4. Hazard is the potential for
harm.
A hazard is often associated
with a condition or activity
that can cause undesired
consequences such as injury
or illness if left uncontrolled.
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5. Basically, a hazard can cause harm
or adverse health effects to
individuals or to organizations as
property or equipment losses.
9/1/2016 5
7. 1) Chemical hazards
Chemicals can affect skin by contact.
Chemicals can also enter our body
either through the inhalation or
digestive system if air is contaminated
with chemicals, vapor, mist or dust.
The accumulation of chemicals in or on
our body will cause acute (immediate)
effect or chronic (long-term) effect.
9/1/2016 7
8. 2) Physical hazards
Physical hazard will cause injury
risks on our body.
This category includes the hazards
from working in confined spaces,
being hit by flying objects, caught in
explosions, hurt by collapsing
machinery, falling from heights and
tripping on obstacles.
9/1/2016 8
9. 3) Biological hazards
(biohazards)
Biohazards refer to biological substances
that pose a harm to the health of living
organisms.
Sources of biological hazards may include
insects, bacteria, fungi, plants, worms,
animals and viruses.
These sources can cause a variety of
health effects ranging from skin irritation
and allergies to infections, cancer and so
on.
9/1/2016 9
10. 4) Ergonomic hazards
Ergonomic hazards refer to workplace
conditions that pose the risk of injury to
the musculoskeletal system of the worker.
These injuries can be caused by
performing repetitive and forceful
movements and awkward postures that
arise from improper work methods and
improperly designed workstations, tools,
and equipment.
9/1/2016 10
11. 5) Noise hazards
Excessive noise can
disrupt concentration,
interfere with communication and
result in loss of hearing.
High impact noises are particularly
damaging.
Noise can also mask out signals and
affecting communication with others.
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13. Hazard
Analysis
Analysing their
potential causes
First step
in a process
used to
assess risk
Result of a hazard
analysis is the
identification of
different type of
hazards
Process of
recognizing
hazards that may
arise from a system
or its environment
9/1/2016 13
14. Job
Hazard
Analysis
Technique that
focuses on job
tasks as a
way to identify
hazards before
they occur
Identify
hazards
potentially created
by a product,
process or
application
Technique to identify the
dangers of specific tasks in order
to reduce the risk of injury to workers.
Focuses on the
relationshi
p between the
worker, the task,
the tools, and the
work environment
9/1/2016 14
16. Determine the
hazards and
hazardous events
of the equipment
under control and
the control
system
Analyse the
event sequences
leading to the
hazardous events
identified
To analyse
the risk
associated with
the hazardous
events
Identify
hazards
Identify causes
Determine
risks
Hazard
Analysis
Objective
s9/1/2016 16
18. Importance
/ Benefit
To train
workers
how to do
their jobs
safely
Policies
and
procedure
improved
investigate
accidents
Increase
quality
Decrease
injury rate.
9/1/2016 18
19. identify what personal protective
equipment
Hearing
protection
Body
protection
Eye
protection
Foot
protection
Material
handling
aids
Hand
protection
Respirator
y
protection
9/1/2016 19
21. Examine the job and determine the
components
Identify tasks likely to present
hazards
Identify and assess hazards
Determine and devise controls
measures
Develop safe work procedures if
hazards cannot be eliminated
9/1/2016 21
23. Identifying The Hazards
Identify the hazards of each step.
For each hazard, ask:
What can go wrong?
What are the consequences?
How could it arise?
What are other contributing
factors?
How likely is it that the hazard will
occur?
9/1/2016 23
25. Hazard may be realized or unrealized
Realized hazard – has happened in the
past and can therefore be identified
from experience.
Unrealized hazard – is a potential for a
hazardous situation that has not
happened yet but can be recognized by
analyzing the characteristic of an
environment or failure modes of
equipment item.
9/1/2016 25
26. Hazard analysis methods
include :
Process Hazard Analysis
Event Tree Analysis
Failure Modes And Effect
Analysis
Fault Tree Analysis
Cause-consequence Diagram
Hazard And Operability Studies
9/1/2016 26
27. 1) PROCESS HAZARD ANALYSIS
A systematic method designed to identify
and analyze hazards associated with the
processing or handling of highly
hazardous material
PHA analyzes
-The potential causes and consequences
of fires, explosions and releases of toxic
chemicals
- the equipment, instrumentation, human
actions and other factors which might
affect the process.
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28. The Most
Hazardous
Processes Are First
-Most hazardous
processes must be
evaluated first
-All PHA must be
completed as soon as
possible
- PHA must be updated
at least every five years
9/1/2016 28
29. 2) Event Tree Analysis (ETA)
ETA defines the consequential
events which flow from the
primary ‘initiating’ event.
Event trees are used to
investigate the consequences of
loss-making events in order to
find ways of mitigating rather
than preventing losses.
9/1/2016 29
30. 3) Failure modes and effect
analysis (FMEA)
To identify which failures in a system can
lead to an undesirable situation.
Particularly suited to electrical and
mechanical processes.
Result are strongly dependent on
analyst’s understanding of the failure
modes
Effects of failure modes can be quantified
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31. 4) Fault tree analysis (FTA)
To evaluate the economic justification
for carrying out improvement to a
system
FTA works back from the undesired or
“top event” to the contributing
causes(backward reasoning logic
techniques)
To identify the causes of top event
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33. 5) Cause-Consequence
analysis (CCA)
Is proving to be a very useful tool to
depict and maintain an up-to date, real-
time working risk management system
enthralled in daily operations (e.g.
operational).
These diagrams combine the inductive
and deductive reasoning of logical
diagrams (e.g. ETA, FTA) to identify the
basic causes and consequences of
potential accidents.
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35. 6) Hazard and Operability Study
(HAZOP)
A structured and systematic method that
identifies equipment that is being used in
a way that it was not designed to be, and
which might create hazards and
operational problems.
HAZOPs are usually conducted by multi-
skilled team that studies piping and
instrument diagrams.
Each pipeline and vessel is evaluated for
certain limitations and deviations in flow,
temperature, pressure, etc.9/1/2016 35
37. Controlling the Hazards
The order of precedence and
effectiveness of hazard
control is the following:
1. Engineering controls.
2. Administrative controls.
3. Personal protective
equipment.
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38. 1) Engineering Controls
Engineering controls include the
following:
Elimination/minimization of the
hazard
Substitution of equipment or process
to decrease hazard
Isolation of the hazard with
interlocks, machine guards, blast
shields, or other means; and
Removal or redirection of the hazard
such as with local and exhaust
ventilation.
9/1/2016 38
39. 2) Administrative Controls
Administrative controls include the
following:
Written operating procedures,
work permits,
and safe work practices;
Exposure time limitations (used most
commonly to control heat stress and
ergonomic hazards);
Monitoring the use of highly
hazardous materials;
Alarms, signs, and warnings;
Buddy system; and training
9/1/2016 39
40. 3) Personal Protective
Equipment (PPE)
Personal Protective Equipment is acceptable
as a control method in the following
circumstances:
When engineering controls are not
feasible or do not totally eliminate the
hazard;
While engineering controls are being
developed;
When safe work practices do not provide
sufficient additional protection; and
During emergencies when engineering
controls may not be feasible.
9/1/2016 40
41. Case Study of Hazard
Analysis
Fire at Formosa Plastic Corporation:
Evaluating Process Hazard
9/1/2016 41
42. INTRODUCTION
This case study describes a fire and
series of explosions in an olefins
production unit located in Point
Comfort, Texas due to hydrocarbon
release.
16 employees were injured and 1
seriously injured.
The fire lasted for 5 days.
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43. At 3:05 PM on October 6, 2005, a trailer being
towed by a forklift snagged and pulled a small
drain valve of a liquid propylene system.
Vaporized propylene forming a large flammable
vapor liquid.
Operators began to shut the plant down and
attempt to isolate the leak. But, the attempt was
failed.
At 3:07 PM, the vapor ignited and created an
explosion. As a result, two operators were
burned and fire reached more than 500 ft in air
as shown in figure 1.
The fires lasted for five days and about 7 million
gallons of water were used to cool vessel.
INCIDENT DESCRIPTION
9/1/2016 43
45. At 9:00 PM, Highway 35 that run
adjacent to the Formosa complex and
through ‘Point Comfort’ was closed. A
shelter-in-place was provided for the
Point Comfort community.
It was recorded about 20 local
residents need medical evaluation at
local hospitals.
Figure 2 shows the view of the
damaged plant from Highway 35.
Figure 3 shows the Olefin II unit ( one
of the 17 units) where the fire and
explosion occurred. 9/1/2016 45
46. Figure 2 : View of the Damaged Plant
from Highway 35
9/1/2016 46
48. INCIDENT SEQUENCE
A worker driving a forklift towing a trailer
under a pipe rack moving backward
between two column to turn around.
When the worker drove forward, the
trailer caught on a valve and stick out a
strainer in propylene piping system.
The trailer pulled the valve and associated
pipe (Figure 4) out of the strainer and
leaving 1.9 inch diameter opening.
Pressurized liquid propylene rapidly
escaped through the opening and partially
vaporized creating both of propylene
liquid and rapidly expanding vapor cloud.
9/1/2016 48
49. The forklift driver and other contractors saw
the release and evacuated.
An operator heard and saw the release and
notified the control room.
The operators closed control valves and
began to shut down the unit as well as pump
from motor control center to slow the leak as
he saw the vapor cloud.
The vapor cloud ignited and operators left the
unit and declared a site-wide emergency.
A large pool of fire burned under the pipe
rack.
The Formosa ERT arrived and took command
of the incident response.
The fire was extinguished about 5 days.
9/1/2016 49
51. CAUSES OF INCIDENT
Figure 6 shows the propylene piping
involved in this incident stick out into an
open space and no impact protection.
Figure 7 shows passive fire protection was
installed on only three of four support
column rows and the columns that
supported the pressure relief valves and
emergency vent piping had no
fireproofing.
9/1/2016 51
54. PROCESS HAZARD ANALYSIS
Figure 8 shows the protection of fire
fighting equipment.
Figure 9 shows the lack of protection
where the impact and release occurred.
Remote equipment isolation is done by
the operators by isolating minor leaks
with local valves.
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55. Figure 8 : Protection of Fire Fighting Equipment9/1/2016 55
57. LESSONS LEARNED
When performing a hazard analysis, facility
sitting analysis or pre-startup safety review,
vehicle impact and remote isolation
catastrophic releases should be investigated.
The use of flame resistant clothing may limit
the severity of injury to employees who work
in plants with large inventories of flammable
gases and liquids.
Evaluate the applicability and use of current
safety standards when designing and
constructing a chemical process plant.
9/1/2016 57
58. References
Fire at Formosa Plastics Corporation:. Case study,
Washington: CSB publications, 2006.
Hazard Analysis Methodologies.
https://www.osha.gov/SLTC/etools/safetyhealt
h/mod4_tools_methodologies.html (accessed
March 27, 2015).
Job Hazard Analysis. 2002.
https://www.osha.gov/Publications/osha3071.h
tml (accessed March 26, 2015).
Types of Hazards.
http://students.fortresslearning.com.au/del30
1/types-of-hazards/ (accessed March 23,
2015).
Fire at BHN platform, ONGC-2005, Bombay High
9/1/2016 58
Editor's Notes
Example of release of toxic methyl-isocynate from Union Carbide plant-Bhopal
Snag : a rough projection
The pipe rack support piping, as well as instrument and power cables to and from columns, vessels, pumps and valves in the unit.
