An “arc flash hazard” is defined by the CSA Z462-15 Workplace Electrical Safety as a “dangerous condition associated with the release of energy caused by an electric arc”. An arc flash is a dangerous condition which involves an explosion, and can result in serious injuries, burns, and damage to the lungs, eardrums, and eyes. Arc flashes may also cause death.
These conditions can lead to arc flash:
An electrical hazard is considered to be removed when protective measures/controls are put in place at the source (e.g., remove the hazard or de-energize), or along the path (e.g., place electrical insulation or a barrier between the worker and the electrical hazard). Where PPE only is needed for worker protection, an electrical hazard is considered to remain and it is necessary to address safety requirements for other workers in the area.
Electrical work performed on or near electrical transmission or distribution systems must be performed according to 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.
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, and appropriate arc flash protective equipment and clothing. Workers must be trained in and familiar with the tools, equipment and protective devices including personal protective equipment as defined from regulations and/or standards. Workers must follow documented safe work procedures and practices to make sure that they are protected from electrical hazards associated with the work.
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 hazards must be identified, workers shall be protected from the electrical hazards to what they are exposed.
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 must be designed, tested, maintained, and used in ways that provide protection to workers.
When working on or near exposed energized machinery and other apparatus,
From the Electrical Utility Safety Rules, s. 113.
Electrical arc flash hazards must be identified. Workers that are exposed to arc flash hazards must be adequately protected from the arc flash hazards. This protection is most commonly achieved through an arc flash hazard risk assessment or the application of task tables from the electrical standards. The risk assessment would include the assessment of the equipment or devices to determine the potential incident energy that may be produced in the case of an electrical incident. Arc flash risk assessments also help establish safe work procedures for the electrical workers when performing electrical tasks. The risk assessments allow the worker to determine the safe approach boundaries for contact and arc flash hazards.
Workers who may be exposed to electrical shocks or burns from flash hazards must be trained to use and wear voltage rated rubber gloves and leather protectors as necessary. Rubber gloves must be worn with adequate leather protectors and cannot be worn inside out. Leather protectors must be visually inspected for damage and adequacy immediately before each use. Inadequate or damaged gloves or protectors should not be used. Workers must be trained in the proper use, care, and storage of rubber gloves and leather protectors. Voltage rated rubber gloves shall be used and maintained according to the manufactures recommendations and industry standards as prescribed.
Rubber gloves with leather protectors, arc flash protective clothing and equipment, voltage rated tools and defined shock hazard boundaries are the most common protective equipment and measures used for shock protection. All protective rubber gloves must:
NOTE: Voltage rated gloves must meet approved industry standards. They shall be maintained on intervals as prescribed by the manufacture or industry standards, in addition to the requirements from provincial regulations. Specific care and maintenance standards can be found within CSA Z462-15 Workplace Electrical Safety or CAN/UL S 801 Electric Utility Workplace Electrical Safety for Generation, Transmission, and Distribution.
O. Reg. 213/91
Part II GENERAL CONSTRUCTION
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]
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]
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]
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]
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]