electrical, mechanical and chemical sources of accidents 1

Chemical, Mechanical And Chemical, Mechanical And Electrical Sources Of Electrical Sources Of

Accidents And fireAccidents And fire

By Prof. Dr. Amjad ParvezBy Prof. Dr. Amjad Parvez

ACCIDENTSACCIDENTS

An An accidentaccident is a specific, identifiable, is a specific, identifiable, unexpected, unusual and unintended unexpected, unusual and unintended external action which occurs in a particular external action which occurs in a particular time and place, without apparent or time and place, without apparent or deliberate cause but with marked effects. deliberate cause but with marked effects.

Chemical AccidentChemical Accident

The terms “The terms “chemical accidentchemical accident” or ” or ““chemical incidentchemical incident” refer to an event ” refer to an event resulting in the release of a substance or resulting in the release of a substance or substances hazardous to human health substances hazardous to human health and/or the environment in the short or long and/or the environment in the short or long term. Such events include fires, term. Such events include fires, explosions, leakages or releases of toxic explosions, leakages or releases of toxic or hazardous materials that can cause or hazardous materials that can cause people illness, injury, disability or death. people illness, injury, disability or death.

HistoryHistory

Industrialization in 18Industrialization in 18 thth century century

Steam enginesSteam engines

Internal Combustion EnginesInternal Combustion Engines

Chemical Weapon IndustryChemical Weapon Industry

Types Of chemicals Types Of chemicals

Flammable chemicalsFlammable chemicals

Toxic chemicalsToxic chemicals

Reactive chemicalsReactive chemicals

Corrosive chemicalsCorrosive chemicals

Leaks and spillsLeaks and spills

Chemical DisastersChemical Disasters

Bhopal disaster Bhopal disaster

Nuclear Attack On JAPANNuclear Attack On JAPAN

Explosion at Azotes de France (AZF) Explosion at Azotes de France (AZF) fertilizer factory near Toulouse.fertilizer factory near Toulouse.

Effects of accidentsEffects of accidents

Human HealthHuman Health

CancerCancer

BurnsBurns

Skin DiseasesSkin Diseases

Effects of accidentsEffects of accidents

EnvironmentEnvironment

Soil CorrosionSoil Corrosion

Air PollutionAir Pollution

Threats To WaterThreats To Water

How To ControlHow To Control

The root causes of chemical accidents: The root causes of chemical accidents: accidents do not just happen. There are accidents do not just happen. There are always causes. always causes.

Risk Assessment Risk Assessment

R= SEVERITYR= SEVERITY**LIKLEYHOOD LIKLEYHOOD

SOP For The UsageSOP For The Usage

General chemical safety procedureGeneral chemical safety procedure

Chemical must be properly labeled and stored in Chemical must be properly labeled and stored in the closed areathe closed areaMSDS must be pasted on the chemicals MSDS must be pasted on the chemicals containers in English and in the local language containers in English and in the local language understand by workersunderstand by workersStore chemicals in the cold, dry, well ventilated Store chemicals in the cold, dry, well ventilated and well drained areaand well drained areaAll chemicals must be segregated according to All chemicals must be segregated according to their nature such as flammable, toxic reactive their nature such as flammable, toxic reactive and corrosiveand corrosive

HISTORYHISTORY

IndustrializationIndustrialization

Textile MachineryTextile Machinery

Steam Engines(18Steam Engines(18 thth century) century)

Internal Combustion Engines(19Internal Combustion Engines(19 thth century)century)

TYPES OF MachineryTYPES OF Machinery

Grinding MachinesGrinding Machines

Milling MachinesMilling Machines

Lathe MachinesLathe Machines

CompressorsCompressors

TurbinesTurbines

Types Of AccidentsTypes Of Accidents

Cancer through RadiationsCancer through Radiations

Severe Cuts Can Be ProducedSevere Cuts Can Be Produced

Slippage Through Leakage Of OilSlippage Through Leakage Of Oil

Chips Produced Can Prove To Be FatalChips Produced Can Prove To Be Fatal

Excessive Heating Can Lead To FireExcessive Heating Can Lead To Fire


Excessive Heating Can Lead To FireExcessive Heating Can Lead To Fire

Mechanical Vibration Can Lead To the Mechanical Vibration Can Lead To the Failure Of Buildings Failure Of Buildings

Mechanical Vibration Produces NoiseMechanical Vibration Produces Noise


Accidents Due To ResonenceAccidents Due To Resonence

Accidents Due To Mechanical Failure in Accidents Due To Mechanical Failure in Aero planes, Motor Cars Aero planes, Motor Cars

Mechanical CatastrophesMechanical Catastrophes

Titanic Titanic

Compressor Failure At Packages Ltd In Compressor Failure At Packages Ltd In 20062006

Air India Flight 182Air India Flight 182: :

Ways To Reduce Ways To Reduce

Calculate Risk Assessment Of each And Calculate Risk Assessment Of each And Every EquipmentEvery Equipment

R=S*LR=S*L

Apply SOP For Equipment HandlingApply SOP For Equipment Handling

Fundamentals of Fundamentals of Electrical HazardsElectrical HazardsFundamentals of Fundamentals of

Electrical HazardsElectrical HazardsVoltage Voltage electrical pressure electrical pressure

CurrentCurrent electrical flow rate electrical flow rate

ImpedanceImpedance restriction to electrical flowrestriction to electrical flow

CircuitCircuit path of flow of electricitypath of flow of electricity

Circuit ElementCircuit Element objects which are part of a circuit andobjects which are part of a circuit and

through which current flows.through which current flows.

FaultFault current flow through an unintended path.current flow through an unintended path.


Electrical HazardsElectrical Hazards

What is Grounding?What is Grounding? Protection from electric shockProtection from electric shock

normally a secondary protection measurenormally a secondary protection measure

A ground is a conductive connectionA ground is a conductive connection between electrical circuit or equipment and between electrical circuit or equipment and

earth or ground planeearth or ground plane creates a low resistance to the earth.creates a low resistance to the earth.


Electrical HazardsElectrical Hazards

√ More than 3 mapainful shock

√ More than 10 mamuscle contraction “no-let-go” danger

√ More than 30 malung paralysis- usually temporary

√ More than 50 mapossible ventricular fib. (heart dysfunction, usually fatal)

√ 100 ma to 4 ampscertain ventricular fibrillation, fatal

√ Over 4 ampsheart paralysis; severe burns. Usually caused by >600 volts

Fundamentals of Electrical Fundamentals of Electrical HazardsHazards


Hazards of ElectricityHazards of Electricity Electrocution/Shock/Burns/DeathElectrocution/Shock/Burns/Death



• Minimum distance from overhead lines 10 ft.

• Inspect all electrical tools and equipment

Frayed, cut, broken wiresgrounding prong missingImproper use of cube tapsimproperly applied or missing strain relief

Electrical Electrical ProtectionProtectionElectrical Electrical ProtectionProtection

Circuit BreakersCircuit Breakers Provided to protect EQUIPMENT not peopleProvided to protect EQUIPMENT not people Do not reset breakers with a line voltage higher than 120V Do not reset breakers with a line voltage higher than 120V

and only reset if you know why it trippedand only reset if you know why it tripped

• GFCI’s- Provided to protect people- Trip range 4-6ma- Monthly test

Electrical ProtectionElectrical ProtectionElectrical ProtectionElectrical Protection

DistanceDistance If you sense the presence of an electrical If you sense the presence of an electrical

hazard or exposed conductors that may be hazard or exposed conductors that may be energized, keep your distance and energized, keep your distance and STAY STAY AWAYAWAY

Basic Rules of Electrical ActionBasic Rules of Electrical ActionBasic Rules of Electrical ActionBasic Rules of Electrical Action

Electricity isn’t live until current flowsElectricity isn’t live until current flows

Electrical current won’t flow until there is a Electrical current won’t flow until there is a complete loop, out from and back to the complete loop, out from and back to the power sourcepower source..

Preventing Accidental Electrical Preventing Accidental Electrical ContactContactPreventing Accidental Electrical Preventing Accidental Electrical ContactContact

Path

Ele

ctri

city

Time

Electrocution Prevention

Kee

p A

way

GFCI

Ground

Do’s and Don'tsDo’s and Don'tsDo’s and Don'tsDo’s and Don'ts

Do Do pplug power equipment into wall receptacles lug power equipment into wall receptacles with power switches in the Off position.with power switches in the Off position.

Do Do unplug electrical equipment by grasping the unplug electrical equipment by grasping the plug and pulling. Do not pull or jerk the cord to plug and pulling. Do not pull or jerk the cord to unplug the equipment.unplug the equipment.

Do notDo not drape power cords over hot pipes, drape power cords over hot pipes, radiators or sharp objects.radiators or sharp objects.


Do Do check the receptacle for check the receptacle for missing or damaged parts. missing or damaged parts. Do notDo not plug equipment into plug equipment into defective receptacles.defective receptacles.Do Do check for frayed, cracked, or check for frayed, cracked, or exposed wiring on equipment exposed wiring on equipment cords.cords.

Do Do check for defective cords clamps at check for defective cords clamps at locations where the power cord enters the locations where the power cord enters the equipment or the attachment plug.equipment or the attachment plug.

Extension cords should not be used in Extension cords should not be used in office areas. Generally, extension cords office areas. Generally, extension cords should be limited to use by maintenance should be limited to use by maintenance personnelpersonnel


Employees Employees should knowshould know the location of the location of electrical circuit breaker panels that electrical circuit breaker panels that control equipment and lighting in their control equipment and lighting in their respective areas. Circuits and equipment respective areas. Circuits and equipment disconnects must be identifieddisconnects must be identified



Temporary or permanent storage of any Temporary or permanent storage of any materials materials must notmust not be allowed within 3 feet be allowed within 3 feet of any electrical panel or electrical of any electrical panel or electrical equipment.equipment.

Any electrical equipment causing shocks Any electrical equipment causing shocks or with high leakage potential must be or with high leakage potential must be tagged with a Danger tag or equivalent. tagged with a Danger tag or equivalent.

Myths and MisconceptionsMyths and MisconceptionsMyths and MisconceptionsMyths and Misconceptions

Electricity takes the path of least Electricity takes the path of least resistance.resistance.

Electricity wants to go to ground.Electricity wants to go to ground.

If an electric tools falls into a sink or tub If an electric tools falls into a sink or tub of water, the item will short out.of water, the item will short out.

Myths and Myths and MisconceptionsMisconceptions

Myths and Myths and MisconceptionsMisconceptions

AC reverse polarity is not hazardous.AC reverse polarity is not hazardous.

It takes high voltage to kill; 120 volts is not It takes high voltage to kill; 120 volts is not dangerous.dangerous.

Double insulated power tools are doubly Double insulated power tools are doubly safe and can be used in wet and damp safe and can be used in wet and damp locations.locations.

electrical, mechanical and chemical sources of accidents 1

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