hazardanalysisppt 5th sem-aug'24
TRANSCRIPT
05/02/2023 1
Title : Hazard Analysis (HAZAN)
05/02/2023 2
Un-thoughtful accidents ?Need for Hazard analysis
05/02/2023 3
What is a hazard?
05/02/2023 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.
05/02/2023 5
Basically, a hazard can cause harm or adverse health effects to individuals or to organizations as property or equipment losses.
05/02/2023 6
Types of hazard
05/02/2023 7
1) Chemical hazardsChemicals 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.
05/02/2023 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.
05/02/2023 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.
05/02/2023 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.
05/02/2023 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.
05/02/2023 12
What is Hazard Analysis?
05/02/2023 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
05/02/2023 14
Job Hazard Analysi
s
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 relationship between the worker, the task, the tools, and the work environment
05/02/2023 15
05/02/2023 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
s
05/02/2023 17
Why Hazard Analysis is important?
05/02/2023 18
Importance / Benefit
To train workers
how to do their jobs
safely
Policies and
procedure improved
investigate
accidents Increase quality
Decrease injury rate.
05/02/2023 19
identify what personal protective equipment
Hearing protection
Body protection
Eye protection
Foot protection
Material handling aids
Hand protection
Respiratory protection
05/02/2023 20
Hazard Analysis Procedure
05/02/2023 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
05/02/2023 22
How to identify and analyze hazard?
05/02/2023 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?
05/02/2023 24
HAZARD ANALYSIS METHODS
05/02/2023 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.
05/02/2023 26
Hazard analysis methods include :
Process Hazard AnalysisEvent Tree AnalysisFailure Modes And Effect Analysis
Fault Tree AnalysisCause-consequence Diagram Hazard And Operability Studies
05/02/2023 27
1) PROCESS HAZARD ANALYSISA 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.
05/02/2023 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
05/02/2023 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.
05/02/2023 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 modesEffects of failure modes can be quantified
05/02/2023 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
05/02/2023 32
Example of FTA
05/02/2023 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.
05/02/2023 34
Example of CCA
05/02/2023 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.
05/02/2023 36
How to control hazard?
05/02/2023 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.
05/02/2023 38
1) Engineering ControlsEngineering controls include the
following:Elimination/minimization of the hazardSubstitution 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.
05/02/2023 39
2) Administrative ControlsAdministrative 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
05/02/2023 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.
05/02/2023 41
Case Study of Hazard Analysis
Fire at Formosa Plastic Corporation:Evaluating Process Hazard
05/02/2023 42
INTRODUCTIONThis 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.
05/02/2023 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
44Figure 1: Propylene Fire
05/02/2023 propylene
05/02/2023 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.
05/02/2023 46Figure 2 : View of the Damaged Plant from Highway 35
05/02/2023 47Figure 3 : Olefin II units
05/02/2023 48
INCIDENT SEQUENCEA 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.
05/02/2023 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.
05/02/2023 50
05/02/2023 51
CAUSES OF INCIDENTFigure 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.
05/02/2023 52
05/02/2023 53
05/02/2023 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.
05/02/2023 55Figure 8 : Protection of Fire Fighting Equipment
05/02/2023 56Figure 9 : Vehicle Impact Point
05/02/2023 57
LESSONS LEARNEDWhen 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.
05/02/2023 58
ReferencesFire at Formosa Plastics Corporation:. Case study,
Washington: CSB publications, 2006.Hazard Analysis Methodologies.
https://www.osha.gov/SLTC/etools/safetyhealth/mod4_tools_methodologies.html (accessed March 27, 2015).
Job Hazard Analysis. 2002. https://www.osha.gov/Publications/osha3071.html (accessed March 26, 2015).
Types of Hazards. http://students.fortresslearning.com.au/del301/types-of-hazards/ (accessed March 23, 2015).
Fire at BHN platform, ONGC-2005, Bombay High