Many types of hazardous substances are transported. Transport takes place by road, rail and water. As the number of substances is too large to determine individual risks, these substances have been combined in ‘substance categories’, and each category poses a different type of risk to the surroundings. Petrol and oil, for instance, are included in the ‘flammable liquids’ category.
The transport of hazardous substances poses the following risks to the surroundings:
• a major fire caused by a flammable liquid, e.g. petrol;
• a large burning gas cloud, e.g. LPG;
• a toxic gas cloud, e.g. chlorine;
• a toxic liquid that vaporizes, e.g. ammonia;
• an explosion, e.g. explosives.
The risk map also follows this classification. Explosives are rarely transported and so this is not shown on the map. Small and local transport flows are not shown.
Keeping a distance
The government uses a ‘risk contour’ for the distance between residential buildings and transport routes. In principle, no building work may be carried out within this risk contour. This contour indicates the possible death rate following an accident at a company or during the transport of hazardous substances. The more transport vehicles using a certain route, the greater the likelihood of an accident. In cases where the standard used by the government is exceeded, residential buildings must be at a safe distance from the route. These areas along the route are indicated by the description ‘risk distance required’.
More information at this website