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Hazards Associated with Operating Skid-Steer Loaders with Bypassed and/or Improperly Maintained Safety Devices
Safety and Health Information Bulletin
Skid-steer loaders (Figure 1) are manufactured with safety features to prevent unexpected or inadvertent movement of the loader arm and hydraulics when the operator is not in the cab. However, these safety features can be bypassed, defeated or improperly maintained which can result in serious injury or death to the operator and/or other employees working on or around the equipment.
The purpose of this Safety and Health Information Bulletin is to:
This SHIB focuses on the seatbelts and safety interlock systems typically found on skid-steer loaders intended primarily for earth moving. Such vehicles are not covered by the requirements of OSHA's Powered Industrial Truck standard, 29 CFR 1910.178.
Common safety features of a skid-steer loader include the seatbelt for operator restraint, Falling Object Protective Structure (FOPS), Roll-Over Protective Structure (ROPS), and a Control Interlock System. Some of these machines are equipped with a pulldown armrest (seat bar) that may be used to interlock the machine control systems (as shown in Figure 2). The seatbelt helps prevent the operator from being thrown about inside or falling out of the skid-steer loader. The FOPS and ROPS protect the operator from falling objects and injury due to accidental rollovers. Control Interlock Systems and/or operator seats used on some machines typically activate a safety interlock system that is intended to prevent inadvertent movement of the machine’s controls when the operator is not in the proper operating position (i.e., seated).
Review of OSHA's Integrated Management Information System (IMIS) reveals that between 1997 and 2007, 100 accidents were recorded specifically involving skid-steer loaders. The deliberate bypassing of safety features (such as seatbelts and control interlock systems) was identified as the direct cause of 20% of these incidents, with all but one resulting in a fatality. Three cases are described below:
An employee was working alone, operating a skid-steer loader for "fine grading" or smoothing out dirt to provide the final contouring around a new home that was nearing completion. While operating the skid-steer loader, one of the bucket bolt pins, which connects the loader arm to the bucket, fell out. The employee dismounted the vehicle with the engine still running, manually lowered the lap bar safety device, and operated the hydraulic controls from outside the vehicle. The employee was attempting to realign the loader arm hole with the bucket hole and reinsert the bucket bolt pin. In the process, he was trapped between the bucket and the body of the skid-steer loader and was crushed. The employee was found in a position that allowed him to operate the controls from outside the vehicle with the bucket bolt pin and a large hammer nearby.
Upon inspecting the skid-steer loaders on this job site, the following conditions were noted:
An employee was ordered by his company to repair a leak in the hydraulic slave cylinder of a skid-steer loader. He drove the skid-steer loader into the warehouse and began the repair. He bypassed the safety bar by jamming it into the interlocks without being seated in the cab. He then started the skid-steer loader and raised the bucket over the cab. Upon exiting the cab, his foot inadvertently pressed the down pedal for the bucket. The bucket came down and trapped him between the lift and the cab. He then hit the left side lever, causing the skid-steer loader to move in reverse. It crashed into a parked forklift and he was killed.
Upon investigation, the three causes of the accident were identified as:
An employee at a tractor implement dealership was cleaning debris from a wash bay using a skid-steer loader. This particular skid-steer loader was equipped with a manual seat bar as well as a pressure switch in the seat to detect the presence of an operator. The operator was able to leave the cab to wash the skid-steer loader bucket while it was still operational. The bucket was left sitting on its nose which prevented the loader arms from resting against the body of the vehicle as it was designed to do. This position made it difficult to enter and exit the cab. As the employee attempted to get back into the cab, he slipped and fell face-first into the cab seat. The loader arms dropped and caught him between the body of the skid-steer loader and the loader arms, and he was killed.
The two major contributing factors to this accident were:
Properly maintained and functioning seatbelts and control interlock systems are critical to the safe operation of skid-steer loaders. Field reports have shown injuries and fatalities can occur by operating skid-steer loaders with one or both of these safety systems bypassed, disabled, or improperly maintained.
While OSHA does not have a standard requiring employers to use control interlock systems or seatbelts on skid-steer loaders, it is important for employers to understand that under the General Duty Clause of the OSH Act (section 5(a)(1)), employers must provide their employees with a workplace free from recognized hazards likely to cause death or serious physical harm. OSHA may cite an employer for a violation under the General Duty Clause if recognized hazards exist and the employer does not take feasible, effective measures to abate such hazards.
OSHA takes the position that an employee who moves from the proper position on a skid-steer loader while it is energized, by doing such activities as performing maintenance or repair operations, creates the recognized hazards of crushed-by and/or caught in-between. The failure to use seatbelts also increases the risk of employee injury in the event of rollover. [1,2]
Employers may abate these hazards by, among other things, communicating and effectively enforcing work rules prohibiting employees from disabling or bypassing safety equipment, including safety interlock systems, and requiring employees to use seatbelts at all times when operating a skid-steer loader.
When equipment such as a skid-steer loader is used in construction activities, 29 CFR 1926.20(b)(2) requires construction employers to develop safety and health programs that provide for frequent and regular inspections by competent persons designated by the employee of 1) the job sites, 2) materials, and 3) equipment. In addition, 29 CFR 1926.21(b)(2) requires construction employers to instruct employees in the recognition and avoidance of unsafe conditions and the regulations applicable in their work environment to control or eliminate hazards or other exposures to prevent illness and injury.
If skid-steer loaders are used in situations covered by 29 CFR Part 1910, then the requirements of OSHA's Control of Hazardous Energy (lockout/tagout) standard, 29 CFR 1910.147, may be applicable. Such situations may include, but are not limited to, use of skid-steer loaders in warehousing operations or servicing and maintenance performed on skid-steer loaders in maintenance facilities.
The following practices will minimize hazardous situations associated with operating and maintaining skid-steer loaders:
References and additional information