2. ➢Safety Moment, What Happened?
➢Hazard Identification
➢Risk Terminology
➢Overview of PHA
➢History of PHA
➢PHA & Risk Analysis
➢Safety Management Systems
➢Human factors in Facility Risk
➢PHA Teams
➢General PHA Procedure Flow Chart
3. The Worst Situation Ever!!
Bhopal Gas Tragedy
The Bhopal gas tragedy:
Toxic legacy - Bing video
4. The Big Dig Ceiling Collapse (2006)
Bing Videos
5. Let us understand with a situation and know how would
you respond to it!!!
A Scenario….
• You are operating a crane with
heavy load on it and suddenly
you receive an important call
from your wife and she tells
something which shocks you
and suddenly you drop the load
which leads to destroying the
product and also hits other
workers on the site??
6. Sensational Significance
• What is the cause of the accident?
• What is the consequence of the event?
• What can we do to prevent all those things
to happen in the first place?
7. What is a Hazard?
Source with a potential to cause harm
Does it have the
potential to cause
harm?
If the answer is yes,
then it is a hazard
People: Injury or
fatality
Environment:
negative impact
Asset: Property
damage
13. Psycho-Social Hazard
Examples include
Work-related stress, whose causal factors include
excessive working time and overwork, violence
from outside the organization, bullying, which may
include emotional and verbal abuse, sexual
harassment, mobbing, burnout, discrimination,
exposure to unhealthy elements during meetings
with business associates.
Psychological hazards
Those that are basically causing stress to a worker.
This kind of hazard troubles an individual very
much to an extent that his general well-being is
affected.
14. But How Do We Identify the Hazard?
The hazard identification methods
may be categorized as
• Comparative methods and
• Fundamental methods
15. • These methods are
based on hazard
identification by
comparing with
standards.
• The various methods
are checklist, safety
audit, hazard indices
and preliminary hazard
analysis
• Four main methods in this
category are what-if
analysis, failure modes and
effects analysis (FMEA),
job safety analysis (JSA)
and hazard and operability
study (HAZOP)
Comparative Method Fundamental Method
16. Terminology
• Hazard: A potential source of harm, damage, or loss. (e.g., flammable materials, falling
objects, exposure to chemicals)
• Risk: The combination of the likelihood of a hazard occurring and the consequences of it
happening. (e.g., the risk of a fire causing significant property damage)
• Severity: The extent of the damage or harm caused by a hazard. (e.g., a minor injury
versus a fatality)
• Likelihood: The probability of a hazard occurring. (e.g., a high likelihood of slips and falls
on a wet floor)
• Vulnerability: The susceptibility of people, property, or the environment to be harmed
by a hazard.
17. What is ?
Risk is a combination of likelihood of harm being done and
severity of that harm.
Risk= Likelihood X Severity
(Probability) (Consequence)
19. Risk Assessment Approaches
Qualitative risk analysis is a subjective
assessment of risks based on their
qualities, characteristics, and subjective
judgment.
Quantitative risk analysis involves a
more objective and numerical
assessment of risks. It attempts to assign
specific values or ranges to the likelihood
and impact of risks and uses
mathematical models for analysis.
21. Risk Control
• It is also referred to as "hazard
control," and it is the step in the risk
management process where
techniques are put into place to
eliminate or lessen hazards that have
been identified.
• It involves responses to risk factors that
could result in an accident or other
negative outcome at work.
22. Overview of PHA
• The application of one or more analytical methods to identify and evaluate
process hazards for the purpose of determining the adequacy of need for control
measures.
• It is used to analyse potential causes and consequences of fires, explosions,
releases of toxic or flammable chemicals, and major spills of hazardous chemicals.
• It focuses on equipment, instrumentation, utilities, routine and non-routine
human actions, and external factors that might impact a process.
24. PHA Requirements
• Block flow diagrams or P&ID (Piping
and instrumentation diagram)
• Process parameters limits
• Qualitative estimates of the
consequences of deviations
25. PHA Must Address …
• The hazards of the process
• Identification of previous incidents with likely potential for
catastrophic consequences
• Engineering and administrative controls applicable to the hazards and
their interrelationships
26. 26/49
PHA Must Address … (cont’d)
• Consequences of failure of engineering and administrative controls,
especially those affecting employees
• Facility siting
• Human Factors
• The need to promptly resolve PHA findings and recommendations
33. Checklists Technique
• This method uses established codes, standards and
well-understood hazardous operations as a checklist
against which to compare a process.
• A good checklist is dependent on the experience level
and knowledge of those who develop it.
34. What If
Technique
• This approach uses a multi-skilled team to create
and answer a series of “what-if” type questions.
• Take example of the condensing system of a
distillation tower.
• Team members ask questions such as:
“What-If there is high pressure in the tower?”
“What-If the operator forgets to open the drain valve?”
“What-If there is an external fire in this area?”
35. Failure Mode
and Effect
Analysis
(FMEA)
• Failure Modes and Effects Analysis (FMEA) is
a technique for determining the ways in
which equipment items and their internal
components can fail, and what the
consequences of such failures would be on
the overall system reliability and safety.
• A systematic study of the consequences of
failure (breakdown) of certain operational
hardware such as transmitters, controllers,
valves, pumps, etc.
36. Hazard and Operability Study (HAZOP):
• A structured, systematic review that identifies equipment that is
being used in a way that it was not designed to be, and which
might create hazards or operational problems.
• HAZOPs are usually conducted by a 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.
37. Fault-Tree Analysis
• This method draws a picture (model) that
shows what undesirable outcomes might
result from a specific initiating event (for
example, a pipe rupture in a pipe rack).
• This method is sometimes used in accident
investigations to determine probable cause.
38. SAFETY MANAGEMENT SYSTEM (SMS)
• An SMS is a systematic framework designed
to proactively identify, assess, and mitigate
risks to ensure a safe work environment.
• It involves following specific rules and
procedures to make sure everyone stays and
health while working.
• SMS should be: Documented, Accessible and
Comprehensible.
• Ensuring the effectiveness and compliance
SMS should be align with the international
standards like ISO 45001.
40. CONTD.
• Key elements of the SMS:
• Policy
• Planning
• Implementing
• Assessing
• Management Review
SMS
Components
Safety Policy
Safety Risk
Management
Safety
Assurance
Safety
Promotion
41. CONTD.
4 COMPONENTS OF SMS
Safety Policy Safety Assurance Safety Risk
Management
Safety Protection
Establishes senior
management’s
commitment to
continually improve
safety, defines the
method, procedures,
and organizational
structure needed to
meet safety goals.
Evaluates the
continued
effectiveness of
implemented risk
control strategies,
supports the
identification of new
hazards.
Determines the need
for, and adequacy of,
new or revised risk
controls based on the
assessment of
acceptable risk.
Includes training,
communication, and
other actions to create
a positive safety
culture within all levels
of the workforce.
43. CONTD.
• Effective SMS:
• Management Leadership and Employee Involvement
• Worksite Analysis
• Hazard Prevention
• Training
44. CONTD.
• SMS should be able to cover:
• Define roles and responsibility
• Ensure adequate skills, information, tools and decision-making are
present in day to day and abnormal operations.
• Maintain awareness of hazards and risks
• Plan, implement, measure and evaluate MA controls and SMS
• Develop performance requirements
• Set targets for improvement of safety at the facility
45. Human factor in Facility Risk
• Human factors are conditions that affect an
employee’s interaction with their workplace,
equipment, work procedures, or even their
team.
• These conditions might arise from physical,
psychological, or social reasons, but ultimately,
they affect employees’ human abilities to
perform their work safely.
47. People
• Employee’s knowledge, abilities and limitations, and expectations will affect
how they interact with others around them.
• Their individual differences such as their age and culture, also matter. If
employees are stressed or distracted, these are predictors that safety
performance might be affected.
48. • The overarching organizational factors, such as
management systems, also play an essential role.
• Managerial policies and decisions about the job design as
well as how the information is communicated to the
employee, will also impact human factors.
• This means that safety professionals must consider things
such as work schedule, workload, task design, and
requirements, besides written and spoken communications
to convey instructions and data to employees.
Management
49. • Work environments also affect safety in the
workplace.
• The facilities, workstation configuration and
accessibility, as well as workplace controls, warning
systems, and other physical aspects that affect human
well-being such as noise, temperature, and heat
exposure all matter.
Work environments
50. • Experience can prevent significant accidents because this process occurs intuitively
and automatically and does not involve analytical, data-driven risk assessments.
• Each time the benefit is realized without a negative consequence, the behavior
becomes automatic. But injuries can also occur when experience becomes a habit,
influencing behavior.
• The act of doing in the workplace becomes careless when people think that the job
is safe.
Another reason why human factors can be challenging to minimize is that
risky behaviors are sometimes driven by experience.
51. • Human factors also result from employees’ lack of awareness of what is
happening in complex and dynamic operating environments.
• Safety systems and risk models often do not describe safety risks or
environmental change.
52. Organizations need to take a proportionate approach to human factors in risk
assessment based on their hazard and risk profile.
Human Factor in Risk Assessment
Key Principles in integrating Human Factors in Risk Assessment:
✓ Through risk assessment, we have to identify those tasks which are safety critical or expose
people occupational health hazards
✓ Ensure to have an understanding of how the tasks are carried out and the environment in which
they are performed. This may include walking and talking through the task where it is carried
out.
✓ Involve the workforce in carrying out the assessment and the identification of appropriate
controls
✓ The people carrying out the assessment should have an understanding of the different types of
failure and the factors that make them more or less likely to occur;
53. ✓ Identify the human failures that could be made in the task which might lead to an accident of
incident and the performance influencing factors that make those failures more or less likely to
occur.
✓ Identify appropriate control measures which prevent or mitigate the human failures identified;
✓ Where possible we should aim to design out the potential for human failure and design for
recovery. This includes design of the plant, system, environment and task, taking into account
the needs and capabilities of users.
✓ Checking if the control measures work. Regularly review risk assessment to see if any further
improvements can be made.
Key Principles in integrating Human Factors in Risk Assessment: (Continued……….)
54. PHA Teams
PHAs are generally team activities.
The team members should represent a cross-section of disciplines and
functions, typically including operations, engineering, maintenance,
and process design.
Having all the disciplines present helps ensure that all types of hazard
scenarios are discussed.
Furthermore, the interaction between team members helps uncover
those hazards that may be created due to communication difficulties
or misunderstandings between departments.
55. Team of PHA…..
i. Engineering principles
ii.Instrumentation
iii.Equipment design/set-up
iv.Research and Development
v.Maintenance
vi.Environmental, Health & Safety
57. Step 1
Establish the
Goals and
Boundaries
Step 2
Select the
Most Effective
PHA
Techniques
Step 3
Collect Useful
Data for
Process Hazard
Analysis
Step 4
Conduct the
Process Hazard
Analysis
Step 5
Assess Risks
and
Consequences
Step 6
Create Risk
Mitigation
Steps
Step 7
Document All
of Your
Analysis
PHA Procedure
58. PHA Sequence
When a new process is being designed and
constructed, it is normal for different types of
PHA to be performed at each stage of the design.
59. Conceptual (theoretical )Design
• Conceptual Design PHA provides a
preliminary safety analysis
• What-If method is probably the
best method for this phase of the
PHA
60. PRELIMINARY DESIGN
• Once the basic process design is
complete
• What-If method works well at this stage
• What-If/Checklist method is also a good
choice at this stage.
• The What-If approach encourages broad-
range thinking, while the Checklist
questions provide a framework on which
to base the analysis
61. FINAL DESIGN
At the conclusion of the final design, a complete set of P&IDs will have been published.
Other documentation available to the PHA team will include electrical loop drawings,
MSDS, and draft operating manuals.
So, the final design PHA is usually a full HAZOP study.
62. PRE-
STARTUP
SAFETY
REVIEW
• The last process safety evaluation to be
carried out before the start-up.
• Pre-startup Safety Review PSSR is not a PHA.
• A PSSR is not a PHA instead it serves to
ensure that the plant was constructed as
required by the original design and that all
required changes (including those stemming
from the PHA) have either been
implemented or meet the original design
intent.
63. MANAGEMENT OF CHANGE (MOC)
Any significant proposed change to a plant that is already running or whose design has been
finalized, should be analyzed with a PHA as part of the Management of Change process.
What-If or a brief HAZOP is a good choice for the PHA.
64. DECOMMISSIONING /DEMOLITION
When a plant is decommissioned, it has two possible fates.
The first is that it will be simply mothballed in the hope that it can be renovated and restarted
at some unspecified time in the future when economic conditions call for such action.
The second possibility is that the plant will be torn down, and the site used for something else.
In either case, a PHA should be performed, with the What-If technique probably being the
preferred method.
If the plant is to be demolished, the checklist will focus on due diligence items
65. Examples of Process Hazard Analysis
• Example: Chemical Production:
• For instance, PHA discovered a potential risk associated with a
particular reaction process in a chemical factory. What-If
Analysis discovered that temperature differences beyond a specific
limit might set off a runaway reaction, increasing the likelihood of an
explosion. Improved temperature control methods and alternative
safety systems were successfully put in place to reduce the
danger and guarantee employee safety.
