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Chemical Accidents (Seveso I, II and III) - Prevention, Preparedness and Response

What is Seveso?

Major accidents in chemical industry have occurred world-wide. In Europe, the Seveso accident in 1976 prompted the adoption of legislation aimed at the prevention and control of such accidents. The resulting 'Seveso' directive now applies to around 10,000 industrial establishments where dangerous substances are used or stored in large quantities, mainly in the chemicals, petrochemicals, storage, and metal refining sectors.

The Seveso Directive obliges Member States to ensure that operators have a policy in place to prevent major accidents. Operators handling dangerous substances above certain thresholds must regularly inform the public likely to be affected by an accident, providing safety reports, a safety management system and an internal emergency plan. Member States must ensure that emergency plans are in place for the surrounding areas and that mitigation actions are planned. Account must also be taken of these objectives in land-use planning.

There is a tiered approach to the level of controls: the larger the quantities of dangerous substances present within an establishment, the stricter the rules ('upper-tier' establishments have bigger quantities than 'lower-tier' establishments and are therefore subject to tighter control).

The Seveso accident

The "Seveso" accident happened in 1976 at a chemical plant in Seveso, Italy, manufacturing pesticides and herbicides. A dense vapour cloud containing tetrachlorodibenzoparadioxin (TCDD) was released from a reactor used for the production of trichlorophenol. Commonly known as dioxin, this was a poisonous and carcinogenic by-product of an uncontrolled exothermic reaction. Although no immediate fatalities were reported, there was widespread dispersal of kilogramme quantities of a substance lethal to man even in microgramme doses. This 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.

Seveso Directives I, II and III

Seveso I: Council Directive 82/501/EEC on the major-accident hazards of certain industrial activities (OJ No L 230 of 5 August 1982) – the so-called Seveso directive – was adopted in 1982. The Directive was amended twice, in 1987 by Directive 87/216/EEC of 19 March 1987 (OJ No L 85 of 28 March 1987) and in 1988 by Directive 88/610/EEC of 24 November 1988 (OJ No L 336 of 7 December 1988). Both amendments aimed at broadening the scope of the Directive, in particular to include the storage of dangerous substances. This was in response to severe accidents at the Union Carbide factory at Bhopal, India in 1984, where a leak of methyl isocyanate caused more than 2500 deaths, and at the Sandoz warehouse in Basel, Switzerland in 1986, where fire-fighting water contaminated with mercury, organophosphate pesticides and other chemicals caused massive pollution of the Rhine and the death of half a million fish.

Seveso II: On 9 December 1996, Council Directive 96/82/EC on the control of major-accident hazards – the so-called Seveso II Directive - was adopted and replaced the original Seveso Directive. Seveso II included a revision and extension of the scope; the introduction of new requirements relating to safety management systems; emergency planning and land-use planning; and a reinforcement of the provisions on inspections to be carried out by Member States.

In the light of industrial accidents (Toulouse, Baia Mare and Enschede) and studies on carcinogens and substances dangerous for the environment, the Seveso II Directive was extended by Directive 2003/105/EC of the European Parliament and of the Council of 16 December 2003 amending Council Directive 96/82/EC. The most important extensions were to cover risks arising from storage and processing activities in mining; from pyrotechnic and explosive substances; and from the storage of ammonium nitrate and ammonium nitrate based fertilizers.

Seveso III: Further adaptation of the provisions on major accidents occurred on 4 July 2012 with publication of a replacement directive - 2012/18/EU. The main changes in this, so-called, Seveso III Directive were:

  • Technical updates to take account of changes in EU chemicals classification. In 2008, the Council and the European Parliament adopted a Regulation on the Classification, Labelling and Packaging (CLP) of substances and mixtures, adapting the EU system to the new UN international chemicals classification (Globally Harmonised System - GHS). In turn, this triggered the need to adapt the Seveso Directive, since its scope is based on the former chemicals classification which will be repealed by the CLP Regulation by June 2015.
  • Better access for citizens to information about risks resulting from activities of nearby companies, and about how to behave in the event of an accident.
  • More effective rules on participation, by the public concerned, in land-use planning projects related to Seveso plants.
  • Access to justice for citizens who have not been granted appropriate access to information or participation.
  • Stricter standards for inspections of establishments to ensure more effective enforcement of safety rules.

The Seveso III Directive 2012/18/EU was adopted on 4th July 2012 and entered into force on 13th August 2012. Member States have to transpose and implement the Directive by 1st June 2015, which is also the date when the new chemicals classification legislation becomes fully applicable in Europe.