Work at elevation always exposes workers to the hazard of a deadly fall. The use of mobile elevating work platforms (MEWPs), also known as aerial work platforms (AWPs), such as boom lifts and scissor lifts, can provide a measure of safety.

Unfortunately, the enhanced safety provided by guardrails, as well as the ability to have both hands free to work and a place to put tools and equipment, are to some degree offset by the hazards of the elevating equipment itself.

According to an analysis published in October 2012 by the International Powered Access Federation (IPAF), 25 deaths resulting from accidents worldwide involving MEWPs from January to September 2012.

Sixty percent (15) of those fatalities occurred in the United States, making the nation a world leader in a dubious statistic. Fifteen of the incidents worldwide involved booms, seven involved vehicle mounts, and three involved scissor lifts.

The analysis also identified the five leading causes of death among workers in these accidents.

1. Falls
Falls from the platform was the leading cause of death for workers on MEWPs in the analysis, killing seven workers. Falls can occur when workers lean too far over the protective structure, try to increase their working height within the platform, or climb out of the platform.

Workers must understand that even though they are inside a protective structure, they can still fall. They must wear personal fall arrest, fall restraint, or positioning devices, and secure themselves to the boom, basket, or tub.  They must not tie off to an adjacent pole, structure, or equipment.  They also should never sit or stand on the edge of the basket or use planks, ladders, or anything else to raise them higher within the bucket or platform. They should never climb out of the bucket or platform while it is elevated.

2. Electrocution
Workers at height encounter electrical hazards that they would not be exposed to on the ground, including overhead power lines and electrical installations and equipment, such as signs and lighting. Electrocution was the second leading cause of death for workers on MEWPs in the IPAF
analysis, killing six workers.

Conduct a prejob hazard analysis to identify overhead power lines and other electrical hazards that are present at the worksite or inherent in the job task. If possible, cut power to electrical installations in the work area before work begins. Make sure workers have appropriate electrical protective equipment and safety gear and know how to use it properly. Also, if the MEWP is insulated against electrical conductivity, it should not be altered in a way that reduces its insulating properties.

3. Overturns
Five workers died when their MEWP overturned. This can happen because of unstable ground conditions, high winds, defective equipment, collisions with other vehicles, or instability caused by moving the platform.

Make sure that ground conditions are adequate to support the MEWP. For outdoor work, that means be careful when working on or near slopes; ensure that conditions remain safe after heavy rain; and look for irregularities such as bumps, pits, or potholes that could cause the MEWP to tip.
For indoor work or work on structures (such as docks), make sure the load-bearing capacity is adequate.

Protect MEWPs against ground traffic to prevent collisions. Define conditions under which the MEWP should not be used (for example, high wind conditions).

4. Mechanical/technical problems
Four workers died because of mechanical/technical problems with their MEWPs. These may include control failures, hydraulic failures, or other problems.

Workers should be trained to operate the specific MEWP they will be using. Before using a MEWP, the operator should perform a visual inspection and test all controls to make sure they work.

Operators should also be aware of the manufacturer’s limits for the MEWP and must not exceed them.

5. Entrapment
The fifth leading cause of death on MEWPs in the IPAF analysis, responsible for three workers’ deaths, was entrapment. This can occur when a forklift tips into water and the worker is trapped underwater. It can also occur when the worker is crushed between the work platform and a structure, such as an overhead beam.

Watch for hazards that could create entrapment problems, including water hazards and overhead crushing or contact hazards. Make sure workers are aware of these and know how to prevent potentially deadly entrapment.

Practice tip
If your workers use MEWPs, you should be aware of the risks they face and how to minimize them. In case something does go wrong with an MEWP, make sure you have an emergency response plan in place and that your workers are trained in emergency procedures.