Scissor lifts are common on construction sites, in warehouses, and industrial settings, providing a mobile platform for workers to access high areas for maintenance or installation. While these machines are engineered with safety features, their safe use depends entirely on the operator’s adherence to established protocols, training, and constant awareness of the environment. Understanding the specific risks and mandatory procedures is the foundation for mitigating accidents.
What is the General Safety Profile of Scissor Lifts?
A scissor lift is a mobile elevated work platform that uses crisscrossing supports to move the platform vertically. This design provides a large work area, often accommodating multiple workers and materials. Due to the wide base and centered weight mechanism, scissor lifts are inherently more stable in the vertical plane than boom lifts. This makes them a reliable option for tasks requiring stable elevation on firm, level ground.
Most serious incidents are not due to mechanical failure but rather a failure to follow operational guidelines and safety procedures. The stability advantage, however, is contingent on the lift being positioned and operated on surfaces that meet the lift’s stability requirements. When properly maintained, used within its rated capacity, and operated by a trained professional, the risk profile remains low.
The Most Common Scissor Lift Hazards
Falls from the Platform
Falls from the elevated platform are one of the most frequent causes of injury. The guardrail system is the primary means of fall protection and must be in excellent condition, with gates closing and locking properly. Personnel must never climb onto or lean over the guardrails to gain extra reach. While some sites require a personal fall arrest system (PFAS), the guardrails are designed to contain the worker within the platform, provided they stand only on the deck.
Tip-Overs and Instability
Tip-overs occur when the lift’s center of gravity shifts beyond its stable base, usually caused by environmental factors or operator error. Driving the lift while elevated, especially at high speeds, can destabilize the unit, as can operating on unlevel surfaces, slopes, or soft ground. Exceeding the maximum load capacity, which includes the combined weight of personnel, tools, and materials, also raises the center of gravity. High wind conditions, which are magnified at height, can exert enough force on the platform to necessitate immediately lowering the lift.
Crushing and Pinch Points
Crushing or entrapment occurs when a worker is pinned between the moving platform or guardrails and a fixed overhead structure, such as a beam or pipe. This typically happens when the lift is raised or driven beneath an obstruction without the operator noticing the decreasing clearance. Operators must maintain constant awareness of overhead hazards and ensure adequate space for the platform to fully clear any structure. Additionally, the scissor mechanism itself presents numerous pinch points where extremities can be caught during the raising or lowering sequence.
Electrocution and Power Line Contact
Contact with energized power lines presents an electrocution risk, which can occur even without direct physical contact due to electrical arcing. Safe work practices require maintaining a minimum clearance distance from all overhead power lines. A common guideline is to ensure the lift and all personnel remain at least ten feet away from any energized line, though this distance may increase depending on the voltage. Operators must conduct a thorough overhead site assessment before beginning work and should assume all power lines are energized until confirmed otherwise.
Mandatory Training and Certification Requirements
All operators of a scissor lift must be properly trained and certified as a “qualified person” before they are permitted to use the equipment. This ensures that the operator possesses the necessary knowledge to safely inspect, operate, and recognize the hazards associated with the machine and the work environment. Training must cover the specific manufacturer’s instructions and warnings for the model being used, as every lift has unique operational characteristics and safety systems.
The curriculum includes practical, hands-on instruction and a formal evaluation of the operator’s ability to perform duties safely. Employers must provide refresher training and re-evaluate proficiency if the equipment type changes, if the operator uses the lift unsafely, or if an accident occurs.
Pre-Operation Safety Inspections and Site Assessment
Before a scissor lift is used at the start of any shift, the operator must conduct a pre-shift inspection to confirm the unit is in safe working order. This mandated check includes a functional test of the operating controls, the emergency stop buttons, and the emergency lowering system to ensure they all operate correctly. The inspection also involves a visual check for physical damage, such as cracked welds, hydraulic fluid leaks, and excessive tire wear.
A comprehensive assessment of the work site and the surrounding environment is also required. The operator must check that the ground is firm, level, and free of holes, debris, or other unstable conditions that could affect stability. The assessment also requires identifying all potential overhead obstructions, power lines, and ground-level hazards like pedestrian traffic or moving vehicles. If any defect is found on the lift or any hazard is identified that cannot be mitigated, the lift must be immediately taken out of service until the issue is corrected.
Safe Operation Procedures While Elevated
When the platform is elevated, operators must follow procedures that maintain the lift’s stability and prevent falls. It is prohibited to use makeshift devices like ladders, boxes, or planks on the platform to gain additional height or reach. This negates the engineered fall protection and increases the risk of a tip-over. Workers must always remain securely on the work deck and should never stand on the guardrails or use them as a brace to lean out.
The lift’s maximum weight capacity must be observed, and the load must be distributed evenly across the platform to maintain a stable center of gravity. If the machine is designed to be driven while elevated, the operator must move at a slow, controlled speed, often limited to a fraction of the ground speed. Operators must always be aware of the potential for sudden jolts from uneven surfaces. Spotters should be used to guide the lift when moving in tight quarters, near obstacles, or in areas with heavy foot or vehicle traffic to prevent collisions.