Equipment covered by the ATEX Directive, risk assessment.

This assessment is not always straightforward, as practical realities are highly diverse and complex.

Protection systems, by definition, always fall under the scope of Directive 2014/34/EU, as do safety and control devices. However, components may be manufactured without a specific purpose, such as a diode or a bearing; in which case their assessment will be included in the conformity assessment of the equipment in which they are incorporated. If they are specifically designed to operate in hazardous environments, they must be accompanied by a relevant certificate of conformity and operating instructions.

Equipment falls under the scope of the ATEX Directive if all of the following conditions are met:

• The equipment must be located wholly or partly in a potentially explosive atmosphere;

•    The potentially explosive atmosphere may also be created by the equipment itself;

•    The potentially explosive atmosphere must be a mixture of flammable substances in the air in the form of gas, vapour, mist or dust;

• This mixture must be present under atmospheric conditions, as a rule;

•    The equipment must have one or more ignition sources for the explosive atmosphere.

RISK ASSESSMENT

The explosion risk assessment process must be carried out on a case-by-case basis and does not represent a definitive solution, taking into account at least the following elements:

• The probability and duration of explosive atmospheres;

•    The probability of ignition sources, including electrostatic discharges, and their activation and effectiveness;

•    The characteristics of the system, substances used, processes and possible interactions;

•    The degree of foreseeable consequences.

Therefore, if it is necessary to analyse activities from the point of view of explosion risk, this assessment must be carried out taking into account the probability of an explosive event occurring (i.e. its frequency) and the consequences of a foreseeable accident. Based on this, it becomes clear that risk assessment, considered as a function of the assumed scenario, is an inevitably complex process.

To conduct an explosion risk assessment, it is necessary to identify the associated hazards. To do this, it is necessary to:

•    Check for the presence of flammable substances (in the form of gases, vapours, mists, liquids, dust and fibres);

•    Assess the possibility of potentially explosive atmospheres forming during the production process.

Once the hazards have been identified, it is necessary to:

•    Determine the sources of emissions;

•    Assess the likelihood of an explosive atmosphere forming and its duration;

•    Assess whether the volumes of the explosive atmosphere are dangerous;

•    Assess the presence of effective ignition sources and their likelihood;