OSEA Safety Blog

Chain Saw Safety

Monday, May 4, 2020 Greg Santo

Safety and the Chainsaw

A chainsaw is a great tool, one of the most powerful tools that can be used, but like all power tools it is dangerous and according to the Journal of Forensic Sciences has caused approximately 28,000 injuries per year, some fatal. The majority of the injuries involve the hands and lower extremities with less than 10% involving injuries to the head and neck regions.

The most common hazards associated with chainsaws are injuries caused by kickback, pushback, and pull-in. Kickback is the most common and poses the greatest hazard. Kickback occurs when the rotating chain is stopped suddenly by contact with a more solid area throwing the saw rapidly backward toward the operator.

The cause of most injuries can be traced to improper use of the saw, inadequate training or poor judgment on part of the operator. You should use all tools with caution. Chainsaws are no exception, they're powerful tools. A saw chain at full throttle moves at over 50 miles per hour and commands extra attention to safety.

There are several safety features you will commonly find on a homeowner-model saw. Some features below are available only on gas-powered saws:

  • Chain brake - designed to stop the chain if kickback occurs.
  • Chain catcher - helps reduce the risk of a broken or derailed chain striking the operator
  • Low-kickback chain - includes links designed to reduce the risk of kickback.
  • Low-kickback bar - has a small tip radius to reduce the risk of kickback.
  • Bar tip guard - covers the bar tip to keep the tip of the saw from touching the wood, reducing the risk of kickback. This is standard on most new chainsaws purchased and can be an after-market product installed for safety.
  • Hand guard - protects your hands from kickback.
  • Chain oiler - provides lubricant to the bar and chain to prevent overheating and binding. Antivibration features - reduces stress to your joints and provides comfort.
  • Throttle lockout trigger - prevents accidental activation of the throttle control; allows the motor to idle without engaging the chain.
  • Stop switch - allows the operator to shut off the saw without releasing the saw.
  • Spark arrester - helps prevent sparks from being expelled by the exhaust and becoming a fire hazard
  • Bumper spikes - help maintain the saw's position against the wood.

Required Personal Protective Equipment

Always follow the manufacturer's instructions for use, maintenance and safety, including safety gear. Consider taking a course in chainsaw use and safety.

Before you even think about cranking the saw and starting to cut, protect yourself. ALWAYS wear protective clothing and gear, including:

  • Leg protection such as chaps or cut-resistant pants
  • Hard hat, Arborist hard hat recommended
  • Gloves with an enhanced gripping surface and cut resistance. Consider anti-vibration gloves to reduce ergonomic stress.
  • Eye protection with side shields and face shield.
  • Hearing protection such as earplugs or earmuffs
  • Boots or shoes with steel toes and non-skid soles

Always follow the manufacturer's instructions for use, maintenance and safety, including safety gear. Consider taking a course in chainsaw use and safety.

Before you even think about cranking the saw and starting to cut, protect yourself. ALWAYS wear protective clothing and gear, including:

  • Leg protection such as chaps or cut-resistant pants
  • Hard hat, Arborist hard hat recommended
  • Gloves with an enhanced gripping surface and cut resistance. Consider anti-vibration gloves to reduce ergonomic stress.
  • Eye protection with side shields and face shield.
  • Hearing protection such as earplugs or earmuffs
  • Boots or shoes with steel toes and non-skid soles

Making the Cut

When cutting trees, you will need to understand the following terms:

  • Felling is the act of cutting down (or dropping) a tree. Look and look again at what you’re going to be cutting — especially where it will fall. Always determine the angle at which the tree will fall and make the correct cuts. Plan a safe place to stand as the tree falls. Falling trees tend to kick straight back. Make sure no one is within a distance of twice the height of the tree you plan to fell. Before you start cutting, plan a clear avenue to escape the falling tree, moving away from the trunk at an angle, not straight back. Clear away obstacles and debris that may cause you to trip.
  • Limbing and bucking are what you do to the tree you just dropped. Just because the tree is down, don't let down your guard. Taking off the limbs (limbing) and cutting the tree into manageable pieces (bucking) still require caution. Always work on the uphill side when cutting. See how the tree is balanced and which way it will move if a supporting branch is cut.
  • Binding, kickback, pushback and pull-in are dangerous situations you face when cutting. In any of these situations the operator loses control of the saw.
  • Binding (or pinching) occurs when the material you're cutting clamps down and stalls the cutting chain inside of the kerf (or cut). Binding can lead to kickback, pushback and pull-in. Be aware of how the weight of the branch or log can shift and bind the saw when you are cutting. Learn cutting techniques that help avoid binding. The proper use of appropriate felling and bucking wedges can also help prevent binding.
  • Kickback occurs when the saw tip touches an object or when the branch or log you're cutting pinches the blade. This causes the reverse action of the guide bar, throwing the saw up and back towards the user. A saw cutting at full throttle can kick back in one-tenth of one second — faster than a person can react. To minimize kickback, never cut with the saw’s tip. Always make sure you know the position of the saw tip and be aware that the upper part of the saw tip is the area most prone to creating kickback. Also consider how cutting the branch or log can cause the weight to shift, potentially pinching the saw.
  • Pushback occurs when the chain at the top of the bar stops suddenly due to pinching or hitting a foreign object when cutting. Pushback instantly sends the saw back toward the user. Minimize pushback by being aware of possible shifts in weight of the material you're cutting that can bind the saw. Cut only one branch or log at a time. When undercutting, draw the blade out of the cut without twisting it.
  • Pull-in occurs when the chain at the bottom of the bar stops suddenly due to pinching or striking a foreign object, immediately drawing the saw forward. To help minimize pull-in, start your cut with bumper spikes set against the branch or log you're cutting and make sure you cut only when the saw is up to full speed. Be aware of weight shifts or situations that can bind the saw.

Basic rules for working with a chainsaw

  • THE THUMB GRIP Keep a steady grip on both handles on the saw. Thumbs and fingers must be completely wrapped around the handles. It is very important to hold the thumb of your left hand under the front handle in order to reduce the force of a possible kickback.
  • CLOSE CONTACT Do not be afraid of the saw. Hold it close to your body for better balance and to make the saw feel less heavy.
  • BALANCE Stand with your feet apart. To achieve the best possible balance, put your left foot slightly in front of your right.
  • BEND YOUR KNEES Spare your back. Do not work with a curved spine, bend your knees instead when working in low positions.
  • MOVING / TRANSPORT The chain must not be rotating when you are moving to another spot. When moving in several steps, you should activate the chain brake or turn off the engine. When you move a longer distance or when transporting, you should fit the guide bar guard.

Chainsaw Dos and Don'ts

Above all, read the owner's manual carefully before operating a chainsaw. The following list is not all-inclusive, merely a reminder to keep safety first at all times.

Do

  • Develop a plan and survey the area before cutting. Diseased woods, density of various woods, nails and other metal objects can cause kickback.
  • Keep the cutting area clear of spectators and pets.
  • Work with a partner if possible.
  • Avoid overhead hazards, such as dead, hanging limbs that may fall and utility lines.
  • Keep the chain clean, sharp and lubricated with the correct oil.
  • Make sure the chain oil supply is full before starting the saw.
  • Be careful of inclines and ground that is uneven.
  • Stand to the side of what you're cutting.
  • Cut at full throttle; bring the saw up to speed before starting cuts.
  • Use a suitable cord when operating an electric saw. Follow the saw manufacturer's instructions for selecting a compatible cord.
  • Keep both hands on the saw handles.
  • Let the saw come to a complete stop before reaching for the chain or bar.
  • Turn off the saw or activate the chain brake when carrying the saw.
  • Carry the saw so that the bar is pointing behind you.

Do Not

  • Do not wear loose clothing.
  • Do not use an electric chainsaw in rain or in a wet or damp area.
  • Do not use the tip to cut.
  • Do not cut with a chainsaw above shoulder height.
  • Do not refuel a hot saw.

The OSHA QuickCard™ on Chain Saw Safety has the following information:

Operating a chain saw is inherently hazardous. Potential injuries can be minimized by using proper personal protective equipment and safe operating procedures.

Before Starting a Chain Saw

  • Check controls, chain tension, and all bolts and handles to ensure that they are functioning properly and that they are adjusted according to the manufacturer's instructions.
  • Make sure that the chain is always sharp, and the lubrication reservoir is full.
  • Start the saw on the ground or on another firm support. Drop starting is never allowed.
  • Start the saw at least 10 feet from the fueling area, with the chain's brake engaged.

Fueling a Chain Saw

  • Use approved containers for transporting fuel to the saw.
  • Dispense fuel at least 10 feet away from any sources of ignition when performing construction activities. No smoking during fueling.
  • Use a funnel or a flexible hose when pouring fuel into the saw.
  • Never attempt to fuel a running or HOT saw.

Chain Saw Safety

  • Clear away dirt, debris, small tree limbs and rocks from the saw's chain path. Look for nails, spikes or other metal in the tree before cutting.
  • Shut off the saw or engage its chain brake when carrying the saw on rough or uneven terrain.
  • Keep your hands on the saw's handles and maintain secure footing while operating the saw.
  • Proper personal protective equipment must be worn when operating the saw, which includes hand, foot, leg, eye, face, hearing and head protection.
  • Do not wear loose-fitting clothing.
  • Be careful that the trunk or tree limbs will not bind against the saw.
  • Watch for branches under tension, they may spring out when cut.
  • Gasoline-powered chain saws must be equipped with a protective device that minimizes chain saw kickback.
  • Be cautious of saw kick-back. To avoid kick-back, do not saw with the tip. If equipped, keep tip guard in place.
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