CTSP Wood Chipper Safety — Questions and Answers
Question 1: According to ANSI Z133, what is the minimum safe distance a bystander must maintain from a wood chipper during operation?
- 10 feet (3 m)
- 25 feet (7.6 m)
- 50 feet (15 m) (Correct answer)
- 100 feet (30 m)
Correct answer: 50 feet (15 m)
ANSI Z133 requires bystanders to stay at least 50 feet (15 m) from an operating chipper to avoid being struck by ejected material. Shorter distances may be acceptable for crew members actively feeding material, but bystanders must remain at 50 feet.
Question 2: Which type of clothing presents the greatest entanglement hazard when operating a wood chipper?
- High-visibility vest with hook-and-loop closures
- Loose-fitting jacket with drawstrings or frayed edges (Correct answer)
- Snug-fitting long-sleeve shirt
- Chaps worn over work pants
Correct answer: Loose-fitting jacket with drawstrings or frayed edges
Loose-fitting garments with drawstrings, frayed edges, or dangling cords can catch on brush or the chipper's feed mechanism and pull the operator into the infeed chute. ANSI Z133 requires workers to avoid loose clothing near chippers.
Question 3: A crew member notices the chipper's infeed chute is jammed with a large branch. What is the correct first action?
- Push the branch harder using a smaller stick
- Use hands to dislodge the jam while the machine is running
- Immediately disengage the feed control and follow the manufacturer's lockout/tagout procedure (Correct answer)
- Reverse the chipper blades using the reverse switch while standing at the infeed
Correct answer: Immediately disengage the feed control and follow the manufacturer's lockout/tagout procedure
Any jam must be cleared only after disengaging the feed control and following lockout/tagout procedures. Attempting to clear a jam on a running chipper is a leading cause of fatal entanglement injuries. Manufacturer procedures must be followed before any contact with jammed material.
Question 4: Under ANSI Z133, which of the following practices is REQUIRED when hand-feeding brush into a wood chipper?
- Feed from the side of the chute, not directly behind the material (Correct answer)
- Keep both hands on the material until it is fully pulled in
- Always use bare hands for better grip and control
- Stand directly behind the infeed chute for maximum leverage
Correct answer: Feed from the side of the chute, not directly behind the material
Operators must feed from the side of the infeed chute, not directly behind the material being fed. This positioning allows the worker to release the material and step away if the chipper begins to pull too aggressively, reducing the risk of entanglement.
Question 5: What is the purpose of the emergency bar or emergency stop bar found on most modern wood chippers?
- It locks the feed roller at a fixed speed to prevent acceleration
- It reverses the infeed rollers when struck by a worker being pulled in (Correct answer)
- It increases blade speed to quickly clear a jam
- It triggers an audible alarm to warn bystanders
Correct answer: It reverses the infeed rollers when struck by a worker being pulled in
The emergency bar (also called a panic bar or anti-kickback bar) surrounds the infeed opening. When struck by a worker being pulled into the machine, it reverses the feed rollers, releasing the person. Workers must be trained on its location and function before operating.
Question 6: According to ANSI Z133, who is responsible for conducting a pre-operation inspection of a wood chipper before each shift?
- The equipment manufacturer's designated service technician
- Any crew member assigned to operate or work near the chipper that day (Correct answer)
- The safety officer at the company's main office
- The crew leader only — workers are not authorized to inspect equipment
Correct answer: Any crew member assigned to operate or work near the chipper that day
ANSI Z133 requires that equipment be inspected by the operator or a designated crew member before each use. Pre-operation checks cover safety guards, emergency stops, feed controls, and blade condition. This responsibility falls on those who will operate or work near the machine that shift.
CTSP Wood Chipper Safety
According to ANSI Z133, what is the minimum safe distance a bystander must maintain from a wood chipper during operation?