Electrical Hazards

Electrical Hazards

Introduction• Electricity if flow of charge through a conductor.• Electricity is essential to modern life, both at home and on the job.

Some employees — engineers, electricians, electronic technicians, and power line workers, among them — work with electricity directly.• Others, such as office workers and sales people, work with it

indirectly.• More importantly, we tend to overlook the hazards electricity poses

and fail to treat it with the respect it deserves.

Quick Fact

Guess what is National Electrical Safety Month?

Current month!May is National Electrical Safety Month

Source: The Electrical Safety Foundation International (ESFI) - Non-profit organization dedicated exclusively to promoting electrical safety in the home, school, and workplace.

Accident #1: Employee Electrocuted While Installing

Electrical Panels• At around 3pm on Nov 28, 2007, a foreman was completing the

installation of electrical panels in an electrical meter room inside a newly-constructed single-story commercial building in Hawthorne, CA.• He was discovered by coworkers on the ground in the panel room, next

to a 480V pull panel from which the cover had been removed.• Rushed to the Little Company of Mary Hospital, where he was

pronounced dead at 4:55 pm• One of the firemen later stated that the 480V pull panel was energized

and that one energized conductor was hanging loose in the panel.

Source: U.S. Department of Labor | OSHA Accident Reports

Accident #1: Employee Electrocuted While Installing

Electrical Panels• Cause of death: Electrocution, from contact with energized electrical

equipment due to the lack of proper work procedures, safeguards, and barriers, and the lack of personal protective equipment.• Employer was cited for a violation, regulatory, of T8CCR 342(a), for

failing to report a serious accident; for a violation, general, of T8CCR 1509(b), for the lack of a code of safe practices for electrical work; and an accident-related violation, serious, of T8CCR 2320.2(a), for work on energized equipment without proper procedures.

Source: U.S. Department of Labor | OSHA Accident Reports

Accident #2: Employees Sustain Electrical Shock, One Is

Electrocuted• At approximately 12:30 p.m. on June 2, 2008, a crew of five employees was removing a

storm-downed tree top and limbs off of two power distribution lines and a neutral line that crossed under and perpendicular to three energized power lines.

• Employee #1 and Employee #2 were using their hands to move a 7,200-volt phase to ground the power distribution lines.

• Employee #3 was standing over a power distribution line using a chain saw to cut limbs from the tree top

• Employee #4 was pulling limbs and brush from the pile and Employee #5 was setting a chain saw down.

• The power distribution lines that the employees were working on had the fused cutouts open on one end and were cut at the other end. Protective grounds were not installed. The power distribution lines that the employees were working on contacted the energized lines.

Source: U.S. Department of Labor | OSHA Accident Reports

Accident #2: Employees Sustain Electrical Shock, One Is

Electrocuted• Employee #1 was electrocuted, CPR was performed at the scene and he

was transported to the hospital where he was pronounced dead.• Employee #2 was air lifted from the scene to another hospital burn unit

with burns to his abdomen, left hand and arm, left and right feet and legs.• Employee #3 was transported to a third hospital by ambulance then to

a burn unit with burns to his right leg which was amputated, left foot and leg.• Employee #4 was transported by private vehicle to the hospital where

he was treated and released.• Employee #5 was not injured.Source: U.S. Department of Labor | OSHA Accident Reports

Why should you be concerned about Electrical Hazards?

• Electricity has long been recognized as a serious workplace hazard, exposing employees to electric shock, electrocution, burns, fires, and explosions• In 1999, for example, 278 workers died from electrocutions at work,

accounting for almost 5 percent of all on-the-job fatalities that year, according to the Bureau of Labor Statistics.• What makes these statistics more tragic is that most of these fatalities

could have been easily avoided.• Let’s look at the statistics!

Annual Electrical fatalities declined by more than 50% for the period 1992-2010Source: U.S. Bureau of Labor Statistics

Statistics

The Construction Industry alone sustained 52% of all electrical fatal accidents for the period 2003-2010Source: U.S. Bureau of Labor Statistics

Statistics

• Contact with Overhead Power lines• Contact with Live Circuits• Not following Lockout/Tagout procedures• Poorly Maintained Extension Cords• Defective Power Tools

Causes of Electrocution Failures

There are three direct and two indirect types of electrical injuries:• Direct:

Electrocution or death due to electrical shockElectrical shockBurns

• Indirect:FallsFire

Electrical Injuries

• 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

Shock Severity

Some examples of potential Electrical Hazards at the

workplace• Office Setting “rats nests”• Overloading• No grounding• Unlabeled or open equipment• Improper chemical storage near electrical equipment• Power lines or other electrified objects• Many others…. Too numerous to name!

Electrical Hazards

Desk Areas/Work Stations(“rat nests”)

Ungrounded EquipmentElectricity will take the path of least resistance.When equipment is grounded, current will take the path through ground wire rather than through the person touching the failed equipment because human body is more resistant than ground wire

Overloaded CircuitsUse a single plug for each connectionDo not overload circuits!

Electrical Hazards

Unlabeled/Open equipmentAll panel/circuit boxes must be labeled with maximum voltage on the outside of the front coverKeep them closed when not being serviced

Improper Chemical StorageThis is a bottle of Xylene (very flammable and combustible substance)Must never be placed near breaker boxes, panels, etc.

Overhead Power LinesKeep 10 feet clearance from overhead power lines with 50kV or less; 4 feet more for every 10kV

Know the hazards of electricity Know the equipmentUse PPE (Personal Protective Equipment) Use Safe Work Practices Don’t work on energized circuits without permission

It’s Your Job to know!

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• All electrical work must comply with the National Electrical Code• Use non-conductive ladders around electrical equipment• Never exceed the capacity by overloading circuits• Never reach blindly into an electrical cabinet• Use illumination when needed• Secure doors and openings that could bump you into an energized

part

Safe Work Practices

Electrical equipment may be maintenance ONLY by employees who have been properly trained and authorized to do so.

Electrical Equipment Safety

Determining Energized partsHow do you determine if something is energized?Voltage testers are used to test poles and any associated hardware’s.Visual inspection• Is the circuit open or closed?• Are there any visible indicators that the system is

energized• Are there audible indicators?

Grounding• Ensure there is a path of low resistance to ground if

there is an equipment failure• Grounding works by connecting all the non-current

carrying metal parts together and then connecting them to ground• It is important that the grounding conductor is

firmly attached

Ground Fault Interrupters (GFI’s)

• Detect “leaks” (but not over-current)• Can be permanently mountable or portable• Must be used on all 120V, single phase, 15- and 20-

ampere receptacle outlets on construction sites, which are not part of permanent wiring• Must be tested to ensure it’s working properly• Must be marked with manufacturer’s name and

applicable rating

Electrical Safety – Lockout / Tagout (LO/TO)

• Lockout and Tagout is a technique used to prevent the release of hazardous energy, or to prevent the hazardous energy from escaping• It is a VERY SPECIFIC and STRINGENT OSHA program• It covers electrical energy sources, as well as other types of energy

such as steam, pressure, weighted objects, and moving machinery parts

Lockout / Tagout (LO/TO) Hazards

• Even office equipment can require some sort of Lockout / Tagout (LO/TO) controls to prevent energization of moving parts or electrical shock• Many types of automatic LO controls exist• For instance, if you open a tray of service door, the equipment will not

run (Example of combination of LO and machine guarding)

“Fatal Five” Main Causes of Lockout / Tagout (LO/TO)

Injuries• Failure to stop equipment• Failure to disconnect from power source• Failure to dissipate residual energy• Accidental restarting of equipment• Failure to clear work areas before restarting

Lockout / Tagout (LO/TO) Devices

Use PPE (Personal Protective Equipment)

While working on electrical equipments, use some of these PPE’s:• Leather gauntlet gloves over rubber insulated gloves• Hard hats (rated for electrical work)• Eye protection gear• Rubber or non-conductive clothing• Rubber-soled shoes or boots• Rubber blankets• Do not wear metal jewellery when working around exposed energized

parts

Effects of Electric Current in the Human Body

Current Reaction

Below 1 mA Generally not perceptible

1 mA Faint tingle

5 mA Slight shock felt; not painful but disturbing. Average individual can let go. Strong involuntary reactions can

lead to other injuries.6 – 25 mA (women) Painful shock, loss of muscular control

9 – 30 mA (men) The freezing current or “let-go” range. Individual cannot let go, but can be thrown away from the circuit

if extensor muscles are stimulated.50 – 150 mA Extreme pain, respiratory arrest, severe muscular

contractions. Death is possible.1,000 – 4,300 mA Rhythmic pumping action of the heart ceases.

Muscular contraction and nerve damage occur; death likely.

10,000 mA Cardiac arrest, severe burns; death probable

What OSHA Standards address Electrical Safety?

• OSHA standards cover many electrical hazards in many different industries.

• OSHA’s general industry electrical safety standards are published in:Title 29 Code of Federal Regulations (CFR), Part 1910.302 through 1910.308 — Design Safety Standards for Electrical Systems, and 1910.331 through 1910.335 — Electrical Safety-Related Work Practices Standards.

• OSHA’s electrical standards are based on the National Fire Protection Association Standards NFPA 70, National Electric Code, and NFPA 70E, Electrical Safety Requirements for Employee Workplaces.

• OSHA also has electrical safety standards for the:• Construction industry, in 29 CFR 1926• Subpart K. OSHA’s standards for marine terminals, in 29 CFR 1917• Longshoring, in 29 CFR 1918, reference the general industry electrical standards in Subpart S of Part

1910.• Shipyard standards, in 29 CFR 1915, cover limited electrical safety work practices in 29 CFR 1915.181.

• Although OSHA operates a federal occupational safety and health program, 24 states and 2 territories operate their own OSHA-approved programs.

How do OSHA’s standards minimize Electrical Hazards?

• OSHA standards focus on the design and use of electrical equipment and systems.• The standards cover only the exposed or operating elements of an

electrical installation such as lighting, equipment, motors, machines, appliances, switches, controls, and enclosures, requiring that they be constructed and installed to minimize workplace electrical dangers.

How can OSHA help you?

• OSHA can provide extensive help through a variety of programs, including assistance about:• Safety and Health programs• State plans• Workplace consultations• Voluntary protection programs• Strategic partnerships• Training and education, and more.

Safety and Health Program Management Assistance

• Working in a safe and healthful environment can stimulate innovation and creativity and result in increased performance and higher productivity

• To assist employers and employees in developing effective safety and health programs, OSHA published recommended Safety and Health Program Management Guidelines (Federal Register 54(18):3904–3916, January 26, 1989).

• These voluntary guidelines can be applied to all worksites covered by OSHA.• The guidelines identify four general elements that are critical to the development of a

successful safety and health management system:• management leadership and employee involvement,• worksite analysis,• hazard prevention and control, and• safety and health training

State Plans• State plans are OSHA-approved job safety and health programs

operated by individual states or territories instead of Federal OSHA.• The Occupational Safety and Health Act of 1970 (OSH Act) encourages

states to develop and operate their own job safety and health plans and permits state enforcement of OSHA standards if the state has an approved plan.• Once OSHA approves a state plan, it funds 50 percent of the

program’s operating costs.• There are 26 state plans: 23 cover both private and public (state and

local government) employment, and 3 (Connecticut, New Jersey, and New York) cover only the public sector

Workplace Consultations• OSHA’s consultation service provides free, onsite assistance in

developing and implementing effective workplace safety and health management systems that emphasize the prevention of worker injuries and illnesses.• Includes:• Hazard survey of the worksite• Appraisal of all aspects of the employer’s existing safety and health

management system• Offers assistance to employers in developing and implementing an effective

safety and health management system• Employers also may receive training and education services, as well as limited

assistance away from the worksite.

Voluntary Protection Program (VPP)

• Voluntary Protection Programs (VPPs) represent one part of OSHA’s effort to extend worker protection beyond the minimum required by OSHA standards.• VPP — along with onsite consultation services, full-service area

offices, and OSHA’s Strategic Partnership Program (OSPP) — represents a cooperative approach which, when coupled with an effective enforcement program, expands worker protection to help meet the goals of the OSH Act.

How does Voluntary Protection Programs (VPP) work?

There are three levels of VPPs: Star, Merit, and Demonstration. All are designed to do the following:• recognize employers who have successfully developed and implemented

effective and comprehensive safety and health management systems;• encourage these employers to continuously improve their safety and

health management systems;• motivate other employers to achieve excellent safety and health results

in the same outstanding way; and• establish a relationship between employers, employees, and OSHA that

is based on cooperation.

OSHA’s Strategic PartnershipProgram (OSPP)

• OSHA Strategic Partnerships are alliances among labor, management, and government to foster improvements in workplace safety and health.• These partnerships are voluntary, cooperative relationships between

OSHA, employers, employee representatives, and others such as trade unions, trade and professional associations, universities, and other government agencies.• OSPPs are the newest member of OSHA’s family of cooperative

programs.

OSHA’s Occupational Safety andHealth training for employers

and employees• OSHA Training Institute in Des Plaines, IL, provides basic and advanced

training and education in safety and health for federal and state compliance officers, state consultants, other federal agency personnel, and private-sector employers, employees, and their representatives.• Institute courses cover diverse safety and health topics including electrical

hazards, machine guarding, personal protective equipment, ventilation, and ergonomics. The facility includes classrooms, laboratories, a library, and an audiovisual unit.• In addition, OSHA’s 73 area offices are full-service centers offering a

variety of informational services such as personnel for speaking engagements, publications, audiovisual aids on workplace hazards, and technical advice.

Does OSHA give money to organizations

for training and education?• OSHA awards grants through its Susan Harwood Training Grant

Program to nonprofit organizations to provide safety and health training and education to employers and workers in the workplace.• Grants are awarded for 1 year and may be renewed for an additional

12 months depending on whether the grantee has performed satisfactorily.

OSHA is making a difference!• In four decades, OSHA and our state partners, coupled with the

efforts of employers, safety and health professionals, unions and advocates, have had a dramatic effect on workplace safety.• Since 1970, workplace fatalities have been reduced by more than 65

percent and occupational injury and illness rates have declined by 67 percent. At the same time, U.S. employment has almost doubled.• Worker deaths in America are down–on average, from about 38

worker deaths a day in 1970 to 12 a day in 2012.• Worker injuries and illnesses are down–from 10.9 incidents per 100

workers in 1972 to 3.4 per 100 in 2011.