NIOSH to Study Scissor Lift Tip-overs

May 19, 2004 —Falls from aerial lifts, specifically related to scissor lift tip-overs, is the focus of a study by the National Institute for Occupational Safety and Health (NIOSH). The project will study three major areas: machinery safety; fall protection, prevention and cost-effectiveness ; and special technology development. NIOSH has completed the first of three phases in the study, which is scheduled for completion in 2006.

According to Christopher Pan, CDC/NIOSH project officer, the first phase used injury and fatality data as well as manufacturer input to narrow the scope of the project. The study will examine 19-foot electric scissor lifts , but in 2006 is projected to shift to a study of other lifts, pending funding approvals. The deadline for scissor lift manufacturers to submit materials for participation as a partner in the study has been extended to June 14. Manufacturers seeking partnership opportunities should go to: www2.eps.gov/spg/HHS/CDCP/MNIOSH/postdatePrevDays_1.html .

In the mid-1990s several manufacturers began providing “pothole protection” devices on scissor lifts designed to operate on firm, flat surfaces. And since 1999, the ANSI A92.6 standard has provided recommendations for scissor lifts to pass a depression test.

Meanwhile, statistics from approximately the same time period show that falls continue to be a concern. Between 1992 and 1999, the Census of Fatal Occupational Injuries (CFOI) data identified 341 deaths—an average of 43 per year—in construction related to the use of personnel lifts. Of those, falls from vertical lifts accounted for 44% of the deaths, almost all involving scissor lifts.

“I would like to know whether pothole protection really works, especially with loads inside and outside the basket perimeter, such as pipe, or other materials,” stated Jeff Stachowiak, the Director of Access Safety and Training for Sunbelt Rentals, Jacksonville , Fla.

If the study holds to its projected outline, Stachowiak and others may get their answer. Four engineering evaluations will be conducted as a part of Phase 2 of the study, a portion of which is to consider the effects of changing centers of gravity on the stability of the machine. The purpose of the engineering evaluations is to develop a reliable computer model that can simulate and evaluate tip-overs and falls from the lift. Those evaluations will:

1. Develop and refine a computer simulation model;
2. Build a workstation to statically measure the center of gravity (CG) of the lift at different heights;
3. Conduct tests to collect changes and interactions in CG and loadings of operator(s) within the platform; and 
4. Collect dynamic response data for the lift during its horizontal movements.

During Phase 3, intervention techniques will be evaluated for cost and overall effectiveness.

Results and recommendations from this study will be proposed to appropriate standards committees, including ANSI A10.29 and ANSI A92.