Professional Organizations Involved
American Society of Safety Engineers.
National Safety Council.
What do they do?
These professional organization consider the safety, health and welfare of workers and the public.
Whenever safety, health and welfare are in question.
They have an obligation to advise employers or appropriate authorities
Center for Chemical Process Safety (CCPS)
By the American Institute of Chemical Engineers
Established in 1985
Develop and disseminate technical information.
Prevention of major chemical accidents.
Chemical safety management
FYI: Chemical industry has fairly low accident rate compared to other industry.
Risk can be further reduce to protect employees and general public.
Requires integrated approach.
Table 10-1 An integrated approach…
Goals and Objectives of the safety program Risk Analysis and Management Industrial process design and operation Mechanical integrity of process equipment Safety Regulations, Codes and Standards Project Safety and Health Review Hazard Evaluation of process design and operation Personnel Motivation and Training Process and Plant Modification and Change Incident Investigation and Safety audits
Goals and Objectives of the Safety Program. Most Important Goal of Process and Plant Design
Safe Development
Design
Construction
Start-up
Operation of the plant
Examples of Major Industrial Accidents
Occurred with Union Carbide in Bhopal, India
Philips Petroleum Company in Houston, Texas
December 3, 1984 , methyl isocyanate (MIC) gas leaked. On Oct. 23, 1989, about 40 tons of flammable vapor were accidentally released and ignited.
ARCO in Channelview, Texas
A deadly blast ripped through the Channelview, Texas ARCO Chemical Co. plant on July 5, 1990, killing 17 nonunionized workers and transforming a 564 acre petrochemical complex into a heap of mangled, charred metal.
Safety Risk Reduced to Lowest Practical Level
Through a clear understanding of the:
Process Design
Operation
Mechanical
Integrity of Equipment
For the EMPLOYERS
Made aware of :
Safety Regulations
Codes
Standards
This should never be knowingly violated in the design and operation of the facility.
Management of projects
Should include a safety and health review.
Hazard evaluation of process and plant design.
Adequate training to personnel involved in development, design, construction and operation of the facility.
Management of projects
Proper motivation for the personnel mentioned in order to accomplish safety goals of the safety program.
Reassessment of all process and plant modifications, future changes in design and operation of the facility.
Management of projects
Any incident involving the process or plant should cause immediate concern and result in thorough, objective critique and investigation to determine the cause of the incident. Near miss accident should also be investigated to determine cause. Periodical safety audit by experienced, qualified team.
Management of projects
Dedicate sufficient resources to reduce risk of hazards.
Personnel
Equipment
Time
Money
Benefits of Safety
Adds to capital expenditures required and the operating costs BUT in the long term return on this short-term investment.
Improved on-stream factors and Product Quality
Better Product Availability for the marketplace
Benefits of Safety
Lower insurance costs
Higher Morale of personnel
More objective project evaluation
Improved public and personnel relations.
Reminder Under no circumstances should the safety function of an organization report to production, marketing, or other line business functions that might have conflicting goals.
Reminder Safety Personnel must communicate with the entire organization to promote safety awareness and knowledge.
Steps
Identify first the risk Identify those alternative actions that can be used
Risk analysis and Management 1.
Starts with hazard identification - check the material safety datasheets
Delphi Method - ranks the hazards according to their probable occurrence and severity.
Risk analysis and Management 1.
All practical steps should be made to reduce both the probability and severity of the risk By integrating risk management in the process and plant design, risk can be managed in a practical and effective manner
Industrial process design and operation
A desirable process and plant safety program starts with a well conceived process and plant design
Material datasheets should be reviewed to identify hazards each chemical represents and the methods to control it
Data and Informationassessment for chemical hazard Name and chemical composition Regulatory requirements Physical and chemical property data Fire and explosion data Reactivity data Health information Spill, leak, and disposal procedures Special protective equipment and precautions
Information Gathering
Process Chemistry
conversion from raw materials to desirable products
can create or reduce hazards in the process and plant design
Process chemistry in process and plant Chemical raw materials and catalysts design Chemical reactions and kinetic data Process operating parameters and ranges Preliminary process flow diagram Material, product, and waste inventories
Technology information for process and Process, plant designby-products and wastes produced Process technology to be used Plant capacity Process flow diagrams Process operating variables Selection of the plant site Hazard identification and safety control Waste identification and safety control Process control techniques Equipment specifications Government permit requirements Piping and instrumentation diagrams
Operational information for process and plant Construction design timetable Inspection and testing of equipment and instrumentation Personnel and training requirements Startup and troubleshooting of potential problems Debottlenecking opportunities Operations, maintenance, and emergency procedures Procedures for upset operating conditions Procedures for safety and environmental audits
Information Gathering
Piping and instrumentation diagram (P&ID)
A diagram which shows the interconnection of process equipment and the instrumentation used to control the process.
Sample P&ID
Water Heater Facility
Plant Operation
Normal plant operation
operating within desirable operating ranges
Significant deviation from the normal operation would result to an upset condition
Safety equipment and systems for process and plant design Fire protection Gas and vapor detection Alarm and interlock Pressure relief and vent Isolation of equipment and plant Emergency relief and vent Emergency and backup services
Plant Operation Critical:
control deviations
restore upset conditions to normal operation
* In start-up period major deviations from normal operations may be expected
Plant Operation
Successful start-up periods are enhanced by training of operators and process design that anticipated start-up problems before they occur. During the shutdown phase, deviation outside normal operation can also be expected. A smooth shutdown greatly assist a successful startup.
Mechanical Integrity of Process Equipment
Design, fabrication, installation, and maintenance affect safety
Specified construction materials should be used in fabrication and maintenance
All equipment used in the operating facility should be fabricated in accordance with design specifications
Mechanical Integrity of Process Equipment
When design specifications are compromised, probability of accident is increased
Inspect, verify and test to confirm reliability
Perform testing prior to start-up and periodically thereafter
Place procedures where hazardous materials are involved
Mechanical Integrity of Process Equipment
During maintenance operations, facility is vulnerable to the creation of a hazardous conditions
Design considerations should be given for different kinds of work during operation
Safety relief devices
Process Hazard Analysis
Hazard analysis is a study to identify, analyze, and evaluate the risk of hazards associated with a process or operating facility
Used to identify limitations in siting, design, layout, and operation of facilities
Improve the safety and management of risk at operating facilities
Process Hazard Analysis
OSHA
US Environmental Protection Agency
US Department of Transportation
Have promulgated regulations concerning safety and health hazards These regulations addresses the probability, severity, and consequences
Process Hazard Analysis
Severity – What can go wrong? How bad can it get?
Probability – How likely is it to occur?
Consequences – What are the impact?
Consequences of Hazard Identification Material Safety Data Sheets
Laboratory experiments
Research and Development
HAZARD ANALYSIS TECHNIQUES
Hazard analysis are used to determine the potential for deviations from or weaknesses in the system design that could pose a hazard to personnel and/or equipment.
Hazard Analysis
Hazard Analysis should identify risks, methods to reduce risk, and any actions needed to ensure that the equipment can be operated and maintained safely.
Hazard Analysis Techniques
What-if
Check list
What-if/Check list
Hazard and operability study (HAZOP)
Failure mode and effects analysis (FMEA)
Fault tree analysis
Appropriate equivalent methodology
What-if
brainstorming techniques, in the form of ‘What If’ questions are used to identify possible deviations and weaknesses in design.
‘What If’ hazard analyses can be used to determine system compliance with SEMI S2 requirements to verify that “no single point of failure or operational error should allow immediate exposure of personnel, facilities or community to hazards or directly result in injury, death or equipment loss.”
What is SEMI S2 Requirements?
Safety Guidelines for Semiconductor Manufacturing Equipment
defines minimum performance-based safety requirements that address a number of hazards, including chemical, electrical, fire safety, sound, radiation, mechanical, and seismic.
What-if
Caution: ‘What If’ hazard analyses are based on brainstorming. Their thoroughness and accuracy are dependent upon the composition and expertise of the team performing the analysis. In addition, the ‘What If’ hazard analyses stops at a single point of failure and does not investigate the system further. (i.e., This method would not evaluate a series of failures and the potential consequence of this series.)
What if (example) What if
Consequence
Comments
Material A does not flow to reactor?
Unreacted B will contaminate Product C
Alarm and shot off valve B
What if equipment temperature exceeds its limit?
Equipment failure.
Off the equipment and increase the cooling system.
Meltdown of components.
Checklist Analysis
It is used for step of the process.
Time consuming in development
Can be apply also to complex processes with similar hazards.
Also like what-if in development
Example of checklist Checklist
Answer
Comments
Is each delivery of material B checked for contamination?
Yes
Supplier of material B has been reliable.
Is the particle count in the room exceeds 3ppm^3
No
The room can be use on process.
Combined what-if and checklist
More broad-based hazard assessment technique.
Involve brainstorming also
Hazard and Operability analysis
(HAZOP)
Systematic study of each process element and requires thorough examination of process-flow diagrams.
Pant operation => improved plant efficiency
Uses guide words
Failure Mode and Effect Analysis
(FMEA)
Begins of all listing the Equipments and process components of the system under study
More applicable to projects that are well into design phase.
Contains failure mode, consequences, safeguards, recommended action
Fault Tree Analysis
Begins with graphical diagrams of all sequence of events that could result on incidents, accidents, or exposure.
Uses logic symbols and event symbols
Fault tree analysis symbols
TOP EVENT
Transfer IN-OUT
BASIC EVENT
UNDEVELOPED EVENT
OR GATE
AND GATE
Fault Tree Analysis Example SYSTEM FAILS
C
A
D
B
Personnel Motivation and Training
Operations and Maintenance Personnel needs training
Highly trained and skilled personnel are excellent resource for improving safety and productivity.
Outside contractors are also to be considered
Well-conceived process control system should reflect a balance between:
Human Control
Reflects human capability at a particular time when the response is required
Hardware Control
Reflects the hardware design and mechanical integrity atupon a particular point of demand
Human Errors
Errors of Omission
Errors of Commission
Employee Performed the task but did it incorrectly
Errors of Sequence
Employee forgot to execute a required task
Employee did the task out of order with the required sequence
Errors of Timing
Employee did the task either too fast or slow
Operator-Induced Error
System-Induced Error
Employee has the knowledge to make the correct decision but acts incorrectly Created by integration of incompatible components into a total system
Design-Induced Error
Results from faulty equipment design, fabrication or installation
Input Errors
Low Stress Errors
Caused by typographical errors associated with data or information Cause by a lapse of memory during a normal environmental condition
High Stress Errors
When employees make wrong decisions in life-threatening situations
Process and Plant Modification Change
It should not result in errors that could lead to accidents
Safety program at the operating facility should have procedures to manage modifications
Hazard Analysis should be performed
Incident Investigation and Safety Audits
Near-miss Incidents should be studied
Safety Audits are used to verify compliance with regulatory standards
Used to protect the safety and health of the employees, surrounding communities and environment
Safety Audits
Review of Relevant Documentation
Review of Process Safety Information
Inspection of Operating Facilities
Interviews with selected plant personnel
