Chainsaw Chain Safety

Chainsaws are an anomaly among modern power tools. Almost everything else with this much energy behind it is guarded, interlocked or operated remotely. A chainsaw exposes the operator to an unshielded cutting surface travelling at more than 20 metres per second, and relies almost entirely on the operator's technique, awareness and equipment to prevent serious injury.

This page covers the mechanics behind that risk: how the cutter and depth gauge actually work, why the chain sometimes drives the saw instead of the wood, what chain shot is, and which Australian standards apply to the gear that protects you. It is written for both the domestic user clearing storm debris and the operator who cuts every week.

Quick reference

The sections below explain why each of those points matters. Reading them is the difference between following rules and understanding the machine.

1. Why chainsaws are different

Whether the saw is used by a professional arborist suspended in a canopy or a homeowner clearing a fallen limb, the fundamental mechanics are unchanged: a handheld power source driving a segmented cutting chain fast enough to sever tissue, bone and protective fibres in a fraction of a second.

Chainsaw injuries are rarely minor. The lacerations produced by a running chain are avulsive — they remove tissue rather than simply slicing it, which complicates surgical repair and increases the risk of infection and permanent disability. Chain shot, the high-velocity ejection of chain fragments after a chain breaks, extends the danger zone well beyond the reach of the bar and threatens bystanders as well as the operator.

Operating safely requires a mindset that goes past the user manual. The chain is not just a cutting tool. It is a mechanical system under load, subject to fatigue, thermal expansion and violent reactive forces. This page works through those elements: cutter geometry, chain metallurgy and failure, the physics of kickback, the ballistics of chain shot, and the standards that govern protective equipment in Australia.

Reference standard. The anchoring Australian document for handheld chainsaw use is AS 2727-1997, Chainsaws — Guide to safe working practices (Standards Australia, second edition 1997, prepared by Committee SF/33 Chainsaw Safety). It covers safe use and care, operator training and supervision, protective clothing, common hazards, maintenance schedules and chain sharpening. Where this page and AS 2727 or your saw manufacturer's instructions differ, follow the standard and the manufacturer.

2. The cutting system: cutters, depth gauges, pitch and gauge

To control a chainsaw you first have to understand what is happening between the steel cutter and the wood fibre. "Chain" is a misnomer in functional terms. It is a flexible, continuous loop of miniature planing devices, each designed to scoop a specific volume of fibre out of the kerf.

Cutter geometry and chip formation

A standard chainsaw chain has three primary components riveted together: the drive link, which engages the sprocket and rides in the bar groove; the tie strap, which connects the links; and the cutter, which does the work.

The cutter functions as a curved chisel. As it enters the wood, the leading corner of the top plate severs the cross-grain fibres while the side plate separates the chip from the sidewall of the kerf. The cutter cannot regulate its own depth. Without a limiter, the hook of the cutter would drive progressively deeper into the wood until resistance exceeded either the engine's torque or the chain's tensile strength — stalling the saw or breaking the chain.

That regulation is the job of the depth gauge, often called the raker. It sits immediately ahead of the cutting edge as a non-cutting projection of steel that rides on the bottom of the kerf, and it determines the thickness of the chip the following cutter can remove — typically between 0.025" (0.64 mm) and 0.030" (0.76 mm).

The danger of altered geometry

The relationship between the top of the depth gauge and the top of the cutter is the depth gauge setting, and it is dynamic. As a cutter is filed back, the sloping top plate becomes lower. The depth gauge must therefore be filed down progressively to maintain the correct chip thickness.

The hazard arises when operators file depth gauges too low, chasing faster cutting or simply not knowing the consequence. An excessively lowered depth gauge lets the cutter take a bite thicker than the engine can clear, which sharply increases cutting resistance. The consequence is not merely a stalled engine — it is kinetic energy transferred into the saw body and back toward the operator. When a cutter grabs the wood aggressively because of a low depth gauge, the chain stops momentarily while the engine keeps applying torque. That energy has to go somewhere. Depending on where the cutter is on the bar, it becomes a push, a pull, or rotational kickback.

An improperly lowered depth gauge negates the safety features of low-kickback chains, effectively converting a compliant safety chain into a high-hazard tool. The cutter hooks the fibre instead of slicing it, creating a mechanical lock that drives the bar violently in the direction opposite the chain's travel — toward the operator.

Depth gauge filing technique, the correct sequence and the tools required are covered in our chain sharpening guide.

Pitch and gauge

The structural integrity of a chain is defined by its pitch and its gauge.

• Pitch is the average distance between three consecutive rivets, divided by two (for example 3/8", .325", .404"). Pitch determines the size of the chain and must match both the drive sprocket and the bar nose sprocket. Mismatched pitch causes the chain to ride high on the sprocket teeth, producing severe vibration, accelerated wear and a high probability of chain breakage and subsequent chain shot.
• Gauge is the thickness of the drive link where it sits in the guide bar groove (for example .050", .058", .063"). A chain with a gauge too narrow for the bar groove leans sideways in the cut. That slop stops the cutters engaging the wood squarely, producing erratic cutting, increased risk of pinching, and uneven wear on the bar rails.

3. Chain selection: the green and yellow label system

Chainsaw chains sold for consumer and professional use are commonly colour-coded to indicate kickback behaviour. The convention originated in North America, where the American National Standards Institute standard ANSI B175.1 sets low-kickback performance requirements for chainsaws and saw chain. The colour coding itself is a manufacturer convention built on top of that standard — adopted widely by makers such as Stihl and Oregon — rather than a scheme mandated by it. There is no equivalent Australian colour-coding standard, which is why the labelling can be confusing on the Australian market.

• Green label (low kickback). Designed with features such as bumper drive links or ramped depth gauges that smooth the entry of the cutter into the wood, particularly as it rounds the nose of the bar. These chains meet the low-kickback performance requirements of ANSI B175.1 and CSA Z62.3. They suit all users, including domestic and casual operators, because they significantly reduce the magnitude of kickback forces.
• Yellow label (professional). These chains omit the aggressive kickback-reduction features in order to maximise cutting speed and bore-cutting efficiency. They are capable of generating high-energy kickback and are intended only for professional operators with specialised training. The distinction is not marketing; it is derived from testing of the saw's reactive potential.

Chain selection is the first engineering control against injury. A domestic user fitting a yellow label professional chain to a homeowner saw is bypassing the primary passive safety system intended to protect them from their own inexperience.

If you are unsure which classification applies to a chain you already own or intend to buy, check the manufacturer's packaging and product markings, or ask before you fit it. Our team will confirm the specification of any chain against your saw.

4. Reactive forces: kickback, pull-in and push-back

"Reactive forces" describes the violent motion of the saw when the cutting chain is stopped or impeded by the wood. These forces obey Newton's third law: for every action — the chain driving into the wood — there is an equal and opposite reaction, the wood driving the saw. Because the chain moves so fast, the reaction is effectively instantaneous and can easily overpower an operator's grip.

Force	Cause	Direction of saw movement	Primary injury site
Rotational kickback	Upper quadrant of the bar nose contacts a solid object	Up and back in a fast arc toward the operator	Head, neck, shoulders
Pull-in	Chain on the bottom of the bar stops suddenly (pinch or foreign object)	Saw pulled forward, away from the operator	Loss of balance, fall onto the saw
Push-back	Chain on the top of the bar pinched by a closing kerf	Saw driven backward toward the operator	Torso, loss of control
Linear kickback	Aggressive pinch on the top of the bar	Straight back, bar tip does not necessarily rise	Midsection

Rotational kickback

Rotational kickback is universally recognised as the most dangerous event in chainsaw operation. It accounts for the majority of severe injuries to the head, neck and shoulders.

It occurs when the upper quadrant of the bar nose — the kickback zone, or "no-go zone" — contacts an object. To understand why, visualise the chain's path. Along the top of the bar the chain travels back toward the power head. As it rounds the nose it travels downward. At the precise moment it traverses the upper quadrant of the nose, the cutter is still moving forward relative to the bar, but the change in the bar's curvature changes the angle of attack.

If a cutter strikes a solid object in that zone — a log, a branch, a hidden rock — it attempts to climb out of the cut. Because the chain is travelling downward around the radius, the resistance acts as a pivot point. The driving force, unable to push the chain through the obstruction, instead drives the bar up and back in a fast arc toward the operator's head.

Reaction time versus machine speed

The lethality of rotational kickback lies in its speed. Testing has demonstrated that the interaction time — from contact to the saw striking the operator — can be less than 0.1 seconds. Average human reaction time is roughly 0.2 to 0.3 seconds. It is physiologically impossible to react to a kickback event once it has begun. By the time the brain registers the movement, the saw has completed its arc.

This is why the chain brake is not optional. Its inertial activation mechanism triggers automatically under the violent deceleration of a kickback, stopping the chain in milliseconds — often before it reaches the operator.

Testing the chain brake

• Static check (before every session). With the saw switched off and cool, engage the brake by pushing the front hand guard forward. Wearing gloves, attempt to pull the chain around the bar by hand. It should not move. Release the brake and confirm the chain then moves freely.
• Visual check. Inspect the brake band for wear, glazing or contamination, and the hand guard for cracks and free movement through its full travel. A hand guard that is stiff, loose or damaged means the saw is out of service until repaired.
• Function check. Follow your manufacturer's procedure for verifying that the brake stops the chain under power, and for checking inertial activation. Do not improvise a kickback test.
• Service. The brake band is a wear item. Have it inspected at scheduled servicing, and treat any hesitation in engagement as a fault, not a quirk.

Pull-in

Pull-in occurs when cutting with the bottom edge of the bar — the pulling chain. If the chain on the bottom of the bar stops suddenly because of pinching or a foreign object, the reaction pulls the saw forward, away from the operator. That can dislodge your footing or pull you off balance, potentially causing a fall onto the saw or into the cutting zone. It is particularly common when the bumper spikes (dogs) are not engaged against the wood before the cut begins.

Push-back

Push-back occurs when cutting with the top edge of the bar — the pushing chain. If the chain on the top of the bar is pinched by the closing kerf, the reaction drives the saw backward toward the operator. It is generally less violent than rotational kickback, but an unexpected push-back can strike the torso or cause loss of control if you are not braced in a proper stance.

Linear kickback (pinch kickback)

A specific subset of push-back, linear kickback occurs when a cut closes aggressively on the top of the bar and pinches the chain. It generates a sudden, straight-line force pushing the saw directly back into the operator. Unlike rotational kickback the bar tip does not necessarily rise, but the force is directed straight at the midsection.

Avoiding reactive forces

Understanding the mechanism is only useful if it changes how you cut. In practice:

• Always know where the bar tip is. Most kickback events happen because the operator lost track of the nose while concentrating on the cut.
• Never cut above shoulder height. A saw that kicks back from above shoulder height arrives at your head with nothing in between.
• Two hands, always. One-handed operation removes any chance of controlling a reactive force and prevents wrist activation of the chain brake.
• Clear the cut path first. Remove small branches, vines and debris that can snag the nose or the chain mid-cut.
• Assume there is metal or stone in the wood until you have looked. Fence wire, nails and embedded rock are the classic causes of both kickback and chain breakage in salvaged and storm timber.
• Read the tension in the timber before cutting. Compression and tension sides determine whether the kerf will close on the bar. Cut the compression side first where possible.
• Stand to the side of the cutting plane, not directly behind it.
• Bore cutting and plunge cutting deliberately place the nose into the wood. Do not attempt either without training, and not on a yellow label chain without both training and supervision.

5. Chain shot: the ballistic hazard

Kickback is a risk created by the saw's motion. Chain shot is the risk created by the saw's disintegration. Chain shot is the high-velocity ejection of chain components — drive links, cutters or rivets — following a catastrophic chain breakage. Once considered a hazard mainly for mechanised harvesters, it is increasingly recognised as a threat to handheld users as modern saws have become more powerful.

The whip and the fracture

Chain shot is not a random explosion. It is a predictable sequence. Chains run under high tension and store significant elastic potential energy. When a chain fails in tension, that energy is released instantly.

The whip effect. Once broken, the free end of the chain is no longer under tension but still carries considerable momentum. It whips away from the break point. If the break occurs on the bottom run, the free end whips forward around the nose or backward toward the drive sprocket. If the chain is not contained, that free end accelerates like the tip of a bullwhip.

The secondary fracture. The dangerous event happens when the whipping end strikes a hard object — the chain catcher, the saw chassis or the drive sprocket. The impact is sufficient to shear rivets or shatter drive links at the tip of the whip. Those liberated fragments separate from the loop and become projectiles.

Kinetic energy

The velocity of chain shot fragments is significant. In mechanised forestry, chain shot has been documented travelling at speeds comparable to a bullet. Forensic investigations by WorkSafeBC and other agencies have recorded chain fragments penetrating 12 mm (1/2") polycarbonate windscreens — protective glazing specified to stop heavy debris.

A handheld operator has clothing and, at best, a plastic helmet. A chain shot strike on an unprotected operator or bystander can be catastrophic. The fragment behaves as high-velocity shrapnel.

The shot cone and danger zones

The trajectory of chain shot is generally described by the "shot cone". Fragments tend to release along the plane of the guide bar.

• The danger zone. The area directly in line with the bar is the most hazardous. Operators are trained to keep their bodies out of that plane wherever possible, though it is difficult to maintain during felling cuts.
• Ricochet. The primary vector is planar, but fragments can deflect off wood, rock or the saw body in unpredictable directions. This is why exclusion zones for bystanders need to be generous. In mechanised forestry the commonly cited safety distance is 70 metres (approximately 230 feet), set to account for the maximum ballistic range of a fragment. For handheld work, the standard "two tree lengths" rule for felling also serves to keep bystanders clear of chain shot.

Prevention and engineering controls

Mitigating chain shot means preventing the break in the first place, and containing the energy if a break occurs.

The chain catcher. A mandatory safety device on all modern chainsaws — a small hook, usually aluminium or plastic, on the underside of the saw body near the clutch cover. It intercepts the whipping chain end, tangles it and dissipates its energy before it can strike the operator's right hand or leg. Chain catchers are sacrificial. If yours is deeply gouged, bent or missing, the saw is unsafe to operate.

Rivet integrity. Chain breakage often begins with an improper repair. Hammered rivets and reused tie straps create weak points. Safe chain repair requires a proper rivet spinner and fresh, matched components. Peening rivets with a hammer is a recipe for failure.

Broken chains: why we apply a once-broken rule

A long-standing rule in professional forestry is that a chain which has broken twice should never be repaired again and must be discarded. A second break indicates the whole loop has accumulated fatigue and that rivets throughout the chain are likely compromised. Continuing to run it invites a chain shot event.

Alpine Chain Co. applies a stricter once-broken rule. If a chain breaks even once, the forces that broke it were usually a high-impact event — hitting hidden metal in the tree, catching a rock, striking another rigid object. Those forces travel through the entire chain, not just the weakest link that happened to fail. The link that broke is the symptom, not the extent of the damage.

If a chain has been subject to those forces, discard it. Do not repair it and do not keep it as a spare.

6. Maintenance as a safety control

In most industrial contexts, maintenance is an efficiency concern. On a chainsaw it is a primary safety control. A poorly maintained saw is not just slow; it is dangerous.

Tensioning and the snap test

Correct chain tension prevents derailment — which can lead to chain shot — and limits wear on the bar and sprocket.

• The setting. The chain should sit snugly against the underside of the bar but still be able to be pulled freely around by hand, with the brake disengaged and the saw switched off.
• The snap test. Pull the chain down from the underside of the bar until one or two drive links are visible, then release. The chain should snap back into the groove instantly. If it sags or returns slowly, it is too loose.
• Thermal expansion. Steel expands as it heats. A chain tensioned while hot will contract as it cools. If you do not slacken the chain after a heavy cutting session, the contracting chain can crush the bar nose sprocket, bend the crankshaft, or stretch the rivets and predispose the chain to failure on its next use.
• Re-check during use. A new chain stretches most in its first period of running. Check tension after the first few cuts and periodically thereafter.

Lubrication, heat and chain metallurgy

Friction between the chain and the bar rails generates substantial heat. Chain cutters are hardened, and hardened steel depends on its heat treatment for both edge retention and toughness. Sustained overheating from inadequate lubrication can temper the steel back, softening the cutting edge, or in localised cases leave the material harder and more brittle than intended — either way, the chain no longer behaves as designed.

Fatigue is the second mechanism. Every rivet hole and every link shoulder is a stress concentration, cycled millions of times over the life of a chain. Cracks initiate at those points and grow invisibly. Heat, contamination and impact all accelerate that process, which is why a chain that has survived a hard impact is compromised even when it looks intact — the reasoning behind the once-broken rule above.

• The plume test. Verify oil flow by running the saw at half throttle with the bar tip pointed at a light-coloured surface, such as a fresh stump. A distinct line of oil spray should appear within seconds. No plume means stop and diagnose before cutting.
• Bar maintenance. Clean the bar groove and oil holes regularly. A blocked groove starves the chain of oil regardless of pump output.
• Sprocket wear. The drive sprocket transfers power to the chain, and over time the chain wears grooves into it. Fitting a new chain to a worn sprocket creates a pitch mismatch, so the drive links hammer against the sprocket teeth. That impact fatigue rapidly destroys the new chain. The industry standard is to replace the drive sprocket after every two chains worn out.

Filing and angles

Filing must respect the manufacturer's geometry — the cutter and depth gauge relationship described in section 2.

• Angles. The top plate angle, usually 30° or 35°, must be consistent across every cutter. Inconsistent angles make the saw chatter and vibrate, increasing both operator fatigue and the risk of hand-arm vibration syndrome.
• Depth gauge maintenance. Check depth gauges every three to four sharpenings using a depth gauge tool. File them with a flat file and round off the leading corner to restore the original ramp profile, so the cutter enters the wood smoothly.

Step-by-step filing procedure, file sizes and tooling: chain sharpening guide. Identifying an unknown chain from its markings: chain identification chart.

7. Operation: stance, grip, starting and environment

The physical interface between the body and the machine is the final determinant of safety. The operator acts as a stable platform, absorbing forces and directing the tool.

Body positioning: the boxer stance

Stability comes from the boxer stance. Stand with your feet shoulder-width apart, one foot — typically the left — slightly forward, and knees bent. This lowers your centre of gravity and lets the large muscle groups of the legs absorb push and pull forces instead of the spine. Never stand directly behind the saw's cutting plane; keeping out of that line protects the head and torso from kickback, derailment and chain shot trajectories.

Grip and the thumb wrap

The grip on a chainsaw is not intuitive for many novices. The thumbs must fully encircle the handles.

• Left hand. The thumb must wrap under the front handlebar. This is critical. In a kickback the saw pivots violently upward. If the thumb is resting on top of the handle — a "monkey grip" — the handle will be ripped out of your hand, leaving the saw free to strike you. The wrapped thumb acts as a lock, keeping the hand on the handle and allowing the wrist to pivot forward and activate the chain brake.
• Right hand. The right hand grips the rear handle and controls the throttle.

Starting a petrol saw

Starting is a high-risk operation because the engine is often set to fast idle during the start sequence, which means the chain may rotate immediately on ignition. Engage the chain brake before you start, every time.

Drop starting is prohibited. Holding the saw handle with one hand and pulling the starter cord with the other while dropping the saw leaves the machine unsupported and swinging in an uncontrolled arc. It is prohibited by all major safety standards and frequently results in the saw striking the operator's leg or an obstruction.

Ground start. Place the saw on flat, firm ground. Engage the chain brake. Place your right foot through the rear handle to pin the saw down, grip the front handle with your left hand, and pull the cord with your right. Alpine Chain Co. recommends the ground start in all circumstances; if the ground is unsuitable, make it suitable before starting rather than adopting an unsupported technique.

Battery and electric saws

Battery platforms now account for a large share of chainsaw use, and much of the standard safety advice was written for petrol machines. The differences matter:

• There is no start sequence and no idle. A battery saw is live the moment the battery is fitted and the lock-off is released. There is no engine noise to tell you the machine is running, and no visual or audible cue before the chain moves.
• The lock-off switch is not a chain brake. It prevents accidental trigger activation. It does nothing during a kickback. Use the chain brake, and verify it works — see section 4.
• Remove the battery before any maintenance. Tensioning, clearing debris, sharpening in place, or clearing a jammed chain — battery out first, every time.
• The kickback physics are identical. Bar nose is bar nose. Chain speed on many battery saws is lower than on comparable petrol machines, which reduces the energy involved but does not eliminate kickback, and does not make the chain safe to touch.
• Noise is reduced, not removed. Battery saws are quieter than petrol, but cutting noise is frequently still above the 85 dB(A) exposure limit. Wear hearing protection unless you have measured otherwise.
• No exhaust means no carbon monoxide hazard, which is a genuine advantage in enclosed or low-lying areas. Every other hazard on this page still applies.

Pole saws

Pole saws remove two of the protections assumed everywhere else on this page: the chain brake and the ability to stand out of the cutting plane.

• Most pole saws have no chain brake. There is no inertial device to stop the chain if the head is deflected. Bar tip discipline is the only control you have.
• You are working underneath the hazard. Cut material falls. Establish a drop zone, keep bystanders out of it, and plan where each limb will go before you cut it — including where the butt end will swing.
• Treat every overhead line as live. Do not work near powerlines. Minimum approach distances are set by state electrical regulators and work near lines is restricted to appropriately trained and authorised people. If the limb is near a line, call the network operator.
• Never operate a pole saw from a ladder. You cannot brace against reactive forces on a ladder.
• Eye and head protection are not optional overhead. Chips and debris fall directly into your face.

Fatigue and environmental factors

Fatigue degrades reaction time and situational awareness. Chainsaw operation subjects the body to significant vibration, noise above 100 dB and, on petrol machines, exhaust fumes.

• Hand-arm vibration syndrome (HAVS) is a permanent vascular and neurological condition caused by prolonged vibration exposure. Modern saws use anti-vibration mounts, but operators still need regular breaks and gloves that keep the hands warm to maintain circulation.
• Carbon monoxide. Exhaust fumes accumulate in dense canopies and depressions. Do not work with your face in the exhaust plume.
• Slip and trip hazards. The ground underfoot is rarely stable. Clear an escape path at roughly 45 degrees to the rear before felling any tree, so you can retreat from the falling load.

8. Personal protective equipment and Australian standards

PPE does not prevent accidents. It reduces the severity of the injury when one occurs. Chainsaw PPE is highly specialised, and in the case of leg protection it works by jamming the saw's mechanism rather than resisting the cut.

Equipment	Australian / New Zealand standard	Key requirement
Leg protection (trousers, chaps)	AS/NZS 4453.3:1997 (R2017)	Cut-resistant fibre pads; discard once cut
Helmet	AS/NZS 1801 (chin straps to EN 12492 for work at height)	Impact protection from falling limbs
Hearing protection	AS/NZS 1270	Class 4 or 5 for petrol saws; SLC80 rating on pack
Eye protection	AS/NZS 1337	Medium impact rating ('I' or 'M'), worn under the mesh visor
Footwear	AS/NZS 2210.3	Steel or composite toe cap, ankle support
Gloves	AS/NZS 2161	Cut-resistant padding on the back of the left hand

Leg protection and the mechanics of jamming

The legs are the most frequent site of chainsaw injury. Chainsaw chaps and trousers work by clogging, not deflection.

• Mechanism. When a moving chain strikes the garment it cuts the outer layer and drags out the long, high-tenacity fibres beneath — Kevlar, ballistic nylon or proprietary fabrics such as Avertic. Those fibres wrap instantly around the drive sprocket, binding the clutch and stalling the saw in a fraction of a second.
• Limitations. The protection is not absolute. Garments are rated for specific chain speeds, commonly 20 m/s. A saw at full throttle with a sharp chain may still cut through, but the injury will be far less severe.
• Maintenance. Oil and dirt degrade fibre performance. Wash chaps according to the manufacturer's instructions to maintain their ability to fluff and jam. If chaps have been cut, discard them — the fibre integrity is gone.

Which legwear standard is on your gear

Australian buyers routinely encounter three different marks on chainsaw legwear, which causes real confusion. Briefly:

• AS/NZS 4453.3:1997 (R2017) — Protective clothing for users of hand-held chainsaws, Part 3: Protective legwear (Standards Australia / Standards New Zealand). Specifies design and performance requirements for protective trousers and leggings, plus identification, marking and manufacturer information. It originated as NZS 5840:1988, was jointly revised and redesignated in 1997, incorporates Amendment 1 (1998), and was reconfirmed in 2017 as still valid.
• NZS 5840:1988 — the predecessor standard. Because AS/NZS 4453.3 was based on the European standard EN 381 and subtle differences made testing to it difficult in practice, a great deal of Australian and New Zealand legwear continued to be manufactured to NZS 5840 performance for years after 1997, with certification to AS/NZS 4453.3 arriving progressively from around 2010. Older gear in service may carry the NZS mark.
• EN 381 / EN ISO 11393 — the European series, seen on imported garments. EN 381 was progressively superseded by EN ISO 11393. These are not the Australian standard, though the performance basis is related.

Practical takeaway: look for certification to AS/NZS 4453.3 by a recognised certification body. If your garment carries only an NZS 5840 mark, it was built to the older performance requirement. If it carries only an EN mark, check what class and chain speed it is rated to.

Head, face and hearing protection

Helmets. A chainsaw helmet is normally a system integrating head, face and hearing protection. The shell, compliant with AS/NZS 1801, protects against falling branches — the widowmakers of forestry work. For arborists working at height, chin straps are mandatory, commonly to EN 12492, to prevent the helmet coming off during a slip or fall.

Hearing. Chainsaws operate above 100 dB(A) and often up to 115 dB(A), against a safe exposure limit of 85 dB(A) over eight hours. Without protection, permanent hearing damage can occur in minutes. Hearing protection must comply with AS/NZS 1270 (Acoustics — Hearing protectors). Petrol chainsaws typically require Class 4 or Class 5 protection to bring noise at the ear down to safe levels. The SLC80 (Sound Level Conversion, 80th percentile) rating on the packaging indicates the decibel reduction; a Class 5 earmuff typically offers an SLC80 of 26 dB or higher.

Eyes. The mesh visor on a chainsaw helmet stops large wood chips and protects the face from whipping branches. It does not stop fine sawdust or high-velocity fluids. Safety glasses or goggles complying with AS/NZS 1337 (Eye protectors for industrial applications) must be worn under the mesh visor. Because chainsaw work generates high-velocity projectiles, eye protection should carry a medium impact rating (marked 'I' or 'M') or higher.

Footwear and hand protection

• Boots. Safety boots must provide ankle support to prevent twisting on uneven ground, and require steel or composite toe caps to AS/NZS 2210.3. Purpose-made chainsaw boots also include cut-resistant inlay fibres across the instep and tongue to protect the foot from a running saw.
• Gloves. Gloves complying with AS/NZS 2161 are required. Chainsaw-specific gloves usually add cut-resistant padding to the back of the left hand, protecting it from a chain derailment or a kickback strike.

Common questions

What causes chainsaw kickback?

Rotational kickback is caused by the upper quadrant of the bar nose contacting a solid object. The cutter tries to climb out of the cut, the obstruction becomes a pivot point, and the bar is driven up and back toward the operator. Excessively low depth gauges and dull chains both increase the severity of kickback.

How tight should a chainsaw chain be?

Snug against the underside of the bar, but still able to be pulled around freely by hand with the brake off and the saw switched off. Use the snap test: pull the chain down until one or two drive links are visible and release — it should snap straight back into the groove. Re-check tension as the saw warms up, and slacken the chain after a hot session so it does not contract onto the bar as it cools.

What is the difference between green label and yellow label chains?

Green label chains include low-kickback features such as bumper drive links and ramped depth gauges, and meet the low-kickback performance requirements of ANSI B175.1. Yellow label chains omit those features for cutting speed and bore-cutting efficiency, and are intended only for trained professional operators. The colour coding is a manufacturer convention rather than an Australian standard.

What is chain shot?

The high-velocity ejection of chain fragments after a chain breaks. The free end whips, strikes a hard part of the saw, and shears off links or rivets that then travel as projectiles along the plane of the bar. It is prevented by correct tension, correct fitment, sound repairs, an intact chain catcher, and by retiring damaged chain.

Can a chainsaw chain be repaired after it breaks?

Professional forestry practice discards a chain after a second break. Alpine Chain Co. applies a once-broken rule: a break usually means a high-impact event whose forces travelled through the whole loop, not just the failed link. Retire the chain.

Do battery chainsaws need the same safety precautions?

Yes, with additions. There is no idle or engine noise to tell you the saw is live, the lock-off switch is not a chain brake, and the battery must come out before any maintenance or clearing of a jam. The kickback physics are unchanged.

What PPE do I legally need to use a chainsaw in Australia?

Requirements depend on whether the work is domestic or workplace activity, and workplace duties sit with your state or territory WHS regulator. As a practical baseline, AS 2727-1997 and manufacturer instructions point to leg protection, helmet, eye and hearing protection, gloves and protective footwear. The standards that apply to each item are listed in the table above.

Training and scope of this guide

This page is general information about chainsaw and saw chain mechanics. It is not a substitute for hands-on training, and reading it does not make anyone competent to operate a chainsaw.

AS 2727-1997 explicitly covers the training and supervision of chainsaw operators, and expressly excludes the full range of tree felling techniques — noting that felling should be undertaken only by experienced operators or under the direct supervision of a skilled operator. If you intend to fell trees, work at height, or use a chainsaw as part of your work, get accredited training through a registered training organisation delivering nationally recognised chainsaw units of competency.

Always follow your saw manufacturer's instructions. Where those instructions differ from anything on this page, follow the manufacturer. For workplace obligations, refer to your state or territory work health and safety regulator.

Standards referenced: AS 2727-1997 Chainsaws — Guide to safe working practices; AS/NZS 4453.3:1997 (R2017) Protective clothing for users of hand-held chainsaws, Part 3: Protective legwear; AS/NZS 1801; AS/NZS 1270; AS/NZS 1337; AS/NZS 2210.3; AS/NZS 2161; ANSI B175.1; CSA Z62.3; EN 12492; EN 381 / EN ISO 11393. Standards are available for purchase from Standards Australia and authorised resellers.