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Guidance Note EH 31 from the Health and Safety Executive Control of exposure to polyvinyl chloride dust Environmental Hygiene 31 (May 1982) These Guidance Notes are published under five subject headings: Medical, Environmental Hygiene, Chemical Safety, Plant and Machinery and General. A*JjriUi 8 Blends of PVC and nitrile rubbers (polyacrylonitrile/ butadiene) are used to make rubber items such as hose, auto motive seals, shoe soles, cable covers, etc., where the product requires good resistance to oils and the ability to withstand atmospheric attack. INTRODUCTION 1 This Guidance Note draws attention to the possible health risks which could result from exposure to polyvinyl chloride (PVC) dust. 2 The Health and Safety Commission's Advisory Committee on Toxic Substances has recommended that, in line with the Commission's general policy: (a) exposure to PVC dust should be kept as low as is reason ably practicable; (b) in any case exposure should not exceed lOmg/m3 for total PVC dust in air and 5mg/m3 for respirable PVC dust in air. EFFECTS OF EXPOSURE 9 Over the past decade attempts have been made to evaluate the toxicity of PVC dust which have involved 'in vitro' studies and studies on both animals and humans. In some studies on humans the effects of exposure to PVC dust were complicated by concurrent exposure to vinyl chloride monomer. Never theless, there is evidence1 to indicate that PVC dust alone may be associated with respiratory dysfunction and radiographic changes and in one report2 the possibility of an excess of lung cancer in exposed workers has been raised. The studies do not indicate the concentration of dust to which individuals had been exposed and consequently it is not possible to relate the specified effects to the degree of exposure. 3 The effects of exposure to PVC dust are referred to in para 9 and advice is given on assessment and control in paras 10 to 13. Methods of sampling and measurement are described in paras 14, 15 and the Appendix. MANUFACTURE AND USE ' 4 PVC is manufactured in the form of a white powder which ' softens at about 80 degrees centigrade. Before PVC is fabri cated, various materials such as stabilisers, plasticisers and antioxidants are added. 5 It is manufactured from vinyl chloride monomer (VCM) mainly by a process in which liquified VCM in the form of a stirred suspension or emulsion in water is polymerised in the presence of an initiator which causes the VCM to polymerise. All PVC polymers contain traces of other reagents used in the polymerisation process to control the size and structure of the particles, e.g. emulsion polymers contain small quantities of emulsifying agents. 6 In its unplasticised form PVC is hard, tough, strong and has good chemical resistance. It is used fora wide variety of construction, domestic and engineering products including pipes, ducts, tanks, bottles and protective claddings. ADEQUATE CONTROL OF EXPOSURE 10 Where exposure to PVC dust cannot be avoided, control should be achieved by material, plant and process controls or other suitable control techniques supplemented where necessary by the wearing of suitable respiratory and other personal protective equipment. 11 Personal exposure should not exceed 10 mg/m3 for total PVC dust in air and 5 mg/m3 for respirable PVC dust in air, 8 hour time-weighted average concentrations, and should be further reduced where reasonably practicable. Inspectors will use these exposure limits when assessing compliance with the HSW Act and relevant statutory provisions. ASSESSMENT OF WORK 12 Work involving PVC should be assessed in order to identify sources of dust, to determine the levels of exposure and to identify any necessary improvement to existing controls or the provision of new controls. The work should be re assessed whenever changes are introduced which significantly affect the material, plant or process controls. 7 In its plasticised form it is more flexible and is used as an insulation material for electric wires, as a coating for various textile products and for many other applications. 13 In practice exposure to PVC dust in manufacturing or in user industries is most likely to arise during the following operations: BFG07913 TOOITG (a) drying and screening, including cyclones, (b) handling, transfer and despatch operations, (c) bagging and weighing, (d) bag opening and powder transfer, (e) batch weighing, (f) mixing and blending, (g) finishing of PVC articles. REFERENCES 1 Soutar C A et al (1980) `Epidemiological study of respiratory disease in workers exposed to polyvinyl chloride dust' Thorax 35, pp 644-652. 2 Waxweiler, R J et al (1978) XIX International Congress on Occupational Health, Dubrovnik. SAMPLING AND MEASUREMENT 3 Hamilton R J & Walton W H (1961) in 'Inhaled Particles and Vapours' (Ed. C N Davies) pp 465-475 (Pergamon, Oxford). 14 Where the information available on the levels of exposure to PVC dust is not sufficient for the work to be properly assessed, or where exposure may be in excess of the limits referred to in para 2, the airborne concentration to which persons are exposed should be measured in order to: 4 Orenstein A S (Editor) (1960) `Recommendations adopted by the Pneumoconiosis Conference', Proceedings of the Pneumoconiosis Conference Johannesburg, 1959, pp 619-621 (Churchill, London). (a) verify whether the 8-hour time-weighted average con centration of PVC dust in the breathing zone exceeds these limits on a given occasion, and (b) monitor the effectiveness of material, plant and process controls. 15 The sampling strategy should be determined having regard to the nature of the work and the duration of exposure. The results obtained should be representative of personal exposure averaged over an 8-hour period. The measuring methods used by HSE for sampling total and respirable dust are described in the Appendix. FURTHER INFORMATION This Guidance Note is produced by the Health and Safety Executive. Further advice on this or any other publications produced by the Executive is obtainable from Baynards House, 1 Chepstow Place, London W2 4TF, or from Area Offices of the HSE. STATUTORY REQUIREMENTS 16 No specific regulations have been made under the Factories Act 1961 or the Health and Safety at Work etc Act 1974 to deal with exposure to PVC dust but control is required under the requirements of Section 2 of the HSW Act and Sections 1, 4 and 63 of the Factories Act. BFG07914 N O CD K* *=* O O is) APPENDIX: SAMPLING AND MEASUREMENT 1 The techniques in current use by the Health and Safety Executive for measuring time weighted average concentrat ions of "respirable" and "total" PVC dust in the breathing zones of persons at work are described below. In both cases, use is made of personal sampling equipment consisting of a filter holder, worn high on the person's chest (e.g. attached to lapel) within 30cm of his nose-mouth region. The filter holder is connected to a battery operated portable pump which is attached to a belt worn around the waist and which is capable of running continuously for 8 hours. Respirable dust sampling 2 The equipment used for respirable dust sampling consists of a cyclone type filter holder fitted with a pre-weighed glass fibre filter (either 25mm or 37 mm diameter) and connected via a flow smoother to either a vane type pump or a diaphragm type pump. The design of the cyclone type holder and the sampling flow rate are such that only the respirable fraction of the dust, as defined by the Medical Research Council3'4' reaches the filter. Total dust sampling 3 The equipment used for total dust sampling consists of a multi-orifice filter holder, as illustrated below, fitted with a pre-weighed, 25mm diameter, glass fibre filter. The filter holder is connected via a flow smoother to a vane type or diaphragm type pump. The pump flow rate is maintained at 2-0 litres/min. The filter holder is attached to the wearer in such a way that the orientation of the filter is close to the vertical plane. Air sample volume 4 For each sample obtained by the use of an unstabilised pump, the flow rate is checked, and adjusted if necessary, against an external flowmeter at the beginning and end of the sampling period and at 1 hourly intervals during sampling. The sample volume for each interval is calculated by multi plying the average of the flow rates at the beginning and end of the interval by the interval duration (in minutes). The total sample volume, V, (m3) is then given by the sum of the volumes for these intervals. Where a stabilised-flow pump is used, the sample volume, V, is given by the flowrate (checked against an external flowmeter) multiplied by the sampling period. Filter weighing and calculation of TWA concentrations 5 Filters are re-weighed after use on an electro balance capable of reading to lOpg to obtain the weight, W, (mg) of dust collected (after treatment to allow for humidity effects). The average concentration of dust for the sampling period, in mg/m3, is then given by dividing weight W by volume V. Exhaust port for connection to pump Filter support grid Filter (glass fibre) 25 mm dia End cap with seven equispaced inlet holes, 4 mm dia BFG07915 N O C O 3 CO 3 GUIDANCE NOTES General Series GS 1 GS 2 GS 3 GS 4 GS 5 GS 6 GS 7 GS S GS 9 GS 10 GS 11 GS 12 GS 13 Fumigation using'methyl bromide Metrication of construction safety regulations Fire risk in the storage and industrial use of cellular plastics Safety in pressure testing Entry into confined spaces Avoidance of danger from overhead electrical lines Accidents to children on construction sites Articles and substances for use at work -- guidance for designers, manufacturers, importers, suppliers, erectors and installers Road transport in factories Roofwork: prevention of falls Whisky cask racking Effluent storage on farms Reporting of accidents to pupils and students Chemical Safety Series CS 1 CS 2 CS 3 CS 4 CS 5 CS 6 Industrial use of flammable gas detectors The storage of highly flammable liquids Storage and use of sodium chlorate The keeping of LPG in cylinders and similar containers The storage of LPG at fixed installations The storage and use of LPG on construction sites Plant and Machinery Series PM 1 PM 2 PM 3 PM 4 PM 5 PM 6 PM 7 PM 8 PM 9 PM 10 PM 13 PM 14 PM 15 PM 16 PM 17 PM 18 PM 19 PM 20 PM 21 PM 22 PM 23 PM 24 PM 25 PM 26 PM 27 PM 28 PM 29 Guarding of portable pipe-threading machines Guards for planing machines Erection and dismantling of tower cranes Safety at high temperature dyeing machines Automatically controlled steam and hot water boilers Dough dividers Lifts Passenger carrying paternosters Access to tower cranes Tripping devices for radial and heavy vertical drilling machines Zinc embrittlement of austenitic stainless steel Safety in the use of cartridge operated tools Safety in the use of timber pallets Eyebolts Pneumatic nailing and stapling tools Locomotive boilers Use of lasers for display purposes Cable-laid slings and grommets Safety in the use of woodworking machines Mounting of abrasive wheels Photo-electric safety systems Safety at rack and pinion hoists Vehicle finishing units: fire and explosion hazards Safety at lift landings Construction hoists Working platforms on fork lift trucks Electrical hazards from steam/water pressure cleaners etc. Medical Series MS 3 MS 4 MS 5 MS 6 MS 7 MS 8 MS 9 MS 10 MS 12 MS 13 MS 15 MS 16 MS 17 MS 18 MS 19 MS 20 Skin tests in dermatitis and occupational chest disease Organic dust surveys Lung function Chest x-rays in dust diseases Colour vision Isocyanates - medical surveillance Byssinosis Beat conditions and tenosynovitis Mercury - medical surveillance Asbestos Welding Training of offshore sick-bay attendants (`rig-medics ) Biological monitoring of workers exposed to organo phosphorus pesticides Health surveillance by routine procedures The control of lead at work: medical surveillance Pre-employment health screening Environmental Hygiene Series EH 2 Chromium - health and safety precautions EH 4 Aniline - health and safety precautions EH 5 Trichloroethylene: health and safety precautions EH 6 Chromic acid concentrations in air EH 7 Petroleum based adhesives in building operations EH 8 Arsenic - health and safety precautions EH 9 Spraying of highly flammable liquids EH 10 Asbestos - hygiene standards and measurements of airborne dust concentrations EH 11 Arsine - health and safety precautions EH 12 Stibine - health and safety precautions EH 13 Beryllium - health and safety precautions EH 14 Level of training for technicians making noise surveys EH 15/80 Threshold limit values EH 16 Isocyanates: toxic hazards and precautions EH 17 Mercury - health and safety precautions EH 18 Toxic substances: a precautionary policy EH 19 Antimony - health and safety precautions EH 20 Phosphine - health and safety precautions EH 21 Carbon dust - health and safety precautions EH 22 Ventilation of buildings: fresh air requirements EH 23 Anthrax: health hazards EH 24 Dust accidents in malthouses EH 25 Cotton dust sampling EH 26 Occupational skin diseases: health and safety precautions EH 27 Acrylonitrile: personal protective equipment EH 28 Control of lead: air sampling techniques and strategies EH 29 Control of lead: outside workers EH 30 Control of lead: pottery and related industries EH 31 Control of exposure to polyvinyl chloride dust ) ) R.UTTB0S HMSO 50p net ISBN 0 11 883541 6 Crown copyright 1982 First published 1982 Printed in England for Her Majesty's Stationery Office by Robendene Ltd., Amersham Dd 023082 Cl 10 5/82 A BFG07916