Process and Plant Safety Hazards Ching, Warren Cu, Joshua Javier, Mike So, Jonathan Uy, Jeckson

Process and Plant Safety Hazards Introduction Process and Plant Safety Hazards

Process and Plant Safety Hazards Involves the application of scientific, engineering, and management principles. Aimed in the identification, characterization and contol of process and plant hazards. To prevent injuries and incidents that can cause harm to employees or the public.

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 December 3, 1984 , methyl isocyanate (MIC) gas leaked. Philips Petroleum Company in Houston, Texas 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 non-unionized 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

This should never be knowingly violated and operation of the facility. 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 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 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 Information for chemical hazard assessment 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 design Chemical raw materials and catalysts Chemical reactions and kinetic data Process operating parameters and ranges Preliminary process flow diagram Material, product, and waste inventories

Technology information for process and plant design Process, by-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 design Construction 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 start-up.

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. Meltdown of components. Off the equipment and increase the cooling system.

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

Fault Tree Analysis Example

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 upon the hardware design and mechanical integrity at a particular point of demand

Human Errors Errors of Omission Errors of Commission Employee forgot to execute a required task Errors of Commission Employee Performed the task but did it incorrectly Errors of Sequence 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 Employee has the knowledge to make the correct decision but acts incorrectly System-Induced Error 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 High Stress Errors Caused by typographical errors associated with data or information Low Stress Errors 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