The regulation of major-accident hazards prevention is one of the first applications of the principles of prevention, precaution and rectification at source of damages caused to human and environmental health, even before they were explicitly recognised by the European Treaties.

The most important source of legislative knowledge in this area is the Directive 82/501/EEC, known as the ‘Seveso Directive’, since it was drafted and adopted to a large extent as a result of the shock and concern over the events which occurred in the Italian town of Seveso on the 10th of July 1976.

Following the explosion of a chemical reactor at ICMESA‘s plant in the neighbouring municipality of Meda, a large cloud of dioxins invaded the area, causing serious diseases in the population and even more in the unborn, together with enormous damage to the environment.

The discipline thus introduced in 1982 has been the subject of a significant process of revision and evolution of legislation, determined in some cases always by the occurrence of dramatic industrial accidents.

To date, the “Seveso III Directive”, i.e. Directive 2012/18/EU, is in force at EU level, and at national level the related implementing regulations, Legislative Decree no. 105 of 26 June 2015.

A major accident is defined as “an event such as an emission, fire or explosion of great magnitude, due to uncontrolled developments that occur during the activity of a plant subject to this decree and that gives rise to a serious danger, immediate or delayed, for human health or the environment, inside or outside the plant, and in which one or more hazardous substances are involved.”

The probability coefficient of the event to occur may therefore be indeterminate or low, but from an obviously precautionary point of view, it is considered appropriate to adopt a system of procedures and precautionary measures in consideration of the seriousness and diffusivity of the potential effects that could derive from it.

With the exception of a number of exclusions provided for by Article 2 of Legislative Decree no. 105 of 2015, the scope of application is very broad, covering all plants in which dangerous substances are present in one or more plants, including infrastructure or common and related activities.

It is further extended by Article 3, letter n), which attaches importance not only to the actual presence of hazardous substances in the plant, but also to the expected or reasonably foreseeable generation of such substances, in the event of any loss of process control, including storage activities within a facility within the plant itself.

However, it should be noted that the reference to “hazardous substances” concerns those listed in Annex 1 to Legislative Decree no. 105 of 2015, and not all the substances defined as hazardous by the worldwide harmonised system adopted by European Regulation no. 1272/2008, the so-called “CLP Regulation“.

The facilities under consideration are divided into two categories, the lower threshold and the upper threshold, depending on the quantity of hazardous substances present, and there are different requirements on the part of the owner.

For both the lower-tier and upper-tier plants, it is compulsory to send the notification to a large group of bodies, namely the Regional Technical Committee, the Region, the Ministry of the Environment through ISPRA, the Prefecture, the Municipality and the Provincial Fire Brigade Command.

The notification, signed in the form of self-certification, must contain the information specified in Article. 13 paragraph 2 and the controls on the truthfulness of the information communicated are carried out by ISPRA, at the expense of the operator.

The operator of the plant must also draw up a document in which he defines his policy for the prevention of major accidents and must attach the program for the implementation of the safety management system.

For upper-tier plants, the operator must also prepare a safety report to be submitted for approval to the Regional Technical Committee, which carries out the preliminary activity and the necessary inspections, indicating within four months from the start of the investigation, the final technical assessments, any additional requirements and, if the measures adopted by the operator for the prevention and limitation of the consequences of major accidents are clearly insufficient, the limitation or prohibition of operation is provided for.

For upper-tier plants only, the operator is required to prepare, after consultation with the staff working in the plant, the internal emergency plan to be followed in order to control and contain accidents in order to minimize their harmful effects on human health and the environment.

The external emergency plan, on the other hand, is prepared by the Prefect for both the lower- and upper-tier plants.

In particular, for the areas where the probability or possibility or consequences of a major accident may be greater due to the geographical position and proximity of the plants themselves due to the so-called “domino effect“, to which Article 19 links duties of collaboration between operators, in the preparation of the external emergency plan, the potential effects of chaining in the event of a major accident in one of the plants are taken into account.

For the purposes of monitoring compliance with the obligations imposed by the legislation and the effective application of precautionary measures, the competent bodies shall draw up and implement a national or regional inspection plan, depending on the threshold of the establishments, at the end of which the operator shall be informed of the relevant conclusions and any measures to be implemented.

For cases of violation of the obligations set forth in Legislative Decree no. 105 of 2015, the majority of cases of violation of the obligations set forth in the Decree provide for the sending of a warning to the operator, the non-compliance of which results in the suspension of the activities of the plant or plant and, in cases of persistent failure to comply with the requirements, even the closure of the plant or, where possible, of the individual plant or a part of it.

Finally, it should be emphasized that the legislative framework in the field of major industrial accidents also sets safety criteria to be complied with in urban planning also providing for forms of public consultation and participation in the decision-making process of adoption of the relevant urban planning tools by local authorities.