1. The work of CEN/TC 305 Potentially explosive atmospheres-
Explosion prevention and protection
Chair: Siegfried Radandt(FSA)
Secretary:Rainer Schmidt(DIN)

2. Available Structures:
WG1: Test methods for determining the flammability characteristics of substances in potentially explosive atmospheres( data for risk assessment and design of devices and systems for explosion prevention and protection )
WG2:Equipment for use in potentially explosive atmospheres
WG3: Devices and systems for explosion prevention and protection
WG4: Terminology and methodology( e.g.risk assessment methods )
WG5: Equipment and protection systems for mining

3. Characteristics of combustable substances for risk assessment, design of equipment, design of protective systems
Dust clouds:
Determination of maximum explosion pressure
Determination of limiting oxygen concentration
Determination of minimum ignition energy
Determination of the maximum rate of pressure rise of an explosion
Determination of the minimum explosive concentration of dust clouds
Determination of the spontaneous ignition behaviour of dust accumulations

4. Characteristics of combustible substances for risk assessment, design of equipment, design of protective systems
Gases and vapours:
Determination of the maximum rate of pressure rise of an explosion
Determination of the maximum explosion pressure
Determination of the lower and upper explosion limits
Determination of the minimum ignition temperature
Determination of the limiting oxygen concentration

5. Specifications for the design of non electrical equipment, components, elements of machinery
Basic method and requirements
Ignition hazard assessment,temperatures, non metallic parts,
Equipment containing light metals,removable parts,verification and tests
Protection by flow restricting enclosures
Protection by flame proof enclosures
Protection by inherent safety
Maximum energy and speeds
Protection by constructional safety
Moving parts, bearings, power transmission systems, clutches and couplings, brakes, springs and absorbing elements, conveyor belts
Protection by control of ignition sources(sensors,actuators)
Protection by pressurisation
Protection by liquid immersion
Safety requirements for ignition protected fans

6. Specifications for the design of protective systems
Explosion suppression systems
Explosion resistant equipment
Explosion venting devices
Dust explosion venting protective systems
Gas explosion venting protective systems
Explosion isolation
New work item as TR: Inertisation ( should not be mandated )

7. Definitions, methodologies, procedures, connections
Terms and definitions
Methodology for risk assessment of equipment
Methodology for risk assessment of protective systems
Requirements of quality systems
Explosion prevention and protection- Basic concepts and methodology ( revision of EN Part1)

8. Specific methods and requirements for prevention and protection in mines
EN 1127 Part 2 ( Basic concepts )
Explosion barriers
Water troughs for explosion barriers
Equipment for firedamp drainage
Automatic explosion installation at road headers
2-bar explosion proof ventilation structure
Machines for underground mines-Requirements for application in areas with firedamp hazards

9. State of Work
Available Documents: 4 ; Formal Vote: 5 ; Enquiry: 13 ; Working Dokuments: 15

10. Back ground Information about the User of Standards
RASE Project ( EU Project : SMT4-CT )
Title: Explosive atmospheres: risk assessment of unit operations and equipment
First Task: Inquiry on current experience from manufacturers
Second Task: Methodology for the risk assessment of unit operations and equipment

11. The main job of the firms
Manufacturers: 86%
Suppliers: 72%
Engineering contractors: 34%

12. The number of employees
5% of the inquired firms have less than 10 employees
44% of the inquired firms have a number of employees between 10 and 99
41% of the inquired firms have a number of employees between 100 and 499
10% of the inquired firms have more than 500 employees
That means that 90% are SMEs -