You Do Not Have to Touch It

Contact with overhead power lines is the single most common cause of electrical fatalities in construction. The word contact is misleading, because at high voltage the electricity will arc across open air once equipment breaches the limit of approach.

You do not have to touch the line. You have to get close enough, and how close that is depends on a voltage most people on site have never confirmed.

The numbers, and the second table

WorkSafeBC's general limits of approach set the minimum distance for working close to exposed electrical equipment or conductors:

Over 750 V to 75 kV, 3 metres or 10 feet. Over 75 kV to 250 kV, 4.5 metres or 15 feet. Over 250 kV to 550 kV, 6 metres or 20 feet. BC Hydro adds 1 metre for service lines under 750 V.

Those are the figures people quote. What far fewer know is that the regulation itself contains a second and separate table for passing under conductors, with smaller distances: 2 metres for the 750 V to 75 kV band and 3 metres for 75 kV to 250 kV.

So the distance that governs a truck driving beneath a line is not the distance that governs a crew working beside one, and treating the working figure as universal either blocks legitimate access or, worse, gets applied the other way round.

The limit applies to whatever is closest: the worker, the tool, the material or the equipment. A ladder, a scaffold, a boom, a forklift mast, a dump box or a length of pipe all count.

And other provinces set their own tables. Alberta distinguishes insulated from bare conductors at low voltage in a way British Columbia's table does not, so a crew working across provincial lines needs each one rather than the one they memorized.

A downed line is a different number entirely

This is the distinction that matters most in an emergency, and it is where the memorized figure becomes dangerous.

BC Hydro's guidance separates intact equipment from damaged equipment. For intact and undamaged electrical equipment, the WorkSafeBC limits above apply. For down or damaged equipment, and anything in contact with it, the distances are far larger: 10 metres for distribution lines and equipment, and 33 metres for transmission lines and equipment.

A worker who knows the three-metre rule and applies it to a line lying on the ground is more than three times too close for distribution and ten times too close for transmission.

The reason is step potential. Current entering the ground spreads outward, and the voltage difference between one foot and the other can be enough to injure or kill. The ground around a downed line is energised, not just the line.

Which is why the escape instruction is to shuffle rather than walk, keeping the feet together and in contact with the ground, for at least ten metres before taking a normal step.

Anything in contact with the line carries it too, including a vehicle, a fence, a tree or a puddle, and the hazard extends to whatever those things touch.

Know the voltage before you plan the work

The limit cannot be determined without the voltage, and the voltage cannot be determined by looking at the line.

Employers and workers are required to know the voltage carried in lines they work near, and the way to find out is to contact the utility that owns them. BC Hydro operates a line for exactly this.

Until it has been confirmed, work to the conservative figure. BC Hydro's guidance is to stay back at least 3 metres, or 6 metres from a transmission line, until the voltage has been verified, and other guidance uses a larger default still. Choose the larger of whatever applies.

Identification helps with the initial judgement without replacing confirmation. Service lines run from a pole directly to a building and are energised up to 750 V. Transmission lines run pole to pole or tower to tower, or to a substation or a large industrial customer, and the instruction is to stay back at least 6 metres unless the utility has identified the voltage.

Where the line voltage has been confirmed as below 75 kV you may work to 3 metres, and where it is between 75 kV and 250 kV you may work to 4.5 metres.

None of these wires are insulated. The covering on an overhead conductor is weatherproofing, not insulation, and it is never safe to touch.

What happens when you cannot keep the distance

Sometimes the work genuinely cannot be done outside the limit, and the regulation provides a route rather than leaving it to judgement.

Where the minimum distance cannot be maintained, an assurance in writing must be obtained, using WorkSafeBC's assurance of compliance form for Part 19 of the regulation. That is a document from the utility, not a decision made on site.

The utility may also have practical alternatives, including de-energizing the line, installing temporary protective covering, or relocating the conductor for the duration of the work. Those take lead time, which is the argument for identifying the problem at the planning stage.

There is also a trained-worker provision. A worker who has completed a Board-approved course of instruction may work to adjusted limits of approach under specified conditions, including that the equipment is energized to not more than 75 kV.

That provision is narrow, conditional and not a general workaround. It applies to trained workers meeting the stated conditions, not to a crew that decided the distance was impractical.

Where equipment must be worked on rather than worked near, the default legal requirement is complete isolation from the power source, verification that it is de-energized, and lockout.

The equipment that causes it

The incidents are concentrated in a short list of machines, and the common factor is reach.

Cranes and boom trucks, excavators with the boom raised, dump trucks with the box up, elevating work platforms, scaffolding being erected or moved, ladders carried upright, and tree work where both the saw and the tree are inside the limit.

Scaffolds deserve a specific mention because the limits of approach must be maintained for the scaffold itself, and because long components carried horizontally swing into lines during erection.

Dump trucks are the classic because the box goes up when the driver is not looking at the line, often at the end of a load on a site they have used fifty times.

Spotters are the practical control where mechanical equipment operates near lines, and a spotter needs to know the limit, be positioned to judge it, and have the authority to stop the movement.

Ground conditions matter too, since a machine that settles or a surface that gives can move a boom closer without the operator touching a control.

No boot protects you from this

Worth stating plainly on a page that sells footwear, because the misunderstanding is common.

The white rectangle with the orange omega marks footwear tested for electric shock resistance, which is a secondary defense against incidental contact with a live circuit underfoot. It is not protection against contact with an overhead power line, and its resistance degrades with wear and moisture.

Our guide to CSA work boot symbols explains what the mark actually covers, and our guide to work boots for electricians covers selection for electrical trades.

Arc-rated clothing is relevant to arc flash exposure from equipment a worker is deliberately working on, covered in our guide to arc rated and FR clothing under CSA Z462. It does not make a line contact survivable.

Head protection has electrical classes worth understanding, covered in our hard hat safety guide, and the same caveat applies.

The control here is distance, confirmed voltage, and planning. Personal protective equipment sits at the bottom of the hierarchy on every hazard and it is close to irrelevant on this one.

If contact happens

The instructions are counterintuitive and the instinct is wrong in every direction.

If you are in a vehicle or machine that contacts a line, stay in it. The machine and its occupants are generally at the same potential, and the danger arrives at the moment someone creates a path to ground.

Warn everyone to stay back, call emergency services and the utility, and wait. Do not let anyone approach the machine, and do not step down while touching it.

Only leave if there is a fire or another immediate threat, and then jump clear with both feet together so that you are never touching the machine and the ground at the same time, landing with feet together and shuffling away.

From outside, never approach a person in contact with a line or a machine that is in contact. Rescuers become casualties in exactly the pattern that recurs across every energy hazard.

Treat the whole area as energized until the utility confirms otherwise, and keep the public back as well, which is where conspicuity and traffic control become relevant. See our guides to CSA Z96 classes and levels and traffic control person equipment.

For the wider programme see the complete PPE checklist for Canadian workers, our guide to PPE requirements for Canadian construction sites, our guide to who pays for PPE in Canada, our guide to CSA Z1220 first aid kit requirements and our guide to CSA certified versus CSA compliant.

Frequently Asked Questions

How far back do I have to stay from a power line?

In British Columbia, 3 metres for lines over 750 V up to 75 kV, 4.5 metres over 75 kV to 250 kV, and 6 metres over 250 kV to 550 kV, with 1 metre for service lines under 750 V. The limit applies to whichever is closest: the worker, the tool, the material or the equipment. Other provinces set their own tables.

Is the distance different for driving underneath?

Yes, and this surprises people. The regulation contains a separate table for passing under exposed conductors, with smaller distances than the working-close figures, at 2 metres for the 750 V to 75 kV band and 3 metres for 75 kV to 250 kV.

What if a line is down?

Stay much further back. BC Hydro's guidance is 10 metres for downed or damaged distribution lines and equipment, and 33 metres for transmission, including anything in contact with them. The ground itself is energized, so leave the area by shuffling with feet together rather than walking.

Do I have to touch the line to be hurt?

No. High-voltage electricity can arc across open air once equipment breaches the limit of approach, which is why the limits exist as distances rather than as a rule against contact. Overhead conductors are also not insulated; any covering is weatherproofing.

What if the work cannot be done outside the limit?

An assurance in writing must be obtained from the utility, using WorkSafeBC's assurance of compliance form for Part 19. The utility may also be able to de-energize, cover or relocate the line. There is a narrow provision allowing workers with Board-approved training to work to adjusted limits under specified conditions, which is not a general workaround.

Will electrical hazard boots protect me?

No. Footwear marked with the white rectangle and orange omega is tested for electric shock resistance as a secondary defense against incidental contact with a live circuit underfoot, and its resistance degrades with wear and moisture. It offers nothing against overhead line contact. The control is distance.

This guide is general workplace safety information and is not training. Limits of approach, clearance distances and the procedures for working inside them are set by provincial regulation and differ between jurisdictions; the figures described here are British Columbia's. Always confirm the voltage with the utility that owns the line, confirm the limits with the occupational health and safety authority that governs your workplace, and never approach a downed line or anything in contact with one.