Seveso and CBRN

What does Seveso mean?

The Seveso accident in Italy gave its name to a European Directive on the risks of industrial accidents. This directive lays down safety requirements and highlights particularly the prevention actions, the establishments inspection programmes, the urbanization and land-use planning in the surroundings of high-risk plants.

The aim of the directive is twofold:

– avoid major accidents with dangerous substances;

– limit the consequences of such accidents for individuals and the environment.

Seveso is a borough of Northern Italy, in the Region of Lombardy. It has been especially known since an industrial accident occurred on July 10th, 1976, when a dioxin cloud spread in the area after the explosion of a chemical plant.

The term Seveso refers since then to the European Seveso Directive which requires a.o. the identification of industrial establishments with major risks.

A Seveso establishment is an establishment which has an activity linked to handling, manufacturing, using or storing dangerous substances (i.e. refineries, petrochemical sites, oil depots or explosives depots).

The Seveso establishments are divided into two categories: Seveso Upper Limit and Seveso Lower Limit. The indication is based on the nature and quantity of dangerous material present in the establishment.

Upper limit establishments are establishments in which dangerous substances are present, whose quantity is equal to or above the “upper limit” value determined

Lower limit establishments are establishments in which dangerous substances are present, whose quantity is equal to or above the “lower limit” value and below the values applied to the “upper limit” establishments.

The effects of a Seveso industrial accident depend on the release of a dangerous substance, its properties, but also its state (gaseous-liquid-solid) and the environment in which this substance is released.

The dangerous substances are diverse. They have been classified, in the European legislation, according to their properties.

A name list with about forty products is added to this generic list of danger categories.

• toxic and ecotoxic;
• inflammable;
• explosive.

In general, three kinds of risks are identified for the Seveso sites:

• The fire risk: following the inflammation of products, a fire can lead to considerable heat flows and can cause burns and suffocation;
• The explosion risk: can be caused by a mix between specific products and others, by the sudden release of gas of the release of explosive products. It can cause burns or wounds by the projection of splinters;
• The toxic pollution risk: a toxic pollution due to the spread of dangerous substances in the air, water or ground can cause nausea or intoxications. The intoxications due to the dangerous substances can be toxic for the body if they are inhaled, swallowed or touched.

Those risks can occur during accidents caused by solid, liquid or gaseous products, and they are apparent through various phenomena.