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Chapter 7: Risk, Safety and

Liability in Engineering

IENG 355

ETHICS IN ENGINEERING

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Case (Part 1)

Don Hayward is employed as a chemical engineer at ABC Manufacturing. Although he does not work with hot metals himself, he supervises workers who are exposed to hot metals eight hours a day, five days a week.

Don becomes concerned when several workers develop respiratory problems and complain about "those bad smelling fumes from the hot metals".

When Don asks his superior, Cal Brundage, about air quality in the workplace, the reply is that the workplace is in full compliance with OSHA guidelines.

However, Don also learns that OSHA guidelines do not apply to chemicals that have not been tested. A relatively small percentage of chemicals in the workplace have actually been tested. This is also the case with the vast majority of chemicals workers are exposed to at ABC.

Should Don do anything further, or should he simply drop the matter?

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Case (Part 2)

Don goes to ABC's science library, talks to the reference librarian about his concerns, and does a literature search to see if he can find anything that might be helpful in determining why the workers have developed respiratory problems. He finds the title of an article that looks promising and asks the reference librarian to send for a copy. The librarian tells Don that the formal request must have the signed approval of Cal Brundage.

Don fills out the request form and sends it to Cal's office for approval. One month later the article has still not arrived. Don asks Cal about the request. Cal replies that he doesn't recall ever seeing it. He tells Don that it must have gotten "lost in the shuffle." Don fills out another form and this time personally hands it to Cal. Cal says he will send it to the reference librarian right away.

Another month passes by and the article has not arrived. Don mentions his frustration to the reference librarian. He replies that he never received a request from Cal.

What should Don do now?

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How should engineers deal with issues of

risk and safety?

Engineering necessarily involves risk.

New hazards could be found in products,

processes, and chemicals that were once

thought to be safe.

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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.

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In this chapter we will go over

The codes and engineering practice regarding risk and safety

Difficulties in estimating risk

Normalizing deviance

Three approaches to acceptable risk: experts,

laypersons, and

government regulators approach to acceptable risk

The Engineers liability for risk

Becoming a responsible engineer regarding risk

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The codes and engineering practice

regarding risk and safety

All engineering codes say that: “Engineers must hold paramount the safety, health, and welfare of the public.

NSPE:

II1b. Engineers shall approve only those engineering documents that are in conformity with applicable standards. (are standards in the case applicable???)

III2b. Engineers shall not complete, sign, or seal plans and/or specifications that are not in conformity with applicable engineering standards. If the client or employer insists on such unprofessional conduct, they shall notify the proper authorities and withdraw from further service on the project. (Case Part 1)

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II1a. If engineers' judgment is overruled under circumstances that endanger life or property, they shall notify their employer or client and such other authority as may be appropriate.

(Case Part 2)

The codes and engineering practice

regarding risk and safety

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Difficulties Estimating Risk

Detecting Failure Modes:

A failure mode is a way in which a structure,

mechanism or process can malfunction.

Fault-Tree Analysis: a diagram of the possible

ways in which a malfunction or accident can

occur.

Event-Tree Analysis (similar with different approach)

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Fault-Tree Analysis

In a Fault-tree analysis one starts with

an undesirable event, and then reasons

backward to determine what might

have led to the event. (p149)

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Fault-Tree Analysis used to discover

why a car wont start F a u lt T re e

1 . R u s t

2 . C o rro s io n

3 . D ir t

4 . L o o s e c o n n e c tio n s

1 . lig h ts le f t o n m o to r o f f

2 . A g e

3 . B a d w e a th e r

4 . D e fe c tiv e ..........

1 . F a u lty g ro u n d c o r re c tio n s

2 . T e rm in a ls lo o s e o r c o r ro d e d

3 . B a te ry w e e k

B a tte ry C h a rg e In s u f f ic ie n t

T yp e tit le h e re

S ta r tin g S ys te m d e fe c tiv e

T yp e tit le h e re

F u e l S ys te m

D e fe c tiv e

ig n itio n s ys te m

d e fe c tiv e

C a r W o n t S ta r t

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Event Tree-Analysis

In event-tree analysis one begins with

an initial event and reason forward to

the state of system to which the event

can lead. (p.150)

These have limitations p.150

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Are There Normal Accidents?

Two characteristics of high-risk

technologies that make them susceptible to

accidents:

Tight Coupling and

Complex Interactions of the parts of

technological systems

**These two factors make accidents likely and

difficult to predict and control

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Processes are TIGHTLY COUPLED if

they are connected in such a way that

one process is known to affect another

and will usually do so within a short time.

Ex: A chemical plat is tightly coupled because the

failure in one part of the plant can quickly affect

other parts of the plant.

Ex: A university is loosely coupled, why?

Tight Coupling

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Processes are COMPLEXLY INTERACTIVE if the parts of the system can interact in unanticipated ways. Like no one expected that when part B failed it would affect part C.

Examples of complexly interactive and tightly coupled technical systems:

chemical plants, nuclear power plants, space missions, nuclear weapon systems. These can have unexpected failures, and little time to correct the problems. (all system affected)

Complex Interactions

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The answer is:

It may not be possible to make a

system both loosely coupled and

noncomplex therefore accidents in

complex, tightly coupled systems are

inevitable and “Normal” (Perrow).

Students should read page 160-161(151-152): an example of an

accident in a system that was complexly interactive and tightly coupled

and that could have been prevented by good engineering.

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Normalizing Deviance

Engineers increase the risk to the public by

allowing increasing numbers of deviances

from proper standards of safety and

acceptable risk.

This is called normalization of deviance.

Accepting anomalies instead of attempting

to correct a design or operating conditions

that led to the anomalies make accidents

inevitable! (page 162/153 example from the challenger disaster)

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Risk

Technology imposes RISK on the

public

RISKs are often difficult to detect and

eliminate

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Three approaches to acceptable risk

The Experts Approach

The Layperson’s Approach

The Government Regulator’s Approach

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Experts Approach to

Acceptable Risk

Identifying risk To assess the risk, an engineer must first identify it. To identify a risk,

an engineer fmust fits know what a risk is. Concept of risk involves the

notion of adverse effect or harm.

Utilitarianism and acceptable risk The risk expert’s approach to risk is usually utilitarian. Apply cost-

benefit analysis by modifying it to risk-benefit analysis because the

“cost” is measured in terms of the risk of deaths, injuries, or other

harms.

Risk as maximizing benefit

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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”

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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.

(Case Ex: Is the risk to the workers from the fumes acceptable? ).

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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.

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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.

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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 coerced

A person must have the relative information

A person must be rational and competent

enough to evaluate the information.

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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.

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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.

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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.

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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.

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(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. Page 168 some issues (6) that arise in applying the principle.