Electrical hazards can cause shock, burns or death. Proper grounding, GFCIs, circuit breakers, insulated tools and locking out power sources are essential protections. Workers must be trained to inspect equipment before use, keep work areas dry, and not use damaged tools or flexible cords. When using power tools, guards and safety switches must be used and tools disconnected when not in operation. Hand tools also require inspection for damage and use of protective equipment like goggles.

1. Fall Protection and
Prevention

2. 2
Power Tools Serious Accident
Last January 2006 in Indonesia, a worker was
cutting aluminium roofing sheets using a grinder,
the grinder’s wheel broke apart and hit his face
causing serious injury between his upper lips
and nose.
After first aid treatment he was sent to Hospital
for further treatment. The doctor at the Hospital
recommended he be hospitalised for about two
weeks!

3. 3
Power Tools Serious Accident
● Based on manufacturer
specification, Makita grinder model
9006B should use 6” grinding
wheel, speed load 10,000 RPM.
● 9.5” grinding wheel was used
instead of using 6” grinding wheel.
● This wheel was oversized and
designed to be run at 3400 RPM.
● Grinding wheel was running at
10,000 RPM causing the wheel fly
apart and hit the mechanic’s face.
● What Went Wrong
- Utilised improper tool.
- No grinder safety guard.
- Not using face shield for PPE.

4. 4
Hazards
Workers using hand and
power tools may be exposed
to these hazards:
• Objects that fall, fly, are
abrasive, or splash
• Harmful dusts, fumes, mists,
vapors, and gases
• Frayed or damaged electrical
cords, hazardous
connections and improper
grounding

5. 5
Basic Tool Safety Rules
● Maintain regularly
● Use right tool for the job
● Inspect before use
● Operate according to
manufacturers’
instructions
● Use the right personal
protective equipment
(PPE)
● Use guards

6. 6
Hand Tool Hazards
Hazards are usually caused by
misuse and improper maintenance
Do not use;
• Wrenches when jaws are sprung
• Tools with taped handles – they
may be hiding cracks
• Tools with loose, cracked or
splintered handles
• Impact tools (chisel and wedges)
when heads have mushroomed
• A screwdriver as a chisel
Crack
Mushroom Head

7. Electrical Safety -
Construction

8. 8
Electricity - The Dangers
● About 5 workers are
electrocuted every week
● Causes 12% of young
worker workplace deaths
● Takes very little electricity
to cause harm
● Significant risk of causing
fires

9. 9
Electricity – How it Works
● Electricity is the flow of
energy from one place to
another
● Requires a source of power:
usually a generating station
● A flow of electrons (current)
travels through a conductor
● Travels in a closed circuit

10. 10
Electrical Terms
● Current -- electrical movement (measured in amps)
● Circuit -- complete path of the current.
Includes electricity source, a conductor, and the output
device or load (such as a lamp, tool, or heater)
● Resistance -- restriction to electrical flow
● Conductors – substances, like metals, with little
resistance to electricity that allow electricity to flow
● Grounding – a conductive connection to the earth
which acts as a protective measure
● Insulators -- substances with high resistance to
electricity like glass, porcelain, plastic, and dry wood
that prevent electricity from getting to unwanted areas

11. 11
Electrical Injuries
There are four main types of electrical injuries:
● Direct:
1. Electrocution or death due to electrical
shock
2. Electrical shock
3. Burns
● Indirect:
4. Falls

12. 12
Electrical Shock
An electrical shock is received when electrical
current passes through the body.
You will get an electrical shock if a part of your
body completes an electrical circuit by…
● Touching a live wire and an electrical ground,
or
● Touching a live wire and another wire at a
different voltage.

13. 13
Shock Severity
● Severity of the shock depends
on:
– Path of current through the body
– Amount of current flowing
through the body (amps)
– Duration of the shocking current
through the body,
● LOW VOLTAGE DOES NOT
MEAN LOW HAZARD

14. 14
Dangers of Electrical Shock
● Currents above 10 mA can
paralyze or “freeze” muscles.
● Currents more than 75 mA
can cause a rapid,
ineffective heartbeat -- death
will occur in a few minutes
unless a defibrillator is used
● 75 mA is not much current –
a small power drill uses 30
times as much
Defibrillator in use

15. 15
Effects of Electrical Shock
1mA 5mA 10mA 15mA 50-100mA
Slight
Sensation
Sensation of
Shock
Painful
Can paralyze
or “freeze”
muscles
Can Kill In A
Second

16. 16
Burns
● Most common shock-
related injury
● Occurs when you touch
electrical wiring or
equipment that is
improperly used or
maintained
● Typically occurs on hands
● Very serious injury that
needs immediate attention

17. 17
Falls
● Electric shock can also
cause indirect injuries
● Workers in elevated
locations who experience
a shock may fall,
resulting in serious injury
or death

18. 18
Electrical Hazards and How to
Control Them
Electrical accidents are
caused by a combination
of three factors:
• Unsafe equipment
and/or installation,
• Workplaces made
unsafe by the
environment, and
• Unsafe work practices.

19. 19
Hazard – Exposed Electrical Parts
Cover removed from wiring or breaker box

20. 20
Control – Isolate Electrical Parts
● Use guards or
barriers
● Replace covers
Guard live parts of electric
equipment operating at 50
volts or more against
accidental contact

21. 21
Control – Isolate Electrical Parts
- Cabinets, Boxes & Fittings
Conductors going into them must be protected, and
unused openings must be closed

22. 22
Control – Close Openings
● Junction boxes, pull
boxes and fittings
must have approved
covers
● Unused openings in
cabinets, boxes and
fittings must be closed
(no missing
knockouts) Photo shows violations
of these two requirements

23. 23
Hazard - Overhead Power Lines
● Usually not insulated
● Examples of equipment that
can contact power lines:
• Crane
• Ladder
• Scaffold
• Backhoe
• Scissors lift
• Raised dump truck bed
• Aluminum paint roller

24. 24
Control - Overhead Power Lines
● Stay at least 10 feet away
● Post warning signs
● Assume that lines are
energized
● Use wood or fiberglass
ladders, not metal
● Power line workers need
special training & PPE

25. 25
Hazard - Inadequate Wiring
● Hazard - wire too small for the
current
● Example - portable tool with an
extension cord that has a wire too
small for the tool
• The tool will draw more current than
the cord can handle, causing
overheating and a possible fire
without tripping the circuit breaker
• The circuit breaker could be the right
size for the circuit but not for the
smaller-wire extension cord
Wire Gauge
WIRE
Wire gauge measures
wires ranging in size from
number 36 to 0 American
wire gauge (AWG)

26. 26
Control – Use the Correct Wire
● Wire used depends on operation, building materials,
electrical load, and environmental factors
● Use fixed cords rather than flexible cords
● Use the correct extension cord
Must be 3-wire type and designed for
hard or extra-hard use

27. 27
Hazard – Defective Cords & Wires
● Plastic or rubber
covering or
insulation is
missing
● Damaged
extension cords
& tools

28. 28
Hazard – Damaged Cords
● Cords can be damaged by:
• Aging
• Door or window edges
• Staples or fastenings
• Abrasion from adjacent
materials
• Activity in the area
● Improper use can cause
shocks, burns or fire

29. 29
Control – Cords & Wires
● Insulate live wires
● Check before use
● Use only cords that are 3-wire type
● Use only cords marked for hard or
extra-hard usage
● Use only cords, connection
devices, and fittings equipped with
strain relief
● Remove cords by pulling on the
plugs, not the cords
● Cords not marked for hard or
extra-hard use, or which have
been modified, must be taken out
of service immediately

30. 30
Control – Cords & Wires
● Insulate live wires
● Check before use
● Use only cords that are 3-wire type
● Use only cords marked for hard or
extra-hard usage
● Use only cords, connection
devices, and fittings equipped with
strain relief
● Remove cords by pulling on the
plugs, not the cords
● Cords not marked for hard or
extra-hard use, or which have
been modified, must be taken out
of service immediately

31. 31
Permissible Use of Flexible Cords
DO NOT use flexible wiring where
frequent inspection would be difficult
or where damage would be likely.
Flexible cords must not be . . .
• run through holes in walls, ceilings, or
floors;
• run through doorways, windows, or
similar openings (unless physically
protected);
• hidden in walls, ceilings, floors,
conduit or other raceways.

32. 32
Grounding
Grounding creates a
low-resistance path
from a tool to the earth
to disperse unwanted
current.
When a short or
lightning occurs,
energy flows to the
ground, protecting you
from electrical shock,
injury and death.

33. 33
Hazard – Improper Grounding
● Tools plugged into
improperly grounded
circuits may become
energized
● Broken wire or plug on
extension cord
● Some of the most
frequently violated
OSHA standards

34. 34
Control – Ground Tools & Equipment
● Ground power supply
systems, electrical circuits,
and electrical equipment
● Frequently inspect electrical
systems to insure path to
ground is continuous
● Inspect electrical equipment
before use
● Don’t remove ground prongs
from tools or extension cords
● Ground exposed metal parts
of equipment

35. 35
Control – Use GFCI (ground-fault
circuit interrupter)
● Protects you from shock
● Detects difference in current
between the black and white
wires
● If ground fault detected, GFCI
shuts off electricity in 1/40th of
a second
● Use GFCI’s on all 120-volt,
single-phase, 15- and 20-
ampere receptacles, or have
an assured equipment
grounding conductor program.

36. 36
Control - Assured Equipment
Grounding Conductor Program
Program must cover:
• All cord sets
• Receptacles not part of a building or structure
• Equipment connected by plug and cord
Program requirements include:
• Specific procedures adopted by the employer
• Competent person to implement the program
• Visual inspection for damage of equipment connected
by cord and plug

37. 37
Hazard – Overloaded Circuits
Hazards may result from:
● Too many devices plugged
into a circuit, causing heated
wires and possibly
a fire
● Damaged tools overheating
● Lack of over current
protection
● Wire insulation melting, which
may cause arcing and a fire in
the area where the overload
exists, even inside a wall

38. 38
Control - Electrical Protective
Devices
● Automatically opens circuit if
excess current from overload
or ground-fault is detected –
shutting off electricity
● Includes GFCI’s, fuses, and
circuit breakers
● Fuses and circuit breakers
are overcurrent devices.
When too much current:
• Fuses melt
• Circuit breakers trip
open

39. 39
Power Tool Requirements
• Have a three-wire cord with
ground plugged into a grounded
receptacle, or
• Be double insulated, or
• Be powered by a low-voltage
isolation transformer

40. 40
Tool Safety Tips
● Use gloves and appropriate footwear
● Store in dry place when not using
● Don’t use in wet/damp conditions
● Keep working areas well lit
● Ensure not a tripping hazard
● Don’t carry a tool by the cord
● Don’t yank the cord to disconnect it
● Keep cords away from heat, oil, &
sharp edges
● Disconnect when not in use and when
changing accessories such as blades &
bits
● Remove damaged tools from use

41. 41
Preventing Electrical Hazards - Tools
● Inspect tools before
use
● Use the right tool
correctly
● Protect your tools
● Use double insulated
tools
Double Insulated marking
GROUNDING
Double
Insulation
Or

42. 42
Temporary Lights
Protect from contact
and damage, and
don’t suspend by
cords unless
designed to do so.

43. 43
Clues that Electrical Hazards Exist
● Tripped circuit breakers or
blown fuses
● Warm tools, wires, cords,
connections, or junction
boxes
● GFCI that shuts off a circuit
● Worn or frayed insulation
around wire or connection

44. 44
Lockout and Tagging of Circuits
● Apply locks to power source
after de-energizing
● Tag deactivated controls
● Tag de-energized
equipment and circuits at all
points where they can be
energized
● Tags must identify
equipment or circuits being
worked on

45. 45
Safety-Related Work Practices
To protect workers from
electrical shock:
• Use barriers and guards to
prevent passage through
areas of exposed energized
equipment
• Pre-plan work, post hazard
warnings and use protective
measures
• Keep working spaces and
walkways clear of cords

46. 46
Safety-Related Work Practices
● Use special insulated
tools when working on
fuses with energized
terminals
● Don’t use worn or
frayed cords and
cables
● Don’t fasten extension
cords with staples,
hang from nails, or
suspend by wire.

47. 47
Preventing Electrical Hazards -
Planning
• Plan your work with others
• Plan to avoid falls
• Plan to lock-out and tag-
out equipment
• Remove jewelry
• Avoid wet conditions and
overhead power lines

48. 48
Avoid Wet Conditions
• If you touch a live wire or other
electrical component while
standing in even a small puddle
of water you’ll get a shock.
• Damaged insulation, equipment,
or tools can expose you to live
electrical parts.
• Improperly grounded metal switch
plates & ceiling lights are
especially hazardous in wet
conditions.
• Wet clothing, high humidity, and
perspiration increase your
chances of being electrocuted.

49. 49
Preventing Electrical Hazards - PPE
● Proper foot protection
(not tennis shoes)
● Rubber insulating gloves,
hoods, sleeves, matting,
and blankets
● Hard hat (insulated -
nonconductive)

50. 50
Preventing Electrical Hazards –
Proper Wiring and Connectors
• Use and test GFCI’s
• Check switches and
insulation
• Use three prong plugs
• Use extension cords only
when necessary & assure in
proper condition and right
type for job
• Use correct connectors

51. 51
Training
● De-energize electric equipment before
inspecting or repairing
● Using cords, cables, and electric tools that
are in good repair
● Lockout / Tagout recognition and procedures
● Use appropriate protective equipment
Train employees working with electric
equipment in safe work practices, including:

52. 52
Summary – Hazards & Protections
Hazards
● Inadequate wiring
● Exposed electrical parts
● Wires with bad insulation
● Ungrounded electrical
systems and tools
● Overloaded circuits
● Damaged power tools and
equipment
● Using the wrong PPE and
tools
● Overhead powerlines
● All hazards are made worse
in wet conditions
Protective Measures
● Proper grounding
● Use GFCI
● Use fuses and circuit
breakers
● Guard live parts
● Lockout/Tagout
● Proper use of flexible
cords
● Close electric panels
● Training

53. 53
Summary
Electrical equipment must be:
• Listed and labeled
• Free from hazards
• Used in the proper manner
If you use electrical tools you must be:
• Protected from electrical shock
• Provided necessary safety equipment

54. 54
Hand Tools - Protection
● Use PPE, such as safety
goggles, face shield and
gloves
● Keep floor surface where
working free from debris
and tripping or slipping
hazards
● Keep cutting tools sharp

55. 55
Power Tools
● Must be fitted with guards
and safety switches (Dead
Man Switch)
● Extremely hazardous
when used improperly
● Different types,determined
by their power source:
⮚ Electric
⮚ Pneumatic
⮚ Liquid fuel
⮚ Hydraulic
⮚ Powder-actuated
Dead Man Switch

56. 56
Switches
Hand-held power tools must be
equipped with one of the
following:
Constant pressure switch
shuts off power upon release
Examples: circular saw, chain
saw, grinder, hand-held power
drill
On-Off Switch
Examples: routers, planers,
laminate trimmers, shears, jig
saws, nibblers, scroll saws

57. 57
Power Tools - Precautions
● Disconnect tools when not in use, before servicing and
cleaning, and when changing accessories
● Keep people not involved with the work away from the
work
● Secure work with clamps or a vise, freeing both hands
to operate the tool
● Don’t hold the switch button while carrying a plugged-in
tool
● Keep tools sharp and clean
● Consider what you wear – loose clothing and jewelry
can get caught in moving parts
● Remove damaged electric tools & tag them: “Do Not
Use”

58. 58
Power Tools – Precautions
Electric Cords
● Don’t carry portable tools
by the cord
● Don’t use electric cords to
hoist or lower tools
● Don’t yank cord or hose
to disconnect it
● Keep cords and hoses
away from heat, oil, and
sharp edges

59. 59
To protect a worker from shock, these tools must:
• Have a 3-wire cord plugged into a grounded receptacle
• Be double insulated
• Be powered by a low-voltage isolation transformer
Electric Power Tools
Plug with a
grounding
pin
Double
Insulation
Marks DOUBLE INSULATION
SYMBOL

60. 60
Electric Tools – Good Practices
• Operate within design limits
• Use gloves and safety shoes
• Store in a dry place
• Don’t use in wet locations
unless approved for that
• Keep work areas well lit
• Ensure that cords don’t
present a tripping hazard

61. 61
Abrasive Wheels and Tools
● May throw off flying
fragments
● Equip with guards that:
- Cover the spindle end, nut,
& flange projections
- Maintain proper alignment
with the wheel
- Don’t exceed the strength
of the fastenings
● Guard so that a minimal
amount of the wheel is
exposed

62. 62
Inspecting Abrasive Wheels
Before mounting:
• Inspect closely for damage
• Perform sound- or ring-test to
ensure free from cracks /
defects
To test:
• Tap wheel gently with a light,
non-metallic instrument
• If wheel sounds cracked or
dead, do not use it because it
could fly apart

63. 63
Abrasive Wheel Use
● To prevent cracking:
- Fit the wheel on the spindle
freely
- Tighten the spindle nut
enough to hold the wheel in
place without distorting the
flange
● Let the tool come up to speed
prior to grinding or cutting
● Don’t stand in front of the
wheel as it comes up to full
speed
● Use eye and/or face
protection
Ensure the spindle
speed doesn’t exceed
the maximum speed
marked on the wheel

64. 64
Abrasive Wheel Work Rests
● Keep work rests not more
than 1/8th inch from
wheel surface
● This prevents jamming
the work between the
wheel and the rest, which
may cause the wheel to
break
● Don’t adjust wheel while it
is rotating

65. 65
Guarding
● Guard exposed moving
parts of power tools
● Guard belts, gears, shafts,
pulleys, sprockets,
spindles, flywheels,
chains, or other moving
parts
● Never remove a guard
when a tool is in use

66. 66
The point of operation is where the work is actually
performed on the materials – it must be guarded
Guarding - Point of Operation
This shows a radial arm saw equipped
with proper point of operation guards

67. 67
Guarding Protection
Machine guards
must protect the
operator and others
from:
• Point of operation
• In-running nip points
• Rotating parts
• Flying chips and
sparks
Nip Point
Glass cover as protection

68. 68
Guard to prevent the
operator from coming in
contact the the rotating
blade
Radial Saw Guarding
Radial arm saw
equipped with an upper
and lower blade guard

69. 69
Guard these saws
above and below
the base plate or
shoe. The lower
guard must cover
the saw to the
depth of the teeth.
Guarding Portable Circular Saws

70. 70

71. 71
Use a hood for guarding
Hood guard
Table Saw Guarding

72. Fall Protection and
Prevention

73. 73
Power Tools Serious Accident
Last January 2006 in Indonesia, a worker was
cutting aluminium roofing sheets using a grinder,
the grinder’s wheel broke apart and hit his face
causing serious injury between his upper lips
and nose.
After first aid treatment he was sent to Hospital
for further treatment. The doctor at the Hospital
recommended he be hospitalised for about two
weeks!

74. 74
Safety Precautions
• All guards in place
• Right disk for the machine
• Cutting discs for cutting
• Grinding discs for grinding
• No damage to disc
• Fitted correctly
⮚ No homemade spacer
⮚ Correct locking spindle
• Correct PPE
⮚ Full face shield

75. 75
Power Tools Serious Accident
● Based on manufacturer
specification, Makita grinder model
9006B should use 6” grinding
wheel, speed load 10,000 RPM.
● 9.5” grinding wheel was used
instead of using 6” grinding wheel.
● This wheel was oversized and
designed to be run at 3400 RPM.
● Grinding wheel was running at
10,000 RPM causing the wheel fly
apart and hit the mechanic’s face.
● What Went Wrong
- Utilised improper tool.
- No grinder safety guard.
- Not using face shield for PPE.

76. 76
Hazards
Workers using hand and
power tools may be exposed
to these hazards:
• Objects that fall, fly, are
abrasive, or splash
• Harmful dusts, fumes, mists,
vapors, and gases
• Frayed or damaged electrical
cords, hazardous
connections and improper
grounding

77. 77
Basic Tool Safety Rules
● Maintain regularly
● Use right tool for the job
● Inspect before use
● Operate according to
manufacturers’
instructions
● Use the right personal
protective equipment
(PPE)
● Use guards

78. 78
Hand Tool Hazards
Hazards are usually caused by
misuse and improper maintenance
Do not use;
• Wrenches when jaws are sprung
• Tools with taped handles – they
may be hiding cracks
• Tools with loose, cracked or
splintered handles
• Impact tools (chisel and wedges)
when heads have mushroomed
• A screwdriver as a chisel
Crack
Mushroom Head

79. Electrical Safety -
Construction

80. 80
Electricity - The Dangers
● About 5 workers are
electrocuted every week
● Causes 12% of young
worker workplace deaths
● Takes very little electricity
to cause harm
● Significant risk of causing
fires

81. 81
Electricity – How it Works
● Electricity is the flow of
energy from one place to
another
● Requires a source of power:
usually a generating station
● A flow of electrons (current)
travels through a conductor
● Travels in a closed circuit

82. 82
Electrical Terms
● Current -- electrical movement (measured in amps)
● Circuit -- complete path of the current.
Includes electricity source, a conductor, and the output
device or load (such as a lamp, tool, or heater)
● Resistance -- restriction to electrical flow
● Conductors – substances, like metals, with little
resistance to electricity that allow electricity to flow
● Grounding – a conductive connection to the earth
which acts as a protective measure
● Insulators -- substances with high resistance to
electricity like glass, porcelain, plastic, and dry wood
that prevent electricity from getting to unwanted areas

83. 83
Electrical Injuries
There are four main types of electrical injuries:
● Direct:
1. Electrocution or death due to electrical
shock
2. Electrical shock
3. Burns
● Indirect:
4. Falls

84. 84
Electrical Shock
An electrical shock is received when electrical
current passes through the body.
You will get an electrical shock if a part of your
body completes an electrical circuit by…
● Touching a live wire and an electrical ground,
or
● Touching a live wire and another wire at a
different voltage.

85. 85
Shock Severity
● Severity of the shock depends
on:
– Path of current through the body
– Amount of current flowing
through the body (amps)
– Duration of the shocking current
through the body,
● LOW VOLTAGE DOES NOT
MEAN LOW HAZARD

86. 86
Dangers of Electrical Shock
● Currents above 10 mA can
paralyze or “freeze” muscles.
● Currents more than 75 mA
can cause a rapid,
ineffective heartbeat -- death
will occur in a few minutes
unless a defibrillator is used
● 75 mA is not much current –
a small power drill uses 30
times as much
Defibrillator in
use

87. 87
Effects of Electrical Shock
1mA 5mA 10mA 15mA 50-100mA
Slight
Sensation
Sensation of
Shock
Painful
Can paralyze
or “freeze”
muscles
Can Kill In A
Second

88. 88
Burns
● Most common shock-
related injury
● Occurs when you touch
electrical wiring or
equipment that is
improperly used or
maintained
● Typically occurs on hands
● Very serious injury that
needs immediate attention

89. 89
Falls
● Electric shock can also
cause indirect injuries
● Workers in elevated
locations who experience
a shock may fall,
resulting in serious injury
or death

90. 90
Electrical Hazards and How to
Control Them
Electrical accidents are
caused by a combination
of three factors:
• Unsafe equipment
and/or installation,
• Workplaces made
unsafe by the
environment, and
• Unsafe work practices.

91. 91
Hazard – Exposed Electrical Parts
Cover removed from wiring or breaker box

92. 92
Control – Isolate Electrical Parts
● Use guards or
barriers
● Replace covers
Guard live parts of electric
equipment operating at 50
volts or more against
accidental contact

93. 93
Control – Isolate Electrical Parts
- Cabinets, Boxes & Fittings
Conductors going into them must be protected, and
unused openings must be closed

94. 94
Control – Close Openings
● Junction boxes, pull
boxes and fittings
must have approved
covers
● Unused openings in
cabinets, boxes and
fittings must be closed
(no missing
knockouts) Photo shows violations
of these two requirements

95. 95
Hazard - Overhead Power Lines
● Usually not insulated
● Examples of equipment that
can contact power lines:
• Crane
• Ladder
• Scaffold
• Backhoe
• Scissors lift
• Raised dump truck bed
• Aluminum paint roller

96. 96
Control - Overhead Power Lines
● Stay at least 10 feet away
● Post warning signs
● Assume that lines are
energized
● Use wood or fiberglass
ladders, not metal
● Power line workers need
special training & PPE

97. 97
Hazard - Inadequate Wiring
● Hazard - wire too small for the
current
● Example - portable tool with an
extension cord that has a wire too
small for the tool
• The tool will draw more current than
the cord can handle, causing
overheating and a possible fire
without tripping the circuit breaker
• The circuit breaker could be the right
size for the circuit but not for the
smaller-wire extension cord
Wire Gauge
WIRE
Wire gauge measures
wires ranging in size
from number 36 to 0
American wire gauge
(AWG)

98. 98
Control – Use the Correct Wire
● Wire used depends on operation, building materials,
electrical load, and environmental factors
● Use fixed cords rather than flexible cords
● Use the correct extension cord
Must be 3-wire type and designed for
hard or extra-hard use

99. 99
Hazard – Defective Cords & Wires
● Plastic or rubber
covering or
insulation is
missing
● Damaged
extension cords
& tools

100. 10
0
Hazard – Damaged Cords
● Cords can be damaged by:
• Aging
• Door or window edges
• Staples or fastenings
• Abrasion from adjacent
materials
• Activity in the area
● Improper use can cause
shocks, burns or fire

101. 10
1
Control – Cords & Wires
● Insulate live wires
● Check before use
● Use only cords that are 3-wire type
● Use only cords marked for hard or
extra-hard usage
● Use only cords, connection
devices, and fittings equipped with
strain relief
● Remove cords by pulling on the
plugs, not the cords
● Cords not marked for hard or
extra-hard use, or which have
been modified, must be taken out
of service immediately

102. 10
2
Control – Cords & Wires
● Insulate live wires
● Check before use
● Use only cords that are 3-wire type
● Use only cords marked for hard or
extra-hard usage
● Use only cords, connection
devices, and fittings equipped with
strain relief
● Remove cords by pulling on the
plugs, not the cords
● Cords not marked for hard or
extra-hard use, or which have
been modified, must be taken out
of service immediately

103. 10
3
Permissible Use of Flexible Cords
DO NOT use flexible wiring where
frequent inspection would be difficult
or where damage would be likely.
Flexible cords must not be . . .
• run through holes in walls, ceilings, or
floors;
• run through doorways, windows, or
similar openings (unless physically
protected);
• hidden in walls, ceilings, floors,
conduit or other raceways.

104. 10
4
Grounding
Grounding creates a
low-resistance path
from a tool to the earth
to disperse unwanted
current.
When a short or
lightning occurs,
energy flows to the
ground, protecting you
from electrical shock,
injury and death.

105. 10
5
Hazard – Improper Grounding
● Tools plugged into
improperly grounded
circuits may become
energized
● Broken wire or plug on
extension cord
● Some of the most
frequently violated
OSHA standards

106. 10
6
Control – Ground Tools & Equipment
● Ground power supply
systems, electrical circuits,
and electrical equipment
● Frequently inspect electrical
systems to insure path to
ground is continuous
● Inspect electrical equipment
before use
● Don’t remove ground prongs
from tools or extension cords
● Ground exposed metal parts
of equipment

107. 10
7
Control – Use GFCI (ground-fault
circuit interrupter)
● Protects you from shock
● Detects difference in current
between the black and white
wires
● If ground fault detected, GFCI
shuts off electricity in 1/40th of
a second
● Use GFCI’s on all 120-volt,
single-phase, 15- and 20-
ampere receptacles, or have
an assured equipment
grounding conductor program.

108. 10
8
Control - Assured Equipment
Grounding Conductor Program
Program must cover:
• All cord sets
• Receptacles not part of a building or structure
• Equipment connected by plug and cord
Program requirements include:
• Specific procedures adopted by the employer
• Competent person to implement the program
• Visual inspection for damage of equipment connected
by cord and plug

109. 10
9
Hazard – Overloaded Circuits
Hazards may result from:
● Too many devices plugged
into a circuit, causing heated
wires and possibly
a fire
● Damaged tools overheating
● Lack of over current
protection
● Wire insulation melting, which
may cause arcing and a fire in
the area where the overload
exists, even inside a wall

110. 11
0
Control - Electrical Protective
Devices
● Automatically opens circuit if
excess current from overload
or ground-fault is detected –
shutting off electricity
● Includes GFCI’s, fuses, and
circuit breakers
● Fuses and circuit breakers
are overcurrent devices.
When too much current:
• Fuses melt
• Circuit breakers trip
open

111. 11
1
Power Tool Requirements
• Have a three-wire cord with
ground plugged into a grounded
receptacle, or
• Be double insulated, or
• Be powered by a low-voltage
isolation transformer

112. 11
2
Tool Safety Tips
● Use gloves and appropriate footwear
● Store in dry place when not using
● Don’t use in wet/damp conditions
● Keep working areas well lit
● Ensure not a tripping hazard
● Don’t carry a tool by the cord
● Don’t yank the cord to disconnect it
● Keep cords away from heat, oil, &
sharp edges
● Disconnect when not in use and when
changing accessories such as blades &
bits
● Remove damaged tools from use

113. 11
3
Preventing Electrical Hazards - Tools
● Inspect tools before
use
● Use the right tool
correctly
● Protect your tools
● Use double insulated
tools
Double Insulated marking
GROUNDING
Double
Insulation
Or

114. 11
4
Temporary Lights
Protect from contact
and damage, and
don’t suspend by
cords unless
designed to do so.

115. 11
5
Clues that Electrical Hazards Exist
● Tripped circuit breakers or
blown fuses
● Warm tools, wires, cords,
connections, or junction
boxes
● GFCI that shuts off a circuit
● Worn or frayed insulation
around wire or connection

116. 11
6
Lockout and Tagging of Circuits
● Apply locks to power source
after de-energizing
● Tag deactivated controls
● Tag de-energized
equipment and circuits at all
points where they can be
energized
● Tags must identify
equipment or circuits being
worked on

117. 11
7
Safety-Related Work Practices
To protect workers from
electrical shock:
• Use barriers and guards to
prevent passage through
areas of exposed energized
equipment
• Pre-plan work, post hazard
warnings and use protective
measures
• Keep working spaces and
walkways clear of cords

118. 11
8
Safety-Related Work Practices
● Use special insulated
tools when working on
fuses with energized
terminals
● Don’t use worn or
frayed cords and
cables
● Don’t fasten extension
cords with staples,
hang from nails, or
suspend by wire.

119. 11
9
Preventing Electrical Hazards -
Planning
• Plan your work with others
• Plan to avoid falls
• Plan to lock-out and tag-
out equipment
• Remove jewelry
• Avoid wet conditions and
overhead power lines

120. 12
0
Avoid Wet Conditions
• If you touch a live wire or other
electrical component while
standing in even a small puddle
of water you’ll get a shock.
• Damaged insulation, equipment,
or tools can expose you to live
electrical parts.
• Improperly grounded metal switch
plates & ceiling lights are
especially hazardous in wet
conditions.
• Wet clothing, high humidity, and
perspiration increase your
chances of being electrocuted.

121. 12
1
Preventing Electrical Hazards - PPE
● Proper foot protection
(not tennis shoes)
● Rubber insulating gloves,
hoods, sleeves, matting,
and blankets
● Hard hat (insulated -
nonconductive)

122. 12
2
Preventing Electrical Hazards –
Proper Wiring and Connectors
• Use and test GFCI’s
• Check switches and
insulation
• Use three prong plugs
• Use extension cords only
when necessary & assure in
proper condition and right
type for job
• Use correct connectors

123. 12
3
Training
● De-energize electric equipment before
inspecting or repairing
● Using cords, cables, and electric tools that
are in good repair
● Lockout / Tagout recognition and procedures
● Use appropriate protective equipment
Train employees working with electric
equipment in safe work practices, including:

124. 12
4
Summary – Hazards & Protections
Hazards
● Inadequate wiring
● Exposed electrical parts
● Wires with bad insulation
● Ungrounded electrical
systems and tools
● Overloaded circuits
● Damaged power tools and
equipment
● Using the wrong PPE and
tools
● Overhead powerlines
● All hazards are made worse
in wet conditions
Protective Measures
● Proper grounding
● Use GFCI
● Use fuses and circuit
breakers
● Guard live parts
● Lockout/Tagout
● Proper use of flexible
cords
● Close electric panels
● Training

125. 12
5
Summary
Electrical equipment must be:
• Listed and labeled
• Free from hazards
• Used in the proper manner
If you use electrical tools you must be:
• Protected from electrical shock
• Provided necessary safety equipment

126. 12
6
Hand Tools - Protection
● Use PPE, such as safety
goggles, face shield and
gloves
● Keep floor surface where
working free from debris
and tripping or slipping
hazards
● Keep cutting tools sharp

127. 12
7
Power Tools
● Must be fitted with guards
and safety switches (Dead
Man Switch)
● Extremely hazardous
when used improperly
● Different types,determined
by their power source:
⮚ Electric
⮚ Pneumatic
⮚ Liquid fuel
⮚ Hydraulic
⮚ Powder-actuated
Dead Man
Switch

128. 12
8
Switches
Hand-held power tools must be
equipped with one of the
following:
Constant pressure switch
shuts off power upon release
Examples: circular saw, chain
saw, grinder, hand-held power
drill
On-Off Switch
Examples: routers, planers,
laminate trimmers, shears, jig
saws, nibblers, scroll saws

129. 12
9
Power Tools - Precautions
● Disconnect tools when not in use, before servicing and
cleaning, and when changing accessories
● Keep people not involved with the work away from the
work
● Secure work with clamps or a vise, freeing both hands
to operate the tool
● Don’t hold the switch button while carrying a plugged-in
tool
● Keep tools sharp and clean
● Consider what you wear – loose clothing and jewelry
can get caught in moving parts
● Remove damaged electric tools & tag them: “Do Not
Use”

130. 13
0
Power Tools – Precautions
Electric Cords
● Don’t carry portable tools
by the cord
● Don’t use electric cords to
hoist or lower tools
● Don’t yank cord or hose
to disconnect it
● Keep cords and hoses
away from heat, oil, and
sharp edges

131. 13
1
To protect a worker from shock, these tools must:
• Have a 3-wire cord plugged into a grounded receptacle
• Be double insulated
• Be powered by a low-voltage isolation transformer
Electric Power Tools
Plug with a
grounding pin
Double
Insulation
Marks DOUBLE INSULATION
SYMBOL

132. 13
2
Electric Tools – Good Practices
• Operate within design limits
• Use gloves and safety shoes
• Store in a dry place
• Don’t use in wet locations
unless approved for that
• Keep work areas well lit
• Ensure that cords don’t
present a tripping hazard

133. 13
3
Abrasive Wheels and Tools
● May throw off flying
fragments
● Equip with guards that:
- Cover the spindle end, nut,
& flange projections
- Maintain proper alignment
with the wheel
- Don’t exceed the strength
of the fastenings
● Guard so that a minimal
amount of the wheel is
exposed

134. 13
4
Inspecting Abrasive Wheels
Before mounting:
• Inspect closely for damage
• Perform sound- or ring-test to
ensure free from cracks /
defects
To test:
• Tap wheel gently with a light,
non-metallic instrument
• If wheel sounds cracked or
dead, do not use it because it
could fly apart

135. 13
5
Abrasive Wheel Use
● To prevent cracking:
- Fit the wheel on the spindle
freely
- Tighten the spindle nut
enough to hold the wheel in
place without distorting the
flange
● Let the tool come up to speed
prior to grinding or cutting
● Don’t stand in front of the
wheel as it comes up to full
speed
● Use eye and/or face
protection
Ensure the spindle
speed doesn’t exceed
the maximum speed
marked on the wheel

136. 13
6
Abrasive Wheel Work Rests
● Keep work rests not more
than 1/8th inch from
wheel surface
● This prevents jamming
the work between the
wheel and the rest, which
may cause the wheel to
break
● Don’t adjust wheel while it
is rotating

137. 13
7
Guarding
● Guard exposed moving
parts of power tools
● Guard belts, gears, shafts,
pulleys, sprockets,
spindles, flywheels,
chains, or other moving
parts
● Never remove a guard
when a tool is in use

138. 13
8
The point of operation is where the work is actually
performed on the materials – it must be guarded
Guarding - Point of Operation
This shows a radial arm saw equipped
with proper point of operation guards

139. 13
9
Guarding Protection
Machine guards
must protect the
operator and others
from:
• Point of operation
• In-running nip points
• Rotating parts
• Flying chips and
sparks
Nip
Point
Glass cover as protection

140. 14
0
Guard to prevent the
operator from coming in
contact the the rotating
blade
Radial Saw Guarding
Radial arm saw
equipped with an upper
and lower blade guard

141. 14
1
Guard these saws
above and below
the base plate or
shoe. The lower
guard must cover
the saw to the
depth of the teeth.
Guarding Portable Circular Saws

142. 14
2

143. 14
3
Use a hood for guarding
Hood guard
Table Saw Guarding

144. Fall Protection and
Prevention

145. 14
5
Power Tools Serious Accident
Last January 2006 in Indonesia, a worker was
cutting aluminium roofing sheets using a grinder,
the grinder’s wheel broke apart and hit his face
causing serious injury between his upper lips
and nose.
After first aid treatment he was sent to Hospital
for further treatment. The doctor at the Hospital
recommended he be hospitalised for about two
weeks!

146. 14
6
Safety Precautions
• All guards in place
• Right disk for the machine
• Cutting discs for cutting
• Grinding discs for grinding
• No damage to disc
• Fitted correctly
⮚ No homemade spacer
⮚ Correct locking spindle
• Correct PPE
⮚ Full face shield

147. 14
7
Power Tools Serious Accident
● Based on manufacturer
specification, Makita grinder model
9006B should use 6” grinding
wheel, speed load 10,000 RPM.
● 9.5” grinding wheel was used
instead of using 6” grinding wheel.
● This wheel was oversized and
designed to be run at 3400 RPM.
● Grinding wheel was running at
10,000 RPM causing the wheel fly
apart and hit the mechanic’s face.
● What Went Wrong
- Utilised improper tool.
- No grinder safety guard.
- Not using face shield for PPE.

148. 14
8
Hazards
Workers using hand and
power tools may be exposed
to these hazards:
• Objects that fall, fly, are
abrasive, or splash
• Harmful dusts, fumes, mists,
vapors, and gases
• Frayed or damaged electrical
cords, hazardous
connections and improper
grounding

149. 14
9
Basic Tool Safety Rules
● Maintain regularly
● Use right tool for the job
● Inspect before use
● Operate according to
manufacturers’
instructions
● Use the right personal
protective equipment
(PPE)
● Use guards

150. 15
0
Hand Tool Hazards
Hazards are usually caused by
misuse and improper maintenance
Do not use;
• Wrenches when jaws are sprung
• Tools with taped handles – they
may be hiding cracks
• Tools with loose, cracked or
splintered handles
• Impact tools (chisel and wedges)
when heads have mushroomed
• A screwdriver as a chisel
Crack
Mushroom Head

151. Electrical Safety -
Construction

152. 15
2
Electricity - The Dangers
● About 5 workers are
electrocuted every week
● Causes 12% of young
worker workplace deaths
● Takes very little electricity
to cause harm
● Significant risk of causing
fires

153. 15
3
Electricity – How it Works
● Electricity is the flow of
energy from one place to
another
● Requires a source of power:
usually a generating station
● A flow of electrons (current)
travels through a conductor
● Travels in a closed circuit

154. 15
4
Electrical Terms
● Current -- electrical movement (measured in amps)
● Circuit -- complete path of the current.
Includes electricity source, a conductor, and the output
device or load (such as a lamp, tool, or heater)
● Resistance -- restriction to electrical flow
● Conductors – substances, like metals, with little
resistance to electricity that allow electricity to flow
● Grounding – a conductive connection to the earth
which acts as a protective measure
● Insulators -- substances with high resistance to
electricity like glass, porcelain, plastic, and dry wood
that prevent electricity from getting to unwanted areas

155. 15
5
Electrical Injuries
There are four main types of electrical injuries:
● Direct:
1. Electrocution or death due to electrical
shock
2. Electrical shock
3. Burns
● Indirect:
4. Falls

156. 15
6
Electrical Shock
An electrical shock is received when electrical
current passes through the body.
You will get an electrical shock if a part of your
body completes an electrical circuit by…
● Touching a live wire and an electrical ground,
or
● Touching a live wire and another wire at a
different voltage.

157. 15
7
Shock Severity
● Severity of the shock depends
on:
– Path of current through the body
– Amount of current flowing
through the body (amps)
– Duration of the shocking current
through the body,
● LOW VOLTAGE DOES NOT
MEAN LOW HAZARD

158. 15
8
Dangers of Electrical Shock
● Currents above 10 mA can
paralyze or “freeze” muscles.
● Currents more than 75 mA
can cause a rapid,
ineffective heartbeat -- death
will occur in a few minutes
unless a defibrillator is used
● 75 mA is not much current –
a small power drill uses 30
times as much
Defibrillator in
use

159. 15
9
Effects of Electrical Shock
1mA 5mA 10mA 15mA 50-100mA
Slight
Sensation
Sensation of
Shock
Painful
Can paralyze
or “freeze”
muscles
Can Kill In A
Second

160. 16
0
Burns
● Most common shock-
related injury
● Occurs when you touch
electrical wiring or
equipment that is
improperly used or
maintained
● Typically occurs on hands
● Very serious injury that
needs immediate attention

161. 16
1
Falls
● Electric shock can also
cause indirect injuries
● Workers in elevated
locations who experience
a shock may fall,
resulting in serious injury
or death

162. 16
2
Electrical Hazards and How to
Control Them
Electrical accidents are
caused by a combination
of three factors:
• Unsafe equipment
and/or installation,
• Workplaces made
unsafe by the
environment, and
• Unsafe work practices.

163. 16
3
Hazard – Exposed Electrical Parts
Cover removed from wiring or breaker box

164. 16
4
Control – Isolate Electrical Parts
● Use guards or
barriers
● Replace covers
Guard live parts of electric
equipment operating at 50
volts or more against
accidental contact

165. 16
5
Control – Isolate Electrical Parts
- Cabinets, Boxes & Fittings
Conductors going into them must be protected, and
unused openings must be closed

166. 16
6
Control – Close Openings
● Junction boxes, pull
boxes and fittings
must have approved
covers
● Unused openings in
cabinets, boxes and
fittings must be closed
(no missing
knockouts) Photo shows violations
of these two requirements

167. 16
7
Hazard - Overhead Power Lines
● Usually not insulated
● Examples of equipment that
can contact power lines:
• Crane
• Ladder
• Scaffold
• Backhoe
• Scissors lift
• Raised dump truck bed
• Aluminum paint roller

168. 16
8
Control - Overhead Power Lines
● Stay at least 10 feet away
● Post warning signs
● Assume that lines are
energized
● Use wood or fiberglass
ladders, not metal
● Power line workers need
special training & PPE

169. 16
9
Hazard - Inadequate Wiring
● Hazard - wire too small for the
current
● Example - portable tool with an
extension cord that has a wire too
small for the tool
• The tool will draw more current than
the cord can handle, causing
overheating and a possible fire
without tripping the circuit breaker
• The circuit breaker could be the right
size for the circuit but not for the
smaller-wire extension cord
Wire Gauge
WIRE
Wire gauge measures
wires ranging in size
from number 36 to 0
American wire gauge
(AWG)

170. 17
0
Control – Use the Correct Wire
● Wire used depends on operation, building materials,
electrical load, and environmental factors
● Use fixed cords rather than flexible cords
● Use the correct extension cord
Must be 3-wire type and designed for
hard or extra-hard use

171. 17
1
Hazard – Defective Cords & Wires
● Plastic or rubber
covering or
insulation is
missing
● Damaged
extension cords
& tools

172. 17
2
Hazard – Damaged Cords
● Cords can be damaged by:
• Aging
• Door or window edges
• Staples or fastenings
• Abrasion from adjacent
materials
• Activity in the area
● Improper use can cause
shocks, burns or fire

173. 17
3
Control – Cords & Wires
● Insulate live wires
● Check before use
● Use only cords that are 3-wire type
● Use only cords marked for hard or
extra-hard usage
● Use only cords, connection
devices, and fittings equipped with
strain relief
● Remove cords by pulling on the
plugs, not the cords
● Cords not marked for hard or
extra-hard use, or which have
been modified, must be taken out
of service immediately

174. 17
4
Control – Cords & Wires
● Insulate live wires
● Check before use
● Use only cords that are 3-wire type
● Use only cords marked for hard or
extra-hard usage
● Use only cords, connection
devices, and fittings equipped with
strain relief
● Remove cords by pulling on the
plugs, not the cords
● Cords not marked for hard or
extra-hard use, or which have
been modified, must be taken out
of service immediately

175. 17
5
Permissible Use of Flexible Cords
DO NOT use flexible wiring where
frequent inspection would be difficult
or where damage would be likely.
Flexible cords must not be . . .
• run through holes in walls, ceilings, or
floors;
• run through doorways, windows, or
similar openings (unless physically
protected);
• hidden in walls, ceilings, floors,
conduit or other raceways.

176. 17
6
Grounding
Grounding creates a
low-resistance path
from a tool to the earth
to disperse unwanted
current.
When a short or
lightning occurs,
energy flows to the
ground, protecting you
from electrical shock,
injury and death.

177. 17
7
Hazard – Improper Grounding
● Tools plugged into
improperly grounded
circuits may become
energized
● Broken wire or plug on
extension cord
● Some of the most
frequently violated
OSHA standards

178. 17
8
Control – Ground Tools & Equipment
● Ground power supply
systems, electrical circuits,
and electrical equipment
● Frequently inspect electrical
systems to insure path to
ground is continuous
● Inspect electrical equipment
before use
● Don’t remove ground prongs
from tools or extension cords
● Ground exposed metal parts
of equipment

179. 17
9
Control – Use GFCI (ground-fault
circuit interrupter)
● Protects you from shock
● Detects difference in current
between the black and white
wires
● If ground fault detected, GFCI
shuts off electricity in 1/40th of
a second
● Use GFCI’s on all 120-volt,
single-phase, 15- and 20-
ampere receptacles, or have
an assured equipment
grounding conductor program.

180. 18
0
Control - Assured Equipment
Grounding Conductor Program
Program must cover:
• All cord sets
• Receptacles not part of a building or structure
• Equipment connected by plug and cord
Program requirements include:
• Specific procedures adopted by the employer
• Competent person to implement the program
• Visual inspection for damage of equipment connected
by cord and plug

181. 18
1
Hazard – Overloaded Circuits
Hazards may result from:
● Too many devices plugged
into a circuit, causing heated
wires and possibly
a fire
● Damaged tools overheating
● Lack of over current
protection
● Wire insulation melting, which
may cause arcing and a fire in
the area where the overload
exists, even inside a wall

182. 18
2
Control - Electrical Protective
Devices
● Automatically opens circuit if
excess current from overload
or ground-fault is detected –
shutting off electricity
● Includes GFCI’s, fuses, and
circuit breakers
● Fuses and circuit breakers
are overcurrent devices.
When too much current:
• Fuses melt
• Circuit breakers trip
open

183. 18
3
Power Tool Requirements
• Have a three-wire cord with
ground plugged into a grounded
receptacle, or
• Be double insulated, or
• Be powered by a low-voltage
isolation transformer

184. 18
4
Tool Safety Tips
● Use gloves and appropriate footwear
● Store in dry place when not using
● Don’t use in wet/damp conditions
● Keep working areas well lit
● Ensure not a tripping hazard
● Don’t carry a tool by the cord
● Don’t yank the cord to disconnect it
● Keep cords away from heat, oil, &
sharp edges
● Disconnect when not in use and when
changing accessories such as blades &
bits
● Remove damaged tools from use

185. 18
5
Preventing Electrical Hazards - Tools
● Inspect tools before
use
● Use the right tool
correctly
● Protect your tools
● Use double insulated
tools
Double Insulated marking
GROUNDING
Double
Insulation
Or

186. 18
6
Temporary Lights
Protect from contact
and damage, and
don’t suspend by
cords unless
designed to do so.

187. 18
7
Clues that Electrical Hazards Exist
● Tripped circuit breakers or
blown fuses
● Warm tools, wires, cords,
connections, or junction
boxes
● GFCI that shuts off a circuit
● Worn or frayed insulation
around wire or connection

188. 18
8
Lockout and Tagging of Circuits
● Apply locks to power source
after de-energizing
● Tag deactivated controls
● Tag de-energized
equipment and circuits at all
points where they can be
energized
● Tags must identify
equipment or circuits being
worked on

189. 18
9
Safety-Related Work Practices
To protect workers from
electrical shock:
• Use barriers and guards to
prevent passage through
areas of exposed energized
equipment
• Pre-plan work, post hazard
warnings and use protective
measures
• Keep working spaces and
walkways clear of cords

190. 19
0
Safety-Related Work Practices
● Use special insulated
tools when working on
fuses with energized
terminals
● Don’t use worn or
frayed cords and
cables
● Don’t fasten extension
cords with staples,
hang from nails, or
suspend by wire.

191. 19
1
Preventing Electrical Hazards -
Planning
• Plan your work with others
• Plan to avoid falls
• Plan to lock-out and tag-
out equipment
• Remove jewelry
• Avoid wet conditions and
overhead power lines

192. 19
2
Avoid Wet Conditions
• If you touch a live wire or other
electrical component while
standing in even a small puddle
of water you’ll get a shock.
• Damaged insulation, equipment,
or tools can expose you to live
electrical parts.
• Improperly grounded metal switch
plates & ceiling lights are
especially hazardous in wet
conditions.
• Wet clothing, high humidity, and
perspiration increase your
chances of being electrocuted.

193. 19
3
Preventing Electrical Hazards - PPE
● Proper foot protection
(not tennis shoes)
● Rubber insulating gloves,
hoods, sleeves, matting,
and blankets
● Hard hat (insulated -
nonconductive)

194. 19
4
Preventing Electrical Hazards –
Proper Wiring and Connectors
• Use and test GFCI’s
• Check switches and
insulation
• Use three prong plugs
• Use extension cords only
when necessary & assure in
proper condition and right
type for job
• Use correct connectors

195. 19
5
Training
● De-energize electric equipment before
inspecting or repairing
● Using cords, cables, and electric tools that
are in good repair
● Lockout / Tagout recognition and procedures
● Use appropriate protective equipment
Train employees working with electric
equipment in safe work practices, including:

196. 19
6
Summary – Hazards & Protections
Hazards
● Inadequate wiring
● Exposed electrical parts
● Wires with bad insulation
● Ungrounded electrical
systems and tools
● Overloaded circuits
● Damaged power tools and
equipment
● Using the wrong PPE and
tools
● Overhead powerlines
● All hazards are made worse
in wet conditions
Protective Measures
● Proper grounding
● Use GFCI
● Use fuses and circuit
breakers
● Guard live parts
● Lockout/Tagout
● Proper use of flexible
cords
● Close electric panels
● Training

197. 19
7
Summary
Electrical equipment must be:
• Listed and labeled
• Free from hazards
• Used in the proper manner
If you use electrical tools you must be:
• Protected from electrical shock
• Provided necessary safety equipment

198. 19
8
Hand Tools - Protection
● Use PPE, such as safety
goggles, face shield and
gloves
● Keep floor surface where
working free from debris
and tripping or slipping
hazards
● Keep cutting tools sharp

199. 19
9
Power Tools
● Must be fitted with guards
and safety switches (Dead
Man Switch)
● Extremely hazardous
when used improperly
● Different types,determined
by their power source:
⮚ Electric
⮚ Pneumatic
⮚ Liquid fuel
⮚ Hydraulic
⮚ Powder-actuated
Dead Man
Switch

200. 20
0
Switches
Hand-held power tools must be
equipped with one of the
following:
Constant pressure switch
shuts off power upon release
Examples: circular saw, chain
saw, grinder, hand-held power
drill
On-Off Switch
Examples: routers, planers,
laminate trimmers, shears, jig
saws, nibblers, scroll saws

201. 20
1
Power Tools - Precautions
● Disconnect tools when not in use, before servicing and
cleaning, and when changing accessories
● Keep people not involved with the work away from the
work
● Secure work with clamps or a vise, freeing both hands
to operate the tool
● Don’t hold the switch button while carrying a plugged-in
tool
● Keep tools sharp and clean
● Consider what you wear – loose clothing and jewelry
can get caught in moving parts
● Remove damaged electric tools & tag them: “Do Not
Use”

202. 20
2
Power Tools – Precautions
Electric Cords
● Don’t carry portable tools
by the cord
● Don’t use electric cords to
hoist or lower tools
● Don’t yank cord or hose
to disconnect it
● Keep cords and hoses
away from heat, oil, and
sharp edges

203. 20
3
To protect a worker from shock, these tools must:
• Have a 3-wire cord plugged into a grounded receptacle
• Be double insulated
• Be powered by a low-voltage isolation transformer
Electric Power Tools
Plug with a
grounding pin
Double
Insulation
Marks DOUBLE INSULATION
SYMBOL

204. 20
4
Electric Tools – Good Practices
• Operate within design limits
• Use gloves and safety shoes
• Store in a dry place
• Don’t use in wet locations
unless approved for that
• Keep work areas well lit
• Ensure that cords don’t
present a tripping hazard

205. 20
5
Abrasive Wheels and Tools
● May throw off flying
fragments
● Equip with guards that:
- Cover the spindle end, nut,
& flange projections
- Maintain proper alignment
with the wheel
- Don’t exceed the strength
of the fastenings
● Guard so that a minimal
amount of the wheel is
exposed

206. 20
6
Inspecting Abrasive Wheels
Before mounting:
• Inspect closely for damage
• Perform sound- or ring-test to
ensure free from cracks /
defects
To test:
• Tap wheel gently with a light,
non-metallic instrument
• If wheel sounds cracked or
dead, do not use it because it
could fly apart

207. 20
7
Abrasive Wheel Use
● To prevent cracking:
- Fit the wheel on the spindle
freely
- Tighten the spindle nut
enough to hold the wheel in
place without distorting the
flange
● Let the tool come up to speed
prior to grinding or cutting
● Don’t stand in front of the
wheel as it comes up to full
speed
● Use eye and/or face
protection
Ensure the spindle
speed doesn’t exceed
the maximum speed
marked on the wheel

208. 20
8
Abrasive Wheel Work Rests
● Keep work rests not more
than 1/8th inch from
wheel surface
● This prevents jamming
the work between the
wheel and the rest, which
may cause the wheel to
break
● Don’t adjust wheel while it
is rotating

209. 20
9
Guarding
● Guard exposed moving
parts of power tools
● Guard belts, gears, shafts,
pulleys, sprockets,
spindles, flywheels,
chains, or other moving
parts
● Never remove a guard
when a tool is in use

210. 21
0
The point of operation is where the work is actually
performed on the materials – it must be guarded
Guarding - Point of Operation
This shows a radial arm saw equipped
with proper point of operation guards

211. 21
1
Guarding Protection
Machine guards
must protect the
operator and others
from:
• Point of operation
• In-running nip points
• Rotating parts
• Flying chips and
sparks
Nip
Point
Glass cover as protection

212. 21
2
Guard to prevent the
operator from coming in
contact the the rotating
blade
Radial Saw Guarding
Radial arm saw
equipped with an upper
and lower blade guard

213. 21
3
Guard these saws
above and below
the base plate or
shoe. The lower
guard must cover
the saw to the
depth of the teeth.
Guarding Portable Circular Saws

214. 21
4

215. 21
5
Use a hood for guarding
Hood guard
Table Saw Guarding

216. 21
6

217. 21
7
Pneumatic Tools
● Powered by compressed
air
● Includes nailers, staplers,
chippers, drills & sanders
● Main hazard - getting hit by
a tool attachment or by a
fastener the worker is using
with the tool
● Take the same precautions
with an air hose that you
take with electric cords

218. 21
8
Pneumatic Tools - Fastening
● Ensure tool is fastened
securely to the air hose to
prevent a disconnection
● Use a short wire or
positive locking device
attaching the air hose to
the tool Wire used to secure hose

219. 21
9
Pneumatic Tool Connections
Hose clamps and connector
Low pressure High pressure

220. 22
0
Pneumatic Tool Safety
● Place a safety device on the
muzzle to prevent the tool
from ejecting fasteners,
unless the muzzle is in
contact with work surface
● Install a safety clip or
retainer to prevent
attachments, such as
chisels on a chipping
hammer, from being ejected
● Wear eye protection. Wear
hearing protection with
jackhammers.

221. 22
1
Compressed Air Cleaning
● Don’t use compressed
air for cleaning
● Exception - where
pressure is reduced to
less than 30 p.s.i. with
effective chip guarding
and PPE

222. 22
2
Liquid Fuel Tools
● Usually gas
powered
● Main hazard – fuel
vapors
● Use only approved
flammable liquid
containers
● Before refilling a
fuel-powered tool
tank, shut down the
engine and allow it
to cool

223. 22
3
Powder-Actuated Tools
● User must be trained and
licensed to operate.
● Test tool each day before
loading to ensure the safety
devices are working properly.
● Wear suitable ear, eye, and
face protection.
● Select a powder level that will
do the work without excessive
force.

224. 22
4
Fatal Fact
● Employee killed when
struck in head by a nail
fired from a powder
actuated tool.
● Tool operator was
attempting to anchor a
plywood form in
preparation for pouring
a concrete wall.

225. 22
5
Easily Penetrated Material
Avoid driving into materials
easily penetrated unless
materials are backed by a
substance that will prevent
the pin or fastener from
passing through.
Also, don’t drive
fasteners into very hard
or brittle material that
might chip or splatter, or
make the fasteners
ricochet.

226. 22
6
Powder-Actuated Tool Safety Tips
● Don’t use in explosive or flammable atmosphere
● Inspect tool before use to ensure:
⮚ it is clean,
⮚ that moving parts operate freely
⮚ the barrel is free from obstructions and has the
proper shield, guard, and attachments
● Don’t load the tool unless using immediately
● Don’t leave a loaded tool unattended
● Keep hands clear of the barrel end
● Never point the tool at anyone
● Store unloaded in a locked box

227. 22
7
Hydraulic Jack
● To set up a jack, ensure:
⮚ The base is on a firm, level
surface
⮚ It’s centered
⮚ The jack head is placed
against a level surface
⮚ You apply the lift force evenly
● Lubricate and inspect jacks
regularly

228. 22
8
Hydraulic Jack
● The manufacturer's rated
capacity must be marked
on all jacks and must not
be exceeded.
● All jacks must have a
stop indicator that should
not be exceeded.

229. 22
9
Immediately block the load
after it is lifted. Put a block
under the base of the jack
when the foundation is not
firm, and place a block
between the jack cap and
load if the cap might slip.
Jacks - Blocking
Photo - handyman jack is
provided a firm base by using
the railroad tie.
The load is cribbed to prevent
it from falling.

230. 23
0
Summary
Hazards are usually the result of improper tool
use or not following one or more of these
protection techniques:
⮚ Inspecting the tool before use
⮚ Using PPE (Personal Protective Equipment)
⮚ Using protective guards
⮚ Properly storing the tool
⮚ Using safe handling techniques

231. 23
1
Falls are the leading cause of
deaths in the construction
industry.
Most fatalities occur when
employees fall from open-sided
floors and through floor openings.
Falls from as little as 1.2 to 1.8
meters can cause serious lost-
time accidents and sometimes
death.
Falls in Construction

232. 23
2
Working at Height means:
• Working on temporary or permanent
structures that are greater than 1.8 meters
above the ground or floor level
What is Fall Protection
Procedure, equipment, plans, work method
put in place to protect people working at
height from falling.
• Guard rails
• Hole covers
• Warning lines
• Lifelines
• Harness

233. 23
3
Hazards when Working at Heights
Working at a significant
elevation above the
ground or floor level can
result in:
• a person falling to the
ground, or
• dropping an object which
could strike another
worker

234. 23
4
• Engineering factors –
missing guardrails and safety
harnesses, unreliable or unstable
scaffoldings, floors, ladders;
• Process factors – mistakes
in method statement or operation
procedures;
• Psychological factors –
fear, coordination impairment,
careless moves, unsafe behavior;
• Weather factors – strong
wind, extremely hot or cold
temperature, rain, snow, fog, ice.
Causes of Falling from Height

235. 23
5
Fall Protection & Prevention
Systems:
Fall Protection (PFAS)
• Safety Harness with Double lanyards
• Retractable lanyard
• Rope Grab
• Safety nets
Fall Prevention
• Ladders
• Railing
• Handrails
• Access
platforms
• Guards
• Hole Cover

236. 23
6
Scaffolding/Temporary Platform
● All temporary platform are to
be equipped with standard
guardrails system and a
solid decking free from
openings
● Personnel traveling or
working on incomplete
structure shall wear and
secure their lanyards to an
anchorage point capable of
supporting 2,500kg
● Every temporary platform
shall be provided with a safe
of access/egress

237. 23
7
Temporary Hole Cover
To make hole safe it can
be covered by steel plates
or wooden planks to get
suitable strength and
support.
The fixed support must not
be easily removable.
A TRIP HAZARD sign
board must be posted

238. 23
8
Guardrail Systems
● Top rail must be 1.1 meters
above the walking/working
platform
● Midrails must be installed in
between top rail and the
working level
● Top rail must be capable of
withstanding without failure a
force of at least 91kg
● If the top rail is wire rope, it
must be flagged with high
visibility material at intervals

239. 23
9
Ladders
● Temporary ladders shall extend at
least 1 meters or 3 rungs above
the landing platform and be
properly secured
● Ladder extending above 3.7m
must be equipped with a
retractable lifeline
● Personnel using these ladder
must secure their retractable
lifeline to the harness
● Personnel using a ladder not yet
secured at the top must have
another person to hold the ladder
at the bottom

240. 24
0
Full Body Harness with Two lanyard
Used during works performed on an
unprotected work location at
elevations higher than 1.8 meters
above the ground
Lanyard must be secured to a
suitable anchorage point that is
capable of supporting an impact load of
2,500Kg
Prior to use, make sure that fall
protection equipment is in good
operating condition
Personal Fall Arrest System (PFAS)

241. 24
1
Retractable Lanyard / Rope Grab
"Deceleration device" - Any
mechanism, such as a rope
grab, rip-stitch lanyard,
specially-woven lanyard,
tearing or deforming lanyards,
automatic self-retracting
lifelines/lanyards, etc., which
serves to dissipate a
substantial amount of energy
during a fall arrest, or
otherwise limit the energy
imposed on an employee
during fall arrest.

242. 24
2
Retractable Lanyard / Rope Grab

243. 24
3
Lifelines
Lifelines shall be secured above the
point of operation to an anchorage
or structural
member capable of supporting a
minimum dead weight of 2,500 Kg.
Lifelines shall be used only for
employee safeguarding. Any lifeline
actually subjected to in-service
loading, as distinguished from static
load testing, shall be immediately
removed from service and shall not
be used again for employee
safeguarding

244. 24
4
Scaffolding should be used when work will be
performed at elevated locations in the following
situations:
● when there is no
permanent access to
the workplace;
● when work cannot be
done safely from a
portable ladder;
● when work cannot be
done from a mechanical
lift or work basket;
● when the job is such
that it is safer to do it
from scaffolding

245. 24
5
Personnel shall not work at height:
● When feeling fatigue or
dizziness
● If fall protection
equipment is defective or
damaged
● During high winds (speed
of approximately 32 km/s
or greater)
● If scaffolds are covered
with ice or snow
● When visibility is poor

246. 24
6
● Understand the potential hazards
of the task to be performed
● Review how you will raise or lower
any tools or equipment
● Ensure required PPE is in good
condition, and make sure you
understand how to properly use it
● Always use the 3-point climbing
method
● Watch out for the safety of others
When Working at Height

247. 24
7
If you are
connected –
you are
protected!
REMEMBER!!!!