequent intervals and some like a pre-employment examination. Usually, clinical examination is supplemented by an X-ray examination, either miniature or fullsize. Very often the examinations are carried out by consultants attached to the local chest clinic. It is reported that at two factories workers are never employed on the more dusty processes for a period exceeding five years, even if they show no signs of asbntosis. N o doubt many other occupiers would lilt change workers periodically from dusty to less dusty processes, but in many lactories the hazard is comparable in all pans, and no advantage would accrue from change of process. 142 v Sk fmp r& jW ! ------------- : - . - V v w - - ^ . - i ^ .^ y g a x B T S ^ a a a a a B a jar~:-rrrrTT:rriaa-rza- f i The'Asbestos Industry Regulations a'rc'dirtctedraljM ^ra6^^toW <^fcc- F 7 f prevention of the inhalation of dust. Unless thematertal'is damp, dustcafli be 7 produced in almost every process covered by the Regulations, although perhaps * the greatest concentrations are likely when the material laorushed and when the f dry fibre is handled. r ,. As indicated above, much can be done to prevent dost from entering the , workroom if all handling is done mechanically in enclosed plant^JAt a large , > asbestos-textile mill the whole of the preparatory processes a n b#hg modified ' ( with this in view. Asbestos is received at the factory from abroad in a partially ' opened state and has to be fully opened, mixed, blended and in some cases crushed as well. One of the main hazards has been at the blending and mixing stage, as a very large proportion o f the asbestos used in the factory is stack- mixed, a type of process common in fine cotton spinning milli. The different kinds o f asbestos arc placed in layers by hand on stacks containing 1,S00 lb. Men using shovels or hand rakes then draw material from these stacks, and let it drop through floor openings to machines below. Exhaust draught is provided, but it is obvious that fine dust cannot be entirely prevented. The new system being installed will eliminate this entirely. Bags o f raw material will be emptied under close exhaust ventilation into mixing drums, which will revolve to give a complete and thorough mix, and at the same time a quantity of oil, which will assist dust suppression, will be added. From the mixing drum the material will be automatically transferred to large hoppers and to willow machine, hammer mills or disintegrators, according to the nature o f the material. From these opening machines, asbestos will be pneumatically fed through trunking to the next process, namely carding. This system has been tried and found to work. It means, in fact, that the asbestos will not see daylight from the moment when it leaves the bag in which it. came to the factory until it is made into rovings on the condenser carding engines. The difference here is the difference between flow production and batch production. The criticism of present methods from the health point o f view is that at several points the material needs to be bagged, weighed and emptied by hand. At each of these points, although close exhaust ventilation may be applied, the operator is near to the open material, and there is spillage, shaking, handling and, therefore, the evolution o f dust. The new methods will also call for less labour, so that a smaller number o f persons will be subject to risk. A further point of interest in the new plant is that provision is being made for diverting some o f the material from the main hoppers to separate bagging points, at which considerable work has been done to provide automatic feed and weighing, so that the operator may come into contact only with the impermeable bag and not with the asbestos itself. ! Regulation 8 (6), envisaging batch processes, requires the use of impermeable sacks for the transport o f asbestos within the factory. In most factories there is good compliance with this Regulation. In some cases rubberised canvas is ,uscd but mostly one finds paper sacks. At one works fine calico sacks were introduced, but though these were much preferable to hessian sacks they could not be regarded as impermeable. Difficulty is sometimes experienced in filling impermeable sacks from hoppers because the air cannot escape through the labnc. Some factories have fitted an " air-balancer ", which allows the air to cscape before the fibre enters. This Regulation does not apply to sacks in which asbestos is delivered to a factory. Most asbestos received from abroad is in Hessian sacks, which do not retain the dust. They are also often tom, and the consequent spillage results in dust entering the air o f the workroom. Many . ^ n p ie r s are trying to get deliveries in impermeable sacks, but so far they have not been successful. The suppliers claim that paper sacks are likely to be i 143 broken in shipping, but judging.by tho experience-with the shipping o f cenici there does not seem to be much foundation for this objection. Factories whic obtain prepared fibre from works in this country can usually obtain i t , bituminised paper sacks. When asbestos fibre is really wet, as in the moulding o f asbestos cement sheet there can be no dust problem. Damping to a lesser extent can reduce th amount o f dust produced, and a number of factories are experimenting on tlies lines. Several firms are now grinding and crushing, both in edge-runner an. roller mills, with the fibre damp. Doubling o f damp yarn is carried out at on mill, where it is hoped in the near future to wind all yarn in a damp condition Experiments are also being made in the weaving o f asbestos cloth from dami yarns. These seem to be proving satisfactory, and one occupier hopes to b doing this regularly in a few years. Owing to the variety o f processes to which the Regulations apply, many type o f exhaust ventilation are found in asbestos factories. Originally some firm relied on cross-ventilation o f the workroom, but in the more modem plant the exhaust is applied close to the origin o f the dust, and better still, mam ingenious developments o f the fume cupboard principle are to be found in thi industry. At one large works the Safety Officer, who for some years has specialised or the exhaust installation, considers that the whole secret o f successful control lit; in applying the exhaust at the point o f origin o f the d u st; once the dust hi; formed a cloud in the atmosphere it is almost impqssible to regain complete control. Wherever possible, plant at this works is totally enclosed and kept under slight negative pressure; where this is not possible, exhaust ventilation is applied on the cabinet or booth principle, the plant being enclosed except for openings necessary for the work. It is often found better to apply exhaust si several points, rather than have one very strong exhaust draught at a single p o in t; for example, in each cabinet over the weighing points where sacks of raw asbestos are emptied into hoppers, there is one exhaust opening at the top to take dust escaping from the bag as it is emptied and other exhaust openings at the bottom to control dust arising from.spillage on to the bottom of thi cabinet. A highly satisfactory standard o f exhaust is reported from an asbestos-cement sheet works. The asbestos is first tipped into the enclosed crushing machine of each unit, and efficient exhaust draught is constantly applied both to the machine itself and to the place near the machine where the sacks are opened. The process o f disintegrating and crushing is continued in an enclosed plant, until the asbestos, in a finely divided state, is discharged automatically into metnl boxes on wheels. This discharge takes place inside a large fume-cupboard type o f enclosure, the door o f which is kept closed until the box is full and ready for withdrawal. The box is then removed and the material tipped into the inclined gridded opening o f the nearby mixing plant. Exhaust draught it constantly applied at the mixing plant, and the tipping arrangements are designed so that there is practically no escape o f dust into the atmosphere. The necessary quantity o f cement is then added. Water is added inside the mixing plant, and the rest o f the process in the manufacture o f the sheets is wet, the machine used for the actual manufacture being similar to a paper-making machine. In the preparation o f cloth, asbestos yarn is often woven with other fibres nr wire. A considerable amount o f dust arises when power looms are used. For special purposes band loom s are still practicable, and with these there is lilt)-' dust formation. The .amount o f dust from looms using chemically treated polished asbestos yarn is also.negligible.. - HA M'.IJjlW '" --"5**& ...... T t w-Tumrrs?*! r ite application o f exhaust ventilation to abloom is* Dust is produced at several parts of the machine and, because constinba^tebfionby the weaver is necessary, it is not practicable to enclose the machine completely jjj a fume cupboard. Although the methods employed vapr from factory to factory, depending upon the type o f loom and the cloth being woven, there is little doubt that there has been a great improvement in the exhaust at looms in jeccnt years. In one instance, the dust is collected by hoods above the cloth at the front o f the loom, and below the warp, both behind and in front o f the sley. At another factory, the top hood at the front o f the loom was adequate, but the dust from the warp threads was not adequately controlled. The firm therefore decided to enclose the warp threads in tunnels with tops o f wired plastic and sides o f american cloth. These allow easy access to the warp threads when necessary, and the dust is carried forward to the front exhaust hood. At another works, exhaust is applied at the fell o f the cloth and also at the shuttle boxes. i ." v. [ "'r s' For the making of asbestos mattresses, the ventilation has to be approved by the Chief Inspector, and it has been found that the larger factories work well within the limits o f the approvals. Here again, the exhaust arrangement is mostly o f the fume-cupboard type. In smaller factories too much work is sometimes taken on, when the exhaust ventilation becomes ineffective. At this type of works the manufacture o f mattresses is often intermittent, and control of conditions by Inspectors is difficult. Regulation 3 requires, in addition to the provision o f exhaust ventilation, that covers o f mattresses, benches and floors should be kept damp where the making or repairing of insulated mattresses is carried on. Compliance with this is extremely variable, depending, it would appear, very much upon whether a fine rose for distributing the water has been supplied. There appears to be considerably less beating o f mattresses than T cfolortmhefrolyr.minTgheonmeossitdeusoufalthme emthaotdtreosfs,mthaennuftaoctauprpe liys tthoe soptrheeardsifdibereanodvesrtitthche round the edge. This removes one o f the greatest hazards associated with mattress making. ' 3? At almost all factories subject to these Regulations the dust-separating plant is situated in the open air or in a ventilated room separate from the workrooms. In many cases mechanical shakers are provided for bag filters, the hazardous process o f manual shaking thus being eliminated. Breathing apparatus as required by Regulation 10 is normally provided by the factory occupier. This invariably takes the form o f an approved dust respirator, rather than a helmet or facepiece with air-line, probably because the respirators allow the wearers greater freedom. It would appear that the respirators are reasonably comfortable, since little difficulty is experienced in getting workers to wear them. CHAPTER 16 Chromium Plating Regulations, 1931 The processes covered by the Chromium Plating Regulations include the electrolytic deposition o f chromium on metal articles and the oxidation o f metals, usually aluminium, by electrolytic methods. These processes are used widely in industry to produce both protective and decorative coatings. Much o f the decorative work is done in small factories, often housed in old premises. Inspectors report that even in these premises there is, on the whole, > re*nable compliance with the Regulations, although maintenance o f good 145