OH&ES Technical Bulletin

Transcription

1 OH&ES Technical Bulletin ASBESTOS INTRODUCTION This Technical Bulletin contains information on Asbestos, it s health effects, and where it may be present in buildings. This bulletin also covers current Health and Safety Legislation (to 1 June 2004), what to do if you suspect you have asbestos, and the requirements of a Respiratory Protective Equipment (RPE) programme for protection against asbestos. This Bulletin provides general guidance only. Appropriate specialist advice should always be sought where necessary. For major asbestos removal work, the Health & Safety Executive (HSE) should be contacted for help and their list of licensed asbestos removal contractors in your area. WHAT IS ASBESTOS? Asbestos is the name given to a group of six different naturally occurring minerals. Asbestos deposits are found throughout the world and are still mined in Australia, Canada, South Africa, and the former Soviet Union. Asbestos differs from other minerals as it is in the form of long thin fibres. Asbestos fibres are very strong and are resistant to heat and chemicals. It is also very stable in the environment and asbestos fibres are not broken down over time. Asbestos is divided into two mineral groups: Serpentine and Amphibole. Serpentines have a sheet or layered structure while Amphiboles have a chain-like structure. Serpentines - Chrysotile (white asbestos). Amphibole - Amosite (brown asbestos), Crocidolite (blue asbestos). The other three types of Amphibole asbestos are Anthophyllite, Tremolite, and Actinolite. Asbestos Material As a result of its physical and chemical properties of temperature, chemical and fire resistance it was used in a wide range of products. From the 1940 s to 1960 s it was used extensively, but not exclusively in the following building products: Spray coating on steel work, concrete walls and ceiling for fire protection and insulation. Insulation lagging in buildings and factories, on pipework, and for boilers and ducts. Asbestos insulating board used as wall partition, fire doors, ceiling tiles, etc. Asbestos cement products such as walls and roofs, tiles, cold water tanks, gutters, pipes and in decorative plaster finishes. Asbestos was also used in bitumen, plastic, resin and rubber products. Effects of Asbestos Exposure Exposure to asbestos in certain circumstances can lead to 3 incurable diseases: Asbestosis. Lung cancer. Mesothelioma of the pleura or peritoneum. 1 3

2 Asbestosis Asbestosis is defined as fibrosis of the lungs caused by asbestos dusts. The symptoms are shortness of breath and cough. The disease is difficult to diagnose in its early stage as there is no sharp point in the development of signs and symptoms at which it can be said that a change in state from healthy to diseased has occurred. Clinical diagnosis is therefore a matter of judgement. Asbestosis develops slowly. Gross asbestos exposure which occurred in the past seldom caused death in less than 10 years. With decreased exposure normally no person with otherwise healthy lungs should die of Asbestosis as they would not develop significant disability before reaching the age where they are likely to die of other causes. Lung Cancer Individuals who smoke and are exposed to asbestos have a greater risk of developing lung cancer than non-smokers who are exposed to asbestos. Individuals who smoke and are exposed to asbestos may significantly reduce their risk of lung cancer by stopping smoking Mesothelioma Mesothelioma is a cancer of the lining of the lung (pleura) or the stomach (peritoneum) mostly caused by asbestos exposure. Mesothelioma seldom occurs within 15 years of exposure. Increasing exposure increases the risk of developing the disease but does not affect the length of the induction period which may be 30, 40 or 50 years. Mesothelioma is unaffected by smoking, but appears to be strongly dependent on the type of asbestos exposure, primarily Crocidolite (Blue). Asbestos Exposure Limits Personal exposure must be prevented or where that is not reasonably practicable reduced to the lowest level that is reasonably practicable. The Control of Asbestos at Work Regulations (CAW) 2002 sets two types of exposure limits, Control Limits and Action Levels. Control Limits There are two Control Limits (CL), one based on an average fibre level over a 4 hour continuous period, the other is the average fibre level over a 10 minute period. The CL to be applied depends on the type of asbestos present. One CL exists for exposure to Chrysotile alone, and the other for other forms of asbestos or mixtures of asbestos which contain Chrysotile. CL are expressed as fibres per millilitre of air (f/ ml). If personal exposure exceeds either of the control limits, 4 hours or 10 minutes, then suitable RPE must be used and the areas designated Respirator Zones, areas where it is mandatory to wear RPE. Table 1 presents the CL. TABLE 1 ASBESTOS CONTROL LIMITS Asbestos Type 4 hour Exposure Period 10 minute Exposure Period (f/ ml) (f/ ml) Chyrostile Other asbestos forms* *: Asbestos other than Chrysotile, or mixtures of asbestos which contain Chyrostile 2

3 Action Levels Action Levels (AL) refer to exposure to asbestos which has been accumulated over a 12 week period, and are expressed as fibre-hours per millilitre of air (fibre-hours/ml). The AL are: Chrysotile alone: 72 fibre-hours/ ml. Exposure to any other form of asbestos either alone or in mixtures including mixtures of Chrysotile with any form of asbestos: 48 fibre-hours/ml. Where both types of exposure occur separately during the 12 week period concerned, a proportionate number of fibre-hours/ ml or air. The third AL applies only when two types of exposure occur at different times during the 12 week period. If both types of asbestos are present then the mixture must be treated if not chrysotile alone. If the AL are exceeded then the HSE must be notified, the area must be designated an Asbestos Area and Medical Surveillance carried out for those individuals exposed. Who is at Risk from Asbestos Exposure? Individuals at risk from asbestos exposure are those carrying out maintenance, repair or refurbishment work in buildings built or refurbished before 1985, for example, carpenters, shopfitters, plumbers, electricians, cable installers. ASBESTOS LEGISLATION The main pieces of Legislation which cover the control of asbestos are: Health & Safety at Work 1974 Requires an employer to make sure that the work that they undertake does not exposure employees or people at work other than employees e.g. contractors, visitors, to health and safety risks. Management of Health & Safety at Work Regualtions 1999 Requires employers to conduct a risk assessment to ensure their employees and other people who step foot on their workplace, are protected from health and safety risks. Construction (Design & Management) Regulations 1994 Requires the client to provide information about the state of premises that might contain asbestos to the planning supervisor (before any work begins) and to keep an up to date file on this information. Control of Asbestos at Work Regulations 2002 Requires employers to prevent and control exposure of employees to asbestos to levels as low as reasonably practicable. This was laid before parliament on 31 October 2002, came into force 21 November An additional Regulation 4 came into force on 21 May This additional duty to manage regulation requires employers to: Take reasonable steps to assess their buildings to be able to identify materials that might contain asbestos. If they are not sure whether asbestos is present, they should assume it is present unless they have strong evidence to suggest that asbestos is not present. Make a written record of the location and condition of materials which contain asbestos, to keep this record up-to-date and to make these records available to all who may come into contact with these materials. Assess the likelihood of whether employees may get exposed to asbestos. If asbestos is in bad condition, to repair or remove this using licensed removers. Monitor the condition of asbestos containing materials (ACM s) and review the records on a regular basis. 3

4 RESPIRATORY PROTECTIVE EQUIPMENT CAW states that employers shall prevent exposure to asbestos. Where is not reasonably practicable to prevent exposure, it must be reduced to the lowest level reasonably practicable with the use of Respiratory Protective Equipment (RPE). However, if despite the use of control measures, personal exposure is still likely to exceed the CL, employers must provide suitable RPE to reduce exposure to the lowest level reasonably practicable, and in any event below the CL. Selection of RPE The RPE selected must be suitable for the wearers and the work to be undertaken, the environment and the anticipated maximum exposure. Factors Affecting Performance of RPE Face size and shape: facial features tend to vary with build, ethnic origin and sex. For tight fitting facepieces an effective seal between the face and respirator is essential - without it the respirator will not give adequate protection. Facial characteristics: Facial hair (beards and side burns) and spectacles interfere with seal and reduce the effectiveness of filtering respirators. Work rate and the work environment: Heat can build up which may cause the wearer to loosen the RPE. Sweat can also cause the faceseal to slip. Medical fitness: Individuals with cardiovascular problems or asthma may find it difficult to draw air through a filtering respirator. Visibility, Mobility and Communication: important issues to consider. Compatibility with other forms of Personal Protective Equipment. Quantitative Fit Testing The CAW Approved Code of Practice (ACoP) states that for respirators that require a good contactbetween the wearer s skin and the face seal of the mask initial selection should include Quantitative Fit Testing (QNFT). Examples of these 3M respirators include: Filtering Facepieces - 3M 9332/3M 8835 (EN149 Class FFP3). Half Mask Respirators - 3M 6000 or 3M 7000 Series or 3M 7500 Series. Full Face Mask Respirators - 3M 6000 or 3M 7000 Series. Full Face Mask Positive Air Pressure Respirator (PAPR) - 3M PowerFlow Plus. QNFT may be undertaken in two ways: Carried out in an enclosure into which standard aerosols of sodium chloride or sulphur hexafluoride gas are introduced and maintained. Using an ambient particulate counting device. QNFT should be repeated if there is a change in RPE model or if there has been a significant change to the facial characteristics, e.g., significant weight loss/ gain, or loss of dentistry. 4

5 TABLE 2: SUGGESTED 3M RESPIRATORY PROTECTIVE EQUPIPMENT FOR PROTECTION AGAINST ASBESTOS Asbestos Abatement & almost continuous exposure to Asbestos Suitable RPE/3M RPE Products Tight fitting facepiece + PAPR 3M Powerflow Plus (shown opposite) Tight fitting facepiece + SA or SCBA Contact 3M for advice Frequent, long term exosure to asbestos contaminated air Tight fitting facepiece + PAPR 3M Powerflow Plus Supplied Air 3M Visionair 3M S200 + Full Face Mask (shown opposite) Infrequent, short term exposure to low-level asbestos contamination Filtering facepiece (EN149 class FFP3) 3M 9332 (shown opposite) 3M 8835 Notes: PAPR - Powered Air Purifying Respirators SA - Supplied Air SCBA - Self Contained Breathing Apparatus P2/P3 - Particulate Filter (EN143) Half mask + P3 filter 3M 6000 Half Face Mask + 3M 6035 Filter (P3) 3M 7000 Half Face Mask (shown opposite) + 3M 6035 Filter (P3) Full Face Mask + P3 filter 3M 6000 Full Face Mask + 3M 6035 Filter (P3) 3M 7000 Full Face Mask + 3M 6035 Filter (P3) Powered Air 3M Dustmaster + P3 Filters 3M Jupiter (shown opposite) + P3 filters 5

6 Information, Instruction & Training Employers are required to provide information, instruction and training to employees who may be exposed to asbestos. This must be carried out to ensure that employees achieve the Assigned Protection Factor (APF) when wearing the RPE. For detailed information on what should be included for to meet the requirements of CAW please refer to, The Control of Asbestos at Work Regulations or the HSE. For information on what should be covered in an RPE training programme please contact the 3M Health and Safety Helpline (UK: Eire: ) 3M RPE Asbestos Selection The current 3M policy on the selection of RPE for use against asbestos in different concentrations is based on 3 categories of exposure: Asbestos Abatement and almost continuous exposure to Asbestos Wet or dry stripping and removal of asbestos. Other peripheral activities carried out by other people working in the abatement environment or in industries/environments where levels of asbestos similar to those found in abatement are present at any time. Frequent, long term exposure to asbestos contaminated air Daily exposure >4 hours. Likely to be in industries where asbestos is processed or used in processes or in building construction works. Infrequent, short term exposure to low-level asbestos contamination. Weekly exposure < 4 hours. Likely to be in areas where residual asbestos is present (verified by measurements). Infrequent use in building and construction. Handling/working with non-friable asbestos products. Table 2 presents the 3M guidance for use of RPE in each of these situations. 5.0 Further Information Information and advice on Asbestos may be obtained from the HSE, Tel: or visit For information on 3M RPE please contact the 3M Health and Safety Helpline (UK: Eire: ). 6 Occupational Health and Environmental Safety Group 3M United Kingdom PLC 3M Ireland 3M Centre, 3M House, Adelphi Centre Cain Road, Bracknell Upper Georges Street Berkshire, RG12 8HT Dun Laoghaire, Co. DUBLIN CHASBESTOS 11/04