Chainsaw Safety and Required PPE

Why this matters

Chainsaw work is one of the most hazardous activities in tree service. The CDC documents approximately 36,000 chainsaw injuries per year in the US, of which the majority involve cuts to the hand, leg, knee, or face. ANSI Z133 (Tree Care Operations standard) and OSHA 1910.266 establish the minimum safety requirements; experienced tree services exceed these. This reference covers the required PPE and the operational safety practices every chainsaw operator must follow.

Required PPE (per ANSI Z133)

Every chainsaw operator must wear, at minimum:

Each item is essential. Omitting any creates an injury risk that the rest can't compensate for.

Cut-resistant chaps

The single most important PPE item:

• Designed to bind in the chainsaw chain, stopping it instantly
• Layers of cut-resistant fiber (similar to Kevlar)
• Adjustable for fit
• Verify compliance with ANSI Z133 or ASTM F1414

Why chaps are mandatory:

• A chainsaw can cut through unprotected pants in less than a second
• Chaps add 8-10 layers of cut-resistant material
• The chain jams in the chap layers, stopping the saw
• Documented injury reduction is dramatic

Customer-side chap requirements: most professional tree services require chaps for any chainsaw work, regardless of the size of the saw.

Operational safety practices

Pre-use inspection

Every saw, every shift:

1. Chain tension: should be snug but loose enough to pull around the bar by hand
2. Bar: straight, not bent or worn
3. Sprocket: not visibly worn
4. Chain brake: engages immediately when activated
5. Throttle interlock: prevents accidental throttle
6. Anti-vibration mounts: intact and functional
7. Spark plug: clean, gapped correctly
8. Fuel: appropriate mix (2-stroke saws)
9. Bar oil: full reservoir

A pre-use inspection takes 60 seconds and prevents the majority of mechanical-failure incidents.

Starting the chainsaw

Proper starting:

1. Place the saw on the ground
2. Foot through the rear handle for stability
3. Engage the chain brake
4. Activate the choke (per manufacturer)
5. Pull the starter cord with one hand on the front handle (the other not in the bar's plane)
6. Once started, release the choke
7. Test the chain brake (the chain should stop immediately when engaged)

Do NOT drop-start (holding the saw in one hand and dropping to start) - this is a major safety violation in current ANSI Z133.

Operating position

When cutting:

1. Stand to the side of the cutting line, never directly above or below
2. Both feet on stable ground; never on a ladder, log, or unstable surface
3. The saw at waist or knee height (never above shoulders or below feet)
4. Both hands on the saw at all times (one on front handle, one on rear)
5. Thumb and fingers fully wrapped around the front handle (not draped over)
6. Body position: clear of the saw's possible kickback path

Kickback and how to prevent it

Kickback is the saw's rotational motion when the tip of the bar contacts something:

• The chain catches, the saw rotates back toward the operator
• Can happen in less than a second
• Cause of most chainsaw operator injuries

Prevention:

• Never touch the bar tip to anything
• Stay aware of where the tip is at all times
• Cut with the lower part of the bar (chain pulling toward the body, not pushing away)
• Use saws with kickback-reduction features (low-kickback chains, kickback bar guards)
• Train operators on kickback recognition

Felling work

When felling a tree:

1. Determine the lean of the tree (front, back, side)
2. Plan the fall direction (perpendicular to the lean, toward open area)
3. Identify retreat path (45-90° opposite the fall direction)
4. Look up for widow-makers (loose branches that may fall when the tree moves)
5. Make the notch cut (face cut) toward the fall direction
6. Make the back cut behind the notch
7. Use wedges to direct the fall
8. Retreat on the planned path; never stand under the tree

The notch + back cut is the standard professional approach. Improper cuts result in barber chair (tree splits vertically) or hangup (tree leans against another tree).

Cutting a downed tree

For limbs and bucking:

1. Identify the wood under tension and compression
2. Cut in stages to release tension safely
3. Don't cut completely through in one motion if the wood is under compression
4. Use chainsaw-specific cribbing or supports if the log is unstable

Chain sharpening

A dull chain:

• Creates more dust (no chip production)
• Smokes from the bar
• Requires excessive force
• Increases kickback risk
• Cuts slowly

Sharpen the chain when:

• The saw cuts to one side (chain unbalanced)
• Chips become dust
• The saw smokes during use
• After 8-16 hours of typical use

Sharpening in the field with a round file or in the shop with a grinder. Each tooth at the same angle (typically 30°).

Safe practices specific to tree work

Aerial work

When the saw is up the tree:

1. Saw is secured by a lanyard
2. Operator is positioned out of the cutting plane
3. The saw is NEVER pushed or thrown
4. Spotter on the ground watches the operation

Ground operations during felling

The ground crew during felling:

1. Stays 1.5x the tree's height away from the fall direction
2. Communicates with the climber/sawyer using clear signals
3. Maintains a safe zone

Multi-person operations

For operations with multiple workers:

1. Pre-job briefing
2. Clear roles and responsibilities
3. Communication signals (whistles, radio, hand signals)
4. Single supervisor for the operation
5. Emergency response plan

Common pitfalls

• Skipping the chap requirement - leg laceration risk
• Using a saw with a damaged chain brake - kickback unstoppable
• Cutting above shoulder height - control compromised; falling debris
• Standing in the fall line - fatal incidents documented
• Chain dull - cutting takes longer, vibration increases, fatigue
• Drop-starting - multiple injuries documented

When to refer to other professionals

Some work exceeds tree-service scope:

References

• ANSI Z133 (Safety Requirements for Arboricultural Operations)
• OSHA 1910.266 (Logging Operations)
• ANSI A300 (Tree Care Standards)
• ISA (International Society of Arboriculture) certification standards
• TCIA (Tree Care Industry Association) standards
• Manufacturer documentation (Stihl, Husqvarna, Echo)
• Manuall internal: Climbing Safety, Tree Pruning Service, Tree Removal Service