The risks and the effects

The risks and the effects

Generally, four types of hazards are identified for the Seveso sites:

  • The fire hazard: following the ignition of products, a fire can lead to considerable heat flows and can cause burns and suffocation.
  • The explosion hazard: an explosion can occur if certain products are accidentally mixed together, or can be caused by the sudden emission of a gas or the trigger of explosive products.  It can cause burns or wounds due to the projection of debris.
  • The toxic release hazard: a toxic pollution due to the leak of dangerous substances into the atmosphere, 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. The toxic release may also cause various nuisances, such as unpleasant odours which can be felt from a certain distance. 
  • The ecotoxic release hazard : is a toxic pollution causing damage for the environment (pollution of the water or soil). 


These risks can occur during accidents involving solid, liquid or gaseous products, and they are visible through various phenomena :

Type of risk Effects Consequences for persons
Fire (Gas-fire, flash-fire, torch fire, fireball, boil-over, flammable liquids fire) Thermal effects Burns
Explosion (BLEVE, VCE, pressurised gas tank explosion)

Overpressure effects


Internal lesions to the lungs and eardrums

Injury due to the projection of debris

(Eco)toxic substance release  (toxic smoke, toxic substances leak)

Toxic effects

Damages to the environment

Respiratory tract irritation, skin leasions