Job Hazard Analysis: Tree trimming

A general example for this task. Your JHA should reflect your crew, equipment and site — review it with a competent person before work starts.

Steps, hazards and controls

1. 1. Walk the site and set up the work zone

   • Overhead power lines near or touching the treeHigh
     • Look up and locate every line before any work starts. Treat all lines as energized.
     • If any limb or tool could come within 10 ft of a line, stop and call the utility or a qualified line-clearance crew.
     • Mark the 10-ft no-go zone and tell every worker where it is.
   • Falling limbs hitting pedestrians, cars, or crewHigh
     • Set a drop zone at least twice the height of the cut and block it with cones and caution tape.
     • Post a ground worker to keep people out. Use a flagger if work blocks a road lane.
     • Move cars, furniture, and other property out of the drop zone.
   • Dead, cracked, or rotten limbs and wasp or bee nestsMedium
     • Inspect the tree from the ground for dead wood, splits, hangers, and nests before climbing or cutting.
     • Remove hanging broken limbs first from a safe position, or skip the tree and tell the supervisor.
     • Ask workers about bee or wasp allergies and keep their epinephrine pen on site.

2. 2. Inspect and fuel chainsaws, pole saws, and the chipper

   • Gasoline fire while fueling a hot chainsawMedium
     • Shut the saw off and let it cool before fueling. No smoking within 50 ft.
     • Use approved safety gas cans and fuel on bare ground, then move 10 ft away before starting.
     • Keep a fire extinguisher on the truck.
   • Defective saw causing kickback or loss of controlHigh
     • Check the chain brake, chain catcher, throttle lock, sharp chain, and correct chain tension before each shift.
     • Tag and remove from service any saw with a broken guard or brake.

3. 3. Prune low limbs from the ground with hand pruners and pole saws

   • Cut limbs falling on the operatorMedium
     • Stand to the side of the limb, never directly under it, and plan an escape path.
     • Cut large limbs in small sections using the three-cut method.
     • Wear a hard hat and safety glasses.
   • Neck and shoulder strain from holding a pole saw overheadLow
     • Use the shortest pole length that reaches the cut and rotate workers every 30 minutes.
   • Pole saw contacting an overhead lineHigh
     • Never use a metal pole. Use a fiberglass pole and keep the whole pole and limb 10 ft from all lines.

4. 4. Cut high limbs from an extension ladder or aerial lift

   • Fall from a ladder when a limb kicks back or the ladder shiftsHigh
     • Use an aerial lift instead of a ladder when possible.
     • Set a fiberglass extension ladder on firm, level ground at a 4-to-1 angle, tied off or held by a ground worker. Never lean it on the limb being cut.
     • Keep three points of contact and do not run a chainsaw from a ladder. Use a hand saw or pole saw on ladders.
   • Fall from an aerial lift bucket or tip-overHigh
     • Inspect the lift before use, set outriggers on pads, and stay off soft ground and slopes.
     • Wear a full-body harness with a short lanyard clipped to the bucket anchor. Never tie off to the tree.
     • Only trained, authorized operators run the lift. Never exceed the rated load.
   • Chainsaw kickback cutting the operatorHigh
     • Hold the saw with both hands, cut below shoulder height, and avoid cutting with the bar tip.
     • Wear chainsaw chaps, face screen, and hearing protection.

5. 5. Drag limbs and feed brush into the chipper

   • Getting pulled into the chipper feed rollersHigh
     • Test the feed control bar and emergency stop before use.
     • Feed butt end first from the side of the chute and let go once the rollers grab. Push short pieces with a long branch, never your hands or feet.
     • No loose clothing, gloves with cuffs, or dangling straps near the chute.
   • Flying chips and loud noiseMedium
     • Point the discharge chute into the truck or away from people.
     • Wear safety glasses with a face screen and earplugs or earmuffs.
   • Back strain from dragging heavy limbsMedium
     • Cut limbs into manageable lengths and use two people for heavy pieces.

6. 6. Clean up the site and load equipment

   • Trips on brush, ropes, and sawdustLow
     • Rake and blow walkways clear before removing cones and tape.
   • Heat illness during long shifts in hot weatherMedium
     • Drink water every 15 minutes, take breaks in the shade, and let new workers build up to full days.
     • Watch each other for dizziness, confusion, or heavy sweating and stop work right away if seen.
   • Cuts from chainsaw chain while loadingLow
     • Put scabbards on saw bars and strap equipment down in the truck.