In 1976, an important industrial accident happened at a chemical plant in Seveso, Italy, manufacturing pesticies and herbicides. A dense vapour cloud containing tetrachlorodibenzo-paradioxin (TCDD) was released from a reactor. Commonly known as dioxin, this was a poisonous and carcinogenic by-product of an uncontrolled exothermic reaction. Although no immediate fatalities were reported, large quantities of the substance, lethal to man even in microgram doses, were dispersed in the environment which resulted in an immediate contamination of some ten square miles of land and vegetation. More than 600 people had to be evacuated from their homes and as many as 2000 were treated for dioxin poisoning. More recently, disastrous industrial accidents took place in Toulouse, Baia Mare and Enschede with deadly casualties involved.

Legislation

In Europe, the Seveso accident lead to the adoption of legislation aimed at the prevention and control of such accidents. In 1982, the first EU Directive 82/501/EEC - so-called Seveso Directive - was adopted. On 9 December 1996, the Seveso Directive was replaced by Council Directive 96/82/EC, so-called Seveso-II Directive. This Directive was extended by the Directive 2003/105/EC. The aim of the Seveso-II Directive is two-fold. Firstly, the Directive aims at the prevention of major-accident hazards involving dangerous substances. Secondly, as accidents do continue to occur, the Directive aims at the limitation of the consequences of such accidents not only for man (safety and health aspects) but also for the environment (environmental aspect). All operators of establishments coming under the scope of the Directive need to send a notification to the competent authority and to establish a Major-Accident Prevention Policy. In addition, operators of upper tier establishments (i.e. having quantities of dangerous subsances above the upper threshold contained in the Directive) need to establish a Safety Report, a Safety Management System and an Emergency Plan. Internal Emergency Plans for response measures to be taken inside establishments have to be supplied to the local authorities to enable them to draw up External Emergency Plans. Emergency Plans have to be reviewed, revised and updated, where necessary. Important new elements require operators to consult with their personnel on Internal Emergency Plans and on the local authorities to consult with the public on Exernal Emergency Plans. The Seveso II Directive contains an obligation to regularly test in practice the Internal and External Emergency Plans.