Bruno Debray

Amjad Abou Assali

Dominique Lenne

Managing knowledge to improve industrial safety

Keywords: Safety management, knowledge management, ontology, Internet

The capacity to manage risks and maintain industrial safety is largely based on the capacity of various actors to acquire, maintain and share knowledge on a large variety of subjects. The actors are, of course, the plant operator but also the employees, the competent authorities, the external maintenance teams or internal or external experts in charge of risk assessment and design of risk management. The knowledge ranges from the regulatory framework to the details of a machine or a process but also includes the general knowledge about the industrial safety, the hazardous phenomena, or the properties of the substances. Part of this knowledge is also largely tacit. It lies in the brain of the scientific experts or the employees who are able to make the connection between apparently disconnected pieces of knowledge. Detecting, extracting, maintaining and communicating this knowledge are typical knowledge management activities. The authors have been developing for several years knowledge access tools dedicated to the communication of generic knowledge on the industrial safety. The structure and content of this system is described in the present paper. New developments are now in progress to improve the capacity to retrieve and exploit this knowledge as well as to facilitate the management of specific knowledge. These developments are based on an ontology of industrial safety. The basic principles for developing and using ontologies are recalled. The process for building such an ontology in the industrial safety domain is then described as well as its use for indexing and searching documents in an industrial safety web platform. Other applications of this ontology are also briefly presented.

INTRODUCTION

The issue of the application of knowledge management to industrial safety is not new. The need for a safety related knowledge management strategy was already stressed in 1996 by F. Lees [START_REF] Lees | Loss prevention in the process industry[END_REF] who wrote "knowledge of its processes and plants is one of the prime assets of a company, but the management of this asset often appears to be relatively neglected". Yet, it seems that the link between knowledge management and industrial safety has not been intensively investigated with by researchers in the last decade except for the implementation and exploitation of a learning from accidents system. In the meantime however, knowledge management has become an issue in many companies. It is therefore more than time to study the matter and propose solutions for the companies to manage their safety critical knowledge. An more generally, as safety is a collective concern, it is an asset for the entire society that the knowledge required to reduce the risk caused by the industry be properly managed. After a short introduction about what knowledge management is, this paper presents a system for the management of generic knowledge through a web resource plate-form. Then it describes a more advanced and complementary approach using an ontology as the main support for the building of a safety related knowledge base. The use of this ontology is briefly described.

INTRODUCTION TO KNOWLEDGE MANAGEMENT

Knowledge Management (KM) refers to a range of practices used by organisations to identify, create, represent, and distribute knowledge for reuse, awareness and learning across the organisation. This very broad definition illustrates the large scope of knowledge management in organisations. In this paper, we focus on the need to better manage knowledge in organisations where risks are present and try to illustrate by practical applications how knowledge management techniques can be used to improve industrial safety.

Managing tacit and explicit knowledge

The knowledge can be described and categorized according a variety of classifications. One of the most famous was introduced by Nonaka [START_REF] Nonaka | Dynamic theory of Organizational Knowledge Creation[END_REF] and makes the distinction between explicit knowledge and tacit knowledge. Explicit knowledge is the knowledge that is conscious and can be documented. Tacit knowledge is the knowledge that resides in the people's mind in a more or less formalised form, most of the time unconsciously. Nonaka identifies the various operations that can be undertaken on knowledge : -Transforming the tacit knowledge into explicit knowledge is often called formalisation or externalisation. -Making explicit knowledge accessible to people who may benefit from it is diffusion.

-Making the explicit knowledge turn into tacit knowledge of actors who will then be able to use it is internalisation. A complete knowledge management system should be able to perform all these tasks. It should also be able to deal with generic and specific knowledge.

Managing generic versus specific knowledge

Beside the traditional tacit versus explicit classification of knowledge the distinction between generic and specific knowledge is essential. Generic knowledge corresponds to the general concepts. Specific corresponds to the instances of these concepts in a given context. Competence is the ability to use generic knowledge in a specific context. Many situations illustrate this need to possess generic knowledge that will be used to extract and interpret specific information or knowledge. Among them, risk analysis is the most emblematic. On the other hand, learning from experience, and especially from past accidents obeys to the opposite process. It is specific knowledge that is used to produce generic information that will be used in other context to interpret specific data. However, there is a large variety of knowledge management system structures and processes answering to a large variety of needs. Designing a KM system requires following a series of steps that will be described in the next paragraphs.

SPECIFYING AND IMPLEMENTING A KNOWLEDGE MANAGEMENT SYSTEM

Specification process

A first approach of the design of a knowledge management system is user-centred. It focuses on the future users of the system, their needs and the way they will use the system. The users are not only the beneficiary of the formalised knowledge but also the actors owning a tacit or explicit knowledge that will be used as input to the system. The following questions are thus in the heart of the design process: • Who will be the users?

• Which are the various user types?

• What are their characteristics and behaviours?

• What are their goals and tasks? • In which situations and contexts will they operate the system? • What types of knowledge is going to be processed by the system? • What are the tools and organisation already existing?

• What is the life cycle of knowledge in the organisation, how is it validated, when and how does it become obsolete?

Users and other actors involved in the knowledge management process

The users of a safety related Knowledge Management system could be all the actors involved in the industrial safety management at the various stages of an industrial plant : design, building, operation, maintenance, shutdown, decommissioning. Those actors are, authorities, process experts, risk experts, plant designers, plant builders, plant operators, plant workers, plant management staff, contractors. Their needs are different but they all interact with common knowledge elements and should be able to share common representations, to be aware of risks associated with given substances or equipment and to take sound decisions within the organisation. The authors have introduced the concept of Safety Critical Knowledge (SCK) to describe the type of knowledge involved in safety management of industrial plants [START_REF] Debray | Knowledge management for industrial safety, generic resource platform combined with an ontology based approach[END_REF].

As far as industrial safety is concerned, various actors have a role to play in the setting of a knowledge management system to answer the needs of the industry. Actors with a public mission such as research centres, health and safety institutes, universities, but also some consulting companies or industry research or service centres, are expected to provide generic knowledge. Plant operators and consulting companies use the generic knowledge combined with the plant specific knowledge to manage the risks and the associated knowledge. The ideal knowledge management system could therefore be described as the combination of a generic knowledge management system operated by actors with a public or collective mission and a specific knowledge management system that would be managed for the plant operator by himself or sub-contractors.

Categories of knowledge to be managed

The structure of a very general Knowledge management process dedicated to safety is described in figure 1. The process involves the acquisition or creation of knowledge, its organization in appropriate structures or systems and the management of these systems, the diffusion of the knowledge to suitable users and their application of knowledge. The systems described in the present paper focus on the organization and diffusion phases. Their initial purpose is to organize and make available the knowledge necessary to carry out the risk assessment of industrial plants.

Acquiring and creating knowledge

Organising and managing knowledge

Diffusuion of knowledge

Application of knowledge

Risk assessment : a knowledge intensive task

Risk analysis, and more generally risk assessment, is a knowledge formalisation process in the sense that it consists in extracting tacit knowledge from the participants of a risk analysis work group and turning it into explicit knowledge. Yet to do so, risk analysis also requires that the participants have quite an extensive explicit knowledge both at a specific and generic level. Figure 1 describes the various types of knowledge involved in the risk analysis process. Projects such as ARAMIS [START_REF] Salvi | A global view on ARAMIS, a risk assessment methodology for industries in the framework of the SEVESO II directive[END_REF] have also produced large amounts of risk analysis specific knowledge. A first issue is how to make this necessary knowledge available to the actors. This is partly the goal of a tool like PRIMARISK described below. As described in figure 1, the risk expert uses a large variety of models and data associated to the various steps of risk assessment processes. To make these models, tools and data available to the risk assessment community, INERIS is presently developing the resource platform PRIMARISK® [START_REF] Debray | Knowledge management and major industrial hazards" : an integrated approach[END_REF]. It is available on INERIS web site since January 2007. The next paragraphs describe the main features of this web platform and present its basic structure in relation with the needs of potential users.

Definition of the target users

PRIMARISK was designed as a tool to facilitate mutual understanding between the competent authorities in charge of the application of the SEVESO directive, the industry, plant operators and safety departments and the risk experts, national institutes such as INERIS and consulting companies. Each of these users expects to find validated information and tools that will enable him to perform risk analysis and risk management tasks, but above all, that will be accepted and recognised by the other parties. For this reason, a large part of the knowledge contained in PRIMARISK has been debated within national working groups that were set up by the authorities in 2004 and is the result of a consensus.

Content of PRIMARISK

The first content is the description of the risk assessment process itself. Whereas the objectives and principles of industrial major accident risk assessment are relatively well defined by the regulation [Arrêté PCIG], the method to achieve these objectives is not fully described. INERIS, as technical support to the ministry of environment was in charge of designing a risk assessment method, which, even if it's use is not mandatory, constitutes a recognised national reference. This method, partly influenced by the results of the ARAMIS project [START_REF] Salvi | A global view on ARAMIS, a risk assessment methodology for industries in the framework of the SEVESO II directive[END_REF], is fully described in a report available on INERIS web site [START_REF] Joly | Etude de dangers d'une installation classée[END_REF] and is structured according to the following sequence : -Description of the plant; -Identification of the hazardous pieces of equipment; -Selection of the relevant equipment for analysis; -Risk analysis; -Identification of the safety barriers; -Assessment of the consequences of accidents; -Definition of the safety control and requirements for the safety management system.

Each of these steps mobilises a specific knowledge. The description of the process is explicit but the understanding of which models, tools and data to use is more of a tacit type. The expertise lies in the ability to use the right model for a given hazardous situation. It lies also in the capacity to understand the results of the process. In PRIMARISK®, each steps is first described in terms of objectives. The relevant legislative texts are given together with other reference text, when they exist. Then the tasks are listed. Each of them is described and linked with useful resources and knowledge elements that will ease the risk assessment. The format of expected results is described.

The resources can be of three main types :

• Local resources : PRIMARISK® lists the elements of information that the person in charge of the risk assessment has to obtain from the plant operator such as the maps or process instrumentation diagrams.

• General resources : these are the resources available elsewhere that the user should consult to obtain useful information. Most of these resources are available online from INERIS or other web sites. Among these are databases, documentation, etc. • Specific resources available directly from PRIMARISK®: These are tools and databases that were developed specially for being made accessible through PRIMARISK®. For example, PRIMARSIK supports a series of computer models for the online calculation of effect distances of hazardous phenomena such as BLEVE, Boil-Over and pool fire. Other models are being developed and should constitute progressively a global tool kit for major industrial risk assessment. Figure 2 shows the general structure of PRIMARISK®. The core system was implemented on a MySQL® database and proposes many internal and external links with classical web pages and more specific online software. The system also contains a glossary of more than 300 terms, which are put in relation with the useful documents, resources and tools. PRIMARISK® is updated on a regular basis and constitutes a generic knowledge management and capitalization tool both for INERIS scientists and the French industrial risk assessment community.

Primarisk main page

Glossary

From centralised to distributed generic knowledge management systems

PRIMARISK® is an example of generic knowledge management tool where experts from a single institution, here INERIS, can formalise and make their knowledge available in a more elaborated format than the usual reports or guides. Its richness lies in the relations established between a variety of resources on a base of semantic content of these resources and of their position in a risk assessment and management process. In the future, it would be valuable that such a tool be fed with expertise from a larger variety of actors from other scientific institutions or administrative or industrial bodies. This would increase the capacity of those actors to communicate and understand each other. The same is true when considering actors from various countries. Experience has shown that risk assessment and management although generally following the same basic principles, were still significantly different in the various European countries. Providing a unified European reference resource repository, filled by a network of European expertise institutions, would be a useful step towards a more harmonised and integrated approach of risk management in Europe. For such a resource to exist it will be necessary to propose a common vocabulary and a common way to structure information. This is the one of the potential objectives of the development of ontologies described in the second part of this paper.

Ontologies are efficient structures used to formalise the knowledge of a specific domain. An ontology contains a set of concepts of the studied domain organised in a hierarchy of classes and sub-classes along with other relations between them. In practical terms, developing an ontology includes defining classes of concepts, arranging them into a taxonomic (subclass-superclass) hierarchy, defining properties and their facets (constraints). A knowledge base can then be created by defining individual instances of these classes, filling in specific property value information and additional property restrictions.

Developing ontologies has many advantages mentioned by N. F. Noy and D. L. McGuinnes [START_REF] Noy | Ontology Development 101: A Guide to Creating Your First Ontology[END_REF]:

• Share a common understanding of the structure of information among people or software agents. • Enable reuse of domain knowledge.

• Make domain assumptions explicit.

• Separate domain knowledge from the operational knowledge.

• Analyse domain knowledge.

Process for building an ontology of industrial safety

As described above, ontologies are powerful tools to formalise and reuse the knowledge of a specific domain. This is the reason why the authors have undertaken the development of an ontology of industrial safety. The initial purpose of this ontology was to improve the structuring, indexing and search of knowledge in PRIMARISK. But its aim is broader. It should eventually constitute a reference on which a large variety of actors could base their knowledge management and their communication. In fact, an ontology can constitute the main structure of a knowledge base that contains much more than traditional databases because of the capacity to create an infinity of relations between the concepts and their instances.

To build the ontology of industrial safety, tools were developed to extract terms from the documents produced by INERIS scientists. Experts were then asked to organise this knowledge into classes and subclasses, and to define the properties of classes and their relations. Building the ontology was initiated using the Protégé 3.3 ontology editor and other tools developed specifically [START_REF] Abou Assali | Ontologies for Industrial Risk Analysis[END_REF]. The process is described in figure 3. A first version of the ontology was built and used as a test the elaboration of an information retrieval system. The evolution of this ontology is now continuing as a central knowledge formalisation process.

Describing the structure of an ontology is not an easy task. Our aim was first that the ontology be a good support for indexing documents in a repository. It should then contain all the concepts of the domains described in the resources and documents in the repository. The objective is now to further formalize the domain knowledge through the definition of the properties and relations between concepts in the ontology.

Hierarchy of concepts

The ontology is therefore first a hierarchy of concepts among which are upper level general concepts and lower level applied concepts. General concepts are, for example risk, hazard, accident. More concrete concepts are, for example equipment, safety devices, documents. For the moment; approximately 500 concepts are defined in the ontology. Figure 1 illustrates the structure of the ontology with a small extract of its present content with terms relevant to the risk analysis of a LPG storage. The structure of the ontology reflects the structure of the concepts involved in the risk assessment process.

Defining properties of concepts

Once the hierarchy of concepts is defined, the ontology allows to define properties to these concepts. The most simple type of property is the attribution of a numerical or string value to a slot. Physical properties of substances are good examples of such properties. Strings or other types of variables can be used to define the properties, which can be organised in hierarchy.

Defining semantic relations in the ontology

At this stage the structure of the ontology is mostly a hierarchical structure where the terms are related to each other by a so called subsumption relation or is_a relation. The next step of developing the ontology is to define the other semantic relations between terms. Those will be exploited, for example, to navigate in the ontology. They are the expression of the expert knowledge.

For example, the ontology contains the information that propane is a flammable gas. That flammable liquefied pressurised gases can produce the hazardous phenomenon BLEVE. This is expressed by a relation produces_hazardous_phenomenon between the concepts flammable liquefied pressurised gas and BLEVE. Other relations can be defined, such as is_stored_in which is used to described the fact that liquefied pressurised gases are stored in pressure vessels. A relation has_safety_device specifies the types of safety devices which should be present on a given storage equipment.

Eventually, a complete net of relations can be established which reflects the knowledge on a substance or a technology. The user of a system based on the ontology can easily navigate between the concepts and access related knowledge. But the system also allows the description of a specific situation by creating instances of the concepts. For example, when studying a specific plant, it is possible to create an instance of a given equipment to which it is then possible to relate instances of specific safety devices categories and instances of initiating events and critical events. By doing so, it becomes possible to express the complete results of a risk analysis in the ontology, turning it into a powerful tool for the management of the knowledge produced during the analysis.

Current use of the ontology

A simple ontology-based information retrieval system was developed to improve the search capabilities in PRIMARISK. From a first input of the user, this tool proposes the list of concepts containing at least one of the entered words. The user chooses the concept that suits most his query. Then, a list of related close terms is proposed. A close term is defined as any term having a direct relationship with the initial term. This relation can be an is_a relation but also any other type of relation such as the produces_hazardous_phenomenon relation described in figure 3. For example, a user entering the keyword "ATEX explosion" will be proposed to refine his query by choosing among "gas explosion" and "dust explosion" but also "overpressure effect" and "thermal effect". This system allows at the same time for a better formulation of the query by the user and offers possibilities of refinement or enrichment of the results. Indeed the user has the choice to limit the search to the specific term of the ontology that best describes his search or to enlarge the results to all the documents linked to this term by a specific relation (close terms).

New developments

New applications of the ontology are now under development. The first one concerns the identification of suitable safety devices for a given equipment containing a given hazardous substance in a given state. Safety devices are associated to safety functions and to the events potentialy causes of an accident scenario. All these concepts were defined in the ARAMIS project. The ontology provides a suitable structure to capitalize the extensive inventory work that was done in this project. Additional applications are under study to improve the selection of safety devices to ensure its compatibility to specific environmental constraints (temperature of use, humidity, presence of dust…).

CONCLUSION

The management of industrial safety requires the use of a large variety of knowledge by many different actors. This knowledge needs to be managed both at a generic level for the entire community and at a specific level in the industrial plants themself. To answer some of these needs, INERIS has set up a knowledge management tool PRIMARISK, which offers a structure to capitalize the knowledge produced by INERIS in its public support mission and make it available to a large variety of users. The authors have also initiated the development of an ontology of industrial safety which will become a basis for knowledge formalisation and capitalization. The ontology is composed of a hierarchy of the main concepts involved in industrial safety to which are associated properties and relations in a very flexible way. It is presently used to improve the search of information in PRIMARISK but other applications are under development to provide a more general Safety Critical Knowledge management system.

Figure 1 :

 1 Figure 1 : Structure of a knowledge management process and variety of knowledge concerned by the process.

Figure 2 :

 2 Figure 2 : general structure of the knowledge resource plate-form PRIMARISK®

Figure 3 :

 3 Figure 3 : extract of the ontology of industrial safety showing hierarchy of concepts and relations between concepts


Roseline Bonnard * -Olivier
email: roseline.bonnard@ineris.fr

COMPARISON OF LEAD CONCENTRATION IN SURFACE SOIL BY INDUCTED COUPLED PLASMA/OPTICAL EMISSION SPECTROMETRY AND X-RAY FLUORESCENCE

Keywords: soil lead concentration, soil samples, in situ measurements, X-ray fluorescence, ICP/OES

The lead concentration in the surface soil of a French village, where a secondary lead smelter had been operating for a long time, was investigated. The objective was to define the source term of contamination for modelling the blood lead levels of the children living in that village and comparing the predicted values with the observed data.

The lead concentration was analysed by Inducted Coupled Plasma/Optical Emission Spectrometry (ICP/OES) and by X-ray fluorescence (XRF). During the first campaign, 48 composite soil samples in the first two centimetre layer were collected and prepared in lab for analysis by ICP/OES. Among these samples, 23 were also analysed by XRF. In a second campaign, field measurements by XRF were performed in 133 spots spread over the village, 24 of these spots being places sampled previously.

The analysis of these datasets showed that measurements of soil lead by XRF can provide correct estimates of the soil lead concentrations measured by the reference method.

Statistical analyses showed that ICP/OES analysis gives lower values than XRF analysis. For the samples prepared in lab, a regression coefficient equal to 0,9 was calculated between the two types of results. Regarding the common places tested by the lab method (ICP/OES) and the in-situ method (XRF), a linear regression coefficient could also be defined between the two datasets, but the regression coefficient was smaller. The larger discrepancy between the two kinds of values may be explained by the spatial variability of lead concentration at a small scale and the difference of soil volume explored by sampling and the in-situ approach.

INTRODUCTION

In a village with a long past of soil contamination by lead, the blood lead level of the children population has to be predicted and compared to the observed levels. As the ingestion of surface soil greatly contributes to the exposure of children living on a contaminated site, since a secondary lead smelter had been operating for a long time in the village and some contaminated sand was brought to the ground locally, the collection of many samples was required to have a sufficient knowledge of the source term of exposure and define a map of the lead concentrations by geostatistical methods.

Two campaigns of measurements were organized. The first one consisted of the collection of composite soil samples and analyses at laboratory by the Inducted Coupled Plasma/Optical Emission Spectrometry (ICP/OES). The second one was carried out with a X-Ray Fluorescence (XRF) portable device to perform in-situ analyses.

The present paper examines the accuracy of the concentrations measured by XRF relative to normative method.

METHODS

During the first campaign, 48 samples were taken from the first two centimetres in public areas and private gardens, spread over the village. Each sample was composed from five subsamples, four subsamples surrounding a central subsample located at a distance equal to one meter. These samples were prepared before being analysed. They were dried, crushed and sieved to 250 µm. Then, they were mineralised according to the European standard procedure EN 13346. Lead concentration was measured by Inducted ICP/OES according to the standard ISO 11885. Among these samples, 23 ones were selected and their lead concentration was also measured, after drying, crushing and sieving, owing a portable XRF portable device.

In a second campaign, surface soil lead concentrations were determined in 133 zones spread over the village by in situ measurement owing the same XRF portable device. Among these zones, 24 ones had been sampled previously to perform a laboratory analysis. The XRF measurement was then carried just close to the location of the central subsample. Depending on the cases, additional measurements were made next to the location of the other subsamples and/or on the bottom surface of the hollows left by the subsamples. So, according to the zones, from one to ten XRF measurements were performed on the area where surface soil had been previously sampled.

RESULTS AND DISCUSSION

Comparison of the lead concentrations measured by ICP/OES and by XRF for the samples prepared at laboratory

In figure 1, the concentrations measured by XRF (C XRF ) are plotted against the concentrations analysed by ICP/OES (C ICP/OES ). The horizontal bars represent the 95% uncertainty interval for the measurements carried out by ICP/OES. The correlation coefficient between the two datasets is equal to 0.99. Nevertheless, two spots have a concentration by XRF slightly higher than the upper bound of the 95% confidence interval of the corresponding concentration measured by ICP/OES. The linear regression between the two datasets were investigated.

The model obtained by the least squares method has a slope equal to 0,86 and an intercept equal to 8.32. The coefficient of determination is very high (0.99). But, the residuals do not follow a normal distribution and the property of homoscedasticity is not checked. Moreover, the residuals are slightly negative for the soil lead concentrations (C ICP/OES ) inferior to 185 mg/kg and beyond they are much larger.

To improve the model, a least square regression weighted by C XRF was tested as variability seems to improve with soil lead concentration . The relationship between the concentrations measured by XRF and those analysed by ICP/OES is the following one :

12 . 1 92 . 0 / XRF OES ICP C C equation 1
with a coefficient of determination ( 2) equal to 0.97.

The residuals from equation 1 have a normal and homogeneous distribution for soil concentrations inferior to 185 mg/kg. Above this value, the residuals are higher and the predicted concentrations are less accurate. Nevertheless, the low bias observed with the former model for the calculated concentrations below 185 mg/kg has disappeared and their 95% uncertainty intervals are narrower.

Furthermore, for all the samples, the 95% uncertainty intervals calculated owing to this linear model based on the XRF measurements overlap with the 95 % confidence intervals of the soil lead concentrations determined by the ICP/OES method (see figure 2).

Comparison of the lead concentrations measured in situ by XRF with the lead concentrations measured at laboratory by ICP/OES in the samples taken at the corresponding locations

The lead concentration measured in situ by XRF in an area was estimated as the mean of the different (from one to ten) measurements carried out in this area. The coefficient of determination between this dataset and the lead concentrations measured at the laboratory ICP/OES in the corresponding samples is equal to 0.97. But in a quarter of the cases, the mean of the concentrations measured by XRF is not included in the 95% confidence interval of the measurement determined by ICP/OES at laboratory (figure 3). The coefficient of determination ( 2) is equal to 0.97 and the residual standard deviation has a value of 29.7.

In spite of the high coefficient of determination, this model is not good because there is a clear linearity of the residuals versus the XRF concentrations. The least-squares regression weighted by C XRF slightly reduces the relative errors attached to the predicted concentrations, but the linearity of the residuals, even for low concentrations, can still be observed.

In fact, the different measurements made by XRF in the area of a composite sample reveal a local variability of the soil lead concentration, the discrepancy between the different measurements being able to go up above 100%.

Besides, in the ten sampling areas where measurements by XRF were performed in the hollows left by the composite samples, the mean concentrations measured in these hollows differ from the mean concentrations determined next to their locations from 2% to 70%.

When the gap between these two means was superior to 40%, the lower of them was used to replace the mean calculated from all the XRF measurements performed in a sampling area. Thereby, four values were removed, three being replaced by the mean concentration in the hollows. The relationship between the concentrations measured in-situ by the XRF method and the concentrations measured by ICP/OES in the samples brought to laboratory was then reinvestigated. In these conditions, the new regression model obtained by least -squares analysis is the following one :

0 . 22 0 . 1 / XRF OES ICP C C equation 3
The coefficient of determination ( 2) is equal to 0.99 and the residual standard deviation has a value of 16.3.

Owing to these changes, the residual standard deviation has decreased with respect to equation 2. The residuals calculated from this relationship are normal and do not reveal linearity. Notwithstanding, a group of a few negative residuals can be observed for concentrations superior to 200 mg/kg. These findings can be explained by the absence of measurement performed in the sampling hollows of the corresponding areas. If some ones had been carried out, lower mean concentrations may have been found, yielding higher residuals, since contamination by atmospheric fallouts tend to induce higher concentrations at the surface of soil.

Unlike the results obtained with equation 2, the 95% uncertainty intervals of the predicted concentrations calculated owing to this model overlap the 95 % confidence intervals of the soil lead concentrations determined by the ICP/OES method for the all 24 spots tested (figure 4).

The calculated concentrations are obtained with a relative error (for a 95% confidence level) comprised between +/-3 and 44%, the larger relative error being found for the lower soil concentration of the dataset. Regarding the uncertainty linked to the reference method (29.4% at the 95% confidence level), this error seems to be acceptable. Yet, if the lead concentration of a new spot needs to be predicted from this model, the equation's error has to be added, which increases the width of the uncertainty on the predicted value. According to the parameters of the model, it appears that the soil lead concentrations measured by XRF should be superior or equal to about 150 mg/kg to get uncertainties on the predicted values inferior or equal to those attached to the values obtained by the reference method. Finally, the increase of the regression coefficient from equation 2 to equation 3 (higher closeness) between the concentrations of the two datasets may be explained, on one hand by the difference of soil volume explored by sampling and the in-situ approach, and on the other hand by the low mobility of lead in soil, since lead contamination can be diluted in the samples with respect to the volume analysed by the XRF portable device.

Figure 1 :

 1 Figure 1 : Comparison of the lead concentrations measured by ICP/OES and by XRF for the samples prepared at laboratory -(a) : a view of the whole range of concentrations tested, (b) : an enlargement for concentrations inferior to 200 mg/kg

Figure 2 :

 2 Figure 2 : Comparison of the lead concentration measured by ICP/OES with the predicted concentrations based on equation 1 -(a) : a view of the whole range of concentrations tested, (b) : an enlargement for concentrations inferior to 200 mg/kg

Figure 3 :

 3 Figure 3 : Comparison of the lead concentrations measured by XRF with the concentrations measured in the corresponding samples prepared at laboratory -(a) : a view of the whole range of concentrations tested, (b) : an enlargement for concentrations inferior to 350 mg/kg The equation of the linear regression between the two datasets can be written as follows : 6 . 25 67 . 0 / XRF OES ICP C C

Figure 4 :

 4 Figure 4 : Comparison of the lead concentration measured by ICP/OES with the predicted concentrations based on equation 3 -(a) : a view of the whole range of concentrations tested, (b) : an enlargement for concentrations inferior to 350 mg/kg

CONCLUSION

The analysis of these datasets showed that measurements of soil lead by XRF can provide correct estimates of the soil lead concentrations measured by the reference method.

Nevertheless, the in-situ measurements can give deviating results because of the small surface investigated by the XRF device during each measurement compared to the area covered by soil sampling. Because of the variability of the soil concentrations at small scale, several points of measurements should be examined in a same area to get a composite result, following the example of what is made for sampling.

On the other hand, the small quantity of soil explored by the XRF technique may provide a more representative estimate of the children's exposure by direct ingestion of soil than an approach by sampling, in which the depth of soil removed is most of the time superior to the one in real contact with children.


INERIS Jean-Marc Brignon
email: jean-marc.brignon@ineris.fr

Comparing socio-economic benefits and risks of chemicals using Socio-Economic Analysis in the context of REACH

What is Socio-Economic Analysis ? What are the tools for SEA?

According to the definition given by the European Chemicals Agency1 , socio-economic analysis (SEA) is a method to evaluate what costs and benefits an action will create for society by comparing what will happen if this action is implemented as compared to the situation where it is not. The analysis typically attempts to include also those effects that are indirect or incompletely reflected by market transactions.

A SEA shall ideally cover all relevant effects related to the introduction of such an action. When the action is to produce, and/or use a chemical, the most important effects to include in the analysis are generally the impacts on health and the environment, on the economy, (e.g. the overall costs to economic actors), and social effects (e.g. on employment and labour quality).

Socio-Economic Analysis is conducted generally using environmental economics tools such as Cost -Benefit analysis (CBA), Cost-Effectiveness Analysis (CEA), or Multi Criteria Analysis (MCA). SEA is also often identified with one or several of these tools.

In Cost Benefit Analysis, costs of benefits of alternative actions are quantified in monetary terms when possible, including items for which the market does not provide a satisfactory measure of economic value (degradation, loss of functionality of ecosystems for instance).

Cost-Effectiveness analysis (CEA) is widely used to determine the least cost means of achieving pre-set targets or goals. CEA can aim at identifying the least-cost option among a set of alternative options that all achieve the targets. In more complicated cases, CEA is used to identify combinations of measures that will achieve the specified target.

Past experience in SEA for designing or enforcing regulations

The use of SEA or one of these tools to support decision-making in environmental issues is of course not new, and we make hereafter a brief review of past experience of SEA in different contexts and in different countries.

Cost-Benefit Analysis has been quite often used in regulatory analysis of proposed regulations in Canada in the USA, for instance for the ban of lead in gasoline, and more recently in the European Union. A recent example of the use of Cost-Benefit Analysis in the EU is the Clean Air For Europe Program. In this case, a Cost-Benefit Analysis concluded that the benefits for human heath and the environment of regulating air pollution were significantly higher than the economic cost of new regulation.

Past experience of SEA in chemicals management and main lessons learned

In the field of the regulation of chemicals, the idea that SEA could help finding the "most appropriate" management options for potentially harmful chemicals can be found in many countries regulations, and international organisation documents from long ago : -In Canada, the Toxic Substances Programs considers CBA for the Life Cycle Management of substances : Socio-economic factors will help determining long-term environmental goals, targets, strategies and time lines to phase out production and use of some substances. Such factors include: the benefits associated with the use or generation of a substance; the cost and feasibility of developing and using alternatives or remediation; the impact on employment, Canadian competitiveness, trade and regional development; and fairness and equity. -In the US, the Toxic Substances Control Act (TSCA) directs US-EPA to use the least burdensome option to reduce the risk to a level that is reasonable given the benefits provided by the chemical product or process.. However, the number of socioeconomic analysis carried out under this Act is quite low. -In the USEPA "Design for the environment" program, USEPA and industry carry out Cleaner Technologies Substitutes Assessments (CTSA), a methodology for evaluating the comparative risk, performance, cost, and resource conservation of alternatives to chemicals currently used by specific industry sectors. A Social Benefits / Costs assessment is part of the CTSA. -In Europe, in the framework of the Existing Substances Regulations that is being replaced by REACH, an "Analysis of Advantages and Drawbacks" was recommended for carrying out a Risk Reduction Strategy, in a Commission Technical Guidance Document. The "economic impact" of the alternatives was also to be taken into account when selecting the "most appropriate" risk reduction measures. -UNITAR, OECD, UNECE (Convention on POPs) and other bodies produced or used guidance on SEA analysis for the Risk Management of Chemicals.

Most, if not all, of these countries or organisations especially consider the Cost-Benefit perspective as the appropriate framework for conducting Socio-Economic Analysis. It seems that there is relatively broad agreement that 1)

The CBA theoretical framework of welfare economics is adapted to the aim of chemicals regulations that aim at contributing to sustainable development.

2)

The Cost/Benefit approach is preferred because no precise environmental/public health objective is assigned to chemical risk management systems, other than reducing the level of risk to some not quantified "acceptable" threshold. However, Cost Effectiveness Analysis and Multicriteria Analysis are in practice not so much different from Cost Benefit Analysis, when monetary valuation cannot be carried out, and CEA/MCA have over CBA the advantage that efficiency indexes can be chosen with a higher degree of flexibility.

Some of the lessons learnt were that -There are data availability problems, especially regarding the technical suitability and the cost of substitutes, that limit the extent to which SEA is actually employed and is actually helpful, until now, especially in Europe. -Going beyond risk analysis towards a quantitative description of the impacts on human health and the environment is very difficult, because dose-response relations and/or exposure data are generally not available -

The overall appraisal of costs and benefits to society in terms of monetary values, even if being the underlying theoretical framework generally accepted, is far from being possible in most of cases -Absolute comparison of Cost and Benefits is difficult because absolute values of costs and benefits not known, and therefore comparison of relative costs and relative benefits between two scenarios (one scenario of continued use of a substance and one scenario of substituting the substance by another one) are preferred -Uncertainty and robustness issues are known, but no procedure was available to handle them in practice.

SEAs in the context of REACH

REACH is the Regulation for Registration, Evaluation, Authorisation and Restriction of Chemicals. It entered into force on 1st June 2007 to streamline and improve the former legislative framework on chemicals of the European Union (EU). REACH places greater responsibility on industry to manage the risks that chemicals may pose to health and the environment.

REACH implements an authorisation system aiming to ensure that substances of "very high concern" are adequately controlled, and progressively substituted by safer substances or technologies or only used where there is an overall benefit for society of using the substance. These substances will be prioritised and over time included in Annex XIV. Once they are included, industry will have to submit applications to the Agency on authorisation for continued use of these substances.

In addition, EU authorities (Member States or the European Chemicals Agency) may impose restrictions on the manufacture, use or placing on the market of substances causing an unacceptable risk to human health or the environment.

Figure 1 is a flowchart of the authorisation procedure in REACH in which it is shown that SEA can appear in the following cases : -The main case for using SEA is when the risks posed by the substance cannot be adequately controlled. In this situation, the applicant must assess whether there are alternatives to the substance, and whether the socio-economic benefits of using the substance are higher than the socio-economic impacts (including public health and environmental impacts). The SEA is one of the tools to undertake these mandatory assessments.

Authorisation may be granted only if there is no alternative and if the benefits of using the substances are higher than the impacts. -When the risks can be adequately controlled, the SEA is not mandatory but may be used to determine some conditions of the requested authorisation.

Possible Procedures and Contents of a SEA under the REACH procedure for authorisations

The currently proposed stepwise approach in draft guidance documents for SEA of ECHA is reproduced in Figure 2. The general idea is to have an iterative approach going through detailed data collection and analysis as far as is really needed to come to a conclusion. As a result of applying these procedures, the SEA report would typically contain (again according to the draft guidance documents for SEA of ECHA) the following information :

Figure 1 (

 1 Figure 1 (from Reference [1])

  The most important steps, which are also the most difficult to carry out, are the description of "what happens" if the authorisation is not granted: how and to what extent the different supply chains down to the final products in which the substance is directly or indirectly involved are affected, and what their likely responses could be. -When these responses are assessed, the evaluation of the different impacts that these responses imply in terms of socio-economic impacts (impacts on the economy : sectors involved and macro-economic effects) and impacts on human health and the environment.

Figure 2 :

 2 Figure 2 : proposed stepwise approach for conducting an SEA under he REACH autorisation procedure (from [1])

http://reach.jrc.it/socio_economic_en.htm

The evaluation of Socio Economic issues in authorisation applications by the SEA Committee of ECHA One of the main tasks of the European Chemicals Agency is to give scientific and technical advice to the Commission on authorisation submissions from industry and restriction proposals from Member States. In order to reach this objective three Committees and a Forum have been established within the Agency before the entry into operation, 1 June 2008. The Committee for Socio-economic Analysis (SEAC), according to the text of REACH, plays a vital role in formulating the opinion of the Agency in regard to: -Assessing the socio-economic factors and the availability, suitability and technical feasibility of alternatives associated with the use(s) of a substance, when an application for authorisation is submitted. Third party contributions linked to the application will also be assessed (Art. 64(4); -Evaluating restrictions suggested by a Member State or the European Chemicals Agency and the related socio-economic impacts. Comments and socio-economic analysis submitted by the interested parties will also be assessed (Art. 71).

SEAC has to formulate a draft opinion within 10 months of receipt of application by ECHA, and should give its opinion on socio-economic factors related to the application for authorisation, and the availability and technical and economic feasibility of alternatives

The following Figure 3 shows how the tasks of the SEA Committee are closely linked with the tasks of the Risk Assessment Committee, and how they interact with the other actors in he Authorisation procedure.

Authorisation Procedure

Applicant and interested 3rd parties (other industry, NGOs, MS)

Agency and the Commission

Challenges ahead and possible ways forward

The "Stakeholder Expert Group" who participated in the development of the REACH SEA Guidance identified some necessary methodological improvements, especially the need for further development of guidance for assessing health and environmental impacts in an SEA context. As a matter of fact, this first challenge of SEA does not lie in economics, but in the fact that assessing socio-economic impacts first requires that physical impacts themselves are assessed. Assessing "real" physical impacts goes beyond traditional risk assessment, and implies, for instance for human health impacts, to go beyond probabilities and make predictive assessment of the number and severity of cases, making extrapolation from toxic effects to disease.

A second challenge lies in the economic assessment of alternatives, because technical and economic data on the availability of the alternatives may be lacking or difficult to get when carrying out the SEA. This technical and economic data challenge is classical in environmental regulation, and has been previously, encountered for instance under the Integrated Pollution Prevention and Control Directive (IPPC Directive 96/61/EC), when it came to determine which are the "Best Available Techniques" and write the "BREF documents". To solve this issue, the Commission established a very extensive data collection process in collaboration with industry that takes place under the coordination of the Institute for Prospective and Technological Studies of the Joint Research Center of the EC, at Seville (Spain). In the case of SEA, the availability of data has very often been one of the main limiting factors in the past. For SEA under REACH, it is desirable that the new process of submission and review of SEAs create, both in Industry and Member States new databases on the cost and effectiveness of options to substitute dangerous chemicals, and new information exchange mechanisms.


Lionel Aufauvre

European Directive 2007/23/EC on the Placing on the Market of Pyrotechnical Articles: Are you concerned?

 on the placing on the market of pyrotechnic articles. This newly published text is another piece of the European regulation concerning explosives and pyrotechnic articles. It completes the Directive 93/15/EEC of 5 April 1993 [2] on the harmonisation of the provision relating to the placing on the market and supervision of explosives for civil uses. These two Directives following the "new approach" aim at ensuring the free movement of products within the European Union (EU), improving safety of both consumers and professionals and implementing harmonised safety requirements for such products in all Members States.

Thus, the Directive 2007/23/EC applies specifically to pyrotechnic articles and their placing on the EU market, but what are they and how do you know if you are concerned? As Notified Body and Official Laboratory in France INERIS has gained a lot of experience in testing, certifying and approving explosives and pyrotechnic articles. In this paper we give an insight of the different parts of the Directive 2007/23/EC, we answer the title question and we present the possible frame of the CE marking and certification procedure for pyrotechnic articles.

Introduction

In the European Union (EU) pyrotechnic articles are now subjected to comply with the EU Directive 2007/23/EC [1] as far as it concerns their placing on the market. By introducing harmonized Essential Safety Requirements (ESR) this new Directive offers the possibilities to replace the National approval procedures concerned by a single legal framework throughout the European Union (EU).

Although this EU directive will reduce the administrative burden for everybody by introducing the CE marking and certification procedure, its substitution and application in replacement of the current National regulatory frameworks may create difficulties at the beginning. In this paper we present the different aspects of the Directive.

Scope of the Directive 2007/23/EC

Since 1993, pyrotechnic articles and ammunitions are explicitly excluded from the scope of the Directive 93/15/EEC that deals with explosives for civil uses. But one had to wait until 2004 and the adoption by the European Commission (EC) of the Directive 2004/57/EC of 23 April 2004 [3] (on the identification of pyrotechnic articles and certain ammunition) to specify what the term pyrotechnic articles actually covers in the context of the former Directive.

Thus, the Directive 2007/23/EC applies specifically to pyrotechnic articles defined as "article containing explosive substances or an explosive mixture of substances designed to produce heat, light, sound, gas or smoke or a combination of such effects through selfsustained exothermic chemical reactions". This broad definition includes namely fireworks, theatrical pyrotechnic articles and pyrotechnic articles for vehicles but also a large variety of other articles designed for more specific applications.

However, some articles are excluded from the scope of the Directive, they are: -pyrotechnic articles intended for noncommercial use by the armed forces, the police or fire departments; -pyrotechnic marine equipment falling within the scope of Directive 96/98/EC [4]; -pyrotechnic articles intended for use in the aerospace industry; -percussion caps intended specifically for toys falling within the scope of Directive 88/378/EEC [5]; -and ammunition as projectiles or propelling charges or blank ammunition used in portable firearms, other guns and artillery.

Benefits of this new Directive

The implementation of the Directive 2007/23/EC by replacing some 27 parallel national approval procedures will guarantee the free movement of pyrotechnic articles while ensuring public security, safety of consumers and environmental protection at the EU level. This is achieved by setting up essential safety requirements that pyrotechnic articles have to conform with. For the manufacturers, importers or distributors concerned that will result in a reduction of costs to obtain technical approvals for their products as the principle "tested once, accepted everywhere" will be followed as long as the essential safety requirements are fulfilled without lowering the level of safety for the end users.

But the benefit of that is still larger, for example in Europe, obviously, firework and automotive pyrotechnic markets are significantly different. Whereas on the one hand, the EU is a net importer of fireworks, on the other hand, it is a net exporter of automotive components containing pyrotechnic articles. The vast majority of fireworks on the EU market are imported from Asia (China, India…). As a result of that, most of the stakeholders in this field are involved in purchasing, storing, distributing and professional displaying of fireworks. These articles are often directly sold to a large public and subject to various regional traditions and habits pertaining to each country. Easy access to consumer fireworks increases every year, and correlatively the number of accidents involving fireworks also increases, leading to a stringent reinforcement of the regulation in some countries. Then, the implementation of the new Directive is a real opportunity to achieve a higher safety level with fireworks articles through harmonized testing and quality assessment procedures.

By contrast, the EU appears as a major automotive pyrotechnics exporter, not only for manufactured components but also for parts of assembled vehicles. In this field, a large number of stakeholders are employed in designing, manufacturing and assembling. There is no direct consumer market for these products and only automotive factory workers or professional in repair shops buy, handle and use them. It seems that there are no records of accidents involving these products, most probably because of the lack of statistics in currently existing accidents/incidents database. Therefore, on this basis the application of an EU Directive can be seen less necessary. However, as the existing approval processes, regulations and laws were different from one Member State to another leading to the multiplication of delays and costs for approval, harmonization was also chosen through an EU Directive for the placing on the market of automotive pyrotechnic articles. This solution was also preferred by the automotive supplier industry to other types of solutions as the "new approach" legislation only lays down essential safety requirements and offers more flexibility to the manufacturer (together with more responsibility) to comply with regulation.

Application of the Directive 2007/23/EC

The Directive entered into force on July 4, 2007 and Member States shall adopt and publish, by January 4, 2010, the appropriate laws, regulations and administrative provisions necessary to comply with this Directive. They shall apply those provisions by July 4, 2013 for other pyrotechnic articles for vehicles.

However, by way of derogation, National authorizations for pyrotechnic articles for vehicles granted before that date should continue to be valid until their expiry.

Categorization

For the purpose of the Directive pyrotechnic articles shall be categorized by the manufacturer according to their type of use, or their purpose and level of hazard, including their noise level (see tables 1 to 3). The categorization has three consequences, firstly it matches age limits for the consumer (see table 4) below which pyrotechnic articles shall not be made available to them, secondly it limits the accessibility of fireworks category 4, theatrical pyrotechnic articles of category T2 and other pyrotechnic articles of category P2 to persons with specialist knowledge and thirdly it requires minimum specific labeling according to the category.

Conformity assessment procedures

For the assessment of conformity of pyrotechnic articles the manufacturer shall follow one of the following procedures: 1. the EC type-examination procedure (Module B), and, at its choice, either:

-the conformity to type procedure (Module C), or -the production quality assurance procedure (Module D), or -the product quality assurance procedure (Module E); 2. the unit verification procedure (Module G); 3. the full product quality assurance procedure (Module H), insofar as it concerns fireworks of category 4.

A description of each module is given in different sections of the annex II of the Directive. Without going in too much details in the content of each module, it is worth to point out that a third body is requested for their application. Such a third body is called a Notified Body and stands as an organism appointed by Member States to carry out different tasks described in the modules. INERIS has officially applied to be notified for the Directive 2007/23/CE. It is likely that other organisms have or will also apply for this notification (lists of all Bodies notified for each Directive can be found on the Internet [6]). The notifications will be registered shortly after the transposition of the Directive by the different Member States.

According to our experience as Notified Body for the Directive 93/15/EC, most of the manufacturers will probably choose the application of Module B + Module D for the certification of their products. Whereas the Module B consists in describing the type of article according to a technical documentation and test results and in assessing the conformity of representative samples with the Essential Safety Requirements given in the Annex I of the Directive, the Module D (or similarly Modules C or E) consists rather in assessing the capability of the manufacturer to ensure the later conformity of pyrotechnic articles actually produced with the type initially defined and thereby mainly by assessment of the quality system applied by the manufacturer. It also requires the marking of each article, the issuing of a written declaration of conformity and the archiving of specific documents by the manufacturer.

The main steps to get the CE mark approval

To briefly described the different things that an applicant shall do in order to receive the CE certification for its products: -Contact the Notified Body (notified for the Directive 2007/23/EC) of your choice and lodge your application by submitting the necessary technical documentation to assess the Essential Safety Requirements.

-The Notified Body will carry out the relevant testing procedures on representative samples you will provide in the frame of the EC typeexamination procedure (module B).

-The Notified Body issues an EC typeexamination certificate to the applicant if the provisions of the Directive are satisfied.

-The Notified Body will either perform examination at random intervals on commercial articles (module C) or assess the quality system of the manufacturer (modules D or E). That is to confirm the later conformity of articles manufactured according to the type certified.

-The manufacturer can affix the CE conformity marking (see Figure 1) on its certified products and issues the corresponding declaration of conformity to the Directive. The Essential Safety Requirements given in the annex I of the Directive are the minimum requirements to be satisfied by the pyrotechnic articles in order to ensure a high level of protection of human health and safety and the protection of consumers and professional end users. Although the ESR do not really intend to guarantee any performance reliabilities in the final use of the articles, an adequate and complete operation of the articles according to what it is expected is in some way a basic condition for safety. Depending of the articles and their intended uses some of the requirements may not be relevant and the articles do not need to comply with.

Harmonized standards

In order to facilitate the process of demonstrating compliance with the essential safety requirements, harmonized standards for the design, manufacture and testing of pyrotechnic articles are being developed by the Technical Committee CEN/TC212 [8] of the European Committee for Standardization. In line with the "New Approach to technical harmonization and standardization", pyrotechnic articles manufactured in compliance with harmonized standards should benefit from a presumption of conformity with the essential safety requirements provided for in the Directive.

However, these harmonized standards will not be available before a few years and the demonstration of the compliance with the ESR will have meantime to be made by the mean of other relevant standards or existing testing procedures used in the frame of the national approvals of pyrotechnic articles. For example, as far as it concerns pyrotechnic articles for vehicles the relevant international ISO standards (for example the ISO 12097 Road vehicles -Airbag components) should be taken into account during the transition period.

Conclusion

In the recently implemented new process of the certification of pyrotechnic articles, to prove the compliance with essential safety requirements is one thing and to prove the ability to produce articles in conformity with the type certified is another thing. The manufacturer of pyrotechnic articles has to do both in the frame of the Directive 2007/23/EC. The application of the Directive requires the intervention of a Notified Body to carry out different tasks. In one hand, it proceeds to a type examination (product certification) in accordance with Essential Safety Requirements based on the manufacturer technical documentation and on test results. And on the other hand, it brings a complementary contribution in the control procedures in terms of periodic audits of the manufacturing and inspection conditions.

Figure 1 :

 1 Figure 1: CE mark [7]

Table 1 : Categorization for fireworks

 1

	Category 1 Fireworks which present a very low
	hazard and negligible noise level and
	which are intended for use in confined
	areas, including fireworks which are
	intended for use inside domestic
	buildings
	Category 2 Fireworks which present a low hazard
	and low noise level and which are
	intended for outdoor use in confined
	areas
	Category 3 Fireworks which present a medium
	hazard, which are intended for outdoor
	use in large open areas and whose noise
	level is not harmful to human health
	Category 4 Fireworks which present a high hazard,
	which are intended for use only by
	persons with specialist knowledge
	(commonly known as fireworks for
	professional use) and whose noise level
	is not harmful to human health

Table 2 : Categorization for theatrical pyrotechnic articles

 2

	Category T1 Pyrotechnic articles for stage use
	which present a low hazard
	Category T2 Pyrotechnic articles for stage use
	which are intended for use only by
	persons with specialist knowledge

Table 3 : Categorization for other pyrotechnic articles

 3

	Category P1 Pyrotechnic articles other than
	fireworks and theatrical pyrotechnic
	articles which present a low hazard
	Category P2 Pyrotechnic articles other than
	fireworks and theatrical pyrotechnic
	articles which are intended for
	handling or use only by persons with
	specialist knowledge

Table 4 :

 4 Age limits

	Fireworks Category 1	12 years
	Fireworks Category 2	16 years
	Fireworks Category 3	18 years
	Category T1 and P1	18 years
	Fireworks Category 4	Only for persons with
	Category T2 and P2	specialist knowledge


Cécilia Solal
email: cecilia.solal@afsset.fr

Christophe Rousselle

Corinne Mandin

Jacques Manel

François Maupetit

VOCs and formaldehyde emissions from cleaning products and air fresheners

Keywords: Formaldehyde, Volatile organic compounds, Household products, Exposure

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Most indoor air pollutants come from the use of cleaning products, air fresheners, pesticides or materials related to furniture and construction. Some of them may trigger adverse health effects such as nasal irritation, respiratory disorders and even asthma [START_REF] Zock | The use of household cleaning sprays and adult asthma[END_REF]. Respiratory conditions including asthma in children have also been correlated to formaldehyde concentrations indoors [START_REF] Mendell | Indoor residential chemical emissions as risk factors for respiratory and allergic effects in children: a review[END_REF].

Little is known about chemical emissions resulting from the use of cleaning products and air fresheners and until now, few regulatory frameworks is in place to define the safety of these products.

In June 2004, the French government set up a National Environmental Health Action Plan (NEHAP) which intends to improve indoor air quality (French Ministries, 2004-2008). In this framework, the French Agency for Environmental and Occupational Health Safety (Afsset) was mandated by the Ministries of Health, Environment and Labour to assess health risks associated with formaldehyde and other Volatile Organic Compounds (VOCs) indoors. In this request, Afsset has to identify everyday life products emitting or containing formaldehyde and analyse and quantify associated human exposure by direct and indirect sources.

In this paper, we report on experimental results of emission tests and measurements of indoor formaldehyde and VOCs concentrations associated with the use of various cleaning products and air fresheners. In order to assess the exposure level of consumers to formaldehyde and VOCs, these tests were conducted in realistic conditions of use and ventilation. The composition of some products is also presented and gives the opportunity to make assumptions about a possible relationship between formaldehyde emissions and formaldehyde or releasing-formaldehyde compounds composition (direct or indirect sources).

METHODS

Product selection

32 consumer products from 16 categories were chosen by Afsset among a list of multiple products compositions registered in the national consumer products library (Base Nationale des Produits et Compositions -BNPC) managed by the French Poison Control Centre in Nancy. The selected categories are expected to contain VOCs or formaldehyde. Once the categories were defined, the more and the less expensive product in each category were bought in supermarkets and department stores. Categories of tested products are briefly presented in Table 1.

Formaldehyde and VOCs emissions

Application protocols

The tests presented in this paper were carried out by the CSTB (Building Technical and Scientific Centre) in realistic conditions of use and ventilation. Laboratory measurements were conducted in emission test chambers or in the CSTB experimental house MARIA (Mechanised house for Advanced Research on Indoor Air), depending on the category of products. Experimental protocols were carried out in the test room in MARIA for air fresheners, furniture polishes, glass cleaners and glass wipes, in the toilets in MARIA for toilet blocks and gels and in emission test chambers for carpet cleaners, stain removers for carpets, floor cleaners and wipes. These scenarios are described in Table 1. (1) A1/A2, B1/B2…: the less expensive / the more expensive product per category (2) the carpet tile corresponds to the carpet tile B, tested in [START_REF] Rousselle | Emissions and toxicological evaluation of VOC and formaldehyde released from solid building materials: a contribution to the French NEHAP[END_REF] Experimental house MARIA The CSTB experimental house MARIA is dedicated to study pollutants transfers, test ventilation systems, settle field investigations methods and validate computational models. It is composed with five main rooms equipped with various ventilation systems (natural draught ducts, extract ventilation and combined extract and input ventilation) and heating systems (convectors, water heated floors) [START_REF] Ribéron | MARIA: an experimental tool at the service of indoor air quality in housing sector[END_REF].

The tests were conducted in the bedroom and the toilets, without any piece of furniture except for the emission test for the furniture polishes (laminated table in the centre of the room). VOCs and formaldehyde were sampled directly from the air extraction system. Measured concentrations are therefore globally representative of the pollutant level in the test room, even if in some cases, the distribution of indoor concentrations can be heterogeneous (e.g. in case of combustion processes, use of sprays etc.).

Parameters such as relative humidity, temperature and air exchange rate were registered during the whole period of the tests. Ventilation conditions were controlled by mechanical extraction during the experiment. The characteristics of the test room and the toilets in MARIA are summarized in Table 2.

Emission test chambers

The emission test chamber method is described in EN ISO 16000-9 (Determination of the emission of volatile organic compounds from building products and furnishing -Emission test chamber method). The characteristics are summarized in Table 3.

Sampling and analytical methods

VOCs were sampled on Tenax-TA and analysed using TD/GC/MSD/FID according to ISO 16000-6. The TVOC was calculated as toluene equivalents from the total integrated FID signal between hexane and hexadecane. The detection limit is in the range of 1 to 10 µg.m -3 depending on the compounds. Formaldehyde has been sampled on DNPH cartridges and analysed using HPLC according to ISO 16000-3. Formaldehyde detection limit is 0.3 µg.m -3 .

RESULTS

The results presented herein do not represent the diversity of marketed cleaning products and air fresheners in France.

VOCs emissions

TVOC and VOCs concentrations are presented in Table 4 (corresponding to the maximal concentrations measured during the whole period of tests). Only some tested products are herein presented with the TVOC and VOCs of concern concentrations (carcinogenic compounds such as benzene, terpenes, high concentrations…). • The TVOC was calculated as toluene equivalents

VOCs levels cover a large range of concentrations and vary widely between different types of products or even between two products from the same category.

For a majority of products, high concentrations of very volatile organic compounds (VVOCs) were measured but the analytical methods used in this study are not suitable for VVOCs quantification.

Over the 32 TVOC concentrations, 37% were below 100 µg.m -3 , 19% were between 100 and 500 and 44% were above 500, with maximum levels above 500000 µg.m -3 (carpet cleaner M2). Sorption of gas-phase analytes including terpene alcohols to chamber surfaces may also contribute to the persistence of elevated concentrations [START_REF] Singer | Cleaning products and air fresheners: emissions and resulting concentrations of glycol ethers and terpenoids[END_REF].

Formaldehyde emissions

For all tested air fresheners, formaldehyde concentrations are generally lower than 10 µg.m -3 after use and then decrease progressively, reflecting pollutant removal by the ventilation system. Concerning burning devices i.e. incense sticks and scented candles, formaldehyde emission is rather related to combustion than to the composition.

For glass cleaners and furniture polishes, the formaldehyde emission profile is presented in Figure 1. While formaldehyde concentrations remain below 10 µg.m -3 just after use, emission profiles then increase although the overall product volatilization rate is declining. This may result from varying volatilization, chemical reactions between airborne pollutants or sorption behaviour among the constituents. For both categories of toilet products, formaldehyde concentrations are increasing with successive flushes, leading to a formaldehyde concentration above 10 µg.m -3 for the toilet block J1. For both carpet cleaners and carpet stain removers, formaldehyde concentrations remain steady after use below 10 µg.m -3 . Except for the pure use of floor cleaners N1 and N2, formaldehyde concentrations for all floor cleaners are around or below 10 µg.m -3 as showed on Figure 2. This trend remains steady after use. The presence of Savon de Marseille does not influence formaldehyde emissions, whether these floor cleaners are diluted or pure. On the contrary, the dilution of the other floor cleaners decreases the formaldehyde concentrations. In this product category, the formaldehyde concentrations for floor wipe P1 are the highest among all the tested products: from 1249 µg.m -3 (0-30 min) to 128 µg.m -3 (not illustrated on Figure 2). This may be explained by the presence of formaldehyde or formaldehyde releasers within the product ("anti-bacterial" wipes).

DISCUSSION

This work shows that the use of some consumer cleaning products and air fresheners may lead to the emission of high levels of VOCs and formaldehyde.

Human exposure to VOCs occurs through inhalation or skin contact. Consumer products (household products, cosmetics, paints…) represent individually minor sources of VOCs emissions but considered together, they all make a significant contribution to the total load of VOCs indoors.

Information regarding the 32 tested products composition was transmitted via the consultation of the BNPC, to try to explain emission profiles. This confidential database registers industrial compositions of various types of products that could be implied in human intoxications. They are declared to the BNPC on a voluntary basis by manufacturers. By using the specific reference of the 32 tested products, the BNPC analysis was performed to investigate the presence of formaldehyde, formaldehyde releasers or other VOCs (terpenes, aldehydes, alcanes) in the tested products. Formaldehyde releasers such as imidazolidinyl urea, diazolidinyl urea, sodium hydroxymethyl glycinate and benzylhemiformal may be used in consumer products as preservatives instead of formaldehyde. The products containing these compounds may release the formaldehyde they contain when dissolved in aqueous or polar solvents. There is little information on the stability of these formaldehyde releasers in consumer products, as well as their safety profile. None of the 32 tested products were declared to contain formaldehyde. For 7 products, a formaldehyde releaser was declared in the composition but for 5 of them, the highest measured concentrations of formaldehyde are below 10 µg.m -3 . One floor cleaning product (N1) and one floor wipe (P1) were declared to contain a formaldehyde releaser and the associated maximal concentrations of formaldehyde emitted are quite high: 48 µg.m -3 for N1 and 1249 µg.m -3 for P1. The possible relationship between formaldehyde emission and the presence of formaldehyde releasers in the composition is not confirmed. Other formaldehyde releasers may not be identified yet such as methylisothiazolinone compounds Chemical reactivity can occur by photochemistry under the influence of sun rays and heat, converting VOCs into so-called "secondary" pollutants such as aldehydes, ketones, organic acids... (BEUC, 2005). Some studies show that reactive chemistry between terpenes and ozone produces formaldehyde [START_REF] Destaillats | Indoor secondary pollutants from household product emissions in the presence of ozone: a bench-scale chamber study[END_REF][START_REF] Fan | Ozone-initiated reactions with mixtures of volatile organic compounds under simulated indoor conditions[END_REF][START_REF] Singer | Cleaning products and air fresheners: emissions and resulting concentrations of glycol ethers and terpenoids[END_REF]. Moreover, specific VOCs are reacting with ozone at a higher rate than others (Destaillats et al., 2006). The effects of these secondary pollutants are still discussed [START_REF] Nöjgaard | The effect on human eye blink frequency of exposure to limonen oxydation products and methacroleine[END_REF] in particular in what extent they contribute to indoor pollution.

For 12 of the 32 tested products, the TVOC concentrations exceeded 1000 µg.m -3 , the maximum limit value in indoor air proposed in the Afsset protocol for qualification of solid building materials (Afsset, 2006;[START_REF] Rousselle | Emissions and toxicological evaluation of VOC and formaldehyde released from solid building materials: a contribution to the French NEHAP[END_REF]. However adverse health effects cannot be assessed specifically on the basis of these values since human exposure and associated risks can only be quantified for each individual compound. Therefore TVOCs concentrations may only be considered as an indicator of significant emissions.

Formaldehyde is identified as a major issue, classified by the International Agency for Research on Cancer (IARC) as a human carcinogenic compound since June 2004, on the basis of observed nasopharyngeal carcinoma in workers (IARC, 2006). In this framework, in 2007, a working group in Afsset proposed formaldehyde Indoor Air Quality guideline values to protect from ocular and nasal irritation. These values will also protect against the occurrence of local carcinogenic effects (nasopharyngeal carcinoma) as nasal irritation is a key-event occurring at lower doses than cytotoxicity [START_REF] Afsset | Valeurs guides de qualité d'air intérieur[END_REF][START_REF] Mandin | Development of French indoor air quality guidelines: method and example for formaldehyde[END_REF]. The indoor air quality guideline value for short term exposure is 50 µg.m -3 over 2 hours. In this study, some measured formaldehyde concentrations exceed this guideline value which may lead to irritative symptoms in the consumers. However the cancer risk of formaldehyde at these noncytotoxic concentrations is likely to be negligible.

CONCLUSIONS

The use of cleaning products and air fresheners can lead to emissions of primary or secondary pollutants indoors. Starting from analytical methods designed for building products and air fresheners, realistic experimental protocols were defined in order to characterise formaldehyde and VOCs emissions of various types of products in order to assess consumers' exposure.

Emissions vary widely depending on the type of products. For some of them, formaldehyde concentrations remained steady or increased after use. This trend may be explained by chemical reactivity between terpenes and ozone but these reaction pathways are still not well characterized. A majority of products released high concentrations of VVOCs that could not be quantified with the analytical methods used in this study.

Even if this study is not representative of emissions from all the consumer products on the French market, it shows that such emissions can really influence indoor air quality and that further studies are necessary to better understand the contribution of these emissions to human exposure to chemicals.

  on the test room glass, no wipe step Use of 4 wipes for the test room window Post-use S1-S2-S3-S4 : 30 min Post-use S1-S2-S3-S4 : 30 min I1/I2 furniture polish Sprays on a laminated table dried up Post-use S1-S2-S3-S4 : S1-S2-S3-S4 : 30 min Post-use S1-S2-S3-S4 : 30 min Post-use S1-S2-S3-S4 : 30 min * min: minute; ** sec: second; *** following the recommendations of use, floor cleaners were either tested diluted or pure

Figure 1 .

 1 Figure 1. Formaldehyde concentrations for glass cleaners and furniture polishes.Glass cleaners and furniture polishes

Figure 2 .

 2 Figure 2. Formaldehyde concentrations for floor cleaners except floor wipe P1. Floor cleaners (except P1)

Table 1 .

 1 Categories of the 32 tested products.

	Product category	Conditions of use	Scenario: number of samples (S)
				and duration between samples
	A1/A2 (1)	incense
	B1/B2	electric diffuser
	C1/C2	liquid air freshener with a
		wick
	D1/D2	scented candle
	E1/E2	spray
	F1/F2	air freshener for vacuum
		cleaners

Table 2 .

 2 MARIA test rooms characteristics.

	Item	Test room (bedroom)	Toilets
	Volume (m 3 )	32.3	4.7
	Window area (m²)	1.5	-
	Temperature (°C)	20 ± 2	-
	Air exchange rate (h -1 )	0.6	3.7

Table 3 .

 3 Summary of emission test chamber characteristics.

	Item	Contents
	Volume (m 3 )	0.0509
	Temperature	23 +/-2
	Relative humidity (%)	50 +/-5
	Specific ventilation rate qc (m 3 /h/m²)	1.25

Table 4 .

 4 TVOC and specific VOCs concentrations for a selection of tested products.

	Tested product	TVOC*	VOCs of concern	Formaldehyde
		(µg.m -3 )	(µg.m -3 )	(µg.m -3 )
	Electric diffuser B1	216	Octanal: 22	< 0.3 (limit of
				quantification)
	Air freshener for vacuum	1737	Limonene: 39	< 0.3
	cleaner F2		Eucalyptol: 275
			Linalool: 98
			Alpha-pinene: 143
			Beta-pinene: 40
			Camphene: 99
	Glass cleaner G1	2662	Trichloroethylene: 14	4
			1-butoxy-2-propanol: 1478
			1,1-diethoxyethane: 1121
	Furniture polish J1	17487	Benzene: 1	11
			Nonane: 1488
			Decane: 2350
			Undecane: 757
	Furniture polish J2	17531	Nonane: 2741	5
			Decane: 1077
	Carpet cleaner M2	523712	1-methoxy-2-propanol: 108924
			p-cymene: 1127