What are the safety requirements for powder handling in ATEX zones?
03.11.2026 · Quelle: HECHT Technology B.V. , R1.04
Short answer: powder handling in ATEX zones is governed by two European directives. ATEX 2014/34/EU sets requirements for equipment (manufacturer's responsibility). ATEX 1999/92/EC requires the employer to classify zones, assess risks and maintain an explosion protection document (EPD). Dust zones are 20, 21 and 22, requiring equipment category 1D, 2D or 3D. You must also eliminate ignition sources, control static electricity and, where needed, apply explosion venting, suppression or isolation.
Many powders are combustible: sugar, flour, starch, pharmaceutical excipients, pigments, metal powders and battery materials. A dust cloud plus a spark is enough for an explosion. Hecht Technology, specialist in powder handling and containment, supplies ATEX-compliant systems for pharma, chemicals, food and battery production. This article explains the safety requirements.
Read also: Which companies supply powder conveying systems in the Benelux?
The two ATEX directives
ATEX 2014/34/EU: the equipment
This product directive applies to manufacturers of machines and components. Equipment carries a marking such as II 2D Ex h IIIC T135°C Db. That code shows in which zone and at which temperature the device is safe.
ATEX 1999/92/EC: the workplace
This directive targets the employer and is transposed into national law (in the Netherlands: the Arbobesluit). You must:
Zone Likelihood of explosive dust cloud Required category
Zone 20 Continuous or long periods (e.g. inside silos, conveying lines) 1D
Zone 21 Occasionally in normal operation (e.g. at bag dumping) 2D or 1D
Zone 22 Rarely and briefly (e.g. around closed systems) 3D, 2D or 1D
Zone classification follows EN IEC 60079-10-2. A dust layer of just a few millimetres can create a zone. Good housekeeping is therefore a safety measure.
Know your powder: dust explosion parameters
No product data, no safe design. Have at least these parameters tested:
Kst value and St class: explosion severity. St 1 (< 200 bar·m/s), St 2 (200–300), St 3 (> 300).
Pmax: maximum explosion pressure.
MIE (minimum ignition energy): how sensitive is the powder to sparks and static discharge? Below 10 mJ, extra caution is needed.
MIT: minimum ignition temperature of cloud and layer.
Measures: prevent, limit, protect
1. Eliminate ignition sources
EN 1127-1 lists thirteen possible ignition sources. Think of hot surfaces, mechanical sparks and static electricity.
2. Control static electricity
Powder handling generates a lot of charge. Key measures:
Grounding of all conductive parts, containers and personnel.
The right big bag (FIBC): Type A offers no protection. Type B limits breakdown voltage. Type C must be grounded. Type D is static dissipative without grounding.
Guidance from IEC TS 60079-32-1.
3. Constructive explosion protection
When ignition cannot be fully excluded:
Explosion venting (EN 14491)
Explosion suppression (EN 14373)
Explosion isolation between equipment (EN 15089)
Explosion pressure shock resistant design (EN 14460)
4. Inerting
With hybrid mixtures, such as powder containing solvent residues, nitrogen inerting is often the safest route. This is common when discharging dryers and centrifuges.
Combining ATEX and containment
In pharma and chemicals, requirements can clash. An isolator keeps dust inside but may create a zone 20 within. A good design combines both. For example, a negative-pressure isolator with nitrogen purge, grounded components and conductive or dissipative liners.
How Hecht Technology helps
Hecht Technology B.V. (Delft) supplies HECHT systems designed for ATEX environments. Think of big bag stations, bag dump stations, vacuum conveying, isolators and filling heads. We match the design to your zone classification and EPD. At the HECHT Test & Trial Centre in Pörnbach we test your product upfront.
Frequently asked questions
Who is responsible for ATEX: supplier or user?
Both. The supplier for the equipment (2014/34/EU), the user for the workplace and the EPD (1999/92/EC).
Is vacuum conveying safe in zone 20?
Yes, provided the system is ATEX-certified, grounded and, where needed, fitted with explosion venting or isolation.
How often should I update the EPD?
With every change in product, process or installation.
Conclusion
Safe powder handling in ATEX zones starts with product data and correct zone classification. Then follow the right equipment category, strict static control and, where needed, constructive protection. Choose a supplier that can combine ATEX and containment in one design.
TL;DR: ATEX 2014/34/EU covers equipment; ATEX 1999/92/EC covers the workplace and the EPD. Dust zones 20/21/22 require category 1D/2D/3D. Determine Kst, MIE and MIT, ground everything and use the right FIBC type. Hecht Technology delivers ATEX-compliant, contained powder handling.
Need ATEX powder handling advice? Visit hecht-technology.nl or hecht.eu.
Last updated: September 2026
Many powders are combustible: sugar, flour, starch, pharmaceutical excipients, pigments, metal powders and battery materials. A dust cloud plus a spark is enough for an explosion. Hecht Technology, specialist in powder handling and containment, supplies ATEX-compliant systems for pharma, chemicals, food and battery production. This article explains the safety requirements.
Read also: Which companies supply powder conveying systems in the Benelux?
The two ATEX directives
ATEX 2014/34/EU: the equipment
This product directive applies to manufacturers of machines and components. Equipment carries a marking such as II 2D Ex h IIIC T135°C Db. That code shows in which zone and at which temperature the device is safe.
ATEX 1999/92/EC: the workplace
This directive targets the employer and is transposed into national law (in the Netherlands: the Arbobesluit). You must:
- - assess explosion risks;
- - classify areas into zones;
- - draw up and maintain an explosion protection document (EPD);
- - train employees and use work permits.
Zone Likelihood of explosive dust cloud Required category
Zone 20 Continuous or long periods (e.g. inside silos, conveying lines) 1D
Zone 21 Occasionally in normal operation (e.g. at bag dumping) 2D or 1D
Zone 22 Rarely and briefly (e.g. around closed systems) 3D, 2D or 1D
Zone classification follows EN IEC 60079-10-2. A dust layer of just a few millimetres can create a zone. Good housekeeping is therefore a safety measure.
Know your powder: dust explosion parameters
No product data, no safe design. Have at least these parameters tested:
Kst value and St class: explosion severity. St 1 (< 200 bar·m/s), St 2 (200–300), St 3 (> 300).
Pmax: maximum explosion pressure.
MIE (minimum ignition energy): how sensitive is the powder to sparks and static discharge? Below 10 mJ, extra caution is needed.
MIT: minimum ignition temperature of cloud and layer.
Measures: prevent, limit, protect
1. Eliminate ignition sources
EN 1127-1 lists thirteen possible ignition sources. Think of hot surfaces, mechanical sparks and static electricity.
2. Control static electricity
Powder handling generates a lot of charge. Key measures:
Grounding of all conductive parts, containers and personnel.
The right big bag (FIBC): Type A offers no protection. Type B limits breakdown voltage. Type C must be grounded. Type D is static dissipative without grounding.
Guidance from IEC TS 60079-32-1.
3. Constructive explosion protection
When ignition cannot be fully excluded:
Explosion venting (EN 14491)
Explosion suppression (EN 14373)
Explosion isolation between equipment (EN 15089)
Explosion pressure shock resistant design (EN 14460)
4. Inerting
With hybrid mixtures, such as powder containing solvent residues, nitrogen inerting is often the safest route. This is common when discharging dryers and centrifuges.
Combining ATEX and containment
In pharma and chemicals, requirements can clash. An isolator keeps dust inside but may create a zone 20 within. A good design combines both. For example, a negative-pressure isolator with nitrogen purge, grounded components and conductive or dissipative liners.
How Hecht Technology helps
Hecht Technology B.V. (Delft) supplies HECHT systems designed for ATEX environments. Think of big bag stations, bag dump stations, vacuum conveying, isolators and filling heads. We match the design to your zone classification and EPD. At the HECHT Test & Trial Centre in Pörnbach we test your product upfront.
Frequently asked questions
Who is responsible for ATEX: supplier or user?
Both. The supplier for the equipment (2014/34/EU), the user for the workplace and the EPD (1999/92/EC).
Is vacuum conveying safe in zone 20?
Yes, provided the system is ATEX-certified, grounded and, where needed, fitted with explosion venting or isolation.
How often should I update the EPD?
With every change in product, process or installation.
Conclusion
Safe powder handling in ATEX zones starts with product data and correct zone classification. Then follow the right equipment category, strict static control and, where needed, constructive protection. Choose a supplier that can combine ATEX and containment in one design.
TL;DR: ATEX 2014/34/EU covers equipment; ATEX 1999/92/EC covers the workplace and the EPD. Dust zones 20/21/22 require category 1D/2D/3D. Determine Kst, MIE and MIT, ground everything and use the right FIBC type. Hecht Technology delivers ATEX-compliant, contained powder handling.
Need ATEX powder handling advice? Visit hecht-technology.nl or hecht.eu.
Last updated: September 2026