Arborist Safety Practice Questions

Correct answer: C. The climber calls “stand clear” and waits for an “all clear” reply from below

Tree crews use a command-and-response system: the worker aloft gives a clear command and does not cut until someone below answers that the drop zone is clear. OSHA's tree care guidance gives “stand clear” from the climber and “all clear” from the ground as its example. A worker being out of sight, the sound of a saw starting, or a shout after the limb is already falling does not confirm that everyone is out of the drop zone.

• A: Being out of the climber's sight does not confirm the worker is clear of the drop zone; the climber needs a spoken reply.
• B: A saw starting is not a command and gives no confirmed warning of when the limb will drop.
• D: A warning given after the cut leaves no time to clear the drop zone; the exchange must be completed before cutting.

Source: Solutions for Tree Care Hazards (OSHA 3940), Occupational Safety and Health Administration (OSHA)

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Correct answer: A. Advanced decay inside the wood that may weaken the trunk or roots

Mushrooms, conks and brackets are the fruiting bodies of wood-decay fungi, and when they grow on the root flare, stem or branches they indicate advanced decay inside. Decay reduces the strength of the wood that a climber or rigging system would rely on, so the tree needs further evaluation before anyone climbs it. Conks are not bark-surface growths, callus tissue, or a sign of nutrient shortage.

• B: Conks are produced by fungi that are decaying the wood; they are not harmless bark-surface growths.
• C: Callus (woundwood) is tree tissue closing over a wound, not a shelf-like fungal structure.
• D: Fertilizer does not address decay, and conks are not a symptom of nutrient shortage.

Source: National Tree Climbing Guide (2015 Electronic Edition), USDA Forest Service

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Correct answer: C. 10 feet (305 cm)

For an unqualified person working in an elevated position, OSHA's electrical work-practice rule requires that neither the person nor the longest conductive object they may contact get closer than 10 feet (305 cm) to unguarded, energized overhead lines at 50 kV or less to ground. The distance increases by 4 inches for every 10 kV above 50 kV. Shorter approach distances apply only to qualified persons trained and equipped for that work.

• A: Three feet is far inside the minimum distance for an unqualified person.
• B: Six feet is not the OSHA distance for unqualified persons; the minimum is 10 feet at 50 kV or less.
• D: Staying 20 feet away is more conservative, but the minimum the rule sets at 50 kV or less is 10 feet.

Sources: 29 CFR 1910.333 - Selection and use of work practices, Occupational Safety and Health Administration (OSHA) ; 29 CFR 1910.333 - Selection and use of work practices, Occupational Safety and Health Administration (OSHA)

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Correct answer: D. Standing to the side of the infeed chute while feeding material

OSHA's tree care guidance tells chipper operators to stand to the side when feeding material, which keeps the body out of line with the infeed if a branch catches clothing. The same guidance calls for close-fitting clothing and gloves without cuffs, and for using larger pieces to feed in small branches rather than hands. Standing in front of the chute, cuffed gloves, and pushing material by hand all increase the caught-in hazard.

• A: Standing directly in front of the chute puts the body in line with material being pulled in by the feed rollers.
• B: Gloves with cuffs can be snagged by branches; OSHA recommends gloves without cuffs.
• C: Hands should stay out of the infeed; small pieces should be pushed in with larger pieces of brush.

Sources: Solutions for Tree Care Hazards (OSHA 3940), Occupational Safety and Health Administration (OSHA) ; Solutions for Tree Care Hazards (OSHA 3940), Occupational Safety and Health Administration (OSHA) ; Solutions for Tree Care Hazards (OSHA 3940), Occupational Safety and Health Administration (OSHA)

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Correct answer: D. Each leg, from the top of the thigh down to the top of the boot

The logging standard requires each chain saw operator to wear leg protection of a cut-resistant material, for example ballistic nylon, that on each leg covers the whole length of the thigh and continues down to the top of the boot. A moving chain can reach either leg above or below the knee, so partial or one-leg coverage leaves exposed areas. The rule has narrow exceptions, such as a climber whose employer shows that leg protection would create a greater hazard.

• A: Coverage that stops at the knee leaves the lower leg exposed to the chain.
• B: Covering only the shin of one leg leaves both thighs and the other leg exposed.
• C: The rule requires protection on each leg, not just the leg usually nearest the bar.

Source: 29 CFR 1910.266 - Logging operations, Occupational Safety and Health Administration (OSHA)

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Correct answer: A. With the climbing line plus a work-positioning lanyard, as two separate attachments

OSHA's tree care hazard bulletin lists, among the things climbers should be trained on, using a second means of fall protection along with the arborist climbing line, for example a work-positioning lanyard or another climbing line, and the Forest Service climbing guide requires at least two systems whenever a chain saw is used in a tree, one of which must be cut-resistant, such as a steel-core lanyard or chain. If the saw damages one attachment, the other still holds the climber. A single attachment has no backup, and anchoring to the piece being cut is never acceptable.

• B: A single climbing line has no backup if the saw contacts it.
• C: A lanyard alone is a single attachment with no backup if it is cut or fails.
• D: The anchor would fall with the limb once it is cut free.

Sources: Tree Care Work: Falls and Falling Object Hazards (Hazard Bulletin HB-3731), Occupational Safety and Health Administration (OSHA) ; National Tree Climbing Guide (2015 Electronic Edition), USDA Forest Service ; National Tree Climbing Guide (2015 Electronic Edition), USDA Forest Service

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Correct answer: D. Adding another wrap of the line around the device

A lowering device works like a capstan: the friction it produces rises with the angle of rope wrapped around it, so each added wrap gives the ground worker more holding power for the same pull on the tail. Taking a wrap off does the opposite. A pulley at the rigging point reduces friction aloft rather than adding it, and a longer rope changes how much energy the system absorbs, not the friction at the device.

• A: A pulley is designed to reduce friction at the rigging point, which leaves more of the load for the ground worker to hold.
• B: Rope length affects how much energy the system absorbs, not how much friction the lowering device creates.
• C: Removing a wrap reduces the wrap angle and therefore the friction.

Sources: Dynamic parameters of lowering loads at gradual tree felling (Journal of Forest Science 71(2): 86-98, 2025), Czech Academy of Agricultural Sciences ; Dynamic parameters of lowering loads at gradual tree felling (Journal of Forest Science 71(2): 86-98, 2025), Czech Academy of Agricultural Sciences

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Correct answer: C. Diagonally back and away, about 45 degrees off the line of fall

OSHA requires the retreat path to run diagonally away from the expected felling line, and its logging guidance shows safe retreat at about 45 degrees to the rear on either side. Retreating straight back puts the sawyer in line with a butt that can kick back off the stump. Paths straight to the side or forward keep the sawyer closer to where the tree, its limbs, or debris thrown back from other trees may land.

• A: OSHA's guidance warns never to move directly behind the tree, where the butt can kick back during the fall.
• B: A path at a right angle keeps the sawyer close to the stump and the side of the falling tree.
• D: Moving forward heads toward the falling crown and the landing area.

Sources: 29 CFR 1910.266 - Logging operations, Occupational Safety and Health Administration (OSHA) ; Logging eTool: Felling Trees - Retreat Path, Occupational Safety and Health Administration (OSHA) ; Logging eTool: Felling Trees - Retreat Path, Occupational Safety and Health Administration (OSHA)

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Correct answer: A. Confirm cell coverage and make sure every worker knows the site address

OSHA's hazard bulletin says emergency procedures should be in place before tree work starts, including finding out whether the site has cell phone coverage and verifying that every worker knows the worksite address so any of them can summon help. Limiting that knowledge to the crew leader fails if he is the one injured, and planning after an injury wastes critical time. A map app is no help where there is no coverage.

• B: If the crew leader is the injured worker, no one else can direct emergency services to the site.
• C: Emergency procedures should be in place before work starts; deciding after an injury delays care.
• D: A phone app cannot help if the site has no cell coverage, which is why coverage should be checked in advance.

Sources: Tree Care Work: Falls and Falling Object Hazards (Hazard Bulletin HB-3731), Occupational Safety and Health Administration (OSHA) ; Tree Care Work: Falls and Falling Object Hazards (Hazard Bulletin HB-3731), Occupational Safety and Health Administration (OSHA)

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Correct answer: D. New equipment is introduced that requires different safety-related work practices

The standard requires additional training when supervision or annual inspections show an employee is not following required safety-related work practices, when new technology, new types of equipment or changed procedures call for different practices, and when an employee must use practices not normally used in the regular job. OSHA treats tasks done less often than once a year as needing retraining first. A safe year, a new supervisor, or identical equipment does not by itself trigger retraining.

• A: An injury-free record is not a retraining trigger; non-compliance found through supervision or inspection is.
• B: A change of supervisor does not change the work practices the trimmer must use.
• C: Identical equipment does not call for different safety-related work practices.

Sources: 29 CFR 1910.269 - Electric power generation, transmission, and distribution, Occupational Safety and Health Administration (OSHA) ; 29 CFR 1910.269 - Electric power generation, transmission, and distribution, Occupational Safety and Health Administration (OSHA) ; 29 CFR 1910.269 - Electric power generation, transmission, and distribution, Occupational Safety and Health Administration (OSHA)

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