What is an Hazardous Area ?
Hazardous areas are defined in order to assess their risk, and to encourage the operator to take appropriate measures to prevent the ignition of flammable gases and dust. The classifications of zones and divisions are defined in the ATEX directives.
The classification of the area may include the following:
- danger zone diagram
- ventilation / air conditioning data that can be carried out in the area
- data on sources of gas and dust releases
- information on flammable substances stored or handled
Prevention of explosion risks in the workplace
- The French regulations concerning explosive atmospheres (ATEX), commonly called “ATEX regulations”, refer to two distinct European directives, which concern:
- the requirements aimed at improving the safety and health protection of workers likely to be exposed to the risk of an explosive atmosphere (Directive 1999/92 / EC of 16 December 1999),
devices and protection systems intended for use in explosive atmospheres (Directive 2014/34 / EU of February 26, 2014).
The first concerns the free movement of equipment. This is Directive 94/9 / EC. It was transposed into French law by decree 96-1010. It defines the essential health and safety requirements with which devices and protection systems intended for use in explosive atmospheres must meet and the means of demonstrating the compliance of these devices and protection systems with standards. This directive also provides for the introduction of an additional directive concerning the dangers of explosion linked to the use and installation of devices.
The second, more recent, concerns the protection of workers. This is Directive 1999/92 / EC. It sets the minimum requirements to be observed in terms of the health and safety of workers likely to be exposed to the risk of explosive atmospheres.
It comes under the framework directive 89/931 / EEC which concerns the implementation of measures aimed at promoting the improvement of the safety and health of workers in the workplace.
This new directive requires the employer to assess the risk of explosion and the probability of occurrence of explosive atmospheres, the probability of the appearance of ignition sources, the substances used, the processes and their possible interactions, the installation of the equipment as well as the extent of the foreseeable consequences.
What should the operator think about to guarantee a safe environment?
In operation, it is the operator’s responsibility to ensure that the conditions for causing an explosion do not arise. However, due to the fact that there is a risk that these events will occur action must be taken with respect to electrical and non-electrical products to prevent tripping.
In the design principle of any site, hazards and risks should be minimized.
The risks of explosion must be assessed globally. If the risk exists, the employer must take technical and organizational measures to:
- prevent the formation of explosive atmospheres, or if this is not possible
- prevent their inflammation, or if this is not possible
- reduce the effects of the explosion so that workers are not at risk
To do this, the employer is required to:
- carry out an explosion risk assessment
- to guarantee security
- to classify the locations at risk of explosion
- install the appropriate equipment
- draw up a document relating to the risks of explosion containing all these points and keep it up to date
When installing, electrical equipment should be installed, if possible, in non-hazardous areas. If this is not possible, the least dangerous zone possible must be selected (see classification of ATEX zones for more details).
All equipment and wiring of electrical connections must be designed, installed, operated and maintained so that they do not become a source of ignition.
Electrical equipment must meet 3 requirements:
Construction and installation must comply with the regulations and requirements for use in hazardous areas of the country concerned.
All electrical products must be installed in accordance with the manufacturer’s instructions, and follow any constraints / limitations that certification requires. (For example, if the product is certified as a component then the equipment to which it is attached may need to be tested and certified with that component in situ).
After installation, the inspection must be carried out by a competent body.
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