Overall project report – Final report · 1.2 Purpose and structure of this report 2 1.2.1 Scope of this report 2 1.2.2 Use of this report 2 1.2.3 Organisation of the reports 3 2

Overall project report – Final report

Development of an assessment methodology under Article 4 of Directive 2012/18/EU on the control of major-accident hazards involving dangerous substances (070307/2013/655473/ENV.C3)

Report for the European Commission (DG Environment)

AMEC Environment & Infrastructure UK Limited

In association with INERIS and EU-VRi

December 2014

December 2014 Doc Reg No. 34075CA010i6

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Document Revisions

No. Details Date

1 Intermediate report 12 May 2014

2 N/A

3 Intermediate report (revised) 21 July 2014

4 Intermediate report (revised) 11 Sept 2014

5 Draft final report 18 Nov 2014

6 Final report 12 Dec 2014

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Contents

1. Introduction 1

1.1 Project overview 1

1.2 Purpose and structure of this report 2

1.2.1 Scope of this report 2

1.2.2 Use of this report 2

1.2.3 Organisation of the reports 3

2. Summary of work undertaken 4

3. Results of the project 6

3.1 Overview 6

3.2 Task 1 – Elements to be considered in the initial screening 8

3.3 Task 2 – Identification and analysis of suitable consequence assessment models 9

3.4 Task 3 – Identification of specific models or guidance allowing assessment of environmental consequences of accidents 9

3.5 Task 4 – Accident scenarios, conditions and parameters for an EU-wide implementation of the assessment models 10

3.6 Task 5 – Guidance on considering additional elements 11

3.7 Task 6 – Guidance on the notion of ‘Major Accident’ 11

3.8 Task 7– Guidance on interpretation of the results of consequence assessment modelling 12

4. Conclusions 14

Figure 3.1 Project tasks within the overall assessment process 7

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1. Introduction

1.1 Project overview

Article 4 of Directive 2012/18/EU (the Seveso III Directive) provides for the Commission to assess, “where appropriate or in any event on the basis of a notification by a Member State [...] whether it is impossible in practice for a particular dangerous substance covered by Part 1 or listed in Part 2 of Annex I, to cause a release of matter or energy that could create a major accident under both normal and abnormal conditions which can reasonably be foreseen”. If justified, the Commission may make a proposal to have this substance excluded from the scope of the Directive.

AMEC, in conjunction with INERIS and EU-VRi, was appointed to support the European Commission in the development of an assessment methodology to assist Member States and the Commission when preparing and assessing notification files made under Article 4.

The objectives of this project were to develop a framework assessment methodology suitable for assisting the Member States and the Commission throughout the assessment process of the major accident potential of a certain substance, identifying the details of the information to be presented, the questions to be addressed and the tools which can be used in each of the following steps:

Identification of a substance by a Member State authority that could be a candidate for undertaking an assessment (likely to be identified initially by industry);

Initial screening of the substance by the Member State in order to decide whether to take it to the next step;

Preparation by the Member State of the notification file including a full assessment, based on the models and further guidance established in the methodology;

Notification by the Member State of the completeness of the notification file to the Commission;

Start by the Commission of its assessment based on the notification file, along the lines described in the assessment methodology, including consultation with Member State technical experts; and

Conclusion by the Commission whether it would be impossible in practice for a specific substance subject to the assessment to cause a major accident.

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1.2 Purpose and structure of this report

1.2.1 Scope of this report

This report provides a summary of the work undertaken on the project as a whole, with the results of project, and a synthesis of information contained within seven related reports (annexes) covering the seven main project tasks. The intermediate results of the project were presented to a group of experts in October 2014, and this report draws conclusions on the potential use of the method, as well as on areas where further work is likely to be required.

The information presented in this report and Annexes is intended to provide a ‘framework’ for an assessment methodology for use in the context of Article 4. It presents various elements to take into account as part of an assessment in the context of Article 4. However, it is not intended to be a complete ‘manual’ presenting the steps which must be followed nor does it provide a ‘one-size-fits-all’ approach to assessments under Article 4.

Because the reports only present these ‘elements’ of a possible approach, it was not appropriate within the scope of the project to follow one example substance through the whole process. However, separate examples are provided for some of the specific stages/elements in the assessment methodology where these help to illustrate the approach.

Specifically assessments under Article 4 may adopt different approaches to those presented in this report, but it is hoped that the material presented provides a useful conceptual framework, as well as details of practical approaches that could be used in determining whether a major accident is “impossible in practice”. In reality, every candidate substance under Article 4 will involve different issues, and therefore the approaches to assessments in this context will necessarily vary.

It is important to note that the report does not describe the administrative procedure for requesting an exclusion from the scope (e.g. by whom, where to, when and in what specific format). This was not within the scope of the project and will be determined at a later stage by the Commission.

The report (including annexes) includes various material on different methodological approaches, as well as on how the Seveso directive is implemented in different Member States. This material is only presented in terms of its use in informing possible assessments under Article 4; it does not reflect any advocacy or criticism of the merits (or otherwise) of how the directive is currently being implemented.

1.2.2 Use of this report

The report is intended to be of use to Member States’ authorities, the Commission and companies in preparing and assessing assessments put forward for exclusion of substances under Article 4.

It is intended to help inform Member States in assessing the merits or otherwise of a case for exclusion of a substance, and in deciding whether to submit a notification to the Commission. In practice, it is expected that the majority of cases for exclusion would actually be developed and put forward (to member states or the Commission) by industrial operators with an interest in having a substance excluded.

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It provides a conceptual approach to undertaking an assessment, examples of specific techniques that could be used and references to other sources of information. However, Member States are of course free to adopt a different approach if they consider it more appropriate.

Specifically:

The approaches presented in this report are not mandatory.

Member states and other assessors may choose to use all, some or none of the elements covered in the project reports.

Other methods can be used. In any case, the use of the method adopted will need to be clearly justified in order to gain acceptance from the Commission and other Member States.

1.2.3 Organisation of the reports

The majority of the work is synthesised in seven separate reports annexed to the present document. These follow the following main tasks in the terms of reference for the project:

Task 1 – Elements to be considered in an initial screening

Task 2 – Identification and analysis of suitable consequence assessment models

Task 3 – Identification of specific models or guidance allowing assessment of environmental consequences of accidents

Task 4 – Accident scenarios, conditions and parameters for an EU-wide implementation of the assessment models

Task 5 – Guidance on considering additional elements

Task 6 – Guidance on the notion of ‘Major Accident’

Task 7 – Guidance on interpretation of the results of consequence assessment modelling

However, it is important to note that the sequence of undertaking an assessment under Article 4 would not necessarily follow these steps in numerical sequence (see Section 3.1).

The two remaining tasks on the project were as follows:

Task 8 – Workshop to discuss results. This was held on 14 October 2014, in Brussels.

Task 9 – Drafting of the framework assessment methodology. This includes the present report and annexes, which have been updated following the workshop.

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2. Summary of work undertaken

The inception meeting for the project was held on 30 August 2013. Following this meeting, work on the first seven tasks on the projects commenced, including extensive review of relevant literature as well as drawing upon the practice experience of the project team in implementing various aspects of the Seveso directive in different Member States and through previous EU-level projects.

In order to draw upon experience of experts in the field of the Seveso directive, a survey was undertaken between October and November 2013. The purpose of the survey was primarily to collect information and views, to avoid missing any important sources of information on key aspects of the project (for example, consequence assessment methods). This was not intended to be an all-encompassing survey but was designed with specific information needs in mind. The survey requested information on:

Available and potentially suitable consequence assessment tools, for both humans and the environment.

Methods and reference guidelines for determining and assessing worst-case scenarios.

National cut-off values that are used in the Member States for determining the limits of where a major accident risk is deemed to exist, as well as other quantitative or qualitative data/information used for defining a major accident in terms of impacts on humans or the environment.

Suggestions on substances which could be candidates for an assessment under Article 4.

The survey was sent to the Seveso Expert Group and also to our own lists of experts in the field, including members of EU-VRi, organisations who provided input to the EU F-Seveso project and members of ETPIS. A total of 46 responses were provided which generated useful information for consideration in the study.

A progress meeting with the Commission was held on 17 January 2014, for which details of progress with each task was provided, along with preliminary drafts of text for Tasks 1, 3 and 6.

Preliminary versions of the intermediate reports on each of Tasks 1-6 were provided to the Commission and discussed at a progress meeting on 3 April 2014. Comments received from both of the above meetings were taken into account in revising the reports.

The draft results were made available in September 2014 to invitees to the project workshop. The project workshop was held on 14 October 2014 and was an opportunity to:

Present the outcomes of the study

Enable discussion and debate on the proposed methodology

Collect technical feedback from the participants

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The workshop provided valuable feedback on the work undertaken. It is clear that the work on this project includes some elements that will be useful to some Member States and other stakeholders, although reservations were expressed on some of the elements of the work. Most participants felt that the work represented a good starting point for development of exemption proposals under Article 4. However, some more contentious areas were highlighted, particularly in terms of the information needed to help judge whether a major accident is possible or not. This is an area where several workshop attendees indicated that further work would be required.

The workshop showed that the project outputs provide elements that may be useful, but that there is little appetite for it to be a mandatory approach, given that each substance relevant under Article 4 will have its own unique issues which will require methods tailored to those issues.

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3. Results of the project

3.1 Overview

This section provides a brief summary of the contents and summary of each of the 7 annexes to the present report, covering Tasks 1 to 7 of the project. It is of note that the report on Task 7 provides a synthesis of how the information from each of the preceding tasks could be taken into account and applied in actually undertaking an assessment in the context of Article 4 of Seveso.

As indicated above, the numbering of the tasks follows the tasks set out in the project terms of reference. However, the steps within each report would not in practice be undertaken in numerical sequence, as can be seen in the figure below. It is more logical to follow the Task 4 and Task 5 reports before Tasks 2 and 3, as one could conclude and demonstrate at a relatively early stage that a major accident is impossible based on substance properties and potential sources of release. There could therefore be no need for detailed consequence modelling.

The figure below provides a visualisation of how the different parts of the project interact.

The figure also highlights the importance of having a thorough and independent third party review of any proposal for exclusion, prior to it being notified to the Commission, particularly where the original suggestion for exemption from scope arises from a third party (e.g. industry suggestion to a Member State)., Such a review would further provide competent authorities with more support and assurance that the notification is justified and thereby increase the chances of achieving consensus during the legislative process.

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Figure 3.1 Project tasks within the overall assessment process

Initial screening (Task 1)

Is it clear based on an initial screening that a MA potential

does exist?

Definition of worst case scenarios (Task 4)Consideration of additional

elements (Task 5)

Modelling tools for assessing health consequences (Task 2)

Methods for assessing environmental consequences (Task 3)

Interpreting results (Task 7)Definition of a “major accident”

(Task 6)

Do the scenarios identify potential for a major accident?

Prepare justification/proposal for exclusion

End process

End process

No

No

Yes

Yes

Can credible major accident scenarios

be ruled out?

No

Yes

Submit notification to Commission

Third party review

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3.2 Task 1 – Elements to be considered in the initial screening

The report (annex) on Task 1 has two parts. The first part begins with some general considerations regarding the main chemical and physical properties for chemical substances, as well as on substance-specific operating conditions. It includes a general overview of the hazards of chemicals.

Details are provided of the range of dangerous phenomena and their effects, including fire, explosion and toxic dispersion.

The key substance-specific parameters and their linkages with dangerous phenomena are presented, with considerations on whether a substance under investigation in the context of Article 4 could generate a fire, explosion, or a toxic dispersion (including dispersion hazardous for the environment).

The second part of the Task 1 report includes a synthesis and some of the key steps that it is suggested could be included in an initial screening stage. It is envisaged that steps which could be taken by Member States in determining whether further investigation of a candidate Article 4 substance could include:

Step 1: Confirmation that the substance or mixture in question does indeed fall under the scope of the Seveso Directive.

Step 2: Analysis of past accidents and other assessments. This would include review of relevant historical data such as accident reports/databases to see if the substance has been implicated in past accidents, as well as review of relevant reports assessing accident potential involving the substance (e.g. Seveso safety reports produced in the member state concerned).

Step 3: Comparison with other relevant substances using one or more different index methods. A description is provided of a number of methods by which simple indices can be derived for a substance based on readily available data for a substance. This allows for comparison with other substances that have already been assessed in the context of Seveso (e.g. well studied substances included in the documentation on the indices, named substances in part 2 of Annex I to the directive, or other – Seveso-relevant – substances with similar physicochemical properties to the one being investigated). The results of these index methods may provide a useful indication as to whether to proceed to more detailed assessment.

Furthermore, a number of other possible considerations are included, based on the points in Article 4(1) and 4(3) of the directive, including:

Whether the physical form in use and under ambient conditions suggest that the substance cannot disperse widely following an accidental release or a fire/explosion.

Whether there are other physicochemical properties (e.g. vapour pressure) which may preclude widespread dispersion of the substance.

Reviewing the properties of mixtures where relevant, for example where concentration is sufficient for hazard classification but not for manifestation of the relevant adverse effects.

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Furthermore, there could be other factors that may need to be taken into account, such as packaging or containment requirements that apply across the EU.

Overall, these steps are not intended to lead to definitive conclusions but rather to identify substances for which a major accident potential clearly does exist, to determine whether further assessment is appropriate.

3.3 Task 2 – Identification and analysis of suitable consequence assessment models

The Task 2 document includes an identification and analysis of potentially suitable consequence assessments tools for use in modelling accidents involving hazardous substances on industrial site. This task focuses on the consequences of industrial accidents on human health.

It should be noted that these modelling approaches would only be applied once relevant accident scenarios had been identified (i.e. after Tasks 4 and 5).

A discussion of some general aspects regarding models is provided, followed by a detailed analysis of modelling aspects related to key dangerous phenomena, including description of the phenomena, effects to be considered, modelling methodologies and details of the main models available. Separate sections are provided on:

Atmospheric dispersion (dispersion of flammable or toxic clouds and dispersion of smoke from fires);

Explosion (solid explosives, vapour cloud explosions, BLEVE, vessel burst, emission of projectiles);

Fires (flash fire, jet fire, solid fire and pool fire); and

Fireballs (classic boil over, thin-layer boil over and pressurisation of storage tanks).

For each of the dangerous phenomena, a summary is provided of models available for consequence assessment.

The main tools available are then considered in more detail, and reference is made to relevant experimental campaigns that have been used to validate these models. Guidance is then provided on choosing suitable models to assess health consequences of accidents, including on how to interpret the results.

3.4 Task 3 – Identification of specific models or guidance allowing assessment of environmental consequences of accidents

This task concerns identification of specific models or guidance for assessing the environmental consequences of accidents. As with Task 2, these approaches would only be applied once relevant accident scenarios had been identified (i.e. after Tasks 4 and 5).

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It was recognised from the outset that methods are much less well developed than those for assessing health consequences, and there is much less uniformity in approach across Europe. Furthermore, the environment varies hugely across the EU, so assessing the consequences of an accident in a generic way (as required in the context of Article 4), is particularly challenging.

The main focus of this task was on the water environment, with toxicity to water understood as being an indicator of the overall environmental impact of a substance, particularly in the context of the Seveso Directive.

Assessment methods were identified through the study survey, as well as through review of relevant literature.

A long list of available methods is presented, followed by a more detailed description of six methods/approaches to environmental consequence assessment that are widely used in the EU. These are grouped as follows:

Indexes of environmental hazard or risk. The examples provided were the Czech Hazard and Vulnerability (H&V) Index and the Swedish Environment-Accident Index (EAI).

Environmental risk assessment approaches, with details provided for the methods used in Spain and the UK.

Approaches for estimating dispersion of substances in water. A generic approach used in several Member States’ safety reports is described, using a published paper (Kontic and Gerbec, 2009) as an illustration. The Dutch Proteus model is also described, as this seems to be one of the main examples of a widely adopted computer modelling approach.

For each of the above, conclusions are drawn on their possible use in the context of Seveso Article 4.

The main methods covered related to the potential for ecotoxic effects, but the potential for accidents to affect drinking water quality is also an important consideration, and relevant environmental standards for water quality may also be of relevance in undertaking an assessment. Some brief considerations are also given to assessing environmental consequences through release to air, but in this context the approaches used are often similar to those used for health consequences.

Overall conclusions are drawn on the use of different methods in the context of Article 4. While all of these approaches (and others not considered here) can potentially be of use, no specific approach is recommended, and it is noted that expert judgement will be needed based on the properties of the substance being assessed, and its expected conditions of use, to select an appropriate method.

3.5 Task 4 – Accident scenarios, conditions and parameters for an EU-wide implementation of the assessment models

This part of the report is focused upon identifying accident scenarios and a set of minimum conditions and parameters to be taken into account when undertaking an assessment in the context of Article 4. The report is intended to assist with drawing conclusions on the “worst case” parameters to be considered, taking into account the need for an EU-wide applicability of results.

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This report provides guidance on the choice of one or more “reference accident scenarios” and the associated conditions that need to be fed into the accident scenarios in order to assess the consequences.

The report highlights accident databases which may be of use in identifying accident scenarios, and then provides a possible methodology for defining and modelling the worst case scenarios. Particular attention is paid to the Methodology for Identification of Major Accident Hazards (MIMAH) developed in the context of the European ARAMIS project. This is considered to represent a well-accepted method of identifying and assessing accident scenarios, which could be used in the context of Article 4, but it should not be considered as the only method that could be applied in this context.

Guidelines are provided on modelling worst-case scenarios, including considerations on:

The source term (substance involved, nature of release)

Environmental conditions particularly meteorology and topography

For each type of dangerous phenomenon, information is provided on the parameters that are typically of most importance in modelling of consequences.

The identification of relevant accident scenarios is key to determining whether a major accident is possible and whether further modelling is appropriate (covered by the Task 2 and 3 reports). It may be the case that no major accident scenarios can be identified, perhaps because of the physicochemical or hazard properties of the substance in question. The assessor would then make a justification for exclusion based on there being no credible accident scenarios. However, in other cases, it may not be so clear-cut and accident scenarios may need to be developed to allow subsequent more detailed analysis and modelling. In such cases, these will need to take into account the range of situations likely to be encountered across the EU, both now and related to possible future uses of the substance.

3.6 Task 5 – Guidance on considering additional elements

This report provides information on other factors which may need to be taken into account in consequence modelling. It includes considerations on:

Type of containment and packaging, which are of potential relevance where there is an EU-wide requirement to apply such measures, and which can limit the potential for a major accident.

Location and segregation of storage, recognising that these are typically very site-specific.

Size of storage units and quantities of substances stored.

3.7 Task 6 – Guidance on the notion of ‘Major Accident’

This report provides further elaboration on the notion of a “major accident”, specifically in the context of Article 4. It recognises that this term is already defined within the Seveso Directive (Article 3(13)), and that there are already

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criteria for reporting on major accidents to the Commission in Annex VI. The focus is therefore on further understanding what criteria could be used when examining accident scenarios for Article 4 candidate substances and how it might be demonstrated that a major accident is impossible in practice.

Different definitions of major accident amongst the Member States are considered, where these provide further elaboration compared to the Directive. Consideration is then given to relevant thresholds for dangerous effects (particularly thermal radiation, overpressure and toxic releases). Approaches adopted in different Member States are considered, as these will need to be taken into account in the context of Article 4, given that the Member States will need to agree upon substances that are exempted from Seveso under this article.

Approaches to land use planning in the context of Seveso are considered, based on methods used in different Member States. Particular attention is given to separation distances for development, related to different types of establishment and types of dangerous phenomena that may occur.

Considering that the criteria in Article 3(13) are not very specific, the more specific criteria in Annex VI might provide a useful starting point for characterising certain types of major accidents. However these alone are unlikely to be sufficient as other major accidents may occur which do not match the reporting criteria in Annex VI whilst matching the more global criteria in Article 3(13). In accordance with the project terms of reference, the report therefore considers examples of relevant thresholds and distances to effects which are in use within the Member States, in land-use planning and other fields. These may potentially be of use in assessing the potential consequences of accidents involving an Article 4 candidate substance, and in concluding whether a major accident is more or less likely to be impossible. However, it is clear that, while these are some of the only examples from related fields with quantitative examples of safety distances, they are not directly usable as a basis for concluding whether a major accident is impossible or not. They are one information source to be taken into account, but expert judgement must be applied in deciding whether a major accident is possible or impossible for the accident scenarios related to each Article 4 candidate substance.

3.8 Task 7– Guidance on interpretation of the results of consequence assessment modelling

This report provides an overall synthesis of the preceding tasks and how the results of consequence assessments could be interpreted for Article 4 candidate substances.

Following the initial screening stage expected of the Member States, the report provides guidance on how to interpret the results of modelling exercises (Task 4 coupled with Tasks 2 and 3) and additional elements (Task 5), taking into account the guidance developed as regards the notion of “major accident” (Task 6). All these elements linked together constitute a generalised approach for the possible steps of the assessment methodology in the context of Article 4 of the Seveso Directive.

The report includes a section on interpreting modelling/assessment results. For environmental consequences, the main comparison is expected to be between assessment results and the criteria in Annex VI of Seveso, though it is suggested that more elaborated criteria in individual Member States should be taken into account, since an Article 4 assessment will need to demonstrate to all Member States that a major accident is impossible in practice across the

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EU, and Member States that have additional criteria will presumably take these into account in their decision-making.

In terms of health consequences, a first possible step in the interpretation phase is to determine whether one or more of the criteria in Annex VI could be met (those criteria that are relevant to the accident scenarios in question). Here, one needs to take into account both the scale of effects (e.g. irreversible harm, fatality) as well as the estimated distance to such effects, in the event of a major accident. A ‘decision grid’ is presented, whereby the distances to relevant effects thresholds (both inside and outside the establishment) can be taken into account, and compared with a possible ‘reference distance’. Based on feedback on the draft results of this project, it appears that the consideration of distances used in land use planning are not a suitable surrogate for use directly in determining such reference distances. Therefore, the assessor will need to exercise judgement in determining what a safe reference distance is for each substance.

Overall, it is suggested that, if the assessment concludes that any one of the Annex VI criteria could be met, no exclusion should be possible. Furthermore, impact on people outside the establishment should be limited. If any calculated effect distance (even for ‘small’ reversible effects) exceeds a distance where widespread effects on people could occur, no exclusion should be possible.

Some possible alternative decision grids, along with other considerations, are also presented in the report.

The Task 7 report concludes with a tabular presentation of the envisaged main steps to be undertaken under each stage of the assessment method.

It is important to recall that the approaches suggested within all of the project reports are suggestions. They should not be considered prescriptive and cannot be expected to cover all circumstances for all potential candidate substances. Member States and the Commission may decide that alternative approaches are more appropriate with any individual substance, and in such cases, it is expected that a robust justification for the methods used in the corresponding notification file should be provided. Member states may decide to consider all, some or none of the elements included in these reports.

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4. Conclusions

Work on this project has involved extensive review of relevant methods and approaches for assessing the potential for accidents and their consequences, involving substances that are possible candidates for exclusion under Article 4 of the Seveso Directive.

The documents provide a generalised approach that could be used by Member States and the Commission in assessing candidate substances. There are a range of existing tools and methods available for assessing consequences of accidents and the project reports provide details of those methods, but in general do not specify that any one single method can be applicable for all substances. There will inevitably always be a requirement for expert judgement in deciding on the best approach to assessing each substance, ideally supported by an independent third party review. In some cases a detailed and extensive analysis may be required whereas in others it may be possible to draw conclusions using rapid approaches and readily-available data – particularly if it quickly becomes clear that a substance does have potential to cause a major accident.

There are differences in approach to deciding what constitutes a major accident across the EU. The reports (particularly Task 6 and 7) provide details of approaches that could be used to help decide whether a major accident is possible in specific cases, as well as options for how to interpret the results of assessments. It is clear, however, that this is one the most contentious aspects of Article 4 and, despite considerable research efforts in this project, it has not been possible to derive a one-size-fits-all approach to concluding whether a major accident is impossible based on identification of accident scenarios and assessment of the consequences of those scenarios. This is in particular due to the wide area of parameters to be considered (e.g. potential substance characteristics, geographical and meteorological conditions throughout the European Union, legal diversity in 28 Member States)This is an area that may warrant further work in the future.

Documents

Overall project report – Final report · 1.2 Purpose and structure of this report 2 1.2.1 Scope of this report 2 1.2.2 Use of this report 2 1.2.3 Organisation of the reports 3 2