- 1-1 Engineering Ethics
- 1-2 Myths about Process Safety
- 1-3 Safety Culture
- 1-4 Individual Risk, Societal Risk, and Risk Populations
- 1-5 Voluntary and Involuntary Risk
- 1-6 Safety Metrics
- 1-7 Accident and Loss Statistics
- 1-8 Risk Perception
- 1-9 Risk Tolerance/Acceptance and Risk Matrix
- 1-10 Codes, Standards, and Regulations
- 1-11 Safeguards
- 1-12 The CCPS 20 Elements of Risk-Based Process Safety
- 1-13 Inherently Safer Design
- 1-14 The Worst Chemical Plant Tragedy: Bhopal, India, 1984<sup><a id="ch01fn13_r" href="ch01.xhtml#ch01fn13">13</a></sup>
- 1-15 Overview of Chemical Process Safety
- Suggested Reading
- Problems
This chapter is from the book
This chapter is from the book
This chapter is from the book
Problems
1-1. Engineering ethics: Write an essay on why you think safety (and process safety) is an important part of any engineering ethics statement.
1-2. Classify the following from 0 to 5 based on the hierarchy of safety programs provided in Table 1-3. Explain why.
The company and plant executive teams are very receptive to any safety suggestions and the suggestions are reviewed and implemented on a timely basis.
A change is made in a laboratory apparatus after a valve has leaked.
A change is made in a laboratory apparatus after a JSA review is completed.
The faculty member in charge of a laboratory has very little knowledge about safety.
The faculty member in charge of a laboratory states that “Safety is very important!” but does nothing after a small accident.
The company uses several leading safety metrics to assess its safety program.
The laboratory meets all the rules in the safety manual.
The faculty member in charge of a laboratory states that the safety program is interfering with the research efforts.
The laboratory is a mess.
1-3. Safety culture: Classify the following activities as either strengthening or weakening process safety culture. Explain why.
The plant manager schedules an important safety meeting that everyone must attend. At the meeting, the plant manager introduces a person from corporate safety and then excuses himself, stating that he has a more important meeting to attend elsewhere.
The faculty member in charge of a research lab states that not everyone in the laboratory needs to wear safety glasses—only people who are doing hazardous operations. Visitors also do not need to wear safety glasses.
The faculty member in charge of a research laboratory states that “No work is ever done in a clean lab!”
The faculty member in charge of a research laboratory states that his students—not him—are in charge of the safety program and does little else.
The plant manager institutes a suggestion box for safety ideas, and these ideas are discussed and resolved at the required safety meeting.
A suggestion box for safety ideas is implemented, but it takes the plant management many months to respond to the suggestions.
A research laboratory requires safety glasses, but the workers in the lab must purchase their own safety glasses.
A research laboratory requires safety glasses. The safety glasses are provided but are available only in a room down the hallway.
The laboratory safety manual has not been reviewed or updated in many years.
The faculty member in charge of a teaching lab tells the students that they have primary responsibility for safety, and the faculty member provides the training, resources, management and continuous auditing to ensure that the students are successful.
1-4. Individual and societal risk: For the following cases, identify the primary risk population, classify the case as involving individual risk and/or societal risk, and identify the risk as voluntary or involuntary.
A worker does not wear the required personal protective equipment for the chemicals being used.
A large butane storage facility is built next to a congested neighborhood.
A person drives a car from New York to Los Angeles.
A person drives a car without wearing the seat belt.
A person drives a car while intoxicated.
An airplane is produced with a manufacturing defect.
A tank truck containing gasoline is driven from the refinery to the gas station for unloading.
An underground pipeline is routed through a residential area.
A person climbs a cliff face solo.
1-5. Safety metrics: Classify the following as either leading or lagging safety metrics. Explain why.
Number of reports of unsafe activities in a plant
Number of near-miss incidents
Money spent on insurance claims
Number of visits to the plant first aid facility
Number of process alarms that were managed without incident
Time duration to complete maintenance
1-6. Accident and loss statistics: Return to Example 1-1. For parts (b) and (c), the length of time for both the hours-based fatal injury rate and the recordable incidence rate was 1 year. What time period is required for the hours-based fatal injury rate and the recordable incidence rate to be equal to the chemical manufacturing rates?
1-7. Accident and loss statistics: If the U.S. population in 2014 was 325 million people, calculate the deaths per 100,000 people from lightning strikes using the total fatalities from lightning in Table 1-13. Also calculate the fatality rate.
1-8. Use the risk matrix in Table 1-14 to determine the risk level for the Bhopal incident. Estimate the severity category, the safety severity level, the likelihood, and the risk level.
1-9. Codes, standards, and regulations: Go to the www.osha.gov web site and look up the OSHA regulation CFR 1910.119: Process Safety Management of Highly Hazardous Chemicals. Use Appendix A to determine the threshold quantities for the following chemicals. If your plant site exceeds this threshold quantity, then this standard applies.
Ammonia, anhydrous
Chlorine
Hydrogen fluoride
Propylene oxide
1-10. Safeguards: Classify the following safeguards as either preventive or mitigative.
A safety instrumented system to shut down a process if an unsafe operating condition occurs.
A foam system to reduce evaporation from a pool of leaked hydrocarbon.
A dike around a storage vessel.
A flow limiter is installed on a feed line to a chemical reactor to ensure that the reaction rate does not exceed a maximum value.
Covers are placed over pipe flanges to prevent liquid spraying.
A containment pond is built to collect any liquid runoff from a plant.
A relief device is installed on a chemical reactor to protect the reactor vessel from the damaging effects of high pressure.
A containment system is installed to collect the effluent from a relief device.
The basic process control system.
An emergency alarm system.
An alarm system to notify the operator of out-of-limits process conditions.
A gas chromatograph is installed to confirm chemical concentrations in a process.
All plant operations personnel are given yearly emergency response training.
1-11. CCPS elements: Classify the following activities as being most directly related to one of the 20 elements of RBPS. Although many elements may be involved, list only the single most applicable element. An element may be used more than once.
The plant has an open house for the local community.
A plant-wide emergency response drill is completed once each quarter.
A wide selection of courses on process safety are made available to the employees, and they are given the time and the motivation to enroll and complete the courses.
The plant manager demonstrates a shared responsibility for the plant safety.
All contractors on site are required to watch a video with an overview of the plant process safety and may be required to complete additional safety training depending on the type of work.
Participation in monthly safety meetings is required of all workers.
A small incident is investigated by the safety committee, with a final report being issued with recommendations and follow-through.
A permit system is developed to ensure that no welding or open flames are present when flammable liquids are handled.
Critical safety instrumentation is calibrated on a regular basis by the instrumentation personnel.
The plant site is audited on a regular basis by the corporate safety personnel.
Plant operating procedures are reviewed and updated to ensure that they conform to actual practice.
A management system is developed to ensure that all replacement equipment is identical in function to the original equipment.
When the electrical code changes, the plant staff reviews the changes to ensure that the plant meets the revised codes.
A hazard identification procedure is implemented for all existing processes.
Technical documents, engineering drawings and calculations, and equipment specifications are placed online for all workers to use.
A shutdown process is verified to be in a safe condition for restart.
A documented operations program is established to maintain reliable worker performance.
Leading and lagging metrics are established to gauge process safety performance.
An annual evaluation is developed to determine if management systems are performing as intended.
Appropriate information is made available to people who need it.
1-12. Inherently safer design: Which inherently safer design strategy applies to each of the following?
A flammable solvent is used to control the temperature in a reactor. The solvent is replaced by a nonflammable solvent.
A valve that requires 10 turns to close is replaced by a quarter-turn valve.
The equipment in a process can withstand 10 bar gauge (barg) of pressure even though the actual process operates normally at 5 barg. The pressure relief valve opening pressure is reduced from 10 barg to 8 barg.
A plant stores a large quantity of a hazardous intermediate chemical to keep the plant operating during upsets in the upstream process. The intermediate storage is eliminated and the process reliability is improved to prevent upsets and downtime.
An alternative reaction pathway is used that involves less hazardous raw materials.
The trays on a distillation column are replaced by structured packing, which operates over a wider range of operating conditions.
Additional homework problems are available in the Pearson Instructor Resource Center.