2. UNIT III
ENGINEER’S RESPONSIBILITY FOR SAFETY

3. Unit III
Safety and Risk – Assessment of Safety and Risk – Risk Benefit Analysis – Reducing Risk – The Government regulator’s Approach to Risk - Chernobyl Case Studies and Bhopal

4. 4.2 Safety State of being Safe
Dictionary meaning – Freedom from damage, injury or risk
Definition:
“A thing is safe if its risks are judged to be acceptable” – William W.Lowrence

5. Drawbacks of Lawrence's Definition
Under-Estimate Risk
Misjudgment of person
Example: Coil Type Water heater
Over-Estimation of Risk
Products Risks comparatively less risks
But people thinks “Unsafe”
Example: Chlorine in drinking water
No estimation of Risk
Person who does not judge about risks
Example: LPG Car

6. A modified Definition by Lowrence
“ A thing is safe ( to certain degree) with respect to a given person or group at a given time, it its risks were fully known, if those risks would be judged acceptable (to certain degree), in light of settled value principles”
Here things means not only products but also services, processes etc.,

7. Relatively Safety (fairly safety)
Safety is expressed in terms of degree and comparisons.
It means safety of the thing in comparison with safety of similar things
Example
Air travel> Car Travel > Bike Travel

8. 4.3 Engineers and Safety
Safety should be integral part of any engineering design.
In order to ensure safety following criteria should meet
Design follow legal standards
Alternate designs that are potentially safer should be explored.
All possible misuse by the consumer should be identified, and that is to be avoided
Designed product should be tested using prototypes

9. Designing for safety
Alan D.Wilcox has summarized the process of incorporating safety into the engineering design as follows
1. Define the problem (issues of safety in the product design)
2. Generate alternate design solutions
Analyze each design solutions
Test the solutions
Select the best ones
Implement the chosen solution

10. 4.4 Risk
Risk increases because engineers are constantly involved in innovation.
New machines are created and new compounds synthesized always without full knowledge of their long-term effects on humans or the environment.

11. Risk
Risk Definition in dictionary “ possibility of suffering harm or loss”
Risk in technology could include dangers of
bodily harm
economic loss
environmental degradation
Engineers risk affects mostly the physical and economical well being
Example: Faulty design of chemical plant
Causes of risk: Delayed job completion, faulty products or systems

12. Risk - Definition

13. Natural Hazards and Disasters
Natural hazards such as floods, earthquake, volcanoes etc greatly threatens and damages the long life of human populations
A Disaster is a “ Serious disruptive event agrees with a state of insufficient preparations”

14. Factors influencing Risk
1. Voluntary Vs In voluntary Risk
If a person knowingly takes any risks, then he feels it safe
voluntary Risks are consider as safe (even if risks are really Unsafe)
Involuntary Risks are consider as unsafe (even if risks are really Safe)

15. Factors influencing Risk
2.Short term vs Long term consequences
If a thing will causes a short-lived illness or disability is safer than the thing that will result in permanent disability
3. Delayed vs immediate Risk
An activity whose harm us delayed for many years will seem less risky than something with an immediate effect

16. Factors influencing Risk
4. Expected probability
A relatively slight harm having more probability of occurring seems to be greater / unacceptable risk than a relatively a severe harm having lesser probability of occurring
Example : 600 people unsafe –
Choose option 50% safe not probability

17. Factors influencing Risk
5. Reversible Effects
Something will seem less risky if the bad effects are ultimately reversible
6. Threshold levels of Risks
Something that is risky only at fairly high exposures will seem safer than something with uniform exposure to risk

18. SAFETY AND RISK
Imagine you are a fresh graduate.
You get a job as an engineer in a large atomic power plant.
Would you take it or not?
Under what conditions would you take it?
Under what conditions would you not?
Why?
People as Consumers:
Active Consumers: directly involve themselves e.g., mowing the lawn, washing clothes or toasting bread.
Passive Consumers: have less choice and less control e.g., Water, Electricity, Petrol,
Bystanders: e.g., exposed to Pollution from unknown sources

19. 4.5 Acceptability of Risk
According to D.Rowe, “ A risk is acceptable when those affected are generally no longer apprehensive about it”
Apprehensiveness- doubtfulness is mainly depends on how the risk is perceived by people

20. Elements of Risks ( Factors influencing the perception of Risk)
Whether risk is influenced voluntarily
The effect of knowledge on how the probabilities of harm are perceived
Job related or other pressures that cause people to be aware of risks
Whether the effects of risky activity or situation are immediately noticeable
Whether the potential victims are identifiable earlier

21. Acceptability of Risk (Effect of Risk Assessment)
1.Voluntarism & Control
Voluntary Risk : If people take risk knowingly, then their involvement of risk is known as voluntary risk
Many people consider safer if they knowingly take on the risk. Also the people believe that they have “Full Control” over their actions
Example:
Buying a Flat near chemical plant
Participating in adventurous sports like bike race
Controlled Risk: If the Risk taken within control limit
Example: horseback riding hill climbing

22. Acceptability of Risk (Effect of Risk Assessment)
2 Effect of Information on Risk Assessment:
The information about the danger should be in systematic and appropriate manner
Many case studies have proved inappropriate manner lead to danger
Threshold limit varies person to person
From many experiments drawn 2 conclusions
Options perceived as yielding company gain will lead to preferred over those from which gains are perceived as risky as convenient
People tend to be more willing to take risk in order to perceived company losses than they are to win only possible gains

23. Acceptability of Risk (Effect of Risk Assessment)
3.Job Related Risk:
The Exposure of Risk depends on the person’s job and his work place
The nature of the job, and the working environment will determine the risk level of a person
Example:
People working in coalmines, oil mines chemical plants have probability of high risk
Because of competition of survival
The union and occupational safety regulations should regulate and enforce the employers to facilitate the standard working environment

24. Acceptability of Risk (Effect of Risk Assessment)
4. Magnitude and proximity:
Our reaction to risk is affected by magnification and the personal identification and relationship we have with the victims
For instance, We feel very bad if one of our close friends are subjected to great harm
Magnitude of risk and proximity with victims greatly influence the degree of reaction of the risk

25. 4.6 Lessons for the engineers
Engineers have the challenge to face the following two different public conceptions of safety
Positive or optimistic Attitude
Some people assume that things that are familiar, that have not hurt them on which they have some control present to real risk
Negative or pessimistic Attitude
Some people feel feared when an accident kills or harms in large numbers or affects their relations, they consider those risk as high risks
Education will not quickly change under/over estimation
The continuous & proper information about the dangers are necessary to educate the people
The risk communication and risk management efforts are structured as two way process

26. 4.7 Risk-Benefit Value Function
The risk and benefits are based on probable gain and probable loss

27. 4.8 Types of accident Procedural Accidents Engineered Accidents
Result of someone making bad choice or not following established rules
Example: - Road accidents
Engineered Accidents
Caused by errors in design
Example: minor casting defects in aircrafts turbine blade
Systematic Accidents
They are difficult to understand & difficult to control
Complex organization that are required to operate them
Example: US Space Shuttle

28. 4.9 Assessment of Safety & Risk

29. Assessment of Safety & Risk
Primary Cost:
Production cost & Cost of Safety
Secondary Cost
Cost associated with warranty expense, lost of customer good will

30. 4.10 Determination of RISK
In order to determine the risk one should have knowledge about the following criterions
1. Knowledge of Risk
To assess risk, an engineer must identify risk, for that he must first know the information about the safety of standard products
The past experience and historical data provide good information
But historical data is inadequate
The information is not freely shared among firms

31. Determination of RISK 2. Uncertainties in Design
While designing a product, the design engineers must deal with uncertainties
The uncertainties are in the form of product, materials used, economic conditions, temperature etc.,
The ‘Factor of safety’ is proposed to account for unpredictably high loads . It must follow
A product is said to be safe if its capability exceeds its duty

32. Determination of RISK 3.Testing For Safety
Once the product is designed, both prototypes and finished devices must be thoroughly tested
It is essential that in engineering design, all the safety systems to be tested

33. Determination of RISK Different Approaches in testing
Scenario Analysis
The test starts from the given event, then studies the different moments that might develop from it
Failure Modes & Effective Analysis
It systematically examines each and every components without focusing on relationship among the elements of complex system
Fault Tree Analysis(***)
This approach propose system failure and then traces the events back to possible causes at component level
Event Free Analysis
This is the reverse of the fault free analysis.
Mathematical oriented version of Testing
This analysis is very useful in identifying a potentially hazardous situation a plant

34. 4.11 Risk Benefit Analysis It answers the following questions
It is technique, used to analyze the risk in project and to determine whether the project should be carried out or not
It answers the following questions
What are the benefits of product/project?
Is the project is worth for the risk?
Do benefits balance the risk?
Everyone is ready to accept certain level of risks

35. Conceptual difficulties in Risk-Benefit Analysis
Both risks and benefits very difficult to calculate because lie in future (uncertainties)
Ensure who takes risk are to be enjoy benefit
It is difficult to express both risk and benefits is a common set of units.

36. Ethical implications on Risk- Benefit Analysis
While performing Risk –benefit analysis, one should keep in mind the following ethical questions:
Under what condition, someone in society is entitled to impose a risk in someone else on behalf of supposed benefit to others?
How can we consider the worst case scenarios of persons exposed to maximum risks while they are obtaining only minimum benefits?
Are their rights violated?
Are they provided safer alternatives?

37. Personal Risk
If sufficient information is given to a person, he can able to decide whether to participate in a risky activity or not.
Many experiments concluded- individuals are willing to face voluntary risks than involuntary risks
They are difficult to assess
Examples:
A person living near chemical plant
A Person working in nuclear plant

38. Assessing personal risk
Answer following ethical questions
How to access the money value of an individuals life?
On what basis, the compensation for a risk can be decided?
Is the compensation is justifiable?
What will be the compensation if the tolerance level is above the tolerance level?

39. Minimize the difficulties in personal risk
Life insurance
Increased wages

40. Public Risk and public acceptance
Public Risk can be easily determine than personal Risk
Assessment studies related to technological safety can be conducted for public risk
According to National Highways Traffic safety Administration(NHTSA) has emphasized following two points
A value of human life can be estimated based on loss of future income and other costs associated with an accident
A estimate of quantifiable losses in social welfare is not based on maximum expenditure allocated to save a life

41. Accounting publicly for Benefits and Risks
Public accountability for risk has been affected by the following problems
An expert or even group of experts cant be expected to know everything
The uncertainties produced by scientist and regulators* also infects the risk regulation
Since the origins of risk vary depending on how the facts are presented, therefore special cause should be given when starting probabilities if rare events
(*regulator- who assure the public that there are no risk, but they know that the answer are not at hand)

42. Becoming responsible engineers regarding risks
Engineer can provide background material to prove the faulty positions
Engineers should actively participate in debates related to safety and risks
Engineers should always insist on meaningful numbers and figures when assessing safety and risk
Engineers should also recognize previously mentioned difficulties with measuring risk and benefits
Engineers should not be influenced by any influential lobby or trade organization
Engineers need to sensitive to various quantitative value judgement related with human and ethical values
Engineers should be aware at the legal liabilities regarding risk.

43. Reducing Risk
It is impossible to design and manufacture anything to be completely risk free
Engineers responsibility to explore all the possible ways to reduce the risk under the given financial and time constraint
Risk Management: Eradication or minimization of the adverse effects of the pure risks to which an organization is exposed
Elements of Risk management Programme:
Risk identification
Risk Evaluation( Risk measurement)
Risk Control

44. Elements of Risk Management
Risk Identification
Risk can be identified by various techniques such as physical inspection, safety audit, job-safety analysis, management and worker discussions,& historical data analysis
Risk Evaluation
Risk can be evaluated on the basis of economic, social or legal considerations
Economic and social considerations include financial aspects, uninsured cost of accidents, insurance premium, overall effect of profitability, possible loss of production
Legal considerations include possible health and safety law, code of practice, guidance notes & accepted standards, fire prevention, pollution and product liability

45. Elements of Risk Management
Risk Control
Risk control consists of 4 areas
Risk Avoidance
It refers to the conscious decision by the management to avoid completely a particular risk by discontinuing the operation producing risk
Risk retention
Retaining a particular risk for which any consequent loss is financed by organization
Risk transfer
Legal assignment of cost of certain potential losses from one party to another (insurance)
Risk reduction
Reduction or elimination of all aspect of accidental loss lead to wastage of an organizations assets.

46. Three approaches to acceptable risk
The Experts Approach
The Layperson’s Approach
The Government Regulator’s Approach

47. Experts Approach to Acceptable Risk
Identifying risk:
Utilitarianism and acceptable risk
Risk as maximizing benefit

48. Identifying risk
concept of risk involves adverse effect or harm. Harm is a limitation of a persons freedom or well being. (physical well being, psychological well being, economical well being)
Risk can be defined as: “a compound measure of the probability and magnitude of adverse effect” (William W. Lowrance)
We can add : “probability of death or injury”

49. Utilitarianism and Acceptable risk
The experts approach to risk is usually utilitarian. That the answer to any moral question is to be found by determining the course of action that maximizes well being.
Cost/benefit technique is often called risk/benefit analysis. Cost is measured in terms of risk of deaths, injuries, or other harms associated with a given course of action.
* Utilitarian - Practical

50. Risk as maximizing benefit
An acceptable risk is one of where , given the options available, the risk of harm is at least equaled by the probability of producing benefit.
Limitations: (that will yield the cost/benefit approach inconclusive)
It might not be possible to anticipate all of the costs and benefits associated with each option
It is not always possible to translate all of the risks and benefits into monetary terms. What is the monetary value of human life?
The method makes no allowances for the distributions of costs and benefits.
The method gives no place for informed consent to the risk imposed by technology.

51. The Laypersons Approach to Acceptable Risk
Expert and Layperson
Public is sometimes mistaken in estimating the probability of death and injury from various activities of technology. Experts and lay person understand risk differently.
Informed consent and justice: lay person approach follows more closely the ethics of respect of persons than utilitarianism.

52. Free and informed consent and compensation
Three necessities to give free and informed consent to the risks imposed by technology:
A person must not be forced
A person must have the relative information
A person must be rational and competent enough to evaluate the information.

53. Lay criterion of acceptable risk:
An acceptable risk is one in which risk is freely assumed by free and informed consent, or properly compensated, and which is justly distributed.

54. The Government Regulator’s Approach to Risk
An acceptable risk is one in which protecting the public from harm has been weighted more heavily than benefiting the public.

55. Three approaches to acceptable risk
Risk Expert: wants to balance risk and benefit in a way that optimizes overall public well-being.
Layperson: wants to protect himself or herself from risk.
The government regulator: wants as much assurance as possible that the public is not being exposed to unexpected harm.

56. Becoming a Responsible Engineer Regarding Risk
Includes to be aware
that risk is often difficult to estimate
that there are different approaches to the determination of acceptable risk
of the legal liabilities regarding risk.

57. (A more general) Principle of Acceptable Risk
People should be protected from the harmful effects of technology, especially when the harms are not consented to or when they are unjustly distributed, accept that this protection must sometimes be balanced against (1) the need to preserve great and irreplaceable benefits and (2) the limitations on our ability to obtain informed consent.

58. Bhopal Gas Tragedy
On December 3, 1984, Union Carbide's pesticide-manufacturing plant in Bhopal, India leaked 40 tons of the deadly gas, methyl isocyanate into a sleeping, impoverished community - killing 2,500 within a few days, permanently disabled and injuring 100,000 people. Ten years later, it increased to 4000 to 7000 deaths and injuries to 600,000.

59. Risks taken:
Storage tank of Methyl Isocyanate gas was filled to more than 75% capacity as against Union Carbide‟s spec. that it should never be more than 60% full.
The company‟s West Virginia plant was controlling the safety systems and detected leakages thro‟ computers but the Bhopal plant only used manual labour for control and leak detection.
The Methyl Isocyanate gas, being highly concentrated, burns parts of body with which it comes into contact, even blinding eyes and destroying lungs.

60. Causal Factors:
Three protective systems out of service
Plant was understaffed due to costs.
Very high inventory of MIC, an extremely toxic material.
The accident occurred in the early morning.
Most of the people killed lived in a shanty (poorly built) town located very close to the plant fence.