You are here : Home > Themes > 7. Risks of accident > SEVESO sites
 
SEVESO sites
 

2The SEVESO directive and its origin2 The emotion caused by the accidental discharge of dioxin in the SEVESO town, Italy, in 1976 encouraged the member States to adopt a common policy in terms of prevention of major industrial risks. On 24 June 1982, the so-called “SEVESO” directive required that member States and companies identify the risks associated with certain hazardous industrial activities and take the necessary measures to deal with them.

The SEVESO directive was amended several times and its scope progressively extended, notably subsequent to the Basel accident in 1986 which caused serious pollution in the Rhine following a fire in an agropharmaceuticals plant.

The European framework of this action is now directive 96/82/EC on the control of hazards associated with major accidents involving hazardous substances, known as SEVESO II directive, which replaced the SEVESO directive as of 3 February 1999.

This directive was notably transposed into French law by the order of 10 May 2000 relative to the prevention of major accidents involving hazardous substances or preparations present in certain categories of permit holding classified installations for environmental protection. This order and its implementing Circular of 10 May 2000 stipulate organisational requirements to be implemented by the operators in terms of major accident prevention.

Its application is one of the top priorities of the Inspectorate of classified installations, under the authority of the Prefects. Other aspects, such as public information and participation, are also reinforced. Progress in terms of risk control can only be achieved by providing transparent information to installation employees and local residents.

Finally, it should be noted that directive 96/82/EC has been subject to modifications recently introduced by directive 2003/105/EC of 16/12/2003. These new operational requirements take into account studies on the hazardous properties of certain substances and feedback from different accidents which have occurred within the European Union in the last few years (cyanide spill in the Danube following the Baia Mare accident in Romania in January 2000, fireworks explosion in Enschede, Netherlands, in May 2000, AZF explosion in Toulouse in September 2001). Thus, the scope of the SEVESO II directive has extended the main modifications relating to ammonium nitrates and fertilisers, flammable liquids, explosives, products hazardous to the environment and certain carcinogens.

2List of high-risk facilities2

For the facilities with major accident risks, potential nuisances and hazards break down as follows, in descending order of importance:

  • AS installations: this category corresponds with permit holding installations with public easement to control urban planning, including the so-called “upper tier” sites of the SEVESO II Directive (670 sites in France in 2005 including 23 underground gas storage facilities)
  • “Lower tier” sites: this category corresponds with the lower tier of the SEVESO II Directive (543 sites in France in 2005)

These two highly specific categories could also be completed by other classified installations requiring a prefectural permit, which are not affected by the SEVESO II directive but are identified due to other accidental risks (silos, fertiliser depots, refrigeration installations using ammonia etc.)

Each operator concerned by the order of 10 May 2000 (articles 3 and 10) must regularly carry out an inventory of the hazardous substances or preparations potentially present in the facility (nature, physical condition and quantity). The so-called “lower tier” and “upper tier” sites of the SEVESO II Directive are concerned.

The Ministry for Ecology, sustainable development and spatial planning has developed a website listing the facilities concerned by the so-called SEVESO II Directive. This allows each operator to carry out a inventory every three years and determine, depending on the amount of hazardous substances or preparations recorded, whether their facility is subject to one of the thresholds of the transposition texts of the SEVESO II directive.
This site is available at: http://www.seveso.ecologie.gouv.fr/

2Major accident prevention policy (PPAM)2 Beyond the regulatory requirements of a technical nature mentioned above, the SEVESO directive focuses on organisational requirements required of the operators in terms of prevention of major accidents involving hazardous substances or preparations. Operators whose facility belongs to the upper or lower tier must therefore display and implement their major accident prevention policy (PPAM). The analysis of the history of major accidents often highlights the importance of organisational malfunctions.
The PPAM must be embraced by the operators at all levels, from the top of the hierarchy to operational agents, as well as by subcontractors or external service providers. It is based on awareness initiatives, training actions followed by plans of action within the framework of integrated management and a continuous improvement approach.

2Safety Management System (SGS)2 The operators of “AS” facilities, generally equivalent to “upper tier” facilities, have the additional obligation of implementing a Safety Management System (SGS) in relation to the risks of major accidents potentially generated by the substances present in their installations.

This system is structured around a controlled number of scheduled or systematic actions, based on written procedures or organisational notes (instructions, guidelines etc.), in line with the already defined PPAM. It includes at least the elements mentioned in appendix III of the ministerial order of 10 May 2000 and is based on a reference system normally defined during the risk analysis, which itself is a focal point of the risk assessment.

The operator should be able to demonstrate the relevance of his SGS with regard to his risk assessment. The main issues mostly relate to the “core” of the SGS, made up of risk reduction measures, for which different management procedures are stipulated by the SGS.

These risk reduction measures are submitted by the operator to the Prefect and subject to the decision of the Inspectorate of classified installations. These are varied measures: prevention (detection etc.) or protection (valves etc.) barriers, active or passive (see MMR approach below), automatic safety chains, but also operations carried out by the personnel or their subcontractors.

2Policy of risk reduction at source2

The law of 30 July 2003 relative to the prevention of technological and natural risks and damage reparation imposed the introduction of an estimation of probability, seriousness and kinetics in the risk assessments issued by the operators of permit holding installations. The ministerial order of 29 September 2005 completes this legislative requirement by determining regulatory thresholds to evaluate the intensity of the physical effects of hazardous phenomena, the seriousness of accidents and the probability of these phenomena and accidents.

The general approach to the risk assessment focuses on risk analysis. The risk assessment carried out by the operator must take account of the accident chains identified and risk control measures implemented.

Risk analysis begins with the description of the site’s external and internal environment, completed by the description of the site’s installations to identify hazard potentials and associated hazards.

This results in the operator drawing up major accident scenarios which may lead to one or several hazardous phenomena, for which he evaluates the effects and consequences, notably the domino effect.

The operator then focuses on the reduction at source and control of these effects to the greatest extent possible. As part of this process, he must envisage the successive risk control functions and measures and implement a number of protections to reduce the occurrence probability of hazardous phenomena or limit their effects. This approach is largely inspired by the concept of “defence in depth”.

These risk control measures (or safety barriers) can be united under the generic term of risk reduction measures. They consist of the necessary technical or organisational elements sufficient to guarantee probability reduction and the limitation of effects and consequences.

Two types of measures are generally distinguished:

  • prevention measures (or barriers), i.e. measures aimed at preventing or limiting the probability of an adverse event, upstream of the hazardous phenomenon,
  • mitigation and protection measures (or barriers), i.e. measures aimed at limiting the effects of a hazardous phenomenon and its consequences on the potential “targets” by reducing vulnerability.

The operator should evaluate the performance level of each barrier with a safety function: efficiency, response time and confidence level associated with its architecture or probability category.

2Evaluation of the risk control approach2 Appendix II of the Circular of 29 September 2005 allows the Prefect to assess the major accident risk control policy undertaken by the operator of a SEVESO site. It is divided into 25 boxes, corresponding with “probability” / “seriousness of the consequences” combinations identical to those of the model in appendix V of the amended order of 10 May 2000 that the operator of the facility should use as a model to position each potential accident within their risk assessment. It is therefore used by superimposing it onto the table appearing in the risk assessment.
The seriousness of the consequences for the individuals corresponding with the interests targeted by article L. 511-1 of the environmental code and the probability of accidents are assessed according to the scales defined by the order of 29 September 2005 on the evaluation and consideration of the occurrence probability, kinetics, effect intensity and seriousness of the consequences of potential accidents in the risk assessments of permit holding classified installations (“A” to “E” for the probability and “Moderate” to “Disastrous” for the seriousness of the consequences for individuals),
An assessment grid is therefore established according to “probability” and “seriousness” combinations, outlining three accidental risk areas:

  • a high-risk area, represented by the word “NO”;
  • an intermediate risk area, represented by the acronym “MMR” (risk control measures), for which a continuous improvement approach is particularly relevant in order to attain, within economically acceptable conditions, a risk level as low as possible, taking into account current knowledge and practices as well as the vulnerability of the installation’s environment;
  • a lesser risk area, which does not involve a “NO” or “MMR”. The gradation of “NO” or “MMR” boxes into “rows” corresponds with an increasing risk, from row 1 to row 4 for “NO” boxes and from row 1 to row 2 for “MMR” boxes. This gradation corresponds with the priority given to risk reduction, focusing first and foremost on reducing the most significant risks (top rows).
Seriousness of the consequences for individuals exposed to the risk (note 1) PROBABILITY (ascending order from E to A) [note 1]
  E D C B A
Disastrous Partial NO (new sites: note 2) / MMR row 2 (existing sites: note 3) NO row 1 NO row 2 NO row 3 NO row 4
Catastrophic MMR row 1 MMR row 2 (note 3) NO row 1 NO row 2 NO row 3
Significant MMR row 1 MMR row 1 MMR row 2 (note 3) NO row 1 NO row 2
Serious MMR row 1 MMR row 2 NO row 1
Moderate MMR row 1

Note 1: probability and seriousness of the consequences are evaluated in accordance with the ministerial order relative to the evaluation and consideration of the occurrence probability, kinetics, effect intensity and seriousness of the consequences of potential accidents in the risk assessments of permit holding classified installations.
Note 2: the operator must implement additional technical measures to retain probability level E in case one of the risk control measures fails.
Note 3: in the case of an “AS” permit application: also check criterion C of section 3 of appendix I.
Note 4: in the specific case of pyrotechnic installations, the criteria to be considered for the assessment of accidental risk control are those of the ministerial order regulating this type of installation.

2Regulatory references2 Art L.512-1 of the environmental code

Amended decree no. 77-1133 of 21 September 1977 implementing law no. 76-663 of 19 July 1976 relative to classified installations for environmental protection

Amended order of 10 May 2000 (OJ of 20 June 2000, amended by the order of 29 September 2005) relative to the prevention of major accidents involving hazardous substances or preparations present in certain categories of permit holding classified installations for environmental protection.

Circular of 10 May 2000 (OJ of 30 August 2000) relative to the prevention of major accidents involving hazardous substances or preparations present in certain categories of permit holding classified installations for environmental protection (application of the Seveso II directive).

Law no. 2003-699 of 30 July 2003 (OJ of 31 July 2003) relative to the prevention of technological and natural risks and damage reparation (in particular article L.512-1 CE relative to risk assessments: article 4 of the law).

Circular of 2 October 2003 relative to immediate application measures introduced by law no. 2003-699 in terms of prevention of technological risks in classified installations and ministry Note of 15 October 2003 regarding the Circular of 2 October 2003.

Ministerial order of 29 September 2005 amending the order of 10 May 2000 relative to the prevention of major accidents involving hazardous substances or preparations present in certain categories of classified installations for environmental protection

Order of 29 September 2005 relative to the evaluation and consideration of the occurrence probability, kinetics, effect intensity and seriousness of the consequences of potential accidents in the risk assessments of permit holding installations

Circular of 29 September 2005 relative to the assessment criteria of the risk control approach to accidents likely to occur in so-called SEVESO sites concerned by the amended order of 10 May 2000.

Circular no. DPPR/SEI2/MM-05-0316 of 07/10/05 relative to classified installations - Publication of the ministerial order relative to the evaluation and consideration of the occurrence probability, kinetics, effect intensity and seriousness of the consequences of potential accidents in the risk assessments of permit holding installations

Circular of 28 December 2006 providing a guide for the development and use of risk assessments for permit holding facilities with public easement and application documents of recent regulations.