ATEX manager

Development of a web-based tool to support companies in controlling explosion risks

Henri Heussen

& Dook Noy

Introduction

• VAST programme (Ministry of Social Affairs)

• Goal: reinforcement of working conditions in SME’s with regard to hazardous substances

• Key elements:– creating awareness– improvement of communication in the chain– development of supporting tools

• Stoffenmanager: generic web-based tool for risk prioritization (www.stoffenmanager.nl)

• 2th stage: development of branche specific versions of Stoffenmanager and additional modules => ATEX manager

• Developed by Arbo Unie, BECO group and TNO

ATEX manager

• Starting point: guidelines for controlling explosion risks in the animal fodder industry

• Conversion to web-based specific tool for animal fodder industry

• Development of generic tool for SME’s

• Modules:– Quick Scan explosion hazards (applicability ATEX guidelines)– Data entry materials, process equipment, production locations– Classification of hazardous areas into zones (combustible

dusts/flammable gases/vapours/mists)– Evaluation of ignition risks– Generation of Explosion Protection Documents

Quick Scan combustible dusts

Combustible dust present?

Interior process

equipment?

Process equipment

located outdoors?

> 50 kg dust (particle size <

0,1 mm)?

> 50 kg dust (particle size

between 0,1-0,5 mm)?

> 1 kg dust (particle size

between 0,1-0,5 mm?

> 0,1 kg dust (particle size <

0,1 mm?

Zoning

not necessary

Zoning necessary

no yes

no

no

no no

no no

yes

yes

yes yes

yes yes

Start quick scan

Data entry materials

• Large set of parameters– Combustible dusts:

• Lower Explosion Limit (LEL)• Minimum Ignition Temperature cloud (IT)• Minimum Ignition Temperature layer (GT)• Mimimum Ignition Energy (MIE)• Maximum Rate of Explosion Pressure Rise

(dp/dt)max

• Kst ( = (dp/dt)max ,volume dependent)

• Dust Explosion Class (based on Kst)• Flammability (BZ)• Particle size• Limiting Oxygen Concentration (LOC)

• Optional future development: explosion hazard banding based on parameters like:– Ignition temperatures and –energy, flammability– Dust Explosion Class

Zoning (dust cloud)

Dust cloud present > 1000

hours/year?

Dust cloud present > 10 hours/year?

Well designed local

ventilation?

Additional guaranties?

Absoluty guaranteed?

Well designed local

ventilation?

Well designed local

ventilation?

Zone 20

Zone 21

no

yes

Additional guaranties?

Zone 22

NHA

no

no

nono

no

no

no

yes

yes

yes

yes

yes yes

yes

Evaluation of ignition risks

Chose potential ignition source

Export to Action Plan?

Document decision

Zone

Describe scenario

Choose frequency scenario

Choose severity of effects scenario

Risk level

acceptable?

Describe and evaluate potential measures

Action Plan

no

no

yes

yes

Risk bands

A: high riskB: substantial riskC: limited riskD: low risk

Likelyhood

Adverse effects

Catastrophal

Serious Not serious Neglectible

Frequently A A A C

Likely A A B D

Possible A B B D

Unlikely A B C D

Highy unlikely

B C C D

Control banding?

Hazard bands

Ignition/combustion

characteristics

Explosion

characteristics

Control bands

Prevention:

- ignition sources => technical measures

=> organ. measures

-inerting => limiting oxygen

- combustible/flammable materials=> product elimination

=> product modification

Protective/corrective:

- explosion relief

- explosion suppression

- explosion resistant design

Explosion

triangle

O2

Ignition

sources

Flammable

substances

Higher hazard ignition band

Higher hazard explosion band

THANK YOU!