2. 2
This presentation explains the explosion hazard
and the related possibility to form a potentially
explosive atmosphere.
The reader will be given information about the
identification of ignition sources and the type of
explosions that could occur. An introduction to the
evaluation of the explosion risk and the prevention
measures that can be put in place to avoid the
creation of potentially explosive atmosphere is also
given.
Introduction
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3. 1. Risk identification
and safety
2. Transport and
storage
3. Fire and explosion
protection
4. Emergency
response
11. Chemical classification
and labelling
21. Internal transport of
chemicals
31. Fire protection
41. Emergency response
plan
12. Risk assessment
22. Internal pedestrian
routes
32. Fire protection in
welding and cutting
operations
13. Safety rules 23. Storage 33. Explosion protection
14. Personal protective
equipment
34. Container cleaning
15. Skin protection
16. Emergency escape
routes
17. Handling of solvents,
acids and bases
18. Safety in gas tank
handling
Hazard Management
Checklists
4. 4
1. Explosion Hazard Concepts
Potentially explosive atmosphere
Ignition sources
Types and effects of explosions
2. Risk Assessment
3. Risk Reduction Measures
Prevention measures
Construction measures
Organizational measures
4. Sources
Contents
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6. 6
Explosion Hazard
What is an explosion?
An explosion is a very fast chemical
reaction of a flammable substance
releasing considerable amounts of energy.
When does an explosion occur?
Potentially explosive
atmosphere
Effective ignition source
+
Mixture with air, under atmospheric conditions,
of combustible substances such as gases,
vapours, mists or dusts in which, after
ignition has occurred, combustion spreads to
the entire unburned mixture.
An ignition source is considered effective if it
provides enough energy to the atmosphere for
the combustion to go on by itself.
Source: Londoño G.
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7. 7
Explosion Hazard – Potentially Explosive Atmosphere
The formation of a potentially explosive atmosphere
depends on:
The presence of a combustible substance
The degree of dispersion of the combustible substance
Whether the concentration of the combustible substance in
the air is in the explosive range
The presence of a potentially explosive atmosphere in such
quantity that it would induce damage if ignited
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8. 8
Explosion Hazard – Ignition Sources
An ignition source is effective if it provides enough energy to the
potentially explosive atmosphere to cause a combustion which
propagates spontaneously.
The energy of the ignition sources
present in an industrial workplace is
generally higher than the minimum
ignition energy, which means that
ignition sources are almost always
effective.
Static discharge
Sparks of electrical origin
Fire, flames, embers
Sparks of mechanical origin
Warm surfaces
Source: Suva
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9. 9
Explosion Hazard – Types of Explosions
What are the different types of explosions?
Physical explosion
Example: explosion of
a boiler containing
water
- Physical rupture of
the boiler
- No chemical
explosion of the
released water
Chemical explosion
Example: chemical
reaction between two
compounds, which
increases the pressure
in the container, leading
to an explosion
BLEVE* (physical/
chemical explosion)
Example: rupture of a
container (e.g. due to a
pressure increase) and
instant chemical
explosion of flammable
butane
Particularly dangerous
type of explosion
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10. 10
Explosion Hazard – Effects of an Explosion
What are the effects of an explosion?
Flames
Thermal radiation
Blast effects
Projections
Release of dangerous substances
The effects depend on:
The chemical, toxic and physical properties of the released and produced
combustion products
The quantity and the confinement of the potentially explosive atmosphere
The geometry of the environment
The solidity of the structures, installations and buildings
The protective equipment worn by the staff at risk
The physical properties of the objects at risk
WARNING: Flames propagating in a
potentially explosive atmosphere can
take a volume up to 10 times greater
than that of the explosive atmosphere
before its ignition.
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11. 11
Explosion Hazard – Warning
Warning:
Warning for companies
producing, using or storing
liquefied gases (e.g.
propane, butane): The
increase in pressure
induced by an increase in
temperature follows an
exponential law!
A slight increase in
temperature can trigger an
explosion.
Source: Suva
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12. 12
Explosion Hazard – Relative Density
Given the properties and the relative density of the substances stored,
produced or used, the potentially explosive mixtures will tend to spread at the
ground level or to rise.
The relative density of
the gas influences the
design of the
ventilation system.
Source: Suva
Flow of liquefied gases
Source: Suva
A
Flow of solvent vapours
Source: Suva
B
Gas examples:
Higher density than air: butane, most solvents
Lower density than air: ammonia, hydrogen
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13. 13
Explosion Hazard – Explosive Range and Flash Point
Explosive range
The mixtures of flammable gases/vapours with the
air can only lead to a spontaneous combustion or
an explosion if the vapour proportion of the mixture
is in the range between the upper and lower
explosive limits.
Flash point
The flash point is the lowest temperature at which
a liquid releases enough vapours to form a
potentially explosive atmosphere at the surface.
With the presence of an ignition source, the
mixture ignites.
Source: CSD Source: Based on FOEN
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15. 15
Risk Assessment
What are the elements of a risk analysis?
To reach the expected safety level, a risk analysis should be
undertaken for each specific case and include the following
elements:
Identification of
explosion hazards
Risk estimation Risk evaluation Risk reduction
Are the substances
combustible?
What is their degree of
inflammability?
Can an explosive atmosphere form?
Are ignition sources present?
What are the consequences?
Prevention/
Protection measures
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16. 16
Combustible substances present?
NoYes
Possible formation of a potentially
explosive mixture by dispersion in the air?
NoYes
Possible formation of a potentially
explosive atmosphere?
NoYes
Formation of a dangerous potentially
explosive atmosphere safely prevented ?
YesNo
No preventive measures against
explosions required
Preventive measures against
explosions required
Preventive measures against
explosions required
Protection measures against
explosions required
Formation of a dangerous potentially
explosive atmosphere safely prevented ?
YesNo
No preventive measures against
explosions required
No preventive measures against
explosions required
Restrict the formation of dangerous
potentially explosive atmospheres
Eliminate the ignition sources in
areas where potentially explosive
atmospheres are likely to occur
Reduce the consequences of
explosions to a harmless level
No preventive measures against
explosions required
No preventive measures against
explosions required
EvaluationoftheExplosionRisk
Source: Based on Suva
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18. 18
Prevention Measures
Prevention measures aim at:
1. Preventing the formation of a potentially explosive atmosphere
2. Avoiding the ignition of the potentially explosive atmosphere
Primary measures
• Replacement
• Inerting
• Closed systems
• Ventilation
• Detection/Action
Secondary measures
• Classification in
explosion hazard zones
• Elimination of the
ignition sources
Tertiary measures
• Hazard-resistant
construction
• Explosion relief
• Explosion suppression
• Explosion decoupling
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19. 19
Hazardous Substances
Prevention measures should be taken for:
Flammable gases
Flammable liquids with a flash point lower than 30°C
Flammable liquids with a flash point superior to 30°C when
they are heated above their flash point temperature
Flammable liquids appearing in the form of mists
Combustible dust formed by particles with a diameter inferior
to 0.5 mm
Potentially explosive
atmosphere
Source: Suva
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20. 20
Preventing the Formation of a Potentially Explosive
Atmosphere – Labelling
The equipment (containers, tanks and pipes) should be
appropriately labelled (always visible and permanently
labelled).
Source: Suva
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21. Risk Reduction Measures
Measures Preventing the Formation of Potentially Explosive
Atmospheres
Measures Preventing the Ignition of Potentially Explosive and
Dangerous Atmospheres
Construction measures
Organizational measures
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21
22. 22
Preventing the Formation of a Potentially Explosive
Atmosphere – Substitution and Restrictions
Replace easily flammable liquids, gases and dusts by
substances that do not cause a potentially explosive
atmosphere:
Aqueous solutions
Non-flammable halogenated hydrocarbons
Solvents or mixtures with a flash point superior to 30°C and/or greater than
the working temperature (15 °C higher for mixtures and 5 °C for pure
liquids)
Low-dust materials
Pasty products
Limit concentrations of flammable substances to ensure that
they are not in the explosive range:
Maintain concentrations below the explosive limit.
Keep the temperature of the mixture 15°C lower than the flash point and
5°C lower for pure flammable liquids.
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23. 23
Preventing the Formation of a Potentially Explosive
Atmosphere – Inerting
Inert the volume of a
container to ensure that the
oxygen concentration is
lower than the critical value
(limiting oxygen
concentration – LOC).
Example: Add an inert
substance (nitrogen, carbon
dioxide) to partially replace the
oxygen in a silo containing
potentially combustible dusts.
Limited O2
concentration
Air
Nitrogen
Source: Suva
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24. 24
Preventing the Formation of a Potentially Explosive
Atmosphere – Closed Systems
Use closed systems to avoid the formation
of a potentially explosive atmosphere
outside the system:
Gas recovery
Filling and emptying with a lock system
Soldered or welded pipes
Crimped pipes
Long-term tight equipment
Reduce leakage:
Limit the number and dimensions of dismountable
connections to a minimum.
Limit the use of flexible pipes.
Ensure the integrity of the piping (e.g. protection). Source: Suva
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25. 25
Preventing the Formation of a Potentially Explosive
Atmosphere – Ventilation
Natural ventilation can be used to prevent or limit the
formation of a potentially explosive atmosphere.
Minimum of two openings leading to the
open air
Transversal ventilation
Position of the openings depends on the
density of the substance
Dimensions: 20 cm2/m2 of floor area
Natural ventilation
Source: Suva
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26. 26
Preventing the Formation of a Potentially Explosive
Atmosphere – Ventilation
Artificial ventilation can be used to prevent or limit the
formation of a potentially explosive atmosphere.
Extraction height depending on the density of the
substances (A: substances denser than the air,
B: substances less dense than the air)
Transversal ventilation
Evacuation to a safe area
Air renewal
3-5 times per hour (storage)
10 times per hour (open handling)
Continuous or intermittent ventilation
Ventilation at the source if technically possible
Artificial ventilation
Source: Suva
Source: Suva
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27. 27
Preventing the Formation of a Potentially Explosive
Atmosphere – Ventilation
Artificial ventilation
If possible, the
ventilation should be
positioned directly
where the flammable
substances are mixed,
treated, opened or
handled.
Source: Suva
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28. 28
Preventing the Formation of a Potentially Explosive
Atmosphere – Ventilation
Artificial and natural ventilation
Ground level
Natural or artificial ventilation
Artificial ventilation required
Source: Suva
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29. 29
Preventing the Formation of a Potentially Explosive
Atmosphere – Storage
Flammable and highly flammable liquids as well as
aqueous substances can trigger dangerous chemical
reactions when mixed together. We call them incompatible
substances.
Such substances should be
stored in a way to prevent any
contact between flammable
liquids and peroxides, chromic
acid, nitric acid or halogens.
Source: Suva
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30. 30
Preventing the Formation of a Potentially Explosive
Atmosphere – Dusts
Dust deposited on the floor may be dispersed in the air.
In the presence of flammable gases or vapours, hybrid
mixtures may form.
Source: Swissi
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31. 31
Preventing the Formation of a Potentially Explosive
Atmosphere – Storage
Legend
+
-
o
Can be stored together
Cannot be stored together
Can be stored together, under
certain conditions (check the
SDSs)
Objective
Avoid dangerous reactions
D23_1_Storage
Source: Based on Neosys
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32. Preventing the Formation of a Potentially Explosive
Atmosphere – GHS Pictograms (Reminder)
Explosive
Flammable
Oxidizing
Compressed gases
Corrosive
Toxic
Irritant
Health hazard
Environmentally damaging
GHS hazard pictograms
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Source: UN GHS 2013
33. 33
Preventing the Formation of a Potentially Explosive
Atmosphere – Storage
The equipment, installations, pipes, etc. should be
protected against thermal impact:
Fireproof premises and doors
Fire compartments
Construction in non-flammable materials
Containment measures should be taken to prevent liquids
from spreading:
Safety sills
Retention basins
Source: Suva
Source: Suva
D23_1_Storage
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34. 34
Preventing the Formation of a Potentially
Explosive Atmosphere – Recap
Substitution of dangerous substances
Limitation of concentrations
Inerting of containers
Use of closed systems
Use of natural and artificial ventilation
Appropriate labelling of containers
Separate storage of incompatible substances
Protecting equipment, installations and pipes against thermal impact
Installing containment measures (safety sills, retention basins)
Artificial ventilation
Source: Suva
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35. 35
Preventing the Formation of a Potentially
Explosive Atmosphere – Exercise
You need to store 500 l of acetone and 500 l of
sulphuric acid .
Which measures do you take to prevent the
formation of a potentially explosive atmosphere?
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36. 36
Preventing the Formation of a Potentially
Explosive Atmosphere – Exercise
Legend
+
-
o
Can be stored together
Cannot be stored together
Can be stored together, under
certain conditions (check the
SDSs)
Objective:
Avoid dangerous reactions
Source: Based on Neosys
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37. 37
Preventing the Formation of a Potentially
Explosive Atmosphere – Exercise
What are the possible storage solutions?
What measures should be taken?
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38. 38
Preventing the Formation of a Potentially
Explosive Atmosphere – Exercise
Source: Suva
Source: Suva
Flammable substances should be isolated by
firewalls.
The two substances are incompatible so they
should be stored in separate premises.
Acetone Sulfuric acid
The storage premises should include retention
basins and safety sills.
An effective ventilation system should be installed.
Natural ventilation
Source: Suva
Artificial ventilation
Source: Suva
Source: CSD
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39. Risk Reduction Measures
Measures Preventing the Formation of Potentially Explosive
Atmospheres
Measures Preventing the Ignition of Potentially Explosive and
Dangerous Atmospheres
Construction measures
Organizational measures
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39
40. 40
Preventing the Ignition of a Potentially Explosive
Atmosphere – Explosion Hazard Zones
Classification in explosion hazard zones:
To reduce the risk of explosions, areas are identified and
classified in explosion hazard zones. Their classification
defines the requisite safety level and the type of
equipment that can or cannot be used within the zone.
Using equipment with appropriate
protection means reduces the risk of
igniting a potentially explosive
atmosphere.
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Source: CSD
41. 41
Preventing the Ignition of a Potentially Explosive
Atmosphere – Explosion Hazard Zones
Classification in explosion hazard zones:
In Europe: ATEX
In USA: NFPA
NFPA 497: Recommended Practice for the Classification of
Flammable Liquids, Gases or Vapors and of Hazardous
(Classified) Locations for Electrical Installations in Chemical
Process Areas
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42. 42
Preventing the Ignition of a Potentially Explosive
Atmosphere – ATEX vs. NFPA Explosion Zones
Correspondence between ATEX and NFPA
ATEX NFPA
Zone 0 (gases/vapours)
Zone 1 (gases/vapours)
Class I, Division 1
Zone 2 (gases/vapours) Class I, Division 2
Zone 20, 21, 22 (dusts) Class II, Divisions 1 and 2
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43. 43
Preventing the Ignition of a Potentially Explosive
Atmosphere – NFPA Explosion Zones (1)
Classification in explosion hazard zones (NFPA):
Class I, Div. 1: Where ignitable concentrations of flammable
gases, vapours or liquids are present continuously or
frequently within the atmosphere under normal operation
conditions.
Class I, Div. 2: Where ignitable concentrations of flammable
gases, vapours, or liquids are present within the atmosphere
under abnormal operating conditions.
Class II, Div. 1: Where ignitable concentrations of
combustible dusts are present within the atmosphere under
normal operation conditions.
Source: www.iebmedia.com
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44. 44
Preventing the Ignition of a Potentially Explosive
Atmosphere – NFPA Explosion Zones (2)
Classification in explosion hazard zones (NFPA):
Class II, Div. 2: Where ignitable concentrations of
combustible dust are present within the atmosphere under
abnormal operating conditions.
Class III, Div. 1 (*): Where easily ignitable fibres or materials
producing combustible flyings are present within the
atmosphere under normal operation conditions.
Class III, Div. 2 (*): Where easily ignitable fibres or materials
producing combustible flyings are present within the
atmosphere under abnormal operating conditions.
(*) – No ATEX correspondence
Source: www.iebmedia.com
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45. 45
Preventing the Ignition of a Potentially Explosive
Atmosphere – ATEX Explosion Zones (1)
Classification in explosion hazard zones (ATEX)
Area where the potentially
explosive atmosphere occurs:
Zone 0 (gases/vapours)
Zone 20 (dusts)
- Constantly present
- Present for long periods
- Frequently present for short periods
Zone 1 (gases/vapours)
Zone 21 (dusts)
- Possible periodically
- Occasionally present under normal
operating conditions
Zone 2 (gases/vapours)
Zone 22 (dusts)
- Rarely possible and for short periods
only
Zone N.D - Very improbable
Nobody should work in
zones 0 and 20
ConcentrationConcentrationConcentration
Time
Time
Time
Zone 0/20
Zone 1/21
Zone 2/22
Source: Suva
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46. 46
Preventing the Ignition of a Potentially Explosive
Atmosphere – ATEX Explosion Zones (2)
Equipment categories and explosion hazard zones
Equipment
category
Usage zones
Requisite
level of
protection
Guaranteed safetyGases
Vapours
Mists
Dusts
Category 1
Zone 0
Zone 1
Zone 2
Zone 20
Zone 21
Zone 22
Very high
Even in the event of rare incidents, these
devices have protection means such that:
- In the event of failure of one means of
protection, at least an independent
second means provides the requisite
level of protection,
- The requisite level of protection is
assured in the event of two faults
occurring independently of each other.
Category 2
Zone 1
Zone 2
Zone 21
Zone 22
High In case of foreseeable disturbances
Category 3 Zone 2 Zone 22 Normal Under normal operating conditions
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47. 47
Classification in Explosion Hazard Zones (ATEX)
Easily flammable liquids (storage)
Zone 2
Source: Suva
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48. 48
Classification in Explosion Hazard Zones (ATEX)
Highly flammable liquids (e.g. blending facilities,
decanting)
Source: Suva
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49. 49
Classification in Explosion Hazard Zones (ATEX)
Flammable gases (for gases lighter than the air)
Source: Suva
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50. 50
Preventing the Ignition of a Potentially Explosive
Atmosphere – Equipment in Explosion Zones
Use of equipment in explosion zones:
USA:
Certification of electrical equipment according to National Electric
Code (NEC)
Europe:
Certification of electrical and mechanical equipment according to
ATEX
Rest of the world:
Local regulations and International Electrical Committee (IEC)
standards
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51. 51
Preventing the Ignition of a Potentially Explosive
Atmosphere – Equipment in Explosion Zones
Marking of explosion-proof equipment
Flammable gas and vapour
Source: SWISSI Process Safety Ltd.
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52. 52
Preventing the Ignition of a Potentially Explosive
Atmosphere – Equipment in Explosion Zones
Marking of explosion-proof equipment
Combustible dust
Source: SWISSI Process Safety Ltd.
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53. 53
Preventing the Ignition of a Potentially Explosive
Atmosphere – Measures (1)
Elimination of ignition sources
In premises exposed to explosion risk, every
electrical device should be protected from the
explosion risk.
In Zones 0 and 20, devices that can produce sparks
should not be used.
In Zones 1 and 2, sparks are tolerated only if
special prevention measures are taken (combination
of adequate materials, etc.)Source: Suva
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54. 54
Preventing the Ignition of a Potentially Explosive
Atmosphere – Measures (2)
Elimination of ignition sources
- Smoking banned
- Open-flame devices should not be used in
explosion zones. Flame or spark generating
maintenance work (e.g. cutting or welding) must be
performed on clean equipment and authorized by
special work permits.
- Preventing smouldering fires:
- Eliminate dust deposits.
- Maintain surfaces humid.
- Use spark detection and extinguishing
systems.
- In Zone 0, the surface temperature should be 20%
lower than the combustible’s ignition
temperature.
- In Zones 1 and 2, the surface temperature should
never be higher than the combustible’s ignition
temperature.
- In Zones 20, 21, 22, the surface temperature
should not exceed two thirds of the combustible’s
minimum ignition temperature.*
Source: Suva
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55. Preventing the Ignition of a Potentially Explosive
Atmosphere – Measures (3)
Elimination of ignition sources
- Only use grounded conductive or dissipative hoses,
pipes, containers, etc. while handling flammable
liquids.
- In Zones 1 and 21, ground the staff by using shoes
and floors enabling the dissipation of electrostatic
charges.
- Use grounded metal containers when decanting
flammable substances.
Metal container not grounded Grounded metal container
Source: Suva
Source: Suva
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56. 56
Preventing the Ignition of a Potentially Explosive
Atmosphere – Measures (4)
- When decanting flammable liquids, the container,
the tank and the other conductor elements should
be conductive, bonded and grounded. The tanks’
support should also be grounded.
- The flow rate of the flammable substances should
be reduced to a minimum.
Source: Suva
Grounded containers
- Any conductor element
from any installation
should be bonded and
grounded.
- Containers and pipes
should not have
insulating inner
linings*.
Source: Suva
Source: Suva
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57. 57
Preventing the Ignition of a Potentially Explosive
Atmosphere – Measures (5)
Eliminating the ignition source
- Buildings and installations comprising
explosion hazard zones should be protected
against lightning strikes (e.g. Faraday cage).
Lightning
Chemical reactions
- Improve the heat dissipation (e.g. smaller storage
units, store in intermediate premises).
- Regulate the pressure and temperature.
- Store at lower temperatures.
- InertingSource: Suva
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58. 58
Preventing the Ignition of a Potentially Explosive
Atmosphere – Recap
Classification in explosion hazard zones (ATEX)
Equipment categories and explosion hazard zones
Elimination of ignition sources
Static discharge
Sparks of electrical origin
Fire, flames, embers
Sparks of mechanical origin
Warm surfaces
Ignition sources
Zone 2
Source: Suva
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59. 59
Preventing the Ignition of a Potentially Explosive
Atmosphere – Question 1
A storage area containing methanol has been
classified as a Hazard Zone 2.
Zone 2
Concentration
Time
Zone 2/22
Source: Suva
Source: Suva
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60. 60
Preventing the Ignition of a Potentially Explosive
Atmosphere – Question 1
What measures should you take to prevent
the ignition of a potentially explosive
atmosphere?
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61. 61
Preventing the Ignition of a Potentially Explosive
Atmosphere – Answer
Zone 2
Eliminate the ignition sources.
Do not smoke.
Ground the containers
to prevent the ignition
by static electricity.
Source: Suva
Source: Suva
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62. 62
Preventing the Ignition of a Potentially Explosive
Atmosphere – Question 2
On a small site, flammable solvents are stored in a room on the ground
floor. The solvents are delivered in metal drums. They are stored
intermediately in a marked area outside the building. Before mounting
them horizontally in the storage room, removable valves are fixed.
Employees who need a particular solvent fill the solvent directly from the
drums into metal cans with a volume of up to 1 litre and small flasks with
up to 2 litres. Grounding clamps are available and the floor of the solvent
room is conductive.
Below the drums, trays are located to contain any liquid that may leak from
the drums or be spilled when the small containers are being filled.
What would the explosion zone be for this installation?
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63. 63
Preventing the Ignition of a Potentially Explosive
Atmosphere – Question 2
Source: CSD
Source: CSD
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64. 1
64
Preventing the Ignition of a Potentially Explosive
Atmosphere – Answer
1m
1m
Zone 0
Zone 1
Zone 2
Source: CSD
Source: CSD
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65. Risk Reduction Measures
Measures Preventing the Formation of Potentially Explosive
Atmospheres
Measures Preventing the Ignition of Potentially Explosive and
Dangerous Atmospheres
Construction measures
Organizational measures
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65
66. 66
Construction Measures
If explosion prevention measures are not feasible, not
sufficiently effective or disproportionate, construction
measures can be taken.
Construction measures do not prevent an explosion but
limit its effects so that the explosion no longer presents a
hazard.
Explosion-resistant
construction
Explosion relief
Suppression of the
explosion
Explosion
decoupling
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68. 68
Construction Measures
Explosion relief devices:
Aim at protecting the containers
from the consequences of an
explosion (burst, deformation).
Once a given internal pressure is
reached, bursting disks/explosion-
proof lids open to release the
pressure and avoid the explosion.
Explosion relief is not an option if
the vented products can harm
people or the environment.
Bursting disks
Explosion-proof lids
Source: Suva
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69. 69
Construction Measures
Explosion suppression:
The explosion is automatically
detected by sensors and
suppressed with an extinguishing
agent before it reaches a
destructive power.
Source: Suva
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70. 70
Construction Measures
Explosion decoupling:
Avoids and prevents the propagation of the explosion to
other parts of the installation/building:
Rapid-action mechanical isolation (e.g. fire damper, quick-
closing valves)
Flame extinction (e.g. flame arrestor)
Water seals
Rotary valves, etc.
Flame extinction:
The flame is cooled
down until it is fully
extinguished.
Source: Suva
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71. 71
Construction Measures – Recap
Explosion-resistant construction/devices (A)
Explosion relief devices (B)
Explosion suppression (C)
Explosion decoupling (D)
D
Source: Suva
Source: Suva
Source: Suva
Source: Suva
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72. Risk Reduction Measures
Measures Preventing the Formation of Potentially Explosive
Atmospheres
Measures Preventing the Ignition of Potentially Explosive and
Dangerous Atmospheres
Construction measures
Organizational measures
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72
73. 73
Organizational Measures
The company should:
Document the explosion prevention
measures
Indicate the explosion hazard zones
Draw up written work instructions
Inform and train employees about
explosion prevention and provide
personal protective equipment
Use an authorization system for the
execution of dangerous activities
Perform necessary checks,
monitoring and maintenance
Instructions
Maintenance
Signs, prohibited
access
Cleaning
Measurements
Information
Source: Suva
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74. 74
Organizational Measures
Small quantities of highly flammable substances (up to
100 litres) should be stored in fire-resistant cabinets.
Large quantities of flammable substances should not be
stored in work areas.
Containers with flammable substances should always be
closed when not used.
No smoking.
Use explosion-proof equipment.
Source: Suva
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75. Organizational Measures – What Not to Do
Source: UNIDO
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Source: UNIDO
Source: Shutterstock
76. Toolkit/CSDandISSPPRO 76
Key messages
Explosion hazard concepts serve the identification, of the
risk, that is therefore assessed to generate options. The
risk reduction measures are implemented according to the
selected options.
Risk reduction measures should be take according to
substances characteristics. In particular constructive and
organizational measures are accompanied by measures
preventing the formation of potentially explosive
atmosphere and iignition of potentially explosive and
dangerous atmospheres.
78. Fusce posuere, magna sed pulvinar ultricies,
purus lectus malesuada libero, sit amet magna
eros quis (ARIAL 32).
Sources
CSD Engineers, Switzerland/ISSPPRO, Germany, 2015
Suva: Prévention des explosions (principes, prescriptions
minimales, zones), Switzerland, 2013
Suva: Explosions – Risques et mesures de prévention,
Switzerland, 2009
Suva: Liste de contrôle – Risques d’explosion, Switzerland,
2013
Suva: Liste de contrôle – Electricité statique, Switzerland, 2010
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79. Fusce posuere, magna sed pulvinar ultricies,
purus lectus malesuada libero, sit amet magna
eros quis (ARIAL 32).
Sources
Suva: Liste de contrôle – Big bags, grands récipients vrac
souples, Switzerland, 2010
OFEV: Guide «Entreposage des matières dangereuses»,
Switzerland, 2011
Neosys: Formation matières dangereuses, Switzerland, 2011
SWISSI Process Safety Ltd.: Explosion prevention, Switzerland,
2014
SWISS Process Safety Ltd.: HSE training, Switzerland, 2014
www.iebmedia.com, May 2014
79UNIDO│IAMC Toolkit | Images may not be copied, transmitted or manipulated
80. Fusce posuere, magna sed pulvinar ultricies,
purus lectus malesuada libero, sit amet magna
eros quis (ARIAL 32).
Supporting documentation
Toolkit checklist : D5_1_Checklist Explosion Prevention,
Switzerland, 2015
80UNIDO│IAMC Toolkit | Images may not be copied, transmitted or manipulated
81. Fusce posuere, magna sed pulvinar ultricies,
purus lectus malesuada libero, sit amet magna
eros quis (ARIAL 32).
Images
CSD Engineers, Switzerland, 2015
United Nations Industrial Development Organization (UNIDO),
2015
Suva: Prévention des explosions (principes, prescriptions
minimales, zones), Switzerland, 2013
Suva: Explosions – Risques et mesures de prévention,
Switzerland, 2009
Suva: Liste de contrôle – Risques d’explosion, Switzerland,
2013
81UNIDO│IAMC Toolkit | Images may not be copied, transmitted or manipulated
82. Fusce posuere, magna sed pulvinar ultricies,
purus lectus malesuada libero, sit amet magna
eros quis (ARIAL 32).
Images
Suva: Liste de contrôle – Electricité statique, Switzerland, 2010
Suva: Liste de contrôle – Big bags, grands récipients vrac
souples, Switzerland, 2010
Neosys: Formation matières dangereuses, Switzerland, 2011
Londoño G. for NCPC Colombia
SWISSI Process Safety Ltd.: Explosion prevention, Switzerland,
2014
Shutterstock, USA, 2015
United Nations, Globally Harmonized System of Classification
and Labelling of Chemicals (GHS), accessed July 2015
82UNIDO│IAMC Toolkit | Images may not be copied, transmitted or manipulated
83. 83
This presentation was prepared with the requested diligence
and with the generally accepted principles of the relevant
field.
If a third party uses the contents of the presentation in order
to take decisions, the authors disclaim any liability for any
kind of direct or indirect (consequential) damage.
Disclaimer
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