1. CHEM 421L Safety Presentation

2. Hazard Symbols You Must Know

4. Take Electricity Seriously
Over 30,000 non-fatal shocks occur each year.
Over 600 deaths occur annually due to electrocution.
Trainer's Notes:
Stress the importance of electrical safety.
Remind them not to underestimate the hazards associated with electricity. We sometimes become complacent about electrical hazards because we cannot hear, smell, or see electricity.
Ask participants if they have ever experienced an electrical shock.
Source: Bureau of Labor Statistics

5. Electrical Accidents Leading Causes of Electrical Accidents:
Drilling and cutting through cables
Using defective tools, cables and equipment
Failure to maintain clearance distance of 10 feet
Failure to de-energize circuits and follow Lockout/Tagout procedures
Failure to guard live parts from accidental worker contact
Unqualified employees working with electricity
Improper installation/use of temporary electrical systems and equipment
By-passing electrical protective devices
Not using GFCI (ground fault circuit interrupters) devices
Missing ground prongs on extension cords
Trainer's Notes:
Leading causes are usually viewed as “symptoms” to a deeper problem.
Often management and leadership problems (root causes) allow the leading causes to exist or form.
Ask the participants to name some root causes which might allow some of these leading causes to exist.

6. Hazards of Electricity
Shock – Most common and can cause electrocution or muscle contraction leading to secondary injury which includes falls
Fires – Enough heat or sparks can ignite combustible materials
Explosions – Electrical spark can ignite vapors in the air
Arc Flash - can cause burns ranging from 14,000 °F to 35,000 °F
Arc Blast – In a short circuit event copper can expand 67,000 times. The expansion causes a pressure wave. Air also expands, adding to the pressure wave.
Trainer's Notes:
Ask the participants the difference between a shock and electrocution. (Electrocution means DEATH. )
Explain that shocks lead to other, secondary injuries such as falls due to the worker’s reaction.
Ask the participants for examples of how each of the accidents might occur.
Explain NFPA 70E which requires workers to stay at least 4 feet away from any exposed electrical devices
such as open disconnects and electrical panels with missing covers

7. Fundamentals of Electricity
Electrical current is the flow of electrons through a conductor.
A conductor is a material that allows electrons (current) to flow through it.
An insulator resists the flow of electrons.
Resistance opposes electron flow.
Trainer's Notes:
Remind them that metals conduct electricity.
Explain that some metals, such as copper, are excellent conductors and are used as wire.
Explain that the human body will conduct electricity.
Explain that things like rubber, plastic, glass and ceramic are insulators. Further explain the sentence ‘Explain that things like
rubber, plastic, glass and ceramic are insulators.’ These materials are especially made to be insulators. For
example, rubber tires for vehicles are not insulators because of the steel belts and carbon black added to
color the tire black.

8. How Shocks Occur
Current travels in closed circuits through conductors (water, metal).
Shock occurs when the human body becomes a part of the circuit.
Current enters at one point & leaves at another.
Trainer's Notes:
Explain that the worst part of the body for current to pass through is the chest cavity. Question: WHY?
ANS. Current directly through the heart is most likely to cause heart fibrillation, that is, interruption of the tiny electrical current that determines the heart’s correct rhythm.
Technically, the heart’s electrical current is 2-3 micro-amps, or amps. Compare that to 20.0 amps in a regular 120 volt circuit – 1.0 amp = 1,000 milliamp = 1,000,000 micro-amp.

9. Severity of the Shock Severity of the Shock depends on:
Amount of current
Determined by voltage and resistance to flow
Path through the body
Duration of flow through the body
Other factors such as general health and individual differences
Trainer's Notes:
Ask to see a show of hands of those that have been shocked.
Remind them that the shock that startled them could very easily have been fatal under different circumstances.
Explain that there are too many variables to not take electricity seriously.

10. Effects of Current Flow
More than 3 milliamps (ma): painful shock
More than 10 ma: muscle contraction
More than 20 ma: considered severe shock
More than 30 ma: lung paralysis - usually temporary
More than 50 ma: possible ventricular fibrillation (usually fatal)
100 ma to 4 amps: certain ventricular fibrillation (fatal)
Over 4 amps: heart paralysis; severe burns
Trainer's Notes:
Explain that when it comes to electricity and the human body’s inability to deal with it, we can no longer talk in terms of Amps and must use smaller units.
Explain that 1 Amp is equal to 1000 milliamps.
Explain that 1/20 of an amp (50 ma) going through the chest cavity can stop the heart and be fatal.
Ask them when the typical circuit breaker will trip ?

11. Electrical Isolation
We can be safe by keeping electricity away from us. We can:
Insulate the conductors
Example: The insulation on extension cords
Elevate the conductors
Example: Overhead powerlines
Guard the conductors by enclosing them
Example: Receptacle covers, boxes, & conduit
Trainer's Notes:
Remind the participants that the whole purpose of electrical isolation is to prevent worker contact with electricity.
Covers shall be installed on all electrical devices, such as panels, disconnects, motor terminal boxes.

12. Insulating the Conductors
Insulated (but not grounded)
The first way to safeguard workers from electrically energized wires is through insulation.
Rubber and plastic is put on wires to prevent shock, fires, short circuits and for strain relief.
It is always necessary to check the insulation on equipment and cords before plugging them in.
Remember, even the smallest defect will allow leakage!
Trainer's Notes:
Explain that an insulator is any material with a high resistance to electric current.
Stress the importance of ensuring that the tools and equipment they use is free from insulation related defects.
Ask participants: How does insulation get damaged?
Insulated (also grounded – see third pin)

13. Defective Extension Cords
Trainer's Notes:
(g)(2)(iii) Splices (repaired)
(f)(6) Path to ground shall be continuous
(e)(1) and (2) Frayed and damaged extension
cords
(g)(2)(iv) Strain relief (explain the hazard)
Damaged and cut cord with exposed conductor.
Remind them of just how serious this situation is.
Ask them: What should they do if they see a cord like this on their site?
Throw this away and buy a new one! Don’t use it!
Photos depict hazardous condition

14. Guarding the Conductors
Another way we safeguard workers from electrically energized wires is by guarding them.
Covers, boxes, and enclosures are often put around conductors to prevent worker contact.
It is always necessary to check that electrical boxes and panels are covered and free from missing “knock-outs.”
Remember, electric equipment operating at 50 volts or more must be guarded!
Trainer's Notes:
Explain that as little 50 volts has the ability to produce enough current flow across the chest to stop the heart within 6 seconds.
Remind them that most of the time they are dealing with at least twice that amount.
When masons need electric power, they need to use a qualified person.
The photo is a violation.
Abatement: Cover the hole with an approved cover.
No knock-outs!
Photo depicts hazardous condition

15. Guarding the Conductors
Trainer's Notes:
1st hazard - No cover around receptacles leaves exposed energized 120 volt parts.
Abatement: Since box is outside, this would need a rain tight cover.
2nd hazard: This box needs to be secured and the non-metallic shield cable (romex) needs to be protected from damage.
Abatement: Mount box on wall, support romex, and protect from damage.
Don’t use either one of these!!
Photos depict hazardous condition

16. Guarding the Conductors
Put a cover on this!
Trainer's Notes:
Stress the serious nature of these situations.
Ask participants if they have seen similar situations on their job sites.
Electrical Safety: As per NFPA 70E, workers should stay at least 4 feet from energized devices.
Abatement: The left photo needs covers. The electrical installation (in the photo on the right side) needs to be replaced with the proper
electrical equipment. It has too many hazards and can not be abated. It must be totally redone by a qualified person.
Yikes!
Photos depict hazardous condition

17. Equipment Grounding
We can be safe by providing a separate, low resistance pathway for electricity when it does not follow normal flow (ground prong/pin).
Grounding gives the stray current somewhere to go and keeps your body from becoming part of the circuit.
Trainer's Notes:
Explain that equipment grounding helps to safeguard the equipment operator in the event that a malfunction causes the metal frame of the tool to become energized.
Ground prong on the extension cord is very important. It provides a low resistance path to ground (or source).
Use non-conducting (wood, plastic) supports when using power tools

18. Defective cord incident with metal support
Worker attempted to climb scaffold with electric drill
Drill was used, even though the cord was damaged with bare wires showing
The bare wire contacted the metal scaffolding
The worker was electrocuted
Trainer’s Notes:
Review the incident with the participants.
Ask them what caused the accident?
Ask them how it could have been prevented?
Use of GFCI would have prevented the accident. Even with the use of GFCI, there is an instant shock which could have resulted in a ‘fall’.
Depicts hazardous condition

19. Can You Rely on Grounding?
Grounding will not work if the electricity can flow through you more easily than the ground. You become the path of least resistance = electrocution
This can happen when:
Your tool doesn’t have a ground pin.
You are working in wet locations.
You are touching a metal object.
Trainer's Notes:
Stress the importance of looking for the ground prong (or the designation for double-insulated) on all equipment, tools and cords.
If the resistance is equal in the ground and in the workers, the current will flow on both paths.
Pay attention to your surroundings when you use grounded portable tools

20. What Must be Grounded? All circuits and extension cords
All noncurrent carrying metal parts
Portable & semi-portable tools and equipment unless double insulated
Trainer's Notes:
Explain the importance of a grounding.
Remind them that without a ground, in the event of a tool’s internal short circuit, their body will most likely become the ground.
Missing ground is a violation and will be cited.
A plug with a ground pin (good!)

21. Do not use a cord or tool if the ground pin has been removed
Don’t Use This!
Don’t Use This!
Trainer's Notes:
Explain that devices which by-pass the ground prong on any piece of equipment, tool, or cord are extremely dangerous and not permitted on site.
Remind them that often these devices are referred to as “suicide plugs”. Show audience the devices called ‘suicide plugs.’
Make sure everyone sees that the ground prong has been removed from the plug on the right and that the cord should be removed from service.
Remind them of the potentially serious consequences of eliminating the ground path.
Photos depict hazardous condition
You will become the path of least resistance for current = electrocution

22. Do Not Reverse Polarity
or use a cord/tool with
reversed polarity
Photo depicts hazardous condition
The prongs are different
sized so you can not turn
the plug around. If you
do, the electrical fields
are always energized.
If there is moisture present, the case is likely to be “hot”.
Even with double-insulated tools, you still could get a shock.
Don’t use this!
Trainer's Notes:
Remind them of the potentially serious consequences of eliminating the ground path. On a three-pronged plug often the other two prongs are the same size and with the ground pin removed, you can reverse the plug, thus reversing the polarity.
Some double insulated tools use a ground prong to ensure that reverse polarity will not occur.

23. GFCI outlets have the reset buttons.
Circuit Interruption
We can be safer by automatically shutting off the flow of electricity in the event of leakage, overload, or short circuit.
Ground Fault Circuit Interrupters (GFCI) are circuit protection (or “overcurrent”) devices that protect you, the worker.
Circuit breakers & fuses protect equipment, not you, because they take too much current & too much time to trip. GFCI protects you.
GFCI outlets have the reset buttons.
Trainer's Notes:
Explain that fuses are designed to melt when too much current flows through them
Explain that circuit breakers are designed to trip open the circuit by electromechanical means.
GFCI protects people. GFCI are the only electrical devices to protect people. Branch circuits require GFCI protection. Not having
GFCI in branch circuits (extension cords) is a violation.

24. Temporary Wiring
There must be separate circuits for electric tools and lighting, each labeled as such.
Light circuits do not require a GFCI.
Unless used in a wet location.
Test branch circuits before use
Maintain vertical clearances
Insulate wires from their supports
Wrong place for cord
Trainer's Notes:
Ask the student why it is important to have separate circuits for electric tools and lighting ?
Double insulated tools and equipment still need GFCI protection.
Cords must be draped overhead to protect you and your labmates

25. Extension Cords and Cables
SUBPART
Must be in good shape without splices
Cannot be secured with staples, nails or bare wire
Must be protected from damage
Must have a ground pin
Should be inspected regularly and pulled from service if defective
Cannot be repaired with electrical or duct tape Must repair with heat-shrink sleeve or bonding/vulcanizing tape to retain original insulation properties
Bad idea!
Trainer's Notes:
Remind the participants how often cords are used on the site.
Ask them how cords can get damaged and how to protect cords from damage.
Explain the rating of cords and read a cord rating to them.
Demonstrate how to inspect a cord.
Extension cords can only be repaired by a qualified person.
Extension cords shall be heavy or extra heavy duty insulation which is stamped on the outer jacket. (see code on cord).
Extension cords can only be repaired if after being repaired the cord is equal or better than the original condition of the cord.
Bad idea!
Photos depict hazardous condition

26. Yikes! Trainer's Notes: Photo depicts hazardous condition
This cord should be pulled from service.
Remind them that splices are not permitted.
This is a violation of the OSHA Standards.
Photo depicts hazardous condition

27. Safe Work Practices
De-energized circuits and equipment must be locked/tagged out.
Lock the box
for
your protection
If you are working on a circuit with a fuse, lock the fuse box while you work – or, someone could come and flip the switch back on while you’re working.
Trainer's Notes:
Remind them that they should not be exposed to energized unguarded electrical circuits.
Workers shall stay away, 4 feet or more, from exposed energized devices which are 600 volts or less. If panels and disconnects are
open, see a qualified person to correct the hazard.

28. Safe Work Practices
SUBPART K 53
No metal supports or ladders used during or near electrical work.
No wet hands when plugging or unplugging cords/equipment.
No raising or lowering tools by the cord.
Unless equipment is designed for it, do not use electrical tools or equipment in damp and wet locations.
Photo depicts
hazardous
condition
Trainer's Notes:
Ask student if they can think of any additional safe work practices?
Ask them what type of ladders should be used around electricity?
Is there a competent person on this jobsite?
Getting through this person to the ladder is now the path of least resistance for the current = electrocution
Bad idea!

29. Summary – Hazards & Protections
SUBPART K 55
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 power lines
All hazards are made worse in wet conditions
Using damaged extension cords
Unqualified workers doing electrical work
Protective Measures
Proper grounding
Use GFCI’s
Use fuses and circuit breakers
Guard live parts
Lockout/Tagout
Proper use of flexible cords
Close electrical panels by Competent Person
Employee training
Ensure competent person on site
Use proper approved electrical equipment
Have qualified person install electrical devices
Trainer's Notes:
Stress the importance of thinking through each operation to determine whether a tool, material or process will effect their proximity to an energy source.

30. Injury Procedure
First Aid kits are available in the lab with band aids and other items for treating small cuts and burns.
Campus public safety can be reached at for non-emergencies.
If it is a serious injury, call 911 for emergencies.
The LiveSafe app can also be used to report emergencies and non-emergencies.
Minor cuts or burns can be treated at the discretion of the instructor, but campus safety officials will be called if the instructor thinks it is necessary.

31. Report any concerns
If you have any safety concerns about the lab you are working in or the people working around you, you can contact:
Your lab instructor
Dr. Marcello Forconi – Head of the departmental safety committee
Dr. Pamela Riggs-Gelasco – Department Chair for Chemistry and Biochemistry
Dr. Jim Deavor, Associate Dean of the School of Science and Mathematics.