This document discusses electrical safety in laboratories. It begins by explaining basic concepts of electricity like voltage, current, resistance and power. It then discusses effects of electric current on the human body and hazards like electric shock. The document outlines various electrical equipment found in labs and safety measures around their use, maintenance and repair. It also discusses electrical accessories like extension cords, power strips and safety devices. Emergency procedures in case of electrical accidents are provided. The key emphasis is on understanding electrical hazards and ensuring proper training before using any electrical equipment or accessories in laboratories.

1. Laboratory Electrical
Safety
PGS 506 Basic Concepts In Laboratory Techniques
ABDUL REHMAN
2020571801
M TECH FPE

2. Contents
2
⦿ Basics of Electricity
⦿ Electric current & Human
body response
⦿ Electrical equipments &
accessories at Lab and
associated hazards
⦿ Emergency procedures

3. 3

4. UNDERSTANDING ELECTRICITY
AT ELEMENTARY LEVEL
1

5. ELECTRICITY: BASICS
⦿ Relationship between power, current, voltage and
resistance
𝑉 = 𝐼 × 𝑅
𝑃 = 𝐼 × 𝑉
𝑃 = 𝐼2 × 𝑅
Where, P = power (watts)
I = current (amperes)
V = voltage (volts)
R = resistance (ohms)
5

6. AC vs. DC Electricity
6
-Direct Current
-Alternating Current

7. Electrical
Components
7

8. 8

9. ELECTRIC CURRENT &
HUMAN BODY
2

10. 10
• Current flow of very low
intensity is perceptible
by a tongue by giving a
tangy sensation.
• Beyond that (at higher
intensity) it becomes
perceptible to the skin
and causes a tingling
sensation, then pain.
Electric
current
perception
Image Source: https://i.pinimg.com/564x/96/71/2f/96712ffc0a56c031e8f77faa6e8f524d.jpg

11. Effects of
Electrical
Current
on human
body
Source: Electric Shock and the Human Body https://i2.wp.com/sub.allaboutcircuits.com/images/quiz/01703x01.png

12. Electric
Shock
hazards
12

13. 13
Image
Source:
Electrical
Shock
Hazard
Mike
Holt
Enterprises
http://www.mikeholt.com/htmlnews/theory/electrical-shock.gif

14. ⦿ Electrical hazards for laboratory employees and students usually
include shock, burn, or fire hazards.
⦿ Occur when a part of the body becomes part of the electrical
circuit.
⦿ One way this can occur is by contacting a metallic part of a piece of
equipment that has become energized by contact with an
electrical conductor.
Introduction
14

15. Factors affecting severity of
the electrical shock
15
Amount of the current (Amps)
Pathway through the body
Duration of the exposure
Skin condition (wet or dry)

16. 16
Electrical
shock
hazards
Primary
Electric shock
Flash burns
Secondary
Fall from heights
Injury from
mechanical hazards
Burns from Electrical
fire

17. Identification
Outlets & Facility wiring
⦿ Avoid overloading electrical
outlets
⦿ Label all circuit-breaker
switches
⦿ Leave at least 36" clearance in
front of electrical panels D
⦿ Ensure proper use of extension
cords
17
Laboratory Equipment
⦿ Inspect tools/ equipment before
use
⦿ Protective measures: 3-prong
plugs, Double insulation on
handheld tools, GFCI-type outlets
⦿ For any tools/ appliances that
generate heat (soldering irons,
hot plates, etc.), unplug when not
in use

18. 18
Hard-wired equipment (e.g. specialty microscopes,
generators)
Plug-and-cord equipment (e.g. refrigeration,
centrifuges, heating baths, electrophoresis devices)
Extension cords
Power cable outlets
General Electricity requirements at Labs &
associated safety concern

19. ELECTRICAL SAFETY:
LAB EQUIPMENTS
3

20. Laboratory Equipments
Typical laboratory contains electrically-powered
equipment such as:
⦿ stirrers
⦿ shakers
⦿ pumps
⦿ hot plates
20
⦿ heaters
⦿ power supplies
⦿ ovens
⦿ electrophoresis equipment

21. Lab Equipments: Input Power requirements
21

22. Lab Equipments*: Approval
⦿ All electrical equipment used by
laboratories must be listed by a
nationally recognized testing
laboratory (NRTL), with a label
showing its approval.
⦿ Must be used in accordance with
the instructions on the listing or
labeling.
22
*Electric-operated instrument

23. Lab Equipments*: Repair & Maintenance
⦿ Work on electrical systems may only be done by an
electrician that is properly licensed.
⦿ Under no circumstances may laboratory personnel
undertake changes to the building electrical service.
23
*Electric-operated instrument

24. Precautionary measures
⦿ Laboratory personnel must always disconnect the
power source to any electrical equipment before
attempting service or repair.
⦿ Live parts of electrical equipment operating at 100
volts or more must be guarded against accidental
contact.
24

25. Precautionary measures (contd.)
⦿ A minimum 36-inch clearance must be maintained
around electrical controls, panels and disconnects at
all times.
⦿ When unplugging a device, be sure to pull from the
plug to prevent wiring damage.
⦿ Never override electrical safety equipment such as
guards or electrical interlocks.
25

26. Electrical
accessories
at Laboratory
26

27. Extension Cords
Power Strips
Clamp Lighting
Ground Fault Circuit Interrupters
27

28. Extension Cords
⦿ In general, extension cords are not appropriate where
a permanent wiring solution is available, regardless
of convenience.
⦿ Should be used only for temporary purposes and
replaced with surge protectors if needed for longer
periods of time.
28

29. Extension Cords (contd.)
⦿ Use only that are listed and labeled
by a Nationally Recognized Testing
Laboratory.
⦿ Adequately rated* for the intended
use and environment.
⦿ Capacity Review (ensure that you are staying within
the cord’s power rating)
29
*The rating (Operational Current, voltage, frequency etc) must be denoted not only on the original package but printed on the extension cord insulating jacket.

30. Extension Cords:
Safety concerns
⦿ May not be run through doors, windows, walls, or
ceilings and may not be attached to building surfaces
(i.e. walls, ceilings) by staples or other means.
⦿ Must be protected from damage and may not be
placed in such a way that they create a tripping
hazard.
30

31. Extension Cords: Safety concerns (contd.)
⦿ Do not run extension cords under carpets or any
other flooring for protection that was not designed
for this purpose.
31
⦿ Extension cords may not be
plugged end-to-end.

32. Extension Cords:
Safety concerns (contd.)
⦿ Must be inspected regularly for wear, as it is likely
occur around the plug.
⦿ Worn or frayed cords must be removed from service
and replaced.
⦿ Cracks in extension cords may not be repaired with
electrical tape.
32

33. Extension Cords: Safety concerns (contd.)
⦿ If the device to be powered has a third prong or
grounding pin, then only use extension cords with a
grounding pin.
33
⦿ Never remove the grounding pin to
make a three prong cord fit in a two-
prong outlet or use an adapter to
make this connection.

34. Power Strips
⦿ Permit more products to be plugged into the same
outlet.
⦿ Convenient but may create safety hazards when used
incorrectly.
⦿ Do not increase the amount of power available to a
location, but rather more access to the same
electrical source.
34

35. Power Strips (contd).
⦿ A heavy reliance generally indicates that additional
wall outlets are needed.
⦿ Use only NRTL (Nationally Recognized Testing
Laboratory) tested power strips, and be sure they are
used only as intended by their NRTL listing.
⦿ Select power strips that are properly rated for the
application.
35

36. Power Strips (contd).
⦿ Read and understand the manufacturer’s instructions
and limitations on the power strip.
⦿ Do not overload the circuit.
⦿ Review the capacity of the circuit and the power
requirements of all of the items plugged into it.
36

37. Clamp
Lighting
⦿ Refers to lamps that can be attached to
objects (such as desks, benchtops, or
equipment) using a clamp connected to
the lamp assembly.
⦿ Poses special hazards in the laboratory
due to the generation of heat and the potential for the equipment to
accidentally fall.
37

38. Clamp Lighting (contd).
⦿ Properly rated.
⦿ Cannot be used in a wet environment*.
⦿ Clamp lights may not be attached to any surface
within 6 feet of a water source (e.g. sinks, emergency
showers, water tanks).
38

39. Clamp Lighting (contd).
⦿ Prevent lights from contacting combustible materials
such as paper goods.
⦿ Do not wrap excess cord around the lamp reflector surface
gets very hot and may damage the cord jacket.
⦿ Inspect cords daily prior to use for cracks, wear, or exposed conductor
wires & discard lamps with damaged cords.
39

40. Ground Fault Circuit Interrupters*
⦿ Designed to protect the end
user from electrical shock.
⦿ Best management practices in
laboratory to have GFCI
protection in a wet
environment.
40
*GFCIs are not required on all circuits in laboratories.
Image
Source:
https://www.electricaltechnology.org/wp-content/uploads/2015/02/GFCI-Ground-Fault-Circuit-Interrupter.-Types-Working.png

41. Ground Fault Circuit Interrupters
⦿ If a laboratory currently has outlets with GFCI
protection, they should be tested at least once per
month.
⦿ Laboratory personnel are responsible for testing the
GFCI.
41

42. 42
Ensuring correct installation of GFCI: Steps
I
• Plug a lamp into the outlet and turn it on.
II
• Next, press the “TEST” button on the GFCI. Under properly functioning conditions, the GFCI’s
“RESET” button should pop out and the light will turn off.
III
• Press the “RESET” button to restore power to the outlet.
IV
• If the “RESET” button pops out but the light does not go out, the GFCI has been improperly wired.
• Contact Maintenance to correct the wiring errors
V
• If the “RESET” button does not pop out, the GFCI is defective and should be replaced.

43. Safety
Considerations
43

44. Finding damaged or defective Equipment
⦿ Experiencing shocks, even
mild shocks, when the
equipment is touched.
⦿ Abnormal heat generation.
⦿ Arcing, sparking, or
smoking from the
equipment.
44

45. Electricity and Flammable Materials
⦿ Keep flammable materials away from electrical
equipment equipment may serve as a source of ignition for flammable or explosive
vapors.
⦿ Receptacles providing power for equipment used
inside a fume hood should be located outside the
hood.
45
Image Source: https://info.muellerelectric.com/hs-
fs/hubfs/grounding%20and%20bonding.gif?width=400&height=235&name=grounding%20and%20bonding.gif

46. Electricity and Flammable Materials
(contd.)
Make sure that equipment
used where flammable
vapors may be present is
specially rated to not
produce sparks
46
Image Source: ABCs of Fire Extinguishers https://fireprevention.utexas.edu/firesafety/abcs-fire-extinguishers

47. Precautions
⦿ Be aware that if drying ovens are used to dry organic
materials, vapors may accumulate inside the oven
and/or escape into the lab atmosphere.
47
⦿ Take care to prevent developing
explosive mixtures in air by not drying
organic materials that can lead to fire.

48. Safety
Devices
48

49. 49

50. 50
Fuses
⦿ Protect electrical wiring from
carrying too much current.
⦿ Protect malfunctioning
equipment from drawing too
much current.
⦿ Conductor melts if too much
current flows through fuse.
⦿ Can only be used once.
⦿ Always use the correct fuse.
Circuit Breakers
⦿ Protect electrical wiring
from carrying too much
current.
⦿ Mechanical switch is driven
by an electromagnet.
⦿ Can be reset many times.

51. EMERGENCY PROCEDURES
4

52. Response to Electrical Shock
Protect
yourself
Call
National
Medical
Emergency
Helpline
Number
112
Warn
others
about the
hazards
Move
victim to a
safe place
is possible
Give
necessary
First Aid (If
trained)
Notify
supervisor
52

53. 53

54. Key take-aways
Understand
the hazards
and
associated
risk of task
being
performed
Carefully
examine the
equipment &
circuit
functions
Ensure
proper
training
before use of
equipment
Don’t be
afraid to ask
for help
54

55. Thank You
55

56. References
⦿ Handbook of laboratory Safety, Furr, A. Keith Ph.D. "Frontmatter“
CRC Boca Raton: CRC Press LLC,2000
⦿ The Effect of Electric Current on the Human Body Conference on
Systems, Signal Processing and Electronics Engineering
(ICSSEE'2012) December 26-27, 2012 Dubai (UAE)
⦿ Electrical Safety in the Laboratory Joshua D. Horvath et al.,
Carnegie Mellon University
⦿ https://www.safety.fsu.edu/safety_manual/Electrical%20Safety
%20in%20the%20Laboratory.pdf
56