Process Safety
R. Bruce Eldridge
Incident Rates of Principle Industries
(fatal accidents per million employees each year)
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Textile
Chemical
Furniture
Industry Average
Retail
Railroad
Construction
Trucking
23
32
39
53
75
123
148
237
Safety Triangle
1
LOST
TIME
RECORDABLE
FIRST AID
10
100
1000
What gets
reported is just
the tip of the
iceberg…..
the foundation
that supports it
is made up of
behaviors and
conditions that
create risk.
Why do we need it ?
In 1970 Congress considered these annual
figures
• 14,000 workers were killed on the job
• 2,500,000 workers were disabled from job-related
accidents
• 10 times as many lost work days from job-related
disabilities as from strikes
• Estimated new cases of occupational diseases
totaled 300,000
The Occupational Safety & Health
Act of 1970 was passed ….
“…to assure so far as
possible every
working man and
woman in the nation
safe and healthful
working conditions
and to preserve our
human resources”
OSHA was created to…
• Encourage employers and employees to
reduce workplace hazards and to implement
new or improve existing safety and health
programs
• Maintain a reporting and recordkeeping
system to monitor job-related injuries and
illnesses
• Develop mandatory job safety and health
standards and enforce them effectively
(OSHA Regulations)
The General Duty Clause states
that each employer…
“shall furnish…a place of employment which
is free from recognized hazards that are
causing or are likely to cause death or
serious physical harm to his employees.”
A Good Health & Safety Program
accomplishes the following:
• It “works” – is effective in reducing the
frequency and severity of accidents
• It addresses recognized hazards –
whether or not they are regulated by
government standards
• It includes compliance with government
agencies, insurance carriers, etc.
Immediate Causes
Work place layout
10%
Inattention/lack of
awareness
19%
Work exposure to
13%
Not following
procedures
23%
Protective systems
16%
Tools & equipment
10%
Use of protective
methods
6%
Use of tools
3%
Who is driving?
• Do we do this because OSHA requires it or
because it’s the right thing to do?
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Injury reporting?
Injury trending?
Behavioral safety observations?
Process hazard analysis?
Job hazard analysis?
Safety procedure development?
Safety procedure audits?
Emergency preparedness?
Process Safety Management
(PSM)
• In February, 1992, OSHA issued a new
standard called Process Safety Management
of Highly Hazardous Chemicals (OSHA
1910.119)
• The purpose of the PSM regulations is to
define the requirements for “preventing or
minimizing the consequences of
catastrophic releases of toxic, reactive,
flammable, or explosive chemicals.”
Pre-PSM Major Disasters
• 1984 Bhopal, India
over 2000 deaths
• 1989 Pasadena, TX
23 deaths
132 injuries
• 1991 Sterlington, LA
8 deaths
128 injuries
Post-PSM Major Disasters
BP Deepwater Horizon
11 deaths
17 injuries
BP Texas City
15 deaths
170 Injuries
Post-PSM Major Disasters
Pemex Refinery Explosion
30 deaths
42 Injuries
Security Camera Video
Elements of
PSM
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Employee Participation
Process Safety Information
Process Hazard Analysis
Operating Procedures
Training
Contractors
Pre-Startup Safety Review
Mechanical Integrity
Safe Work Permits
Management of Change
Incident Investigation
Emergency Planning & Response
Compliance Audits
Trade Secrets
How incidents occur
• Internal causes
– Control failure
– Equipment failure
– Human error
• External causes
– Weather
– Vehicle impact
Anticipate what we can
• Initiating event
– Process upsets
– Human error
– External factors
• Intermediate events
– Propagating factors
• Additional circumstances
• Protective system failures
• Incident outcome
Process Hazard Analysis (PHA’s)
• The process hazard analysis shall be
appropriate to the complexity of the
process
– Hazard & Operability Study (HAZOP)
– What-if
– Checklist
– Fault Tree Analysis
– Failure Mode & Effects Analysis
Process Hazard Analysis Shall
Address:
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The hazards of the process
Previous incidents
Engineering & administrative controls
Consequences of failure
Facility siting
Human factors
Evaluation of possible safety & health effects of
failure of controls on workers
More details…
• The process hazard analysis shall be
performed by a team with
– Expertise in engineering
– Expertise in process operations
– At least one employee with experience and
knowledge specific to the process being
evaluated
– At least one employee trained in process
hazard analysis methodology
More details…
• The employer shall establish a system
to promptly address, resolve and
document the team’s findings,
recommendations and the corrective
actions taken
• The process hazard analysis shall be
revalidated at least every 5 years
• All PHA’s and revalidations shall be
retained by the employer for the life of
the process
What do we look at?
• Process & Instrumentation
Diagrams
• Equipment Design Specifications
• Material Hazards (MSDS)
• Process Technology (operational
design parameters)
• Siting Criteria
• Safety Equipment
Design/Intent/Reliability
HAZOP Studies & Guidewords
• Used to ensure a thorough discussion of
deviating from normal operating conditions
• Area under study is broken into sections of
manageable size
• For each section the team goes through the
list of guidewords
• For each guideword the team discusses
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Causes
Consequences
Safeguards
Recommendations
Examples of Guidewords
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No flow
More flow
Less flow
Reverse flow
More pressure
Less pressure
More level
Less level
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More temperature
Less temperature
Service failure
Maintenance
Chemical properties
Contamination
Human factors
Previous incidents
The thought process is…
• What can cause the deviation? (List
everything the team can think of)
• For each cause, if it happens what are
the consequences?
• What safeguards do we have in place
to prevent or control this situation?
• Is it enough or do we recommend
something more?
Example for “No Flow” guideword
• Cause - Block valves closed
on cooling water supply and
return to exchanger.
• Consequence - Possible
overpressure of tube side of
exchanger if thermal
expansion occurs.
• Safeguards – Procedures in
place that call for valves
being left open
Is the recommendation adequate?
• Liquids can expand in volume
approximately 1600 times upon
vaporization
1
pint
4
55 gal
drums
Example for “No Flow” guideword
• Recommendations – Investigate need
for and install as necessary a relief valve
on tube side of exchanger to prevent
exchanger overpressure.
• Corrective actions – Investigation
complete, recommend thermal RV. Work
order written to install 6/99. Work
complete in field, 9/99. Recommendation
closed.
Other types of safety devices
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Alarms
Trips
Interlocks
Analyzers
Area monitors
Containment
The objective is to:
• Anticipate ahead of time as many
potential incidents and hazards as
possible
• Engineer out as many hazards as
possible
• Put safeguards in place to prevent
incidents and control hazards when they
can’t be engineered out
Management of Change (MOC)
• Employer will establish
and implement written
procedures to manage
changes except for
“replacements in kind” to
process chemicals,
technology, equipment
and procedures; and
changes to facilities that
affect a covered process.
MOC Procedures
• The procedure shall assure the following
considerations are addressed prior to any
change:
– Technical basis for the proposed change
– Impact of change on safety & health
– Modifications to operating procedures
– Training of workers affected by change
– Process information updated to reflect change
A good MOC process addresses all
of the following:
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Equipment installed per design specifications
Update Equipment Files/Data Books
Update P&IDs and Process Flow Diagrams
Update Lock Out / Tag Out Isolation list
Update DCS Screens or Logic
Update Material and Energy Balance
Update Relief System Data
A good MOC process addresses all
of the following:
• Hazard Review Completed
• Hazard Review Safety Recommendations
Resolved
• HSE review impacts: PPE, Environmental,
Regulatory
• Update Chemical Information (MSDS)
• Update Operating Procedures
• Updating Operating Limits
• Update Safety/Shutdown System Data
A good MOC process addresses all of
the following:
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Update Training Materials
Train Operating Personnel
Train Maintenance Personnel
Train Contractors
Update Inspection Records
Update Maintenance Records/Procedures
Update Storehouse Stock Information
Incidents resulting from poor
Management of Change
• Bhopal
• Three mile island
• Houston Chemical Complex
The project engineer’s role
• Ensure proper MOC is
followed on your
projects
• Provide relevant
information and
expertise to process
hazard analysis
• Include safety devices in
design and budget
Our Responsibility to safety
• Moral/Humanistic
• Financial
• Legal