GISO Article 12, sections 3420 to 3428: where the general orders bite
8 CCR Article 12, sections 3420 to 3428, applies to work performed and equipment used in tree and ornamental palm maintenance and removal, with no line clearance exception. Section 3423(c) sends proximity work above 600 volts to Article 38. Article 12 still governs the climbing system, the saw, the chipper and the felling cut.
A line clearance crew spends the morning inside Article 38 of the High-Voltage Electrical Safety Orders, working a 12 kV primary at the mandated distance. At 11:00 the same crew moves two properties down to take out a dead coast live oak in a back yard, forty feet from the nearest service drop. That tree sits outside Article 38 entirely. Article 12 of the General Industry Safety Orders has nine sections about it, and it had nine sections about the morning's work too.
This is the article that governs tree work in California on both kinds of day. It runs from section 3420 to section 3428, sits in Subchapter 7, Group 3, General Plant Equipment and Special Operations, and is headed Tree Work, Maintenance or Removal.
Nine sections, and what each one governs
Section | Heading | What it binds |
Scope and Definition | The work the article reaches, and 38 defined entries the rest of it runs on | |
General | Program, supervision, training, briefing, inspection, water, traffic, rescue, first aid, noise | |
Ropes and Tree Worker Climbing Equipment | Saddle approval, line strength and diameter, inspection, storage, climbing spurs | |
Electrical Hazards, General | Instruction near conductors, the 10 foot and 1 foot lines, the handoff to Article 38 | |
Mobile Equipment | Vehicles, aerial devices, and twelve brush chipper requirements | |
Portable Power Hand Tools | Power saws, in twelve numbered paragraphs | |
Hand Tools | Carrying, throwing, chopping tools, pole pruners and pole saws | |
Safe Work Procedures | Climbing and access, pruning and removal, felling, bucking, cabling and lightning protection | |
Stump Cutters | Guarding, and protective equipment in the immediate area |
Appendix A is still listed on the article's table of contents, and what it says there is "(Repealed)."
The scope sentence has no line clearance exception
(a) Scope. This standard applies to work performed and equipment used in tree and ornamental palm maintenance and removal.
That is all of section 3420(a). It names no industry, no employer type and no voltage. Two notes follow it. Note 1 sends date palm fall protection and date palm ladders to sections 3458 and 3458.1, which is why the article defines an ornamental palm as one grown for landscaping rather than for fruit. Note 2 does the electrical handoff:
NOTE 2: For line clearance tree trimming operations in proximity to high voltage energized conductors, refer to the provisions of Article 38 of the High-Voltage Electrical Safety Orders, Title 8, California Code of Regulations.
What that note moves is the proximity work, and section 3423(c) is the operative version of it. The rest of the article stays where it is. A crew holding the line clearance credential is still climbing under section 3427, still tied in under section 3422, still feeding a chipper under section 3424(c) and still cutting a notch under section 3427(c).
Article 38 and Article 12 are wired to each other in both directions, and an appeals decision has already sustained a serious citation under section 3427 against an employer whose employee was a qualified line clearance tree trimmer.
Section 3421 is mostly a switchboard
Section 3421 has fourteen subsections, lettered (a) through (n). Five of them do not state a requirement so much as hand the reader an address elsewhere in Title 8.
Subsection | Subject | Where it sends you |
(a) | Injury and Illness Prevention Program | |
(i) | Potable water | |
(j) | Traffic control | Sections 1598 and 1599 of the Construction Safety Orders |
(k) | Refilling engine fuel tanks | |
(n) | Hearing protection and training |
Subsection (j) is the pointer that crosses from one set of safety orders into another. A general industry crew pruning a street tree owes traffic control written in the Construction Safety Orders, section 1598 being Traffic Control for Public Streets and Highways and section 1599 being Flaggers. Two more subsections set duties with their own pages here. Subsection (l) requires the employer to establish rescue procedures and to train in aerial rescue where job assignments may require it.
Subsection (m) sets the first aid and CPR requirement, including a 90 day clock on new hires. The four subsections that put a named qualified tree worker at the site, in the briefing, over the daily inspection and behind the training record are (b), (f), (h) and (d), and what each of those asks of one person is set out separately.
The training list, and the three things that start it again
Section 3421(c) is an open list with a floor under it:
Employees shall be trained and instructed in areas that include, but are not limited to the following: (1) The hazards involved in their job assignments. (2) The proper and safe use of all equipment, including, but not limited to, safety equipment and personal protective equipment. (3) The identification of, and preventive measures relating to, common poisonous plants and harmful animals. (4) Operations that include pesticide and fertilizer applications for employers whose employees are exposed to, or engage in, such operations. (5) The recognition and avoidance of electrical hazards applicable to employee job assignments including the instructions and training outlined in Section 3423 for tree work performed in proximity to energized power lines and conductors.
Item (3) is the only one with no equipment in it, and in California it means poison oak and yellowjackets. Item (5) is the hinge into the electrical section.
Subsection (e) then names three events that oblige the employer to provide refresher or additional training. An employee observed to violate a requirement of the article triggers it. An employee involved in an accident or a near miss incident triggers it, which means a limb that lands in the drop zone with nobody under it still generates a training obligation.
And a new job assignment involving equipment, machinery, tools or work practices the employee is unfamiliar with triggers it. Each of the three stands on the event alone, and each is something a foreman can see happen. Whether the resulting session leaves a trace is a records question, and what that file has to contain is a page of its own.
What every worker near a conductor has to be told
Section 3423(a) is a training subsection, not an approach distance subsection. It binds everyone engaged in tree work in proximity to electrical equipment and conductors, and it lists four things they have to be instructed about:
(1) To consider all such equipment to be energized with potentially fatal voltages, never to be touched (contacted) either directly or indirectly. (2) Electrical shock will occur when a person, by either direct contact or indirect contact with an energized electrical conductor, energized tree limb, tool, equipment, or other object, provides a path for the flow of electricity to a grounded object or to the ground itself. Simultaneous contact with two energized conductors phase to phase will also cause electric shock that may result in serious or fatal injury. (3) Electrical shock may occur as a result of ground fault when a person stands near a grounded object. For example, if an uninsulated aerial device with its outriggers down comes into contact with a conductor. (4) In the event of a downed energized electrical conductor or energized grounded object, there exists the hazard of step potential.
The regulation supplies its own worked example in (3): an uninsulated aerial device, outriggers down, touching a conductor. Step potential in (4) is defined back in section 3420(b) as the voltage difference between the feet of a person standing near an energized grounded object.
Two details about the trigger are worth holding. First, subsections (a) and (d) both key on the word "proximity." Section 3420(b) defines that as a zone which widens above 50 kV, so the trigger for this instruction grows with voltage.
The trimming prohibition in section 3423(b)(1) stays at a flat 10 feet whatever the voltage. On a 115 kV line the instruction duty and the rope rule reach out to 12 feet 2 inches. Second, subsection (d) is a one-sentence equipment ban that sits inside the electrical section rather than the rope section:
Metal core rope used in a climbing system shall not be used in proximity to energized electrical equipment and conductors.
A crew that reads section 3422 for its rope rules and stops there will miss it. What subsections (b) and (c) do, and which credential opens which distance, is the subject of a separate page.
What a climbing system has to be made of
Section 3422(a) fixes one number for the whole system: every load bearing component of a climbing system needs a minimum tensile strength of 5,000 pounds. A mechanical ascending device is excepted, and only where it runs with a secondary device that meets the 5,000 pounds. Section 3422(c) then specifies the line itself:
Climbing lines shall be constructed from a synthetic fiber with a minimum rated tensile strength of 5,000 pounds (22.24 kilonewtons [kN]) and shall have a minimum diameter of 1/2 inch (12.7 mm). Maximum working elongation shall not exceed seven percent at a load of 500 pounds (2.22 kN).
A 7/16 inch line is legal under the exception, and only when three things hold at once. The strength and elongation have to match a 1/2 inch line. The manufacturer has to identify the line as suitable for tree climbing, and the line has to be used per the manufacturer's recommendations. The employee has to have been trained in its use. Drop any one condition and the line is out of spec on its diameter.
Three further rules are easy to break without noticing:
Subsection (f) is a one-way door. Use a climbing line for anything other than supporting the worker aloft, beyond raising and lowering tools, and it may never serve as a climbing line again.
Subsection (g) lets a climbing line stay in a tree only while a qualified tree worker is at the job site location. Lunch counts.
Subsection (i)(1), added on April 1, 2018, requires stored rope to be coiled and piled, or suspended, so that air can circulate through the coils. A sealed bin in a truck box is what that rules out.
Strength, inspection and the ban on splicing a climbing line also fill the gaps in the federal rope paragraph, and which five federal provisions California put here instead of in Article 38 is worked through elsewhere.
Before anybody leaves the ground
Section 3427(a)(1) puts the pre-climb inspection on a named person and gives it two objects:
Prior to climbing the tree, the employer shall ensure that the tree, including the root collar, is visually inspected by a qualified tree worker who shall determine and ensure a safe method of entry into the tree. The location of all electrical conductors and equipment within the work area shall be identified in relation to the work being performed.
The root collar is named separately from the tree, and it is the part of the inspection that happens at ground level. The conductor sentence is an Article 12 duty, owed on every tree the article reaches, back yard removals included.
Three requirements follow from there. Working aloft means wearing a tree workers' saddle and having at least two means of being secured, such as a climbing line and a work positioning lanyard. Employees stay tied in or secured from the start of the ascent until the work is done and they are back on the ground. And subsection (a)(4) governs where the tie-in point goes:
The crotch selected for tying-in shall be over the work area as nearly as possible, but located in such a way that a slip or fall would not permit the employee to come in contact with any electrical conductor, equipment or other hazard.
That sentence asks a swing-path question rather than a distance question. It wants to know where the climber ends up after a slip, and on a back yard removal with a service drop down one side the only way to answer it is to stand under the tree and look up.
The drop zone, the command, and the second employee
Before pruning or removal starts, section 3427(b)(1) requires the employer to establish a verbal or visual communication method and to review it in the job briefing. It has to be a command and response system or pre-arranged two-way hand signals, and the regulation offers "stand clear" from aloft and "all clear" from the ground as the sort of thing it means.
Section 3427(b)(2) requires a drop zone to be established before the operation starts, and only a qualified tree worker directly involved in it can tell anyone else the zone is safe to enter. Under a suspended load the zone shuts further: subsection (b)(3) permits only qualified tree workers directly involved in the operation to be inside it.
Then the height rule:
When an employee is elevated above 12 feet in any tree work operations including climbing ladders, climbing into the tree or using an aerial device, a second employee shall be present to render immediate assistance.
Twelve feet is low, and the trigger is the height rather than the voltage or the tool. A one-person truck sent to clear a 15 foot limb off a gutter is out of compliance before the ladder is set. Article 38 imposes a separate second person requirement on line clearance work, and the 2018 amendment to it added a test of normal, unassisted voice communication. Both run at once on a line clearance job.
The crane route into a tree, and the conditions on it
Using a crane to place a climber is permitted, and the permission opens with a limit rather than a method:
Only when a tree cannot be safely accessed by climbing or the use of aerial devices, a qualified tree worker may be hoisted into position by using an approved tree worker's saddle secured to a crane's hook that shall be closed with a positive locking device.
Ten numbered criteria follow. The saddle also goes to an independent line attached above the crane hook. All climbing equipment, lines and rigging need a minimum breaking strength of at least 5,000 pounds. The crane needs a functional load indicating device.
The operator stays at the controls the whole time the worker is attached, and the worker is in continuous communication with the operator or with a qualified signal person under section 5001. Several of the personnel platform rules at section 5004 are pulled across. And the worker comes off the hook before any load goes up:
8. The qualified tree worker shall be detached from the crane while the load is hoisted.
Subsection (a)(1)(B) then adds nine training areas every qualified tree worker on this method has to be competent in, and subsection (a)(1)(C) requires that training to be documented as prescribed by section 3203. The whole crane package arrived as emergency rulemaking on April 29, 2004, was refiled as an emergency that August, and was made permanent by a certificate of compliance filed January 24, 2005. A note under it points back to Article 38 for line clearance operations, which is the second time the article makes that handoff.
The felling cuts are specified in the regulation
Most safety orders stop at outcomes. Section 3427(c)(3) specifies geometry, for any tree over 5 inches in diameter:
A notch and back cut establish a hinge.
The notch is a conventional, Humboldt or open-faced notch as defined in section 3420(b), which is why those three definitions are in the definitions section.
Notch depth does not exceed one-third of the diameter of the tree. On a 30 inch trunk that is 10 inches, and it is a measurement.
The back cut does not penetrate into the predetermined hinge area.
With a conventional or Humboldt notch the back cut sits 1 to 2 inches above the apex. With an open-faced notch, over 70 degrees, it sits at the same level as the apex.
The two saw cuts forming the notch do not cross where they meet.
Subsection (c)(5) adds a nine-item pre-felling assessment covering species and shape, lean, loose overhead material, wind, decay, terrain, protection of persons, property and electrical conductors, and evidence of bees or other wildlife in the tree. Subsection (c)(2) requires a planned escape route for all workers before any cutting starts.
Saws, chippers and stump cutters
Section 3425 is twelve paragraphs on power saws. Four of them change what a climber does with the saw in hand:
Chain saws shall not be drop started. The prohibition and the definition of drop starting both became operative on October 1, 2020, so any training material written before that date predates the ban.
Saws weighing more than fifteen pounds used in trees are supported by a separate line or tool lanyard, except from an aerial lift or where topping or removal leaves no supporting limb.
Chain brakes are engaged or the engine stopped when the saw is carried more than 10 feet. The engine is stopped altogether past 100 feet.
A tree worker running a chain saw in a tree uses a second point of attachment, unless the employer can demonstrate that the second point poses the greater hazard in that particular situation.
Section 3424(c) covers chippers in twelve paragraphs of its own. The one with a number in it is (c)(1): a rotary drum or disk-type chipper without a mechanical infeed system needs an infeed hopper of not less than 85 inches, measured from the blades or knives to ground level over the centerline of the hopper.
Subsection (c)(9) is one sentence, and it is the one broken by habit: climbing equipment, ropes, body belts, harnesses and lanyards are not worn while operating chippers. A climber who comes down, walks to the chipper and starts feeding while still in the saddle is in violation the moment the rotor turns.
Section 3428, the newest section in the article, has two subsections. Stump cutters carry enclosures or guards. Everyone in the immediate area of stump grinding, the operator included, wears protective equipment as required by Article 10. That cross-reference matters more than it looks: the phrase "personal protective equipment" appears five times in Article 12, and section 3428(b) is the only place that says where the equipment itself is specified. What a saw operator actually has to wear is a separate question with its own page.
What changed, and when
Filed | Operative | Register | What the filing did |
11-12-1975 | thirtieth day after | 1975, No. 46 | Article 12 created at sections 3415 to 3418, not consecutive |
04-16-1980 | thirtieth day after | 1980, No. 16 | That article repealed; Article 12 refiled at sections 3420 to 3428 with Appendix A |
08-08-1985 | thirtieth day after | 1985, No. 32 | Amendments across 3420, 3421, 3422, 3423, 3424, 3425, 3426 and 3427 |
04-02-1992 | on filing | 1992, No. 14 | Changes without regulatory effect to 3420(a), 3421(h) and 3422 |
08-04-1995 | 09-03-1995 | 1995, No. 31 | Section 3422 repealed and rewritten |
10-28-1997 | on filing | 1997, No. 44 | Change without regulatory effect to 3423(b) |
04-29-2004 | 04-29-2004 | 2004, No. 18 | Crane access added to 3427(a) as an emergency, made permanent 01-24-2005 |
09-25-2012 | 10-25-2012 | 2012, No. 39 | Sections 3420 through 3427 all amended in one rulemaking |
02-27-2018 | 04-01-2018 | 2018, No. 9 | New 3422(i)(1); 3425(a) reworked; section 3428 filed as a new section |
07-30-2020 | 10-01-2020 | 2020, No. 31 | "Drop starting" defined in 3420(b); 3425(a)(2) amended and (a)(3) added |
Two entries in that table deserve a second look. The September 25, 2012 rulemaking touched every section from 3420 to 3427, and it is the same register entry that put Table 1 into section 2950. Anything written about California tree work before October 25, 2012 should be treated as describing a different article.
The second is section 3428. The 1980 filing created Article 12 "sections 3420-3428 and Appendix A," yet the section 3428 now in force carries exactly one history entry, a new section filed February 27, 2018. The number was reused, and the record on the section's own page begins in 2018. The article's table of contents adds one more line to the story, which is that Appendix A is repealed.
Five questions Article 12 hands to somebody else
The article is thorough about the tree and deliberately thin about the conductor. Five questions a reader arrives with are answered elsewhere.
The question | Where Article 12 sends it |
Approach distance above 600 volts | Section 3423(c) to Article 38, and Table 1 of section 2950 prints the numbers |
A period of training for a credential | Section 3420(b) describes familiarity and stops there; section 2700 is where a clock appears |
A certifying body, an examination or a card | Title 8 names none, and the employer's determination stands in their place |
What a worker wears | Section 3428(b) to Article 10 |
How long a record is kept | Section 3421(d) requires the documentation; section 3427(a)(1)(C) sends crane training records to section 3203, and the retention answer is there |
For the crew in the back yard at 11:00, the practical reading is short. Article 38 went quiet when they left the primary. Article 12 kept running, because it was always about the tree. The root collar inspection, the second employee above 12 feet and the saddle that comes off before anyone feeds the chipper are all owed on a tree no utility has ever heard of.
Further reading
8 CCR 2951: line clearance (tree trimming) operations, subsection by subsection: The Article 38 half of the same day's work, and the appeals decision that shows both articles being enforced against one crew.
Qualified line clearance tree trimmer versus qualified tree worker: The two credentials Article 12 runs on, including the 10 foot and 1 foot lines in section 3423(b).
Table 1 of 8 CCR 2950: the minimum approach distance, and who owes it: Where the distances live once section 3423(c) hands the work across.
Frequently asked questions
Does Article 12 of the General Industry Safety Orders apply to a line clearance crew?
Yes, except for the part section 3423(c) hands across. Section 3420(a) sets the scope as work performed and equipment used in tree and ornamental palm maintenance and removal, with no exception for utility work or for line clearance employers. Note 2 to that subsection refers line clearance tree trimming in proximity to high voltage energized conductors to Article 38 of the High-Voltage Electrical Safety Orders, and section 3423(c) makes that referral operative. Everything else in the article, meaning the climbing system in section 3422, the safe work procedures in section 3427, the chipper rules in section 3424(c) and the saw rules in section 3425, continues to apply to the same crew on the same day.
What are the nine sections of Article 12?
Section 3420 Scope and Definition, section 3421 General, section 3422 Ropes and Tree Worker Climbing Equipment, section 3423 Electrical Hazards General, section 3424 Mobile Equipment, section 3425 Portable Power Hand Tools, section 3426 Hand Tools, section 3427 Safe Work Procedures, and section 3428 Stump Cutters. The article also carries an Appendix A, which is shown as repealed on the article's table of contents.
What does Article 12 require a climbing line to be?
Section 3422(c) requires climbing lines to be constructed from a synthetic fiber with a minimum rated tensile strength of 5,000 pounds and a minimum diameter of 1/2 inch, with maximum working elongation not exceeding seven percent at a load of 500 pounds. An exception permits a line of not less than 7/16 inch, but only where the strength and elongation requirements meet those of a 1/2 inch line, the manufacturer identifies the line as suitable for tree climbing and it is used per the manufacturer's recommendations, and the employee has been trained in its use. All three conditions have to hold together.
When does Article 12 require a second employee on site?
Section 3427(b)(9) requires a second employee to be present to render immediate assistance whenever an employee is elevated above 12 feet in any tree work operation, including climbing ladders, climbing into the tree or using an aerial device. The trigger is the height, not the voltage, so it reaches a removal nowhere near a conductor. Article 38 sets a separate second person requirement for line clearance work, and the two run at the same time.
Does Article 12 set approach distances?
Only two, and only in section 3423(b). Employees may not perform tree trimming within 10 feet of high voltage energized power lines and conductors unless they meet subsection (c), and a qualified tree worker may work within 10 feet but no closer than 1 foot of lines at 600 volts or less. Above 600 volts, section 3423(c) requires the work to be conducted under Article 38, and Table 1 of section 2950 is where the voltage-by-voltage distances are printed. Article 12 prints no table of its own.
