Any human activity can be the cause of an accident. Each carries its part of risk. It is true in everyday life: in the car, on the sports field, at sea … It is even true at home, since there are 18 000 accidental deaths in the home each year in France.
It is the same thing as far as activities calling for the application of technology are concerned: there is no such thing as “zero risk”. As soon as man decides to produce, transport or work on material for profit, risks appear. Technological risk is the possibility of an accidental event on a site using products or processes that are dangerous.
These products and processes can exacerbate the consequences of an accident. The personnel of a factory, the people living close by, or even the environment itself, can be affected, sometimes dramatically. It is therefore essential to be able to measure these risks in order to anticipate them better.
1. Measuring technological risk
a) Where are the biggest risks to be found? The activities presenting technological risk.
All industrial activities generate risks, mainly linked to the products that are stored or manufactured:
- Mining industries: those presenting operational risks (roof falls, firedamp explosions, and dust explosions in coal mines …) and those using highly toxic products (mercury salts, cyanides, …);
- Nuclear power plants , where highly radioactive material is both manipulated and produced. Security measures are extremely severe, for example to anticipate the risk of fusion of a reactor core, or of an escape of radioactive material into the atmosphere;
- Chemical industries produce and/or use large quantities of substances that are often dangerous. These products are used in the manufacture of plastics, pharmaceutical products, fertilisers, sometimes explosives … In certain conditions they present risks of explosion or of the emission of toxic substances;
- Petroleum and petrochemical industries use, store and process gas, oil and all their derivatives. These plants must anticipate risks of fire, explosion, marine and ground pollution;
- Iron and steel industries process metallic derivatives at very high temperatures and can present risks of explosion and the escape of molten material.
- Very large hydroelectric dams , with the risks of bursting and consequent submersion of everything downstream;
- And other places, such as large grain silos, where explosions can happen caused by conflagration of dust …
b) What are the risks? How are the consequences of a technological accident measured
An industrial accident can have three types of impact:
- Mechanical: an explosion causes a shockwave resulting from the sudden pressure increase at the centre. Specialists calculate the excess pressure engendered by the explosion and in this way determine risks to health (eardrums, lungs …) and to goods and property.
- Thermal: this results from combustion of a product, sometimes accompanied by an explosion. The consequences for people (1 st, 2 nd and 3 rd degree burns), are determined by calculating the amount of heat received per unit of surface area.
- Toxic: the inhaling or digesting of substances that are irritant, harmful or toxic, or the contact of such substances with the skin or mucous areas. The effects on human health can be immediate (acute toxicity), or long-term (chronic toxicity), and range from the benign (irritant substances) to the fatal (toxic substances).
How can the consequences of a technological accident be quantified?
The seriousness of a technological accident is defined by taking account at one and the same time of the gravity of its effects (cf. above) and of the area affected. For example, a roof collapse at the bottom of a mine does not have an impact over the same area as a rail accident.
In February 1994, the European Union decided to adopt the “European scale for industrial accidents”. Based on 18 parameters, this scale is extremely precise and enables clear definition of the impact and consequences of accidents. The scale contains:
2 parameters related to the quantities of dangerous materials (Q),
7 parameters related to human and social aspects (H),
5 parameters concerning consequences for the environment (ENV),
4 parameters covering financial aspects (€).
For each of these parameters, there is a scale of 6 levels permitting quantification of the seriousness of the effects of an industrial accident.
All that having been said, industrial activities are not like “the devil’s cauldron”:
- The activities have a reason. They supply the products necessary in our daily lives (energy, food, plastic materials, fertilisers, pharmaceutical products …)
- It is therefore essential to anticipate the risks. Prevention is an essential for public health. The protection of people and the safety of installations come before performance.
2. Anticipating industrial risks
a) What are the regulations in force?
In France, as in numerous other countries, the State defines a legal framework for measures for the prevention of technological risk.
Depending on the types of product stored or manufactured, companies whose activities imply an element of risk are classified according to three levels of potential danger:
- Companies subject to declaration are those that can be involved in low level risks or problems. There are some 450 000 such companies in France, ranging from pig farms to candle making workshops to small gas storage units.
- Companies subject to authorisation are those that can be involved in significant risks. For example, storage units for more than 1.5 tons of ammonia, paper and carton warehouses... There are about 61 300 such companies in France.
- Companies subject to authorisation with the same constraints as a public utility (they are commonly known as “Seveso classification” companies). In this case, the risks are major and require control of urban planning around the site. Included in the list are sites using or storing more than 20 tons of a highly toxic substance, or other high-risk sites. There are 1239 in France.
In each of these cases, the company submits its activities to the Prefect of the region who
determines
the safety measures to be taken.
In order to define the level of danger applicable to the site, the nomenclature “ICPE” (installations classified for the protection of the environment) is used. This text defines the levels of quantities of product and types of activity beyond which the site is subject to one or another of the three danger level classifications.
Finally, since what is known as the “Bachelot” law was passed in July 2003, plans for the prevention of technological risks (PPTR) have been progressively put in place.
This law reinforces the legislation on industrial risks by putting into place:
- “ Comités Locaux d’Information et de Concertation (CLIC) ”, local committees for information and consultation, which keep the public informed and involved in the prevention of industrial risks;
- Protective measures to be taken by local people if their buildings do not provide sufficient protection in the case of an accident;
-Measures of control of urban planning which restrict the construction of dwellings around the sites. These measures can also impact on existing urban planning to safeguard or displace existing populations.
In Europe, a directive exists for industrial risks: the SEVESO directive of 1982. Since 1996, it has been extended by the directive 96/82/CE known as SEVESO 2:
- New products were added to the list of dangerous substances.
- The legislation no longer aims simply at one particular installation within the plant, but at the whole site as soon as at least one of the installations has the SEVESO classification.
- This directive defines two classification levels according to the substances stored on the site and their quantity.
The SEVESO directives also aim at improved exchange of information between member states and give a lot of attention to the potential cross-border impact of serious accidents.
At an international level, the prevention of technological risks is covered by:
- Convention n°174 of the International Labour Organisation (ILO) concerning the prevention of industrial accidents (Geneva 1993),
- Convention of the Economic Commission of the United Nations for Europe (CEE-UNO) concerning the cross-border impact of industrial accidents (Helsinki 1992).
b) What do industrial organisations themselves do to limit technological risks?
Risk prevention is essential for industrial organisations. Safe surroundings where one feels at ease are essential for working.
- Above all it is necessary to evaluate the risks to which the enterprise is exposed and to measure the potential impact.
- Then, steps must be taken to reduce risks at source. This is achieved by ensuring satisfactory handling procedures for the products, providing safe installations, ensuring systems of surveillance and detection and rigorous training of employees. Finally it is essential to ensure strict control of the application of all these safety measures.
- Then procedures, which are to be applied in the case of an accident, must be put in place to ensure that the impact of an accident is brought under control as rapidly as possible. These procedures include fire safety installations (lances, extinguishers …), equipment to limit the impact of an explosion (protective banks, water curtains …) or of pollution (leak-proof installations …) and evacuation plans for the populations involved.
To ensure the safety of sites and the control of operations and equipment installations, emergency safety teams have been set up on all industrial sites. These intervention teams have two essential missions: to ensure the security of each employee at his post (what is called the “operational security” aspect) and to protect industrial installations (what is called the “control of technological risks”). |