Solutions for Tree Care Hazards
Traffic Control Drop Zones Chippers Aerial lifts Power Lines 

Risk Factors

Vehicle and pedestrian traffic control 

safety measures are essential to tree 

care operations. Workers can be struck 

by moving vehicles and the traffic zone 

could interfere with pedestrian traffic. 

Workers can be struck by falling trees, 

tree limbs, and hand tools. These falling 

objects have enough force to cause 

serious or even fatal injuries to workers. 

Chipper hazards arise when workers 

manually push material or lean too far 

into the chipper hopper. Workers can 

be injured by material thrown from 

the machine. Chippers also produce 

hazardous noise levels. 

Workers can fall or be thrown from an 

elevated bucket. The major causes of 

injuries and fatalities involving aerial lifts 

are falls, electrocutions, and equipment 

collapses or tip-overs.

Workers can be electrocuted when a 

tree limb, branch, or uninsulated aerial 

lift touches or comes into contact with a 

live electrical power line. 

Prevention Tips

•	 Brief workers on traffic zone safety 

and site setup.

•	 Develop traffic control plans that 

include the proper use of control 

devices. See the U.S. Department of 

Transportation’s Manual on Uniform 

Traffic Control Devices.

•	 Use cones, barricades, and flaggers to 

guide vehicles and pedestrian traffic 

through or around the traffic zone.

•	 Wear high visibility vests.

•	 If operations interfere with traffic, use 

certified flaggers to help manage traffic. 

•	 Provide pedestrians a safe route away 

from activity area.

•	 Use lights at night. 

•	 Use cones or caution barrier tape to 

establish, mark, and manage the drop 

zone. 

•	 Provide training on drop zone entry 

and exit procedures. 

•	 Wear a hard hat and eye protection.

•	 Allow only qualified workers near the 

drop zone. 

•	 Establish and maintain visual or 

audible communication between 

overhead and ground workers.

•	 Use verbal command and response 

exchanges, such as the command 

“stand clear” from the worker aloft 

and the response “all clear” from 

persons below, before cutting and 

dropping limbs.

•	 Train workers to inspect and operate 

chippers.

•	 Always follow the manufacturer’s 

instructions.

•	 Make sure that safety guards, controls, 

and emergency shut-off devices are 

working properly.

•	 Stand to the side when feeding 

materials.

•	 Wear safety glasses, a hard hat and 

hearing protection. 

•	 Wear close-fitting clothing, gloves 

without cuffs, and skid-resistant shoes. 

•	 Stow all ropes and lines away from 

the chipper. 

•	 Feed the cut end in first, and use larger 

pieces to feed in small branches. 

•	 Never reach into the chipper’s in-feed 

chute to un-jam materials while it is 

operating.

•	 Only feed wood material into the 

machine, never rocks or metal. 

•	 Always follow manufacturer’s 

instructions.

•	 Allow only qualified and trained 

workers to operate aerial lifts.

•	 Inspect the lift and worksite before 

each use. 

•	 Set outriggers on pads or on a level, 

solid surface.

•	 Set brakes when outriggers are used.

•	 Watch out for overhead power lines or 

other obstructions.

•	 Use wheel chocks on sloped surfaces.

•	 Use a body harness or a restraining 

belt with a lanyard attached to the 

bucket.

•	 Wear eye protection and a hard hat. 

Do not wear climbing spurs inside 

the bucket.

•	 Tie off to an approved anchor point, 

and stand firmly on the bucket’s floor.

•	 Do not overreach beyond the edge of 

the bucket.

•	 Do not use bucket for material 

handling, unless designed for it.

•	 Train workers to identify and avoid power 

line hazards, before beginning work.

•	 Treat all overhead power lines and 

communication cables as energized. 

Stay at least 10 feet (3 meters) away, 

unless specifically qualified.

•	 Provide proper personal protective 

equipment.

•	 Stay alert. 

•	 If an overhead power line falls near a 

worker or equipment, move away from 

the equipment with short, shuffling 

steps and keeping feet close together.

•	 Do not trim trees in dangerous weather 

conditions.

•	 Do not use corded electric power tools 

in trees near energized power lines.

•	 Never use ladders made of metal 

or other conductive materials near 

overhead power lines. Only use 

wooden ladders or those made of 

synthetic material.

Links

Highway Work Zones Topics Page Tree Care Topics Page Wood Chipper Safety and 

Health Bulletin Aerial Lifts Fact Sheet Electricity and Tree Care Work

www.osha.gov

(800) 321-OSHA (6742)

OSHA 3940-02 2018