This document discusses safety concepts, risk assessment, and methods to determine risk. It covers the following key points: 1. It defines safety, risk, and different types of risks like acceptable risk, voluntary vs involuntary risk, and job-related vs personal risks. 2. It explains factors that influence risk and how risk is assessed using concepts like probability and magnitude of harm. 3. It outlines goals of risk assessment to identify hazards and minimize risk through control measures to create a safer workplace. 4. It describes different methods used to determine risk, including testing safety systems, dealing with uncertainties in design, and various testing approaches like destructive, prototype, and simulation testing.

1. SAFETY, RESPONSIBILITY AND RIGHTS
PEE - CHAPTER 4
S A N T H O S H - K H AV I YA N - A K S H I T H A A - N AVA L A D I

2. TOPICS
1 .SA F E TY A ND ITS CO NCEPTS
2.RISK AND ITS TYPES
3 . A S S ES E ME NT O F SA F E TY A ND R IS K
4 .ME THO DS TO DE TE R MINE R IS K
2

3. SAFETY AND ITS CONCEPTS
W H AT I S S A F E T Y ?
Safety: The state of being safe
Safe: Protected from danger
Safety differs for every person, where
what may be safe for one person may
not be for another.
Absolute safety that satisfies all
individuals or group under all
conditions is neither attainable nor
affordable.
3

4. WILLIAM W.LOWRENCE’S
DEFINITION
W H AT I S S A F E T Y ?
INITIAL VERSION:
A thing is safe if its risks are judged to be
acceptable
MODIEFIED DEFINITION:
A thing is safe(to a certain degree) with
respect to a given person or group at a
given time, if its risks were fully known, if
those risks would be judged acceptable(to
that certain degree), in light settled value
principle.
4

5. RISK
WHAT IS RISK?
5
It is the potential that something unwanted and
harmful may occur.
LOWRENCE: “Risk is the compound measure of the
probability and magnitude of adverse effect”.
RISK= Probability of the harm x Magnitude of the
harm
Effects of risk: it includes dangers of bodily harm,
economic loss, environment degradation.
Causes of risk: Risks or harms are caused by delayed
job completion, faulty products or systems and
economically or environmentally injurious solutions to
technological problems.

6. FACTORS INFLUENCING RISK
1. Probability of risk (possibility of occurrence of risk)
2. Consequences of risk (Physical damage or death, economic loss,
damage to property, loss of money, degradation of environment)
3. Voluntary risk (some people may take risk voluntarily for thrill and
fun)
4. Magnitude of risk (number of people / area involved in risk)
5. Proximity of risk (closeness of effects caused by risk)
6. Method of information widely spreaded on risk
7. Job related risk (whether the risk is compulsorily / forcibly taken by
persons)

7. SAFETY SND RISK
The knowledge about acceptance level of risk is useful to engineers.
Designers can redesign the product/project to include safety measures so as to:
1. To allow the product to fail safely
2. Abandon it safely.
3. Provide for safe escape/evacuation from the product or site, and thus
eliminate or minimize the human loss.
Risk is the result of unsafe situation, sometime unanticipated during its uses.
Probability of Safety = 1-Probability of risk
= Probability of occurrence x consequences in magnitude

8. TYPES OF RISKS
1. Acceptable risk
2. Voluntary and involuntary risk
3. Job related risks
4. Personal risks
5. Public risks
8

9. Acceptable risk:
 It refers to the level of human and property injury or
loss from an industrial process that is considered to be
tolerable by individual, household, group, organization,
community, region, state, or nation in view of social,
political & economic-benefit analysis.
 Ex: the risk of flooding can be accepted once every
500yrs but its unacceptable in every 10yrs.
 Its management’s responsibility to set their company’s
level of risk. Each company has its own acceptable risk
level, which is derived from its legal regulatory
compliance responsibilities. 9

10. Voluntary risk:
 To risk either by own actions or action taken by others .
 Risk happening with lifestyle choices.
 They are the risk that people take knowing that they
may have consequences.
 Ex: smoking tobacco, driving car and climbing ladder.
Involuntary risk:
 Risk that people take either not knowing they are at risk
or they are unable to control.
 Ex: tsunamis, lightning, tornadoes.
10

11. Job related to risk:
 Exposure to such risk is voluntary in nature cuz one
always refuse to work or may control over job.
 But generally workers don’t have choice; stick only
jobs available to them.
Personal risk:
 Assessing is difficult.
 Ex: people living near chemical plant voluntarily or
involuntarily; a person working in nuclear plant.
Public risk:
 Assessing is relatively easy.
 Ex: accidents in transportation, treatment. 11

12. ASSESSMENT OF SAFETY AND RISK:
12
I. It is very difficult to attain 100% absolute safety.
II. In an engineering product, if there is any improvement in safety, it often
goes with an increase in the cost of the product.
III. On the other side, the products which are not safe always increase the
secondary costs to the producer such as warranty expenses, loss of
customer’s good will and down time production process.
IV. It is always a great challenge to engineers to balance quality and safety
against cost.
V. In general, engineer’s tendency is to design and produce high quality
products, but business managers tend to keep the cost down.
VI. Therefore it is necessary to understand relationship between safety,
costs and price

13. GOAL OF RISK ASSESSMENT
13
 The aim of risk assessment
process is to evaluate
hazards, then remove that
hazard or minimize the level
of its risk by adding control
measures, as necessary.
 By doing so, you have
created a safer and
healthier workplace.
Relationship between risk and cost to manufacture

14. 14

15. DETERMINATION OF RISK
1. KNOWLEDGE OF RISK: To assess a risk, an engineer must first identify it.
To identify a risk, an engineer must first know the information about the
safety of standard products.
2. UNCERTAINITIES IN DESGN: while designing a product, the design
engineer must deal with many uncertainties. Many of risks can be
expressed as probabilities and as educated guesses.
3. TESTING FOR SAFETY: Once the product is designed, bot prototypes and
finished devices must be thoroughly tested. The testing is not just to
determine whether the product meets the specification, it should also
involve in testing to see if the product is safe. It is essential that in any
engineering design, all safety systems be tested to ensure that they work
as planned.
IN ORDER TO DETERMINE THE RISK, ONE SHOULD HAVE KNOWLEDGE ABOUT:

16. DIFFERENT METHODS TO DETERMINE THE RISK
1. TESTING ON THE FUNCTIONS OF SAFETY SYSTEM COMPONENTS
2. DESTRUCTIVE TESTING: In this approach, testing is done till the
component fails. It is too expensive, but very realistic and useful.
3. PROTOTYPE TESTING: In this approach, the testing is done on a
proportional scale model with all vital components fixed in the system.
Dimensional analysis could be used to project the result at the actual
conditions.
4. SIMULATION TESTING: With the help of computer. The simulations are
done. The safe boundary may be obtained. The effects of some controlled
input variables on the outcomes can be predicted in a better way.

17. THANK YOU