Inter-linkages between Process Safety
and APELL for Accident Prevention
and Preparedness
Promoting Safer Operations and
Emergency Preparedness Chemical Sector
26-27 April-2010
Zhangjiagang- CHINA
ING. NESTOR SPOSITO
DOW ARGENTINA
Argentina NFPA Chapter President
BAHIA BLANCA APELL PROCESS
Coordinator UNEP/Bs.As. Province.
Notwithstanding… They Keep On
Happening
Notwithstanding the enormous ongoing
efforts and the significant progress so far
attained in the last few years to increase our
knowledge about the root causes of fires and
explosions in process plants and even in
spite of the remarkable technological
progress accomplished in the field of
materials and the development of safe
design methodologies, such disastrous
occurrences keep on happening
Inter-linkages Process Safety and APELL
Topics
•BASIC CONCEPT
• FIRE AND EXPLOSIONS
• Fires. Classification. Effects.
• Explosions. Classification. Effects.
•Learning experiences about accidents.
•PREVENTION AND MITIGATION METHODS.
•IMPORTANCE OF A SAFE DESIGN AND THE USE OF PROPER
STANDARDS.
• Conclusions
Inter-linkages Process Safety and APELL
Basic Concepts
Rich
mixture
(Upper Flammability Level )
Explossive
Range
(Lower Flammability Level)
Lean
mixture
DOW RESTRICTED - For internal use only
Inter-linkages Process Safety and APELL
Basic Concepts
Flammability - Variation of Temperature Limits
  0.75 t  25 

L.I .I .t   L.I .I .25 ºC   1  

comb



  0.75 t  25 

L.S .I .t   L.S .I .25 ºC   1  

  comb
Temperature ºC
400
DOW RESTRICTED - For internal use only
L.L.I
0
L.S.I
Concentration % vol.
Inter-linkages Process Safety and APELL
Basic Concepts
Variation of Flammability-Pressure Limits
L.S.I. (p) = L.S.I. (1 atm) + 20.6(log P + 1)
@ atm press.
@ P press.
Slight
impact
Big increase
L.I.I
L.S.I
DOW RESTRICTED - For internal
use only
Inter-linkages Process Safety and APELL
Basic Concepts
Variation of Flammability - O2 Concentration Limits
55.0% (oxygen)
Propane
R.I.(Oxygen)
9.5% (air)
2.3% (oxygen)
R.I.(air)
2.1% (air)
L.I.I.
L.S.I.
DOW RESTRICTED - For internal
use only
Inter-linkages Process Safety and APELL
Basic Concepts
Minimun Ignition Energy (MIE)
MINIMUM IGNITION
ENERGY (MIE)
IGNITION
- Characteristic for every material.
-Varies with environmental conditions,
pressure and composition.
- For HC is of about 0.25 mj
DOW RESTRICTED - For internal
use only
Inter-linkages Process Safety and APELL
Basic Concepts
Minimun Ignition Energy (MIE)
Ignition Energy (mj)
0.5
CH4
MIE
0.2
H2
MIE
0.02
10
20
30
DOW RESTRICTED - For internal
only
40 Flammable Gas Concentration (% use
v/v)
Inter-linkages Process Safety and APELL
Fire and Explosion
Pool Fire




Begins with the release of flammable material from process
equipment.
Thermal effects depends on:
 Type of fuel
 Geometry of the pool
 Duration of the fire
 Location of the radiation receiver .
Localized in their effects
Main concern domino effect/ setup employee safety zones.
Inter-linkages Process Safety and APELL
Fire and Explosion
Jet Fire

Combustion of a material released from a
pressurized process unit.

Localized in their effects

Main concern domino effect.
Inter-linkages Process Safety and APELL
Fire and Explosion
Vapor Cloud Explosion (VCE).

“A release of energy that causes a blast” AICheE/CCPS
(1994) .

“Blast is a transient change in the gas density,
pressure and velocity of the air surrounding an
explosion point” NFPA 69.

“A rapid expansion of gases resulting in a rapidly
moving pressure or shock wave”. Crowl and Louvar
(1990)
Inter-linkages Process Safety and APELL
Fire and Explosion
Vapor Cloud Explosion (VCE).

Material flammable. Suitable conditions P y T.

Cloud sufficient size prior to ignition ( Dispersion
phase).

Ignition delays 1 to 5 minutes ( more probable) .

Sufficient amount of the cloud must be within the
flammable range
Inter-linkages Process Safety and APELL
Fire and Explosion
Vapor Cloud Explosion (VCE).

Sufficient confinement or turbulent mixing of a portion
of the vapor cloud must be present.

Minimum mass of flammable material required:

1 ton (Wiekema, 1979) to 15 tons (Health &Safety Executive,
1979).

More reactive species such as hydrogen and acetylene
Gugan(1988) with quantities as low as 100 kg.
A Long and Sad History
of Fire and Explosion in
Process Industry
Inter-linkages Process Safety and APELL
Lesson Learned
28 death
Total destruction
( 70 MMU$S)
104injuries
1800
damages
home
Inter-linkages Process Safety and APELL
Fire and Explosion
Inter-linkages Process Safety and APELL
Lesson Learned
•Importance of Management of Change (MOC).
•The need to eliminate expansion joints in dangerous
services.
•Control Room design concept in High Hazards Plants.
 Structural design to withstand major hazardous
events
•Plant Layout. Positioning of occupied buildings
Inter-linkages Process Safety and APELL
Lesson Learned
Inter-linkages Process Safety and APELL
Lesson Learned BHOPAL
MOC (Management of Change)
•The change was about the inadequate state of the
facilities supporting the safe operation of the MIC
storage.
•Layers of Protection Identified and installed in the
design/construction but out of operation.
 There were 5 levels of protection available to
minimize the Release to atmosphere, all of which
failed.
Inter-linkages Process Safety and APELL
Lesson Learned BHOPAL
•American Institute of Chemical & Process Safety
organization & programs (AIChE –CCPS).
•UNEP Awareness Preparedness Emergency Local level
Process ( APELL Process).
•Chemical Manufacturer’s Association Community
Awareness and Emergency Response (CAER).
•Local Emergency Planning /Risk communication.
•Community Engagement.
Inter-linkages Process Safety and APELL
Lesson Learned
Inter-linkages Process Safety and APELL
Lesson Learned BP
Effective safety culture leadership and oversight to prevent
catastrophic accident.
•Focus on process safety besides personal safety.
• Personal safety metrics are important to track low-consequence,
high-probability incidents, but are not a good indicator of process
safety performance .
•Create an effective reporting and learning culture.
Inter-linkages Process Safety and APELL
Lesson Learned
•Provide adequate resources to prevent major accidents; budget cuts
impaired process safety performance at the Texas City refinery.
•Effective vehicle traffic policy to control vehicle traffic into hazardous
process areas.
•Nonessential personnel must be removed from areas in and around
process units during the hazardous unit startup
Inter-linkages Process Safety and APELL
Lesson Learned
•Effective mechanical integrity program to maintain instruments and
process equipment .
•MOC guidelines that address the safe control of the following:
•Major organizational changes including mergers, acquisitions,
reorganizations.
•Changes in policies and budgets.
•Personal changes. Staffing during process
Inter-linkages Process Safety and APELL
Prevention and Mitigation
Avoid or minimize releases.
 The occurrence of releases shall be minimized by
measures which include:
 Proper operating and design conditions
 Material selection
 Preventive maintenance, procedures, alarm systems
 No flanges shall be installed inside the skirt of a
vessel containing flammable materials.
 Welded connections instead of flanged connection.
Inter-linkages Process Safety and APELL
Prevention and Mitigation

The amount of released material within flammability
limits shall be minimized by:
 Proper atmosphere control
 Accelerated dispersion through water spray
 Proper storage and installation of check valves,
remotely operated isolation valves and excess flow
valves
 other systems where appropriate.
Avoid the use of trhreaded
connections in critical
hazardous material services.
DOW RESTRICTED - For internal
use only
Inter-linkages Process Safety and APELL
Prevention and Mitigation
Ignition Sources
 Potential ignition sources should be eliminated. Where
they cannot be eliminated protection should be
provided by:

Proper spacing.

Installing equipment which meet the area classification
standard (NFPA 70).

Installing water curtains to prevent flammable gas mixtures
from reaching ignition sources.
Inter-linkages Process Safety and APELL
Prevention and Mitigation
Ignition Sources
 Static electricity is a potential ignition source.

It is crucial to prevent the simultaneous occurrence of a
flammable mixture and static spark.
Safe Design of Storage Tanks
Sprinkler
System
Grade:
1-2 %
Containment dike
Fire protection
DOWcontrolled
RESTRICTED - For internal
Remote
use only
diked area
Avoid small
connections at the
bottom and liquid
areas.
EBV
DOW RESTRICTED - For internal
use only
Inter-linkages Process Safety and APELL
Prevention and Mitigation
Buildings


Critical buildings (Control Room) shall be designed to
withstand the consequences of explosions.
CR cannot meet this requirement shall be

Relocation.

Strengthening for pressure effects.

Shielding the critical equipment with a blast wall.

Shielding the area where a release can occur from possible
ignition sources by providing properly grounded water or steam
spray.
Adequate Buildings
Explosion proof control room
Explosion resistant
door
Demand closing
and opening
DOW RESTRICTED - For internal
use only
Inter-linkages Process Safety and APELL
Enhancement PS Knowledge
Risk analysis,
Consequence calculations,
inherently safe design more
reliable engineering
practices and standards
Awareness raising
and dissemination
Process Safety
knowledge
Inter-linkages Process Safety and APELL
Enhancement PS Knowledge

How to explain fire and explosion incidents in High-tech
plants :






Violations to or non compliance with safety regulations
Not using supposedly very well known safe procedures.
Layers of Protection disable.
Lacks of compromise with PS.
Lack of knowledge or commitment with Safe Design.
Other, other,……
 Process Safety knowledge should be open.




Throughout all organizations
Control Agencies.
Technical schools and universities.
Contractors/EPCM
Inter-linkages Process Safety and APELL
Enhancement PS Knowledge
We must break the paradigm
Good personal safety record is enough to ensure
that we are sufficiently safe to prevent all types of
major accidents.
“The lost time rate is not a measure of process safety”
(Kletz, 2003).
“An emphasis on personal safety statistics can lead
companies to lose sight of deteriorating process
safety performance (Hopkins, 2000)”

Inter-linkages Process Safety and APELL
Enhancement PS Knowledge
We must break the paradigm

“Nothing bad will ever happen to us” or that
any action made with impunity for some time against
Safety Process rules could be repeated forever with
the same lack of adverse results
Inter-linkages Process Safety and APELL
Enhancement PS Knowledge
Another great challenge is to find a way to expand the
knowledge in a worldwide context characterized by

Global economical crisis.

A progressive expansion of plant capacities and inventories.

A progressive increase of investments in places where there is
not enough background and experience about the operation,
maintenance, Process safety and loss prevention (Middle East).

High labor turnover.

More reduced budgets.
Inter-linkages Process Safety and APELL
Enhancement PS Knowledge
Our Proposal

Raising awareness.


Commitment.


Companies, local community, local authorities (APELL)
Promoted throughout the whole organization, all project
stages and the whole project life span.
Creativity.

To improve and expand even more the existing PS
knowledge and its dissemination, encouraging the universal
creation, expansion and application of a Process Safety
Culture in a world of continuous change.
Inter-linkages Process Safety and APELL
Enhancement PS Knowledge
Our Proposal

The study highlights the need for accident
forecasting, enhancement PS knowledge
consequence assessment, and development of upto-date emergency preparedness and disaster
management plans in the chemical process
industries and raising community awareness
trough plan like APELL Process from UNEP

APELL Process must include Process Safety as a
key deliverable.
Inter-linkages Process Safety and APELL
Enhancement PS Knowledge
PROCESS SAFETY IS NOT
A MERE
INTELLECTUAL EXCERCISE
BUT THE
DIFFERENCE BETWEEN
LIFE AND DEATH
QUESTIONS?
ING. NESTOR SPOSITO
DOW ARGENTINA
Argentina NFPA Chapter President
BAHIA BLANCA APELL PROCESS
Coordinator UNEP/Bs.As. Province.
nspósito@dow.com