ENGINEER’S RESPONSIBILITY FOR SAFETY

ByM.Dhilsath Fathima

TOPICS TO COVER..

• Safety and Risk• Assessment of Safety and Risk • Risk-Benefit Analysis-Reducing Risk • The Government Regulator’s Approach to Risk

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?

SAFETY AND RISK• One of the main duties of an engineer is to ensure the

safety of the people who will be affected by the products that he designs.

• The code of ethics of the professional engineering societies make it clear that safety is of paramount importance to the engineer.

• The engineering codes of ethics show that engineers have a responsibility to society to produce products that are safe.

• Nothing can be 100% safe, but engineers are required to make products as safe as reasonably possible.

• Thus safety should be an integral part of any engineering design.

SAFETY AND RISK(Cont..)• What may be safe for one person may not be safe for

another person. – Ex 1: A Power Saw in the hands of a child is unsafe, but it is safe

in hand of adult.– Ex 2:A sick adult is more prone to ill effects from air pollution

than a healthy adult.

• What is safe to Entrepreneurs, may not be so to Engineers. e.g., Pilots: "Indian Airports are not safe; Low Vision in Fog“

• What is safe to Engineers, may not be so to Public.

• Typically several groups of people are involved in safety matters but have their own interests at stake. Each group may differ in what is safe and what is not.

Concept of Safety• “A ship in harbor is safe, but that is not what ships are built

for”• ‘A thing is safe if its risks are judged to be acceptable’• Definition for Safety

– “A thing is safe (to a certain degree) with respect to a given person or group at a given time if, were they fully aware of its risks and expressing their most settled values, they would judge those risks to be acceptable (to that certain degree.

– Safety: Safe operation of system and the prevention of natural or human caused disaster.

Ex 1 : We judge fluoride in water can kill lots of people -> Overestimating risk.Ex2: We hire a taxi, without thinking about its safety -> Not estimating risk• A thing is NOT SAFE if it exposes us to unacceptable danger

or hazard

Concept of Risk• Risk in technology could include dangers of – bodily harm, – economic loss, or – environmental degradation.– a situation involving exposure to danger

• Absolute safety is not possible .Any improvement in making a product safe involves an increase in the cost of production.

• It is very important for the manufacturer and the user to have some understanding to know about the risk connected with any product and know how much it will cost to reduce those risk.

• RISK is the potential that something unwanted and harmful may occur.– We take a risk when we undertake something or use a product that is not

safe.

Types of Risk

• Acceptable Risk• Voluntary risk and Control • JOB RELATED RISKS

Acceptable Risk• Acceptable risk refers to the level of human and property injury or loss

from an industrial process that is considered to be tolerable by an individual, household, group, organization, community, region, state, or nation in view of the social, political, and economic cost-benefit analysis.

• Example: For instance, the risk of flooding can be accepted once every 500 years but it is not unacceptable in every ten years.

• it is management's responsibility to set their company's level of risk. As a security professional, it is your responsibility to work with management and help them understand what it means to define an acceptable level of risk.

• Each company has its own acceptable risk level, which is derived from its legal and regulatory compliance responsibilities.

Acceptable Risk vs Unacceptable Risk

Voluntary risk• A person is said to take ‘VOLUNTARY RISK’• - when he is subjected to risk by either his own actions or action

taken by others• -volunteers to take that risk without any apprehension.• Ex: over rough ground for amusement• Voluntary risks have to do with lifestyle choices. They are the risks

that people take knowing that they may have consequences. These risks include smoking tobacco, driving a car, skydiving, and climbing a ladder.

• Involuntary risks are risks that people take either not knowing that they are at risk, or they are unable to control the fact that they are at risk, such as secondhand smoke. These risks often include environmental hazards such as lightning, tsunamis, and tornadoes.

•

Voluntary risk vs Involuntary risk

JOB RELATED RISKS• Many workers are taking risks in their jobs in their stride like

being exposed to asbestos.• Exposure to risks on a job is in one sense of voluntary nature

since one can always refuse to submit to the work or may have control over how the job is done.

• But generally workers have no choice other than what they are told to do since they want to stick to the only job available to them.

• But they are not generally informed about the exposure to toxic substances and other dangers which are not readily seen, smelt, heard or otherwise sensed.

• Occupational health and safety regulations and unions can have a better say in correcting these situations but still things are far below expected safety standards.

ASSESSMENT OF SAFETY AND RISK• Absolute safety is never possible to attain and safety can

be improved in an engineering product only with an increase in cost.

• On the other hand, unsafe products increase secondary costs to the producer beyond the primary (production) costs, like warranty costs loss of goodwill, loss of customers, legal action costs, downtime costs in manufacturing, etc.

• Figure indicates that P- Primary costs are high for a highly safe (low risk) product and S- Secondary costs are high for a highly risky (low safe) product.

• It should now be clear that ‘safety comes with a price’ only.

ASSESSMENT OF SAFETY AND RISK

What is the goal of risk assessment?

• The aim of the risk assessment process is to remove a hazard or reduce the level of its risk by adding precautions or control measures, as necessary. By doing so, you have created a safer and healthier workplace.

Uncertainties encountered in design process

• Coordination problems.• Contractor-caused delays.• Uncertainties regarding materials and skills required in the

manufacturing• Changing economic realities.• Unfamiliar environmental conditions like very low temperature• A decision on maximizing profit or maximizing the return on

investment.• Uncertainties about applications like dynamic loading instead

of static loading, vibrations, wind speeds.• The available standard data on items like steel, resistors,

insulators, optical glass, etc are based on statistical averages only.

Testing strategies for safety Some commonly used testing methods:

• Using the past experience in checking the design and performance.

• Prototype testing. Here the one product tested may not be representative of the population of products.

• Tests simulated under approximately actual conditions to know the performance flaws on safety.

• Routine quality assurance tests on production runs.

Testing strategies for safety • The above testing procedures are not always carried out

properly. Hence we cannot trust the testing procedures uncritically. Some tests are also destructive and obviously it is impossible to do destructive testing and improve safety.

• In such cases, a simulation that traces hypothetical risky outcomes could be applied.

• Scenario Analysis (Event -> Consequences)• Failure Modes & Effects Analysis (Failure modes of each

component)• Fault Tree Analysis (System Failure -> Possible Causes at

component level)

Example of Testing for safety• Failure modes and effect analysis (FMEA) :• This approach systematically examines the failure modes of each

component, without however, focusing on relationships among the elements of a complex system.

• Fault Tree Analysis (FTA) :• A system failure is proposed and then events are traced back to possible

causes at the component level. The reverse of the fault-tree analysis is ‘event – tree analysis’. This method most effectively illustrates the disciplined approach required to capture as much as possible of everything that affects proper functioning and safety of a complex system.

Risk Benefit Analysis• Risk-benefit analysis involving studies, testing about the comparison of

the risk of a situation to its related benefits. • Risk Benefit analysis (RBA) is an approach to risk assessment that focuses

not just on the risks of the activity, but on the benefits of the activity. • Risk–benefit analysis is analysis that seeks to quantify the risk and

benefits and hence their ratio. Exposure to personal risk is recognized as a normal aspect of everyday life. A certain level of risk in our lives is accepted as necessary to achieve certain benefits.

• Risk is an essential element in the development of children’s physical, emotional and intellectual development.

• Risk isn’t just about physical actions – for example climbing a tree or skateboarding. It’s also about taking intellectual risks – trying anything for the first time, testing new ideas, accepting other people’s opinions (even if you don’t agree with them).

• Ex:For example, driving an automobile is a risk most people take daily.

RISK BENEFIT ASSESSMENT-ExampleACTIVITY How will young

people BENEFIT from this activity?

Possible hazards

Who is at risk?

PRECAUTIONS in place to reduce the risk of injury

Overall risk RATING: L/M/H

POND DIPPING: Slippery pond decking

The decking allows close access to the contents of the pond and is an essential component of exploring this habitat.

Slips, trips and falls.Cuts, grazes and abrasions.Drowning(die through submersion in and inhalation of water).

Young people; adults

Banks shallow and planted to prevent accidental entry.

No access to banks for young people; use decking or ‘beach’ area only.

Deepest area is centre of pond– keep to edges.

Dipping platform kept clear of trip hazards (e.g. nets, trays)

Pond use rules clearly displayed and reviewed at the start of each session.

Low

Example-Pond dipping

• Pond dipping is a fun and simple way for children to explore an aquatic habitat.

• Children will be able to observe a diversity of different creatures from leeches to dragonfly nymphs.

Example-Nuclear Reactor Risk Assessment ACTIVITY How

will people BENEFIT from this?

Possible hazards

Who is at risk?

PRECAUTIONS in place to reduce the risk of injury

Overall risk RATING: L/M/H

Nuclear Power Plant

Produces electricity.

•Radioactive Waste Disposal•Environmental Impact.•Nuclear Accidents•High cost•Can explode anytime.

•People•Environment•Nature

Use with proper training High

The Government Regulator approach to risk

Two approaches to acceptable risk

• 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.

Example(Fire accident)

Example(Flooding)-Before Flooding

Example(Flooding)-During Flooding