Updated ATEX standards

In sectors such as the (petro)chemical industry, paint industry, food sector, and wood processing, the risk of explosion is a daily concern. To optimally protect employees and ensure workplace safety, strict European guidelines and regulations apply: the ATEX standard.

Since the revision of the European directives, the ATEX 2014/34/EU directive (replacing the old ATEX 95) has been in effect. But what exactly does this regulation entail? What is the difference between machinery directives and safety regulations for employees? And what clothing and personal protective equipment (PPE) do you need to comply with the legislation?

In this comprehensive article, we will explain exactly how ATEX works, how the zone classification is structured, and what to look out for when it comes to antistatic and flame-retardant workwear.

What is ATEX?

The term ATEX is derived from the French name ATmosphères EXplosibles. It covers all situations where there is a risk of an explosive atmosphere forming.

An explosion can occur when flammable substances mix with oxygen from the air and an ignition source is present. This danger is not limited to gas or gasoline vapors; even invisible dust clouds from, for example, flour, wood, sugar, paper, or toner can lead to a violent dust explosion under the right conditions.

The explosion triangle

To better understand explosion hazards, we look at the explosion triangle. An explosion can only occur when the following three elements are simultaneously present:

1. Flammable substance: Gases, vapors, mists, or agitated dust (such as powder or flour).
2. Oxygen: Present in the ambient air (approximately 21%).
3. Ignition source: A spark (for example, due to static electricity from clothing or equipment), friction, a hot surface, or an open flame.

The purpose of the ATEX legislation is to prevent these three elements from coming together or to minimize the risk.

The difference between ATEX 114 and ATEX 153

Within the European Union, ATEX legislation is divided into two specific directives. These directives are enshrined in the Netherlands in the Commodities Act and the Working Conditions Act, respectively.

1. ATEX 114 (formerly ATEX 95) – Directive 2014/34/EU

• Focus: Equipment, machinery, and protective systems.
• Target group: Manufacturers, importers, and suppliers.
• Content: This directive determines the technical safety requirements that devices, tools, and safety systems must meet when used in potentially explosive atmospheres.
• Identification: Approved equipment and protective devices are provided with a specific hexagonal Ex symbol in combination with the CE marking and extensive technical documentation.

2. ATEX 153 (formerly ATEX 137) – Directive 1999/92/EC

• Focus: The working environment and employee safety in the workplace.
• Target group: Employers.
• Content: Under the Working Conditions Decree, employers are legally obliged to implement a policy that protects employees against explosion risks.

Employers must record the risks in an Explosion Protection Document (EPD), which includes:

• A thorough risk analysis and inventory (RA&E).
• A clear hazardous area classification of the workplace.
• Appropriate technical and organizational safety measures.
• Mandatory training and instruction of employees on safe working in ATEX zones.
• The physical marking of hazardous areas with the yellow warning triangle with 'EX'.

What types of explosion hazards are there?

Explosion hazards can manifest in three different forms:

1. Gas explosion hazard: Occurs when flammable gases are released and form mixtures with the air. This risk is measured in the workplace with a special LEL meter (Lower Explosive Limit).
2. Mist explosion hazard: Liquid flammable substances evaporate quickly, especially at higher temperatures. When liquids are atomized into very small droplets (as in spraying processes), the mist behaves like a gas and can easily ignite.
3. Dust explosion hazard: Finely divided solid substances (such as wood dust, flour, or chemical powders) agitated in the air can form an explosive dust cloud. A practical rule of thumb in the workplace: if visibility due to agitated dust is less than 1 meter, or if you can see clear footprints in a dust layer of at least 0.1 mm on the floor, there is an immediate risk of a dust explosion.

Classification of ATEX zones

Based on the ATEX 153 directive, the employer is obliged to divide risk areas into specific ATEX zones. This classification is based on the frequency and duration in which an explosive mixture may be present.

Zones for gases, vapors, and mists are assigned numbers 0, 1, and 2. Zones for combustible dust are assigned numbers 20, 21, and 22.

Equipment and protective devices are categorized based on these zones, ensuring the correct level of protection is always present.

Is ATEX a standard for clothing?

A common misconception in the workplace is the search for "ATEX-certified clothing". ATEX is not a clothing standard, but a European legal directive for the entire working environment and equipment.

Because garments and human skin can build up electrostatic charges, a sudden spark discharge can cause an explosion in an ATEX zone. To eliminate this risk, the ATEX directive states that workwear and shoes worn must comply with specific European safety standards.

EN 1149-5: The overarching standard for antistatic clothing

Protective clothing worn in ATEX environments must be certified according to the EN 1149-5 standard (Electrostatic properties - Performance requirements). Clothing with this certification prevents static electricity from building up, thus eliminating the risk of sparking.

What requirements does the EN 1149 standard impose?

• Conduction via an earthed system: Antistatic clothing only works optimally when the wearer is fully earthed. This means that the clothing must be worn in combination with electrically conductive footwear (such as ESD or antistatic work shoes).
• Combination requirement with flame retardancy (EN ISO 11612 / EN 531): Clothing that complies with EN 1149-5 may only be accepted if the fabric is also certified for flame-retardant properties (EN ISO 11612). After all, if there is an explosion hazard in an environment, there is also an immediate risk of fire and heat upon ignition.
• Covered metal parts: Metal buttons, zippers, and fasteners must never be directly exposed on the outside; they must always be covered by the fabric to prevent sparks on contact.
• Continuous contact: The conductive outer fabric or hem must remain in direct or indirect contact with the skin/earthing.

Questions about ATEX and the right safety clothing?

Working in an ATEX environment requires extreme precision and the right protective equipment. At Unishore Workwear, we have a wide range of Multinorm workwear, flame-retardant clothing, and antistatic work shoes that fully comply with the EN 1149-5 and EN ISO 11612 standards.

Do you want to know which multinorm clothing is suitable for the zone classification within your company? Feel free to contact our PPE specialists for tailor-made advice.