Working near power lines: who may do it and what training it takes

This page reports what regulators and standards say. It is not a table of safe distances to rely on. Where a distance appears, it is quoted from the page named beside it, for the case that page describes. The owner of the line, the regulator and your employer decide what applies on a given job.

United States

Two federal rules matter most: OSHA 1910.269 for line-clearance tree trimming, and 1910.333 for people who are not qualified. The text is on the eCFR, the official online edition of the federal regulations.

1910.269 and line-clearance tree trimming

The rule covers line-clearance tree trimming done to clear space around electric power generation, transmission or distribution lines or equipment, on behalf of an organization that operates, or controls the operating procedures for, those lines. For workers who are qualified employees, the whole section applies except paragraph (r)(1). For trimmers who are not qualified employees, the rule names a smaller list of paragraphs, including (r). The exact lists are in 29 CFR 1910.269.

The rule defines two kinds of worker. A line-clearance tree trimmer is "an employee who, through related training or on-the-job experience or both, is familiar with the special techniques and hazards involved in line-clearance tree trimming." A qualified employee is "an employee (person) knowledgeable in the construction and operation of the electric power generation, transmission, and distribution equipment involved, along with the associated hazards."

A trimmer who is not a qualified employee must still be trained and competent in listed skills. They include telling exposed live parts from other parts of the equipment, and determining the nominal voltage of exposed live parts.

What paragraph (r) says about tree work

Before an employee climbs, enters or works around any tree, the nominal voltage of the power lines posing a hazard must be determined.
A second line-clearance tree trimmer must be within normal voice range in listed cases. One is when a trimmer is to approach closer than 3.05 meters (10 feet) to a conductor or apparatus energized at more than 750 volts.
Trimmers must keep the minimum approach distances in Tables R-5 to R-8. Those tables hold the figures.
Ladders, platforms and aerial devices may not be brought closer to an energized part than the table distances.
Thunderstorms in the immediate vicinity, high winds, snow storms and ice storms are presumed to make line-clearance tree trimming too hazardous to perform safely.

1910.333 for people who are not qualified

Section 1910.333(c)(3) says that if work is to be performed near overhead lines, the lines shall be deenergized and grounded, or other protective measures provided, before work starts. For an unqualified person working at height near an unguarded, energized line, it sets 10 feet for voltages to ground of 50 kV or below, plus 4 inches for every 10 kV over 50 kV. See 29 CFR 1910.333. Which rule fits a given crew depends on who the work is for and who is qualified.

ANSI Z133

The ISA says the Z133-2026 standard became available on May 27, 2026, and that for individual use the digital version is a free downloadable PDF; see the ISA release page. TCI Magazine, published by the Tree Care Industry Association, describes the ANSI Z133-2026 revision, in an August 12, 2026 article, as sorting arborists into four electrical levels: Level 1 unqualified for any voltage, Level 2 qualified for 750 volts or less, Level 3 qualified for voltages up to 35 kV, and Level 4 for line clearance, qualified for all voltages. See the TCI Magazine article. A standard is not a law unless a regulator adopts it.

Canada

Workplace safety is provincial, so there is no single national rule.

British Columbia

Part 19 of the Occupational Health and Safety Regulation has a section on tree pruning and falling near energized conductors. It says that tree pruning or falling within the Table 19-1A distances of overhead energized high voltage conductors must be carried out by a worker authorized by the owner of the power system. It also says the work is not permitted inside those distances unless a certified utility arborist or a qualified electrical worker is on site and directing the work, and at least one more qualified person trained in emergency rescue is present.

The regulation defines a certified utility arborist as a person who has completed a course of instruction, has at least 1,200 hours of practical experience and is certified by an authority acceptable to WorkSafeBC. Other parts of the section say that:

A qualified person authorized by the owner of the power system must inspect the worksite first.
Work in a hazardous area does not start until the owner assures that any reclose feature is disabled and workers are told the conductor voltages.
An apprentice utility arborist works to larger limits than a certified one, unless in the presence of and under the direct supervision of a certified utility arborist.
Insulated hand tools and insulated aerial devices must be kept clean and dielectrically tested to a standard acceptable to WorkSafeBC.

The tables are in the regulation. Table 19-1A gives, for example, 3 metres (10 feet) for over 750 V to 75 kV, phase to phase. Table 19-3 sets separate limits for certified utility arborists and apprentices. The full text is in Part 19 on the WorkSafeBC site.

Ontario

Skilled Trades Ontario lists Utility Arborist as a trade. It says the trade prunes, rigs or moves tree branches and woody vegetation that is in proximity to, or could contact, electrical apparatus. Training is generally 6,000 hours, about three years: 5,340 hours on the job and 660 in school. The page says the trade is non-compulsory, so the certificate does not need renewing. See the Utility Arborist trade page.

United Kingdom

The Health and Safety Executive publishes guidance note GS6, Avoiding danger from overhead power lines. It says it is primarily aimed at employers and employees supervising or in control of work near live overhead lines. It says to manage the risks when work is within 10 m, measured at ground level horizontally from below the nearest wire. It adds that the line's owner can advise on safe clearance distances. See HSE GS6.

HSE's tree work page repeats the 10 m trigger and tells readers to seek specialist advice from the power line owner, the Network Operator, before work within it. It also counts machines that could fall within 10 m, such as MEWPs and cranes. It says the first choice is to work dead, and that any decision to work live must be justified and documented under the Electricity at Work Regulations. It says to work only as the Network Operator recommends, using appropriately qualified and competent people, and that the Network Operator may arrange a specialised utility arboricultural contractor. See HSE on power lines and tree work.

Australia

Electrical safety is a state matter. Energy Safe Victoria is the example used here.

Energy Safe says vegetation workers face three different sets of requirements, depending on whether they work for a private company or person, a local council, or a Victorian Electricity Supply Industry company. For private work it recommends a 3 m No Go Zone. It adds that private contractors must at a minimum comply with Regulations 614, 616, 617 and 618 of the Electricity Safety (General) Regulations 2019. See Energy Safe Victoria on tree workers near powerlines.

Its page on managing trees says Regulation 614 sets minimum distances from electric lines for a person, tool, equipment, vehicle and elevating work platform, and Regulation 616 sets distances for vegetation being pruned. A person is exempt from those distances only if they work for a Responsible Person, hold a current certificate from a training course in tree clearing approved by Energy Safe, and comply with the Blue Book and the Vegetation Management Rules. The page also says only authorised powerline pruning contractors should prune trees touching or close to power lines. See Energy Safe on managing trees near powerlines.

The Electrical Safety Rules for vegetation management work, dated September 1, 2013, define a vegetation management worker as someone who has completed an Energy Safe approved training course, has the knowledge or experience for the duty, and is endorsed in writing by an organisation such as the employer. They say a trainee working toward the Certificate II in ESI Powerline Vegetation Control must be effectively supervised by such a worker. See the Electrical Safety Rules PDF. Rules in other states differ.

New Zealand

The Electrical Code of Practice for Electrical Safe Distances, NZECP 34:2001, is published by WorkSafe. Clause 1.1.4 says it does not apply to hazards from trees. A network company page says the Electricity (Hazards from Trees) Regulations 2003 put growth-zone duties on tree owners, and that they were updated in October 2024.

The code does cover mobile plant and people near live parts. Clause 5.2.1 says the distance between any live overhead line and any part of any mobile plant or load carried shall be at least 4.0 metres, unless the operator has written consent from the line owner for a reduced distance. Clause 9.2.1 says non-competent persons without the owner's consent have a limit of 4 m for circuits of 110 kV and below, and 6 m above that. Clause 5.5.1 lets a competent employee operating mobile plant work closer under the safety practices of the line owner. See NZECP 34:2001 on the WorkSafe site and the Centralines page on trees.

At a glance

Country	Source named	Who it speaks to
US	OSHA 1910.269, 1910.333	Qualified and non-qualified trimmers
Canada	BC Part 19; Ontario trade page	Utility arborists, owner-authorised workers
UK	HSE GS6	Employers and supervisors; line owner advises
Australia	Energy Safe Victoria	Private, council and utility work differ
New Zealand	NZECP 34:2001	Mobile plant and persons; trees are separate

The wider rules by country are in safety rules by country, and aerial lifts used near lines are in bucket trucks and EWPs.