This document discusses various electrical hazards and safety measures related to them. It defines electric shock as the sudden stimulation of the body's nervous system by an electric current. The severity of shock depends on the amount of current, its path through the body, and duration of exposure. Currents between 1-20 mA can cause tingling to severe muscle contractions. Above 50 mA can cause ventricular fibrillation and death. It also describes flashover, flash burns and joules burns caused by electric arcs. The document outlines various shock protection methods like proper insulation, grounding, use of PPE etc. It discusses hazards of static electricity and importance of maintaining proper grounding to prevent failures.

1. PSF

2. Why is it a Hazard ?
It is a Hazard because it by
itself or by interacting with
other variables can result in
Death, Injury, Property
damage and any other loss.
Safety Control Department

3. Classification of Electrical Hazards
Electrical Hazards
Secondary Hazard
( Involuntary Reflex
Action )
Electrical
Shock
Burns Fire &
Explosion
Static Electricity Spark
Dropping of
Tools
& Objets
Pearson
Falling
From
Height
Safety Coordination Department
Flash
Over Burn
Joules Burn
Primary Hazards

4. HEALTH HAZARD
WELDING OF STAINLESS STEEL AND ALUMINIUM MAY
GENERATE UNACCEPTABLE LEVELS OF OZONE
OZONE IS GENERATED BY THE EFFECT OF ULTRA VIOLET RADIATION
ON THE AIR IMMEDIATELY SURROUNDING THE GAS SHIELD

9. What is Electric Shock ?
Electric Shock is a sudden and
accidental stimulation of body’s
nervous system by electric
current.
Current will flow due to voltage
difference through a low
resistance i.e. the human body in
this case.
Safety Control Department

10. Severity of shock is not determined
by Voltage alone but….
depends on:
1. Quantity of current flowing through the body
2. The path of the current flowing through the
body.
3. The length of time, current flowing through the
body.
Safety Control Department

11. Effect of Current flowing through the body.
• 1 to 8 mA - Tingling sensations, Not painful
• 8 to 15 mA - Painful shock, Individual Can let go at
will as muscular control is not lost
• 15 to 20 mA - Painful shock, Muscular control of
adjacent muscles lost, cannot let go
• 20 to 50 mA - Severe muscular contraction, breathing
difficulty
• 50 to 200 mA - ( Possible) Ventricular fibrillation, a
heart condition that results in instant
death
• 200 - 500 mA - Severe burns, muscular contraction so
severe that chest muscles clamp down the
heart and stop it.
Note: Reaction will vary with frequency and time of exposure

13. Human resistance to electric current
Dry skin resistance - 100,000 to 500,000 Ohms
Wet skin resistance - 1000 Ohms or Less
Internal body resistance - Hand to feet 400 Ohms
Ear to ear 100 Ohms
3 Times DC is equal to AC in effect.
Frequencies 20 to 100 Hz are very dangerous.
Danger Limit : 24 Volts AC for children
60 Volts AC for Adults

14. What is Flash Over?
-If an earthed conductor is brought close
to another conductor at a high voltage.
-The insulation of the air between them
may break down giving rise to a spark.
-This ionises the air considerably lowering
its resistance,
- Which in turn allows the current to
increase so that an electric arc is set-up.
Safety Control Department

15. What is Flash Burn ?
If the earthed conductor is human being ,
he will be burned by the arc rather than
directly coming in contact with the
conductor.
Since air resistance is lowered large
current flows and victim is subjected to
double event…
a) burn by arc
b) shock by passage of current
Safety Control Department

16. What is Joules burn ?
The passage of an electric current along-with
any conductor is accompanied by the dissipation
of heat according to Joules Law…
Heat Produced = I2 ×
R ×
t
where
I  Current in Amps.
R  Resistance in Ohms
t  Time in seconds.
As the skin is the site of highest resistance in
the body it is here that burning is most likely
to occur .
Safety Control Department

17. Do you think electric shock
discriminates on Gender basis ?
Yes, it does so.
Provided all the physical conditions
are same, women get shock more
severe
than men
Safety Control Department

18. Other factors affecting the degree of
shock
- Frequency of the current
- Phase of the heart cycle at the time of
current.
- Physical and psychological
condition of the person
Safety Control Department

19. # Isolation
# Marking danger signs
# Routine insulation of common parts
e.g.( knobs, dials, handles, etc.)
# Rubber mats at places from where
electrical panels are to be operated.
# Use of (PPE) rubber gloves and
non- conductive shoes.
Safety Control Department
What are the shock Protection Methods ?

20. About a quarter of all
reportable electrical
accidents involve
portable electric
apparatus
Safety Control Department

21. 1) Use double insulated tools ( make sure the
casing is not broken )
2) Use properly earthed tools
3) Use good condition cable
4) Always use a plug top ( three pin plug )
5) Use tool at rated voltage
6) Routing of cables must be proper
7) Never mis-use a portable tool
8) Get the tool properly checked periodically
9) If possible use portable tool with low voltage
system
Safety Control Department
Ways of safely using portable electric tools

24. Work Permit System
Why Permit System needed ?
• Prior communication to all concerned about work,
associated hazards etc.
• Hazards involved and preventive steps to be taken
can easily be implemented
• Easy to handle the emergency preparedness
• Legal liability
• Effective control of work
• Helps in work planning

25. The “Fatal Five” Main Causes of
Lockout/Tagout Injuries
 Failure to stop equipment
 Failure to disconnect from power
source
 Failure to dissipate (bleed,
neutralize) residual energy
 Accidental restarting of
equipment
 Failure to clear work areas
before restarting

26. Hazardous Energy Sources
Found in the Workplace
Electrical
Generated
Static
Mechanical
Transitional
Rotational
Thermal
Machines or
Equipment
Chemical
Reactions
Potential
Pressure
Hydraulic
Pneumatic
Vacuum
Springs
Gravity

27. Types of Lockout Devices
Plug Locks
Ball Valve
Lockout
Gate Valve
Lockout
Group
Lockout
Electrical
Hydraulic,
pneumatic, and
other
pressurized
systems

28. Lockout Procedure
 Alert the operator (s) that power is being disconnected.
 Preparation for Shutdown
 Equipment Shutdown
 Equipment Isolation
 Application of Lockout Devices
 Control of Stored Energy
 Equipment Isolation-Verification

29. Removal of Lockout
Ensure equipment is safe to
operate
Safeguard all employees
Remove lockout/tagout devices.
Except in emergencies, each
device must be removed by the
person who put it on.
Last person to take off lock
Follow checklist

30. Special Situations
Servicing lasts
longer than one
shift.
Contractors are
performing
service or
maintenance at
your workplace
Worker who
applied lock is
not available

31. Remember
 Never attempt lockout/tagout procedures
unless you have been trained and certified
by your employer
 Never loan or share your lock,
combination, or key with anybody else.
 Always be sure all lockout/tagout devices
are compatible with the environment in
which they will be used i.e. corrosive,
humid, etc.

36. Can earthing fail ?
Yes, earthing can fail due to
following reasons :
* Loose contacts in earthing
electrode.
* Earthing pit not maintained
properly.
* Continuity broken in earthing plate.
Safety Control Department

37. What should be done to maintain
proper earthing ?
The following points should be taken care
of:
- All contacts in earthing wiring should
be tight
- Resistance of earthing pit should be
checked regularly
- Continuity should be checked regularly
Safety Control Department

38. Safety Control Department
Static electricity is:
- The electrical charging of materials
- Through physical contact and separation
- The effects that result from the positive and
negative electrical charges formed by various
process.
- Transfer of electrons between bodies
When an electrical charge is present on the surface of
a non conducting body, where it is trapped or
prevented from escaping, it is called static electricity
Static
Electricity

39. Safety Control Department
(a) Pulverized materials passing through
chutes or pneumatic conveyors
(b) Steam, air, or gas flowing from any
opening in a pipe or hose, when the
steam is wet or the air or gas stream
contains particulate matter
(c) Nonconductive power or conveyor belts
in motion
(d) Moving vehicles
Common sources of Static
Electricity
Cont...

40. Safety Control Department
(e) Nonconductive liquids flowing through pipes
or splashing, pouring, or falling
(f) Movement of clothing layers against each
other or contact of footwear with floors
and floor coverings while walking
(g) Thunderstorms that produce violent air
currents and temperature differences that
move water, dust, and ice crystals creating
lightning
(h) Motions of all sorts that involve changes in
relative position of contacting surfaces,
usually of dissimilar liquids or solids
Common sources of Static Electricity

41. Safety Control Department
- The discharge of static electricity can cause
shock or a fire or explosion.
- Electrical charges may not in itself be a
potential fire or explosion hazard.
- For there to be an ignition there must be a
discharge or sudden recombination of the
separated positive and negative charges in
the form of an electric arc in an ignitable
atmosphere.
Static electricity Hazards

43. TREAT
ELECTICITY
WITH
RESPECT

44. Any Questions?