What does ATEX mean?

ATEX definition: Safety in potentially explosive atmospheres

ATEX, derived from the French “ATmosphère EXplosible”, defines the EU directives for explosion protection. These include, firstly, the Product Directive 2014/34/EU and, in addition, the Operational Directive 1999/92/EC, which has been in force since April 2016. As a result, these directives set standards for equipment and protective systems in potentially explosive atmospheres that must be transposed into national law by EU member states.

Fundamentals of the ATEX directives

The main purpose of the ATEX directives is to protect people in potentially explosive atmospheres. Accordingly, manufacturers must comply with essential health and safety requirements and demonstrate this through conformity assessment procedures.

In addition, the ATEX directive applies to explosion-protected electrical and mechanical systems, components and protective systems. Since July 1, 2003, only these may be used in potentially explosive atmospheres. In Germany, the EU Directive was implemented into national law by the Explosion Protection Products Regulation (11th ProdSV).

Explosion Hazard in the Workplace

When handling substances that react with oxygen, there is a risk of explosion if:

Oxygen is present in a space volume with a certain partial pressure
Oxygen is suspended in the air as a fine-grained dust
The proportion of flammable gas is between the lower and upper explosion limit = explosive gas-air mixture

Furthermore, an explosive atmosphere can be created by the dispersion of combustible substances in the air.

The explosion triangle makes it clear: flammable substance + oxygen + ignition source = explosion

Primary explosion protection: Avoid explosive atmospheres

Secondary explosion protection: Avoid effective sources of ignition

Tertiary explosion protection: Constructive explosion protection

ATEX equipment group classification

Since the introduction of EN 60079-0:2009, systems have been divided into three groups:

Group I	Group II	Group III
Mines at risk of firedamp – depending on explosive substance – Hazard increases from A to C	Explosive gases, which are divided into the following subgroups for some types of ignition protection (EX i, EX d, Ex n): IIA IIB IIC	Dusts are subdivided into Fiber IIIA Non-conductive dusts IIIB Conductive dusts IIIC
	Ex d = Flameproof enclosure Ex i = intrinsic safety Ex n = depending on the type, Ex nA or Ex nL or Ex ic
	Subgroup A: gasoline, diesel, ethane Subgroup B: town gas, ethylene, hydrogen sulfide Subgroup C: hydrogen, carbon disulfide

TBH extraction systems for explosion-proof areas

TBH offers extraction systems for explosion-proof areas that comply with the ATEX Product Directive 2014/34/EU and the DIN EN 1127-1:2007 standard. Here, systems in a category may only be used for certain zones; for example, category 2 systems are only permitted for zone 1 (for gases and vapors) or for zone 21 (for dusts). The following factors must be considered when selecting an extraction system:

Type and quantity of the material to be extracted
Possibility of reducing the released quantity
Contaminated air collection method
Existing ATEX zones and regulations
Necessity of an ignition hazard analysis

Based on these findings, the operator defines the ATEX zones in their production. For this, an ATEX consulting service provider can also be used. They can also create an explosion protection document. After evaluating the risk posed by the released substances and classifying the zones, the appropriate extraction system can finally be selected. TBH employees check the process parameters (amount of dust or gas, capture, required air volume flow, etc.) and the customer’s zone classification.

How is an ATEX system monitored?

When a system is operated in accordance with 137, it must be regularly inspected by approved inspection bodies in accordance with the Industrial Safety Regulation. To have the necessary expertise, qualified inspectors have professional training and experience and have recently carried out the activity. Systems must completely prevent the ignition of explosive atmospheres or at least reduce the effects to a sufficiently safe level. The inspection is carried out by TÜV Süd.

The CE mark is used for products whose manufacture must be supervised by a notified body. It applies to systems with an EC type examination certificate from a notified body (electrical equipment 0, 20, 1, 21 including combustion engines) and mechanical equipment for zones 0, 20.

Finally, systems and protective devices covered by the directive require a CE marking, an EC declaration of conformity (confirmation of compliance with the essential health and safety requirements) and a conformity assessment procedure. Only then can products be made available on the EU market, whether for a fee or free of charge.

For further information

Do you have any further questions?
Please call us at +49 (0) 7082/9473-0 or send us an e-mail to info@tbh.eu.