Hazard management in Power Sector: Techniques for Hazard Identification &

Risk Mitigation

By

Dr. Rohit Verma Dy.Director NPTI

Dr. Manisha Rani Fellow,NPTI

DEFINATIONSHAZARD

Source or situation with a potential for harm in term of injury or ill health, damage to property, damage to workplace environment, or combination of these.

HAZARD IDENTIFICATION

Process of recognizing that a hazard exists and defining its characteristic

RISK

Combination of likelihood & consequences of a specified hazardous event

RISK ASSESSMENT

Overall process of estimating the magnitude of risk and deciding weather or not the risk is tolerable

ACCIDENT

Unplanned & unexpected event which results into injury or property damage is known as accident.

CAUSES OF ACCIDENTS

Unsafe conditionsunsuitable clothing for a particular jobuntidy work areatools in poor conditionpoor lighting in work area

Unsafe actusing equipment without having received

proper training in its usefailing to use the appropriate protective

equipment distracting others from their work or allowing

yourself to be distractedusing tools or equipment incorrectly.

TYPES OF OCCUPATIONAL HAZARDS

· Physical hazards

· Chemical hazards

· Biological hazards

· Mechanical / Electrical hazards

· Psychosocial hazards

TYPES OF OCCUPATIONAL HAZARDS

Physical hazards Heat Cold Light Vibration Radiation Noise

ChemicalBiologicalMechanical-electricalPsychological

PHYSICAL HAZARDSHEAT The direct effects of heat exposure are

• Heat exhaustion heat stroke [civil works]• Burns [boiler area, electrical flash over]• Heat cramp [civil works, boiler area]

COLD[[[[[[Important hazards associated with cold work

• Frost bite• Chilblains• Immersion foot• General hypothermia as a result of

cutaneous vasoconstriction

PHYSICAL HAZARDSHEAT- As a hazard in power stations can cause

1. Heat stress-it is the aggregate of environmental & physical work factor i.e. Total heat imposed on the body.

2. Heat strain- it is the physiological responses to the heat stress.

3. Heat disorders-these result in heat cramps, heat exhaustion, heat stroke.

4. Heat cramps: painful intermittent spasms of voluntary muscles after hard physical work in hot environment. Cramps usually occur after heavy sweating.

5. Heat exhaustion: profuse sweating, weakness, rapid pulse, dizziness, nausea & headache. Skin is cool/pale. Body temperature is normal, nausea, vomiting and unconsciousness may occur.

Light as a hazard in working condition can be due to:

Less lighted areaswhen the light is insufficient person strains his eyes to see the work object/area. Light requirements are increasing with age of a person to see and work on the object.

Excessive light-it is dangerous for eyes when light in work area is excessive since it causes glare.

Physical Hazards

LIGHT

Effect of poor illuminations are :-• Headache• Eye pain• Lachrymation• Congestion around the cornea • Eye strain• Eye fatigue

Exposure to excessive brightness is associated with discomfort, visual fatigue, blurring of vision and may lead to accidents.

Physical Hazards

VIBRATIONVIBRATION ESPECIALLY IN THE FREQUENCY OF 10 TO 500 HZ, CAN AFFECT HAND AND ARM AFTER MONTH OF YEARS OF EXPOSURE

Ill effects:

• The fine blood vessel of finger becomes increasingly sensitive to spasm (white fingers).

• Injuries of the joints, of the hands elbow and shoulders may take place

Physical Hazards

Hearing impairment due to Noise is, as per the schedule of the Factories act, is reportable as well as compensable.

Hearing loss in most cases is not sudden but increases with the length of the work time in the noisy zone.

Physical HazardsNOISE• Industrial noise can give rise to deafness • Non auditory effects are irritation, nervousness,

annoyance, fatigue, inefficiency etc.

Threshold Limit Value for noisy working conditions:(An 8 hour shift in all following cases)

8 hours work – 90 dBA 4 hours working – 95 dBA 2 hours working – 100 dBA 1 hour working – 105 dBA half hour work – 110 dBA

Threshold of hearing – 125 dBA Sudden deafness/rupture of ear drum can occur at 140 dBA

Physical HazardsNOISE

RADIATION

A. ULTRAVIOLET RADIATION HAZARD- SEEN IN WORK WITH ARC WELDING AND MAINLY AFFECTS THE EYES.

EXPOSURE TO SUCH RADIATION MAY LEAD TO CONJUNCTIVITIS AND KERATITIS (WELDER’ S FLASH)

B. IONIZING RADIATION HAZARDS[X ROOM USG CT]ANEMIA LEUKEMIACANCERSTERILITYFETAL MALFORMATION IN CASE OF PREGNANCYULCERATION IN EXTREME CASES DEATH CAN TAKE PLACE

Physical Hazards

MECHANICAL / ELECTRICAL HAZARDS

Accident

Fall

Injury

Electricity burn

Electric shock.

ELECTRICAL HAZARDS

Injury from direct contact1. Injury by shock2. Injury from internal burns

Injury without current flow through body1. Direct burns from electrical arcs2. Radiation burns from very heavy arcs3. Injury from fire & explosion from electrical arc4. Physical injury from false starting of machinery, failure

of controls5. Eye injury from electrical arc welding

CHEMICAL HAZARDS

Chemical hazards – liquid and gaseous hazards

1. Dust 2. Smoke3. Fumes 4. Poisonous gases5. Acids6. Alkalis

CHEMICAL HAZARDS

They enter our body through Skin Inhalation MouthThey can cause internal as well external

injuries Skin diseases Lung diseases Internal blood and other diseases

BIOLOGICAL HAZARDS

• Exposure to infective and parasitic agents • Inset bite Dog bite Snake bite

PSYCHOSOCIAL HAZARDS

FACTORS -• Maladjustment with work environment.• Lack of job satisfaction• Insecurity• Emotional tension • Poor human relationships Health problems

Fatigue Headache Hypertension Heart diseasePeptic ulcer

Behaviors changes •Anxiety/Depression

•Sickness absentees

PREVENTION

MECHANICAL HAZARD

PREVENTION

• Preventive maintenance• Adequate job training• Ensuring safe working

environments• Establishment of safety

department with qualified safety engineer

• Periodic survey for finding out hazards

• Application of ergonomics

Noise can be controlled by;1. Reducing vibrations2. Enclosing the noise

producing equipment3. Enclosing the operator4. Moving away from the

noisy area5. Use of personal

protective equipments

Physical Hazards

NOISE

Effective temperature and heat effect in an environment can be controlled by:

Increasing air changes Reducing radiated heat by

insulation Reflection of heat Drinking plenty of water and

intake of salt Use of personal protective

equipments

Physical Hazards

Continuous working should be avoided and rest pauses after some time of work must be allowed to workers.

The driving force of vibrating surfaces may be reduced by;

1. Reducing the forces2. Minimizing rotational speed3. Isolating

The response of vibrating surfaces may be reduced by1. Damping2. Additional3. Increasing mass of vibrating surfaces4. Changing size to change resonance frequency

Physical HazardsVIBRATION

MECHANICAL HAZARDS

MACINERY HAZARDS: These are due to revolving parts of the machines. These can be controlled by providing machine guards

which are a statutory requirements under Sections 21 to 26 of the Factories Act 1948.

As per section 21 of the Factories Act- provide guards at following; Moving parts of the machinery including fly wheels Transmission machinery Point of operation Any other dangerous part

SAFETY OF MAINTENANCE PERSONNEL

Safety precautions are required to safe guard the maintenance personnel from getting involved in machinery accidents owing to inadvertent starting of machinery by;

Design of control switchesSafe guards for the operating leversInterlocking of power system

Mechanical Hazards

PREVENTIONPhysical hazards • Application of ergonomics • Maintenance of temperature- 69 to 80 deg. F is the

comfortable zone • Proper ventilation• Good housekeeping• Proper illumination• Personal protection• Personal hygiene• Health education• Job rotation • Periodic health Check up

PREVENTION

• Personal Protection• Post Control

Biological Hazards

PREVENTION• Good induction program.• Management by participation.• Establishment of Proper communication channel.• Establishment of Healthy personnel policies• Establishment of healthy HR relationship.• Regular stress management program.

Psychosocial Hazards

Chemical Safety There are thousnands of chemical compounds,

which presents some form of hazards either major or minor incidents usually termed as chemical accidents.

To avoid chemical accidents some points to be kept in mind.

1. knowledge of chemicals

2. knowledge of pocessing plant

3. knowledge of operator

CHEMICAL HAZARDS

CHEMICAL HAZARDS IN POWER PLANT

Coal/silica dust is major health hazard in power station

These dusts enter our body through inhalation Respirable dust particles can enter our lung sacks and

reduce our breathing capacity since this reparable dust settles there,

Normally coal dust particle less than 1 micron only can enter in our lung sacks.

Bigger dust particles either remain in our nose or get stuck in throat. Then they go into stomach and get removed from our body system in natural way.

Coal dust is non toxic and as such no effects are caused on body due to the particles of dust in stomach.

CHEMICAL HAZARDS

Respirable dust particle which enter into our lungs can not be removed and they remain settled there.

Disease which can occur due to inhalation of coal dust is known as “pneumoconiosis” and is irreversible till person is shifted from job

Silica dust can cause “silicosis”

Both are reportable as well as compensable diseases under the schedule of the factories act

CHEMICAL HAZARDS

Control of coal dust by

Reduction of dust emission by suppression by wetting coal in wagons, at the time of tippling, water spray in coal conveyors.

Suction of coal dust from environment in above areas.

Use of personal protective equipments like filter respirators which can filter out reparable coal dust particles.

Continuous monitoring of environment by measuring and keeping it below.

2. Gases Gases are the common hazards in many industries leads to

suffocation and asphyxia.

Asphyxiating gases are – CO, Cyanide, SO2, Chlorine etc.

Chemical Hazards

Smoke: inhalation of smoke which can contain poisonous gaseous fumes also and can have effects on our health;

Fumes: fumes emanating from liquid chemicals can cause ill effects on our health when inhaled;

Vapor: vapors of chemicals liquids are also dangerous to our health when inhaled. Vapours of hydrazine hydrate can cause unconsciousness when inhaled.

3.Metals and compounds Toxic hazards are seen from Lead, Mercury, Chromium, Arsenic etc

4.Chemicals Acid (water treatment/ chemistry), Alkali and Pesticides.

Chemical Hazards

Hazardous chemicals used in thermal power stations: Chlorine Hydrochloric acid Euphoric acid Hydrazine hydrate Liquor ammonia Sodium hydroxide

CHEMICAL HAZARDS

It is the most hazardous chemical used It is used in water treatment plant It is procured in toners for use in chlorinationation When more than 10 tons of chlorine is stored/

handled/used in any industry, a Disaster Management Plan (DMP) is required to be prepared and submitted to statutory authorities.

This DMP is required to be practiced through mock drills periodically and review meeting are to be conducted for checking discrepancies.

Chlorine

CHEMICAL HAZARDS

Chlorine vapor is poisonous when inhaled Will cause burn in eyes Chlorine liquid can cause burn on skin and eyes Threshold Limit Value (TLV) for chlorine is 1 ppm At 100 ppm it can be fatal.

Chlorine

PLANT / SECTIONS WHICH ARE PRONE TO EMERGENCIES

1. Coal handling plant2. Main plant3. Water treatment

plant4. Hydrogen

generation plant5. Mgr transpiration

system

PREVENTION OF CHEMICAL HAZARD (PNEUMOCONIOSIS)

1.Dust control- · Proper Ventilation · Exhaust · Enclosed apparatus · Good house keeping2.Personnel protection· Mask, clothing, cloves, apron, boots barrier cream

etc3.Personal hygiene

4.Health education about respiratory evolvement and personal protection5.Medical control

Periodic medical check up for early detection6. Bagasse control-· Spraying with 2% propionic acid-· Keep the moisture content around 20%

Fire hazard

Fire is a chemical reaction or series of chemical reaction accomplished by heat, light, smoke or other gases.

FIRE HAZARDS IN POWER PLANTS

Coal handling plant: coal dust accumulation on conveyor decks,

cable trays, head & tail pulleys, jamming of idlers and pulleys, belt sway, belt tension, dust & coal deposited at tops, crusher house and vibrating scene floors, bunker house , failure of belt joints, snapping of belts, partially damaged belt in operation, smoldering fire in bunkers

FIRE HAZARDS IN POWER PLANTS

Cables in cable galleries and on trays in all plant sections, coal dust deposited on cable trays in mill area

Fuel oil handling and oil tanks (hsd,hfo,lshs, naphtha, petrol, diesel oil )

Transformer oil, turbine oil, control fluid, seal oil,

Natural gas Electrical system Heat path damaged insulation Grass Accumulation of waste material etc.

EXPLOSION HAZARD IN POWER PLANT

Hydrogen plant Turbo generators where hydrogen

is used for cooling of Generator. Boilers

How to Control Hazard ?

3 step process

Step 1: Hazard Identification Techniques

50

• Safety audit

• Safety survey

• Safety inspection

• Safety tour

• Safety sampling

• Job safety analysis

• Hazard & operability studies

• Fault & event tree analysis

• Failure mode & effect analysis (FMEA)

Hazard Identification Techniques

Safety audit

A systematic & independent examination of all or

part of a total operating system to determine

whether safety activities comply with planned

arrangements for ensuring safety and health of

workers and other interested parties who may be

affected and whether these arrangements are

effective and are suitable to achieve objectives.

Hazard Identification Techniques

Safety survey Safety survey is a detailed & in-depth examination of a narrow field of activity eg...

•Major key areas revealed by safety audit,

•Individual plants,

•Procedures or

•A specific problem.

Hazard Identification Techniques

Safety inspection

A routine scheduled inspection of a

department or unit which may be carried

out by personnel within the unit. During

inspection deviations from safety standards,

employee’s unsafe work practices and unsafe

conditions are checked.

Hazard Identification Techniques

Safety tour

Safety tour is an unscheduled examination of a

work area, carried out by any personnel from

manager to safety committee members to

ensure that company’s safety standards and

procedures are being observed.

Hazard Identification Techniques

Safety sampling

A specific application of safety inspection /

tour designed for random sampling of any

activity posing serious accident potential.

During safety sampling number of defects

Are observing for immediate corrective

actions.

Hazard Identification Techniques

Hazard and operability studies

Hazop is essentially a examination procedure

takes full description of the process,

systematically questioning of every part of process

to discover how deviations from the intention of

the design can occur and decides whether these

deviations can give rise to hazard.

Hazard Identification Techniques

Principles of examination

•Full description of the process, systematically questions on every part of the process

•Discover deviations from the intention of the design can occur

•Decides weather these deviations can give rise to Hazards

Hazard Identification Techniques

Failure Mode and Effect Analysis (FMEA)

• Failure or Malfunction of each component is considered

• Effect or Consequences of failure traced • Frequency of Occurrence, Severity of Failure and

detecting the problem• Impact on the System Functioning is evaluated• Remedial method for Possible Impact

Fault Tree Analysis

• Starts with Undesired event. • All possible happenings contributing Undesired

event is listed.• Put these happenings in the form of tree with

logic signals OR and AND.

JOB SAFTEY ANALYSIS (JSA)

•JSA is a procedure used to review job methods at the design stage itself to ensure safe working at the site places and to adopt the safe working practices.

• However, it may also be used successfully to uncover hazards that may have developed after production started: or that resulted from change in work procedures.

•The procedure of job safety analysis is simple and consists of 4 basic steps. a) Jobs with potential for more frequent accidents, b) Severity of injury c) New jobs in which the accident potential is unknown should be selected first from the entire job list.d) Proper Care for analyzing the job condition.

PLANT SAFETY INSPECTION

Inspections are that monitoring function conducted in the organization to locate and report existing and potential hazards which have the capacity to cause accidents in the work place.

Inspections are not primarily aimed at unearthing new types of hazards; though that may be achieved also; but rather at locating and correcting known hazards.

• Continuous Inspection

• Periodic Inspection:

Steps to Control Hazard

Step 2. List, rank and set priorities for hazardous jobs -

List jobs with hazards that present unacceptable risks, based on those most likely to occur and with the most severe consequences. These jobs should be your first priority for analysis.

Steps to Control Hazard

Step 3. Controlling Hazards Solutions to the Control of Hazard are identified and measures are executed

Hazard can be eliminated (i) At the Source(ii) Along the path from hazard to the Worker(iii) At the level of the worker

Hazard Removal at the Source

1.Elimination - Getting rid of a hazardous job, tool, process, machine or substance is perhaps the best way of protecting workers.

2.Substitution - Sometimes doing the same work in a less hazardous way is possible.

3.Redesign - Jobs and processes can be reworked to make them safer.

4. Isolation - If a hazard cannot be eliminated or replaced, it can sometimes be isolated, contained or otherwise kept away from workers.

5.Automation - Dangerous processes can be automated or mechanized.

Hazard Removal along the path from Hazard to

Worker

1. Barriers - A hazard can be blocked before it reaches workers. Proper equipment

guarding will protect workers from contacting moving parts.

2. Absorption - Baffles can block or absorb noise.

3. Dilution - Some hazards can be diluted or dissipated. For example, ventilation

systems can dilute toxic gasses before they reach operators.

Hazard Removal at the Level of Worker

Work procedures, supervision and training Administrative controls Job rotations and other procedures can reduce

the time that workers are exposed to a hazard Housekeeping, repair and maintenance

programs Hygiene - Hygiene practices can reduce the

risk of toxic materials being absorbed by workers or carried home to their families.

Personal protective equipment (PPE) and clothing - This is used when other controls aren’t feasible and where additional protection is needed. Workers must be trained to use and maintain their equipment properly.

RISK MANAGEMENT

Risk Management is the Identification, Analysis and Economic control of those risks which can threaten the assets, human being or earning capacity of an enterprise

STAGES IN RISK MANAGEMENT

Identifying the hazards Evaluating the associated risks

The likely effect of a hazard may for Example be rated: Major, Serious, Slight-

The likelihood of harm may be rated: High, Medium, Low

Controlling the risks

CONTROLLING RISK

Risk Avoidance Risk Retention Risk Transfer Risk Reduction

CONCLUSIONS The thought process behind selecting hazard

evaluation techniques is complex, and a variety of factors can influence the decision-making process.

Hazards identification, hazards categorization, and hazards analysis are key components of integrated safety management for facilities and activities in industries.

Each hazard evaluation technique has unique strengths and weaknesses.

These techniques can provide the industrial hygienist with the tools needed to protect both workers and the community from both major and small-scale hazards.

Probability of occurrence of hazard increases the risks associated with an industry.

A risk management proposal has been given for the ready reference in this paper.

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