Whenever handling or processing flammable materials, whether it be gas, vapour, mist, or dust, there is often a risk of the existence of explosive atmospheres and thus the possibility of dangerous situations arising.
An explosion in a workplace could potentially cause serious injuries and devastating damage. Preventing loss of containment of flammables and/or build-up of hazardous substances, as well as minimizing the consequences of explosions if they happen, are necessary to protect employees, properties, and the surrounding environment.
Regulations, such as ATEX, exist for this purpose. The ATEX Directives cover the minimum requirements and safety measures or practices necessary to be implemented in places, processes, and industrial plants where potentially explosive atmospheres can arise.
In this questions-answers-based article, we will take a look at the basic information surrounding ATEX Directives.
What is ATEX?
ATEX (ATmosphere EXplosibles) is a set of two European Union Directives that have been established to protect employees from explosion risks within industries – anywhere handling or treating/processing flammable materials where potentially explosive atmospheres can be created. These two directives are as follows:
Directive 1999/92/EC on minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres (also known as the ‘ATEX Workplace Directive’)
This Directive aims at establishing and harmonizing minimum requirements for improving the safety and health of workers potentially at risk from explosive atmospheres.
It covers the obligations of employers regarding risk identification and management of risk from potentially explosive atmospheres to protect their workers, such as:
- Performing explosion risk assessments
- Performing hazardous area classification
- Implementing prevention and protection measures against explosions
- Coordinating all workers’ health and safety measures implementation and stating them in the explosion protection document
- Creating and updating explosion protection document
Full text is available for reading here.
Directive 2014/34/EU on the harmonization of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres (also known as the ‘ATEX Product Directive’)
This Directive applies to electrical and non-electrical equipment and protective devices and systems intended for use in potentially explosive atmospheres.
Applicable from 20 April 2016, it replaces the previous ATEX Directive 94/9/EC which was applicable from 1 July 2003 until 19 April 2016.
Equipment and protective systems intended for use in areas where potentially explosive atmospheres can exist must be designed from an integrated explosion safety point of view. Therefore, the equipment manufacturer must ensure the following details:
- Prevent the equipment and protective systems from generating explosive atmospheres or causing explosions
- Prevent the equipment and protective system from becoming an effective ignition source
- If an explosion should occur, the equipment and protective system should be designed and used such that it is able to halt immediately and/or limit the consequence of the explosion overpressures to a sufficient level of safety
Full text is available for reading here.
What are explosive atmospheres?
According to the ATEX Workplace Directive, an ‘explosive atmosphere’ means a mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mists, or dusts in which, after ignition has occurred, combustion spreads to the entire unburned mixture.
Where can explosive atmospheres be found?
Any facilities processing flammable substances are exposed to the risks from explosive atmospheres. This includes facilities in industries such as biotechnology, chemicals, food and drink, logistics & supply chain, mining, oil & energy, pharmaceutical, renewables, wine & spirits, etc.
What is the sufficient level of safety for equipment to be used in potentially explosive atmospheres according to the ATEX Product Directive?
The level of safety of equipment is dependent on the likelihood of a flammable atmosphere arising. The higher the likelihood of a flammable atmosphere being present the stronger the demands that need to be put on equipment when operating in such a place. Should an explosion nevertheless occur which could directly or indirectly endanger persons and, as the case may be, domestic animals or property, to halt it immediately and/or to limit the range of explosion flames and explosion pressures to a sufficient level of safety.
In addition, protective systems must be dimensioned in such a way as to reduce the effects of an explosion to a sufficient level of safety.
Where do ATEX Directives’ jurisdiction apply?
ATEX Directives are mandatory for facilities handling flammable substances located within the European Union and the countries of the European Economic Area, i.e. Liechtenstein, Iceland, and Norway, and for equipment manufacturers who would like to market their products in this region.
What are ATEX zones and hazardous area classifications?
According to the ATEX Workplace Directive, workplaces must classify industrial plant and process areas where potentially explosive atmospheres can exist into “hazardous zones” on the basis of the frequency and duration of the occurrence of an explosive atmosphere. The Directives distinguish between two main types of explosive atmospheres: gas/vapour/mist and dusts.
The hazardous zones for these two types of explosive atmospheres according to ATEX are as follows:
What are ATEX equipment groups & categories and in which ATEX zones do they apply?
The ATEX Directives divide ATEX equipment into groups and categories to accommodate each ATEX zone.
How is ATEX information displayed?
The ATEX Product Directive requires relevant equipment and protective systems to be marked with the CE mark, the ‘Ex’ mark, together with a series of equipment codes. For example, please see the two pictures below for mechanical equipment.
The above picture is an example of mechanical equipment (not for use in mining) for dusty atmospheres (Group III, subgroup IIIB), protection principle: constructional safety, maximum surface temperature 110o C, and an equipment protection level of Db (i.e. for use in zone 21 & 22).
The above picture is an example of mechanical equipment (not for use in mining) for gas atmospheres (Group II, subgroup IIB), protection principle: constructional safety, Temperature class rating T3 (≥ 200o C), and an equipment protection level of Gc (i.e. for use in zone 2 only).
Why equipment and protective systems intended for use in explosive atmospheres must be ATEX-approved or certified?
ATEX approval and/or certification is a requirement to ensure that equipment and protective systems are suitable for their intended use within designated areas containing potentially explosive atmospheres.
Depending on the equipment category, which depends on the applicable hazardous zone for the intended use, the approval or certification process typically involves a Notified Body who can assess the conformity of the product and a third-party organization with a certified testing facility to test the product.
Gexcon’s explosion testing facility can help you with solutions related to ATEX equipment testing & approval, such as:
- The performance of Ignition Hazard Assessments (IHA) of non-electrical equipment
- Testing of protective devices and systems to obtain an ATEX approval
- Testing of non-electrical equipment for use in potentially explosive atmospheres: Category 1G/1D, 2G/2D & 3G/3D equipment for EX-zones 0/20, 1/21 & 2/22
- Tests to determine the electrostatic properties of mechanical equipment used in explosive atmospheres based on ISO 80079-36:2016
- Drop and mechanical impact test as referred to in ISO 80079-36:2016
We have tested various types of mechanical equipment and protective systems for use in potentially explosive atmospheres, such as pumps, valves, cutting tools, surface treatment equipment, explosion venting panels, flameless venting systems, explosion suppression systems, explosion isolation systems, flame arresters, etc.
To learn more about our ATEX equipment testing & approval solutions, please click here.
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