Electrical Hazards - Working on Energized Systems

Electrical work performed on or near electrical transmission or distribution systems must be performed in accordance with the “Electrical Utility Safety Rules” published by the Infrastructure Health and Safety Association. Workplaces are required to take every reasonable precaution to prevent hazards from energized electrical equipment, installations and conductors.


The above electrical work is performed under the authority of the electrical utility and the electrical work is performed by authorized workers, workers are given formal permission from the owner and employer and they are competent to perform work on and in proximity to electrical transmission and distribution systems. Examples are powerline technicians that are performing approved work methods to install and maintain electrical transmission and distribution systems.

Electrical work outside of the above scope must be performed according to the following requirements.

Where work must be done on, or near enough to the hazard, to make electrical contact or near enough to be exposed to injury from an arc flash, work while the system is energized is permitted only if specific conditions are met. Testing/Diagnostic testing with a meter/testing device is considered to be working on energized equipment, and requires appropriate protection including electrical contact and arc flash personal protective equipment. Written safe work procedures are also required.

Electrical hazards must be identified, workers shall be protected from the electrical hazards to what they are exposed.

No worker can connect, maintain, or modify electrical equipment or installations unless they hold the appropriate certificate of qualification, or are otherwise allowed. Workers who do not hold these qualifications are allowed to attach a cord of an electrical equipment or tool and remove it from a receptacle.

Only the authorized person (authorized by the supervisor in charge of the project) may enter a room or other enclosure that contains exposed energized electrical parts. The entrance to this room or enclosure must be marked with warning signs stating that unauthorized people may not enter.

Electrical equipment, installations, conductors, and insulating materials must be suitable for their intended use, and be installed, maintained, modified, and operated in a way that is not a hazard to a worker. Electrical equipment, installations and conductors that are not used for the purpose they were designed for must be removed, left in an electrically non-hazardous condition by being disconnected, de-energized, tagged, and either grounded if a power line or locked out if it is electrical equipment.

Electrical tools and equipment must meet industry standards examples may include but not limited to voltage rated tools, correct categories of diagnostic equipment, multi-meters, proximity testers, amp meters and other diagnostic equipment as required, non-conductive ladders, non-conductive scaffolding, voltage rated gloves, appropriate arc flash protective equipment and clothing. Workers shall be trained in and familiar with the tools, equipment and protective devices including personal protective equipment as defined from regulations. Workers shall follow documented safe work procedures and practices to ensure that they are protected from electrical hazards associated with the work.

Tools, ladders, scaffolding and other equipment or material that is able to conduct electricity must not be stored or used so close to energized electrical equipment, installations or conductors that they can make electrical contact.

When work is to be done on or near energized exposed parts of electrical equipment, installation or conductor, the employer must:

  • Establish and implement written measures and procedures that comply with the law, and ensure workers are protected from electrical shock and burn, and
  • Make a copy of the written measures and procedures available to every worker on the project.

The worker must follow the written measures and procedures.

The power supply to the electrical equipment, installation or conductor must be disconnected, locked out of service, and tagged before the work begins. It must also be kept in this state while the work continues. Hazardous stored energy must be adequately discharged or contained before the work begins, and kept in that state while the work continues. Workers must verify that these conditions are met before beginning work.

Work on energized equipment is permitted only if:

  • it is not reasonably possible to disconnect the equipment, installation, or conductor from the power supply,
  • the equipment is rated at a nominal voltage of 600 volts or less, and disconnecting the equipment would create a greater hazard to workers than proceeding without disconnecting it, or
  • the work consists only of diagnostic testing.

All tools, devices and equipment, including personal protective equipment must be designed, tested, maintained so that they provide adequate protection to workers when they are working on or near energized exposed parts of electrical equipment, installations or conductors.

Defective electrical equipment and tools that may be a hazard must be immediately disconnected, removed from service, and tagged as being defective.

Any case of a ground fault or the tripping of a ground fault circuit interrupter must be immediately investigated to determine the hazard. Corrective action must be taken immediately.

Unless the work consists only of diagnostic testing or involves a nominal voltage under 300 volts, an adequately equipped competent worker who can perform rescue operations, including cardiopulmonary resuscitation (CPR), must be stationed where he or she can see the workers performing the live work.

Work on energized equipment nominally rated greater than 400 amperes and greater than 200 volts, or greater than 200 amperes and greater than 300 volts, can only be done if:

  • the owner of the equipment provides the employer and the constructor with a record showing that it has been maintained according to the manufacturer’s specifications
  • a copy of the maintenance record is readily available at the project
  • the employer has determined from the maintenance record that work on the equipment can be performed safely without disconnecting it
  • before beginning live work, the worker has verified that requirements have been met
  • workers must use mats, shields or other protective devices or equipment, including personal protective equipment, adequate to protect the worker from electrical shock and burn

Workers who may be exposed to electrical shocks or burns from flash hazards must be trained to use and wear rubber gloves and leather protectors when necessary. Rubber gloves must be worn with adequate leather protectors and cannot be worn inside out. Leather protectors and rubber gloves must be visually inspected for damage and adequacy immediately before each use. Inadequate or damaged gloves or protectors should not be used. Voltage rated rubber gloves shall be used and maintained as per the manufactures recommendations and industry standards.

Rubber gloves, leather protectors and defined shock hazard boundaries are the most common protective measures and equipment used for shock protection. All protective rubber gloves must:

  • protect the worker against electrical shock and burn, and
  • be air tested and visually inspected for damage and adequacy immediately before each use.

Rubber gloves rated for voltages above 5,000 volts ACmust be tested and certified that they can withstand the voltages for which they are rated.

Voltage rated gloves also must meet approved industry standards, they shall be maintained on intervals as prescribe by the manufacture or industry standards if additional requirements from provincial regulations. Voltage rated gloves also must be tested in accordance with manufacture and industry approved testing procedures as prescribe from the manufactures.

  • at least once every three months, if they are in service, and
  • at least once every six months, if they are not in service.

Construction Projects
O. Reg. 213/91

Part II GENERAL CONSTRUCTION

Section 181

181. (1) Except where otherwise required by this Regulation, electrical work performed on or near electrical transmission or distribution systems shall be performed in accordance with the document entitled "Electrical Utility Safety Rules" published by the Infrastructure Health and Safety Association and revised 2014.

(2) Sections 182, 187, 188, 189, 190, 191 and 193 do not apply to electrical work that is performed on or near electrical transmission or distribution systems if the work is performed in accordance with the document referred to in subsection (1).

[O. Reg. 631/94, s. 6; 627/05, s. 4; 443/09, s. 5; 345/15, s. 22]

Section 182

182. (1) No worker shall connect, maintain or modify electrical equipment or installations unless,

(a) the worker holds a certificate of qualification issued under the Ontario College of Trades and Apprenticeship Act, 2009 , that is not suspended, in the trade of,

(i) electrician - construction and maintenance, or

(ii) electrician - domestic and rural, if the worker is performing work that is limited to the scope of practice for that trade; or

(b) the worker is otherwise permitted to connect, maintain or modify electrical equipment or installations under the Ontario College of Trades and Apprenticeship Act, 2009 or the Technical Standards and Safety Act, 2000. .

(2) A worker who does not meet the requirements of clause (1) (a) or (b) may insert an attachment plug cap on the cord of electrical equipment or an electrical tool into, or remove it from, a convenience receptacle.

[O. Reg. 627/05, s. 4; 88/13, s. 2]

Section 183

183. Every reasonable precaution shall be taken to prevent hazards to workers from energized electrical equipment, installations and conductors.

[O. Reg. 143/99, s. 1; 627/05, ss. 5, 6]

Section 184

184. (1) No person, other than a person authorized to do so by the supervisor in charge of the project, shall enter or be permitted to enter a room or other enclosure containing exposed energized electrical parts.

(2) The entrance to a room or other enclosure containing exposed energized electrical parts shall be marked by conspicuous warning signs stating that entry by unauthorized persons is prohibited.

[O. Reg. 627/05, s. 7]

Section 185

185. (1) Electrical equipment, installations, conductors and insulating materials shall be suitable for their intended use and shall be installed, maintained, modified and operated so as not to pose a hazard to a worker.

(2) For greater certainty, the regulations made under section 113 of the Electricity Act, 1998 apply to electrical equipment, installations, conductors and insulating materials and to temporary wiring installations on projects.

[O. Reg. 627/05, s. 7]

Section 186

186. Electrical equipment, installations and conductors that are not to be used for the purpose for which they were designed shall be,

(a) removed; or

(b) left in an electrically non-hazardous condition by being disconnected, de-energized, tagged and,

(i) grounded, in the case of power lines,

(ii) locked out, in the case of electrical equipment.

[O. Reg. 627/05, s. 7]

Section 187

187. Tools, ladders, scaffolding and other equipment or materials capable of conducting electricity shall not be stored or used so close to energized electrical equipment, installations or conductors that they can make electrical contact.

[O. Reg. 627/05, s. 7]

Section 190

190. (1) This section applies if work is to be done on or near energized exposed parts of electrical equipment or of an electrical installation or conductor.

(2) An employer shall,

(a) establish and implement written measures and procedures for complying with this section to ensure that workers are adequately protected from electrical shock and burn; and

(b) make a copy of the written measures and procedures available to every worker on the project.

(3) The worker shall follow the written measures and procedures.

(4) Subject to subsection (9), the power supply to the electrical equipment, installation or conductor shall be disconnected, locked out of service and tagged in accordance with subsection (6) before the work begins, and kept disconnected, locked out of service and tagged while the work continues.

(5) Hazardous stored electrical energy shall be adequately discharged or contained before the work begins and shall be kept discharged or contained while the work continues.

(6) The following rules apply to the tagging of the power supply under subsection (4):

1. The tag shall be made of non-conducting material and shall be installed so as not to become energized.

2. The tag shall be placed in a conspicuous location and shall be secured to prevent its inadvertent removal.

3. The tag shall indicate,

i. why the equipment, installation or conductor is disconnected,

ii. the name of the person who disconnected the equipment, installation or conductor,

iii. the name of the person's employer, and

iv. the date on which the equipment, installation or conductor was disconnected.

4. The tag shall not be removed unless it is safe to do so.

(7) A worker, before beginning work to which this section applies, shall verify that subsections (4) and (5) have been complied with.

(8) If more than one worker is involved in work to which this section applies, a means shall be provided to communicate the purpose and status of,

(a) the disconnecting, locking out and tagging of the electrical equipment, installation or conductor; and

(b) the discharging and containment of any hazardous stored electrical energy.

(9) Locking out is not required under subsection (4) if,

(a) in the case of a conductor, it is adequately grounded with a visible grounding mechanism;

(b) in the case of equipment or an installation,

(i) the power supply is less than 300 volts, the equipment or installation was not manufactured with provision for a locking device for the circuit breakers or fuses, and a written procedure has been implemented that is adequate to ensure that the circuit is not inadvertently energized, or

(ii) the power supply is 300 or more volts but not more than 600 volts, the equipment or installation was not manufactured with provision for a locking device for the circuit breakers or fuses, a written procedure as to how work is to be done has been implemented and the work is supervised by a competent worker to ensure that the circuit is not inadvertently energized.

[O. Reg. 627/05, s. 7]

Section 191

191. (1) This section applies instead of section 190 if work is to be done on or near energized exposed parts of electrical equipment or of an electrical installation or conductor and,

(a) it is not reasonably possible to disconnect the equipment, installation or conductor from the power supply before working on or near the energized exposed parts;

(b) the equipment, installation or conductor is rated at a nominal voltage of 600 volts or less, and disconnecting the equipment, installation or conductor would create a greater hazard to a worker than proceeding without disconnecting it; or

(c) the work consists only of diagnostic testing of the equipment, installation or conductor.

(2) Subsection (10) applies, in addition to subsections (3) to (9), if the equipment, installation or conductor is nominally rated at,

(a) greater than 400 amperes and greater than 200 volts; or

(b) greater than 200 amperes and greater than 300 volts.

(3) Only a worker who meets the requirements of clause 182(1)(a) or (b) shall perform the work.

(4) The constructor shall,

(a) ensure that written measures and procedures for complying with this section are established and implemented, so that workers are adequately protected from electrical shock and burn; and

(b) make a copy of the written measures and procedures available to every employer on the project.

(5) Before a worker begins work to which this section applies, the employer shall provide a copy of the written measures and procedures to the worker and explain them to him or her.

(6) The worker shall follow the written procedures.

(7) A worker shall use mats, shields or other protective devices or equipment, including personal protective equipment, adequate to protect the worker from electrical shock and burn.

(8) If the electrical equipment, installation or conductor is rated at a nominal voltage of 300 volts or more, an adequately equipped competent worker who can perform rescue operations, including cardiopulmonary resuscitation, shall be stationed so that he or she can see the worker who is performing the work.

(9) Subsection (8) does not apply if the work consists only of diagnostic testing of the equipment, installation or conductors.

(10) In the case of equipment or of an installation or conductor described in subsection (2), a worker shall not perform the work unless the following additional conditions are satisfied:

1. The owner of the equipment, installation or conductor has provided the employer and the constructor with a record showing that it has been maintained according to the manufacturer's specifications.

2. A copy of the maintenance record is readily available at the project.

3. The employer has determined from the maintenance record that the work on the equipment, installation or conductor can be performed safely without disconnecting it.

4. Before beginning the work, the worker has verified that paragraphs 1, 2 and 3 have been complied with.

[O. Reg. 627/05, s. 7]

Section 192

192. All tools, devices and equipment, including personal protective equipment, that are used for working on or near energized exposed parts of electrical equipment, installations or conductors shall be designed, tested, maintained and used so as to provide adequate protection to workers.

[O. Reg. 627/05, s. 7]

Section 193

193. (1) A worker who may be exposed to the hazard of electrical shock or burn while performing work shall use rubber gloves,

(a) that are adequate to protect him or her against electrical shock and burn;

(b) that have been tested and certified in accordance with subsection (2), if applicable; and

(c) that have been air tested and visually inspected for damage and adequacy immediately before each use.

(2) Rubber gloves rated for use with voltages above 5,000 volts AC shall be tested and certified to ensure that they can withstand the voltages for which they are rated,

(a) at least once every three months, if they are in service;

(b) at least once every six months, if they are not in service.

(3) Rubber gloves shall be worn with adequate leather protectors and shall not be worn inside out.

(4) Leather protectors shall be visually inspected for damage and adequacy immediately before each use.

(5) Rubber gloves or leather protectors that are damaged or not adequate to protect workers from electrical shock and burn shall not be used.

(6) Workers shall be trained in the proper use, care and storage of rubber gloves and leather protectors.

[O. Reg. 627/05, s. 7]

Section 195.3

195.3 (1) Defective electrical equipment and tools that may pose a hazard shall be immediately disconnected, removed from service and tagged as being defective.

(2) The cause of a ground fault or the tripping of a ground fault circuit interrupter shall be immediately investigated to determine the hazard and corrective action shall be taken immediately.

[O. Reg. 627/05, s. 7]

Explosives