Types of risks and consequences


The major accident hazard is the chance of a major accident occurring in a Seveso establishment.

A major accident: 

  • can have different causes, such as an error in the system, a human error or a chain reaction
  • has serious consequences for the environment, people in the company or people living in the surroundings of the company. These consequences can be noticeable immediately, or only much later.

4 types of risks

There are four different types of risks in a Seveso establishment:

  1. Fire hazard: when products ignite, there can be a fire. This can lead to major temperature fluctuations, which can lead to other risks. Fire can also cause burns or suffocation. 
  2. Explosion hazard: when certain products are mixed, an explosion can take place, for example in case of a sudden release of gas or use of explosive products. Such an explosion can cause burns or injury due to flying fragments. 
  3. Risk of toxic emissions: in case of toxic emissions, dangerous substances spread through the air, the water or the soil. This can make people or animals nauseous, or poison them. You can be intoxicated when you inhale, touch or eat these substances, for example after eating contaminated vegetables from your garden. Toxic emissions can also have other consequences, such as odour nuisance which can be noticed at a considerable distance.
  4. Ecotoxic risk: an ecotoxic risk exists when there are emissions of poisonous substances with consequences for the environment, e.g. contamination of water or soil. 

Each type of risk can be caused by solids, liquids or gases and can have different effects. 

Type of risk  Effect Consequences for humans
Fire (e.g. flammable liquids, fireball, jet fire, gas fire) Heat  Burns, suffocation
Explosion (gas explosion, explosion of a pressurised reservoir)


Flying debris  

Internal injuries in the lungs and eardrums


(Eco)toxic cloud (release of toxic substances, toxic smoke)


Contamination of the environment

Irritation of the airways or the skin