1 Page 1 of 9 Year 28 Nº 112 fourth quarter 2008 Main aspects of the asbestos-exposure tecnical guide SECURITY La Guía técnica de exposición al amianto ha arrojado luz sobre los aspectos más interpretativos del Real Decreto 396/2006, relativo a disposiciones de seguridad y salud aplicables a los trabajos con riesgo de exposición al amianto. Este artículo aborda los puntos que suponen un mayor cambio a la hora de proteger a los trabajadores expuestos. By MARIANO MARTÍNEZ. Licenciado en Ciencias Químicas. Director de Higiene Industrial. Sociedad de Prevención de FREMAP. Over two years after the appearance of Royal Decree (Real Decreto) 396/2006 of 31 March, establishing the minimum health-and-safety provisions for work with asbestos-exposure risk, the Technical Guide developing this Royal Decree has finally seen the light of day. The guide aims to clarify those points of the Royal Decree that have been differently interpreted and acted upon by the stakeholders involved in the prevention of asbestosexposure risks. It should be pointed out from the start that all the technical guides of the National Institute of Health and Safety at Work (Instituto Nacional de Seguridad e Higiene en el Trabajo: INSHT) are non binding in character and there is hence no legal obligation to comply with them. Nonetheless, from a technical point of view, the guide is of unquestioned prestige and lays down the recognised path to follow in assessing asbestos exposure. Moreover, as with the rest of the technical guides published beforehand, the Asbestos-Exposure Technical Guide (Guía Técnica de Exposición al Amianto), will have its share of defenders and detractors. Some will uphold it as necessary and advocate its criteria, which, even though they may often be part of the armoury of measures already being implemented by employers or industrial hygienists, needed to be pooled in one reference document. Others, on the contrary, will argue that the guide or even the decree itself is unnecessary on the grounds that there is already a risk-prevention royal decree dealing with carcinogenic agents, including all varieties of asbestos. It may also be claimed that the Technical Guide is more lenient than the Practical guide on best practice to prevent or minimise asbestos risks of the European Commission s Senior Labour Inspectors Committee (SLIC). But all these guides, the asbestos guide, the carcinogenic agents guide and the good practice guide, should in fact be regarded as complementary rather than mutually exclusive; proper protection of exposed workers will be obtained only by the joint application of all of them. The aim of this article is not to give a detailed analysis of said Technical Guide, which would call for a document bigger than the Figure 1. Identificación pmca. Figure 2. pacm Cata (sampling)
2 Page 2 of 9 guide itself, but merely to bring out those points of interest that involve a significant and groundbreaking change in the way of protecting exposed or potentially exposed workers and how to assess this exposure From our point of view the most important points, in no particular order, would be the following: Identification of asbestos-containing material Material with asbestos: Removal or containment Assessment of the exposure Occupational exposure limits and decontamination indices Scope of application and any exceptions Figure 3. Sealing the sampling zone Identification of asbestos-containing material Much of the material currently present in our daily life was originally made with asbestos. Existing technical studies seem to show that only a small percentage of buildings in which asbestos was used in their construction have since been refitted to remove it. Furthermore, asbestos might be present in pipelines, lagging, union joints or insulation, vinyl type flooring or even in such decorative elements as jardinières. This widespread presence of asbestos, and the difficulty of knowing with any certainty whether or not any element is asbestos-free, means that identification is the first step to be taken whenever confronting material suspected of containing asbestos. Figure 4. Identification of fibres in materials No. of annual samples We also have to bear in mind here that a wrong identification of said asbestos-containing material (ACM) could lead to unnoticed exposure without the due preventive measures being taken, thus undermining the organisational and economic efforts made elsewhere to prevent asbestos exposure risks. The ACM identification process could itself imply exposure to asbestos. This process should therefore be properly planned and the due preventive measures taken. The first step in this process should be to draw up an inventory of potential asbestoscontaining material (pacm), including, as we have already pointed out, all items suspected of containing asbestos due to their manufacture, constituent products or purpose. The pacm inventory will therefore be the result of a document study and a reconnaissance of the zone in question. Once the inventory has been drawn up, the pacms then have to be classified. Although it is inadvisable to break up or perforate the pacms, it is often the only classification procedure possible. The collection of said material, a process known in Spanish as cata (testing or sampling), shall be considered as a situation of potential asbestos exposure risk, calling therefore for adoption of the proper preventive measures. It is vital to bear this in mind for, although the intervention on the material involved is usually minimal, the object thereof is to release fibres or material made up by fibres. Once the sampling has been performed the material obtained shall be enclosed in keeping with the stipulations of royal decree 396/2006 while the sampled zones should be sealed to avoid any residual risks for the sample-transporting personnel, the analytical laboratory personnel and the personnel of the sites the material has been taken from. Finally, it is vital for the analyses to be carried out in certified labs with a recognised quality management system, which participate in intercomparison programmes to ensure the
3 Page 3 of 9 dependability of the identifications made. It would also be recommendable, in accordance with the technical guide, to ask the laboratories not only to identify whether or not the material contains asbestos but also to specify the type of fibre present in the material analysed, since, even if asbestos is ruled out, there might still be another chemical agent classified as carcinogenic. Fremap Prevention Society s Central Laboratories (Laboratorios Centrales de la Sociedad de Prevención de Fremap) boast a microscopy area for identifying asbestos in material and also for counting the fibres captured in working environments. This area has noted a certain change both in the amount and type of samples received since the appearance of Royal Decree 396/2006; we believe this change could be a telltale sign of the current asbestos situation. An analysis of the numbers of received samples for fibreidentification shows a really significant change (Figure 4). The spectacular increase in the number of samples for identification of asbestos-containing material over these two years (up by 150%), shows a deep-seated change in the perception of the public at large and of the people working in the prevention of occupational risks, while also indicating a higher awareness of the importance of finding out about the risks workers are exposed to. Asbestos containing material: removal or containment In general, whenever asbestos is detected in any area, the first idea that occurs to us is its removal. Without doubt there is a strong association of ideas, quite rightly, between asbestos and cancer, asbestosis and extreme toxicity; the knee-jerk reaction is therefore to remove it from our presence. But is removal necessarily always the best idea or might there in fact be situations where it would be best to keep it and monitor its state of conservation? This aspect of asbestos is where the technical guide gives us least to go on. As might have been supposed, the first option upon discovering any asbestos-containing material should not always be removal. On the contrary the removal option should be resorted to only when the material cannot be kept in such a state of conservation as to guarantee no release of fibres into the environment. Various methods are recorded in today s bibliography to help us decide whether we can conserve the ACM without risks or, on the contrary, whether we should replace it. Of all these methods there are two deemed to be the most recommendable, on the strength of their methodology and the prestige of the organisations that have drawn them up. These methods are the Decision flow chart for asbestos containing material from the Practical guide on best practice to prevent or minimise asbestos risks in work that involves (or may involve) asbestos: for the employer, the workers and the labour inspectors of the Senior Labour Inspectors Committee (SLIC) and the ACM Assessment of MDHS 100 Surveying, Sampling and Assessment of Asbestos Containing Materials of the Health & Safety Laboratory of the HSE. The decision flow chart of the SLIC s Guide of Good Practices involves a logical yes-no decision process for ACMs to decide whether to remove or repair the material in question. The logical sequence begins with a question about the material s state of conservation, continuing with a consideration of its ease of repair and accessibility of the ACM. If the state of conservation or ease of repair are considered feasible the flow chart leads us off
4 Page 4 of 9 towards the non-removal option. A second phase then confirms the need to remove the ACM. These phases, as can be seen from the attached chart, consist of establishing whether the damage actually or potentially suffered is superficial and whether or not sealing or encapsulating is feasible. Should the damage be established as extensive in this phase or should it be thought impossible to repair it safely, the flow chart obviously leads you to the removal decision. Figure 5: Decision flow chart for asbestos-containing materials The ACM Assessment included in the Method for Determination of Hazardous Substances number 100 of the Health and Safety Executive (INSHT s opposite number in the United Kingdom) consists of a method of similar characteristics to the SLIC s Guide of Good Practices, including a material assessment algorithm to assess likely magnitude of fibre release. This classification is made in terms of four parameters: type of product, extent of damage or deterioration, surface treatment and type of asbestos. Each of these parameters is scored as high, medium or low. In the case of deterioration and surface treatment a nil score is possible. All these values will give us a numerical-type ACM classification enabling us to rate the risk of fibre release. It should be pointed out that strict application of this method is not in accord with Spanish legislation, since this algorithm penalises crocidolite as more hazardous than the rest of the amphiboles and these in turn more than chrysotile, while Spanish legislation
5 Page 5 of 9 establishes no difference between the hazardousness of the various asbestos varieties. According to the score obtained, the assessment is as follows: HSE Material Assessment Algorithm. The potential risk in score 4 or less is very low; in score 5-6 is low: In score 7-9 is medium and in the score over 10 is high The resulting assessment, together with the rest of the information gleaned on the location of material, extent thereof, activities carried out on the premises, occupancy, etc, will give employers enough wherewithal for establishing their order of ACM-removal priorities and also for deciding which material can be maintained. Nonetheless, in those cases in which the decision is taken not to remove the ACM, a careful control should be kept over this material thereafter, checking that the conditions at the moment of assessment are maintained. Any change in these conditions would then prompt a new assessment and even new removal decisions. Exposure assesment Without doubt the most important aspect from the technical prevention point of view is assessment of the asbestos exposure risk, and this has not gone unnoticed to those who drafted the Technical Guide of Royal Decree 396/2006, who have dealt with this aspect in great depth The Royal Decree lays it down that the risk assessment should be carried out with the work in progress; witness point 1 of article 5, which runs as follows. the risk assessment.. should include measurement of the airborne concentration of asbestos fibres in the workplace. Nonetheless the guide itself, with an eminently preventive outlook, recommends that said risk assessment should begin at an earlier stage, during the asbestos removal plan or work plan. In other words, before beginning any work an assessment should be made of the potential risk that said work might entail, including the preventive measures in the plan. A previous risk assessment should be carried out. Furthermore, the previous assessment should be carried out regardless of the nature of the jobs or whether a work plan is needed to carry them out. The previous assessment could be carried out with values drawn from the bibliography, databases or earlier assessments. In default of any figures to go on, the working assumption shall be that threshold limits are exceeded. It will therefore not be the measurement that determines the adoption of preventive measures. Nonetheless, the assumption is that whenever the work plan has been approved, either explicitly or tacitly, there will be no need for a previous assessment since this would be intrinsically included in the plan. Once the previous assessment has been carried out, with the work in execution phase and the work plan already approved, the necessary measurements shall be made to establish the exposure level and decide, accordingly, whether the preventive measures adopted are the most fitting. The airborne fibre concentration will be measured for each type of given activity, including all the tasks carried out by the firm during any particular job. Likewise, for those jobs that have been carried out previously and in the
6 Page 6 of 9 same conditions, it will not be necessary to repeat the measurement for the purpose of carrying out the assessment. Both the previous assessment and the risk assessment will be conducted not only for the workstations directly exposed to asbestos but also for those that might be exposed by residual risk, including zones that might be contaminated with asbestos. Even though an assessment measurement is made, the work itself will still be subjected to control measurements to confirm that accidental exposure is not occurring to other workers in the immediate surroundings. The number of control measurements will be determined by the friability of the material concerned and the duration of the jobs. For friable material a measurement should be made every 5 working days while for non-friable material the measurement would be every 20 days or even oneoff. These assessments, in view of their complexity, the experience required and the need of minimising error in the measurement itself and interpretation of results, shall be carried out by industrial hygienists with specific training in this field, from the INSHT or similar organisations. These organisations, such as Fremap s Prevention Society (Sociedad de Prevención de Fremap), have trained up specialist technicians, with skills exceeding even the level laid down in article 5 of said Royal Decree ( the risk assessments shall be made by qualified personnel with high skills levels and specialising in industrial hygiene ). These technicians, apart from their training in industrial hygiene, have also received specific training in asbestos-related matters, from identification of potential ACMs to the taking of analysis samples, the drawing up of work plans and, of course, the taking of environmental samples and assessment of the risks faced by potentially exposed workers. Finally, another factor to be taken into account in asbestosexposure assessments is the need for the asbestos analysis (fibre counts) to be carried out by specialist laboratories recognised by the Factory Inspectorate (Dirección General de Trabajo). These labs have to be included in INSHT s fibre control programme (PICC-FA), to ensure the validity of the results. We would also make bold to suggest that the pacm analyses to ascertain whether or not the material contains asbestos should be carried out in labs with similar types of controls and recognition levels. Occupational exposure limits and decontamination indices As is well known, Royal Decree 396/2006 laid down a Threshold Limit Value, Time Weighted Average (TLV-TWA) [in Spanish valor límite ambiental de exposición diaria (VAL-ED)], weighted for a period of 8 hours, as the concentration above which no worker should be exposed. For varieties of asbestos this value was set at: TLV-TWA = 0.1 fibres/cm 3 As can be seen this concentration will be determined by the number of fibres collected in a sampling filter and the volume of air that has been driven through said filter. Nonetheless, in its keenness to meet all the needs of the preventive work, the technical guide goes beyond this value of daily exposure. Neither should we forget that the Royal Decree laid down a maximum working period of 4 hours a day. As of today, therefore, where work with asbestos should be limited to the removal and withdrawal thereof, we usually find a host of exposures where the exposure time is no higher than a few
7 Page 7 of 9 minutes. For these short-duration exposures, and in default of any shortterm TLVs (VLA-EC in Spanish initials), the guide recommends that Deviation Limits should be applied (DLs) defined in the document of occupational exposure limits for chemical agents in Spain. These deviation limits, complementary to the TLV-TWAs, are statistically established as 3 x TLV-TWA where the concentration should not be exceeded for more than 30 minutes throughout the working day and as 5 x TLV-TWA as the concentration that should not be exceeded at any moment of the working day. Applying these deviation limits to asbestos, we would have: Concentration not to be exceeded for more than 30 minutes: 0.3 fib/cm 3 Concentration not to be exceeded at any moment of the working day: 0.5 fib/cm 3 Lastly, with regard to the TLVs, it should be made clear here that, as with the other carcinogenic agents, these values should be taken solely as indicators of the concentration of fibres present in the working environment and not as indicators of the potential inhalation of fibres by workers, which should without a shadow of a doubt be nil. In other words these values will serve to gauge only the suitability of the control measures set up, and hence the sufficiency thereof, but under no circumstances should they be taken as indicators of the concentration of fibres breathed in by the worker. In its article dealing with work plans the Royal Decree stipulates that once the asbestos demolition or removal work is over it will then be necessary to ensure that there are no asbestos exposure risks in the workplace. This would involve carrying out measures to ascertain the Decontamination Index in the workplace. The Decontamination Index is an indicator of the air quality in terms of its possible content of asbestos fibre. Its aim is to ensure that the air is not contaminated with fibre and that there is therefore no asbestos exposure risk. This index should be checked after the final cleaning of the workplace and before definitively removing the protection measures; this would involve a visual inspection and an environmental control measurement to confirm the absence of fibres in the atmosphere. The guide stipulates that this measurement will not be necessary when the work has been carried out outdoors or when indoor demolition or removal work involves only non-friable material; in these cases there is unlikely to be any dispersion of fibres in the environment or the working environment in the case of indoor working. On the other hand, a thoroughgoing visual inspection must always be carried out after the final cleaning. Spanish regulation lays down no threshold level below which any environment may be considered to be decontaminated. The guide therefore gives a series of guideline criteria to allow employers involved in the work to establish a reference value for said decontamination index. These criteria are defined as follows: Background concentration: the concentration as measured after carrying out the work shall be no higher than the concentration measured before beginning same. Fibre concentration outdoors: the fibre concentration measured after carrying out the work shall be less than the fibre concentration outdoors. International reference values: these are based on the values laid down in other countries. Although these differ from country to country, the most widespread figure used is 0.01 fibre/cm 3.
8 Page 8 of 9 In relation to these criteria it is important to carry out additional measures before going ahead with the work in the case of opting for the first two options, either in the working environment in normal occupancy conditions or in the environment adjacent to the site where the work was carried out. Lastly, in the case of control measures, the criterion for ascertaining the reference value to be used can be established in the same way as the decontamination index. Scope of application and any exceptions Chronologically speaking this point should have been dealt with first but we have left it to the end because we consider that the guide s recommendations are going to produce a significant change in the modus operandi of the various stakeholders involved, both in the execution and assessment of work involving exposure to asbestos. Royal Decree 396/2006, when coming into force, established its field of application as the work of demolition, dismantling, removal, withdrawal and maintenance of asbestos-containing material with workers actually or potentially exposed thereto. Notwithstanding the above, said royal decree also laid down a series of exceptions for sporadic, low-intensity exposures where the assessment clearly indicates that the TLV is not exceeded. For these situations, even though the rest of the royal decree is still applicable, there is no obligation to comply with the articles dealing with work plans or health surveillance: neither is there any obligation to enrol with the Registry of Firms with Asbestos Risk (Registro de Empresas con Riesgo de Amianto: RERA). Examples cited of such work are short and discontinuous maintenance work with non-friable material, removal without deterioration of non-friable material, encapsulating and sealing work on material in a good state and surveillance and sampletaking activities for detecting the presence of asbestos. As already pointed out, the main condition for invoking these exceptions was that the work be carried out sporadically. Before the appearance of the guide, the term sporadic was defined in INSHT s Technical Prevention Note 330 on a Simplified Accident Risk Assessment System where sporadic is defined as that risk exposure that occurs with irregular frequency. Solely by way of example we should remember that the technical note itself defined Occasional as that exposure to risk that might occur at some time during the working day with a short time period. On the contrary, the technical guide, referring to the definition given by the Spanish Language Dictionary of the Spanish Royal Academy, defines sporadic as occasional, bearing no relationship to preceding or following events, ie. exposure that has not occurred beforehand and is unlikely to recur in the future. The guide also points out that any activity not meeting this condition, whether or not the other conditions are complied with, falls within the field of application of royal decree 396/2006 and is hence subject to all the articles of the royal decree. In view of this new definition of sporadic given in the guide and the study of work with ACMs, including of course the abovementioned exceptions, there is unlikely to be any activity that is not bound to comply with all the articles of royal decree 396/2006. Conclusions Other points are dealt with thoroughly in the guide, though they are not considered here. These include personal protection equipment, where information is given to help in compliance with
9 Page 9 of 9 the obligations laid down in Royal Decree 396/2006. We therefore see that the Asbestos-Exposure Technical Guide meets its remit of helping to fill in the interpretative loopholes of Royal Decree 396/2006 on the protection of workers from asbestos-exposure risks. There are certain other aspects where there is still room for improvement, such as: Removal and encapsulation Why such an important risk, worthy of legislation in its own right, should have its work plans automatically approved if no government response is forthcoming within 45 days. The real need of making a biennial radiographic study of workers when it can be proven that the exposure was low intensity and the respiratory function study shows no anomaly. The ongoing advances in this field and the experience learnt from applying the technical guide mean that there will almost certainly be a need for future revisions. ACRONYMS USED ACM: Asbestos-containing material pacm: Potential asbestos-containing material INSHT: Instituto Nacional de Seguridad e Higiene en el Trabajo SLIC: Senior Labour Inspectors Committee RERA: Registro de Empresas con Riesgo de Amianto BIBLIOGRAPHY 1. Guía Técnica para la evaluación y prevención de los riesgos relacionados con la Exposición al Amianto. INSHT. 2. Practical guide on best practice to prevent or minimise asbestos risks in work that involves (or may involve) asbestos: for the employer, the workers and the labour inspectors. Senior Labour Inspectors Committee (SLIC). European Commission. Directorate General for Employment, Social Affairs and Equal Opportunities. 3. Límites de Exposición Profesional para Agentes Químicos en España. INSHT. 4. MTA/MA-051/A04. Determinación de fibras de amianto y otras fibras en aire. Método del filtro de membrana / microscopia óptica de contraste de fases. INSHT. 5. CR-02/2005. Medida fiable de las concentraciones de fibras de amianto en aire. Aplicación del método de toma de muestras y análisis MTA/MA-051/A04. INSHT. 6. MDHS 100 Surveying, sampling and assessment of asbestos-containing materials Health and Safety Laboratory. HSE. 7. Prospección sobre la presencia de amianto o de materiales que lo contengan en edificios. Identificación práctica de amianto en edificios y metodologías de análisis. Fundación para la Prevención de Riesgos Laborales.