However, the report concludes that order-pickers could face an elevated risk of back and other musculoskeletal injuries if the volume of work increases or workers stray from their current safe practices.
A project supervisor employed by Atlanta-based building products distributor BlueLinx Corp. asked NIOSH to come to the company's Bellingham, Mass., distribution center to determine whether order-pickers were at risk of injuries. NIOSH, in response, sent two ergonomics specialists to the facility, which is an OSHA VPP Star site employing 118 workers.
The NIOSH investigators concluded that "no immediate ergonomic health hazards" exist at the BlueLinx facility.
"The workers took the time to avoid reaching across pallets when lifting, adjusted the height of storage and delivery pallets to enable lifting at waist height and slid or rolled loads to the front edge of pallets before lifting," the report says.
However, based on the safe lifting standards set forth in the Revised NIOSH Lifting Equation and the Michigan 3-Dimensional Static Strength Prediction Program, the workers "were at elevated risk of injury … due to the weight of the object lifted," which ranged from 48 to 64 pounds, the report adds.
Picking Molding Orders Poses Higher Risk
Workers at the BlueLinx distribution center in Bellingham, Mass., fill warehouse orders and deliver more than 6,000 different building products to approximately 50 home building products retail stores in the area, according to the HHE report.
BlueLinx asked NIOSH to evaluate three types of order-picking jobs: picking boxes of nails that weigh approximately 50 pounds; picking boxes of vinyl siding; and picking bundles of molding.
In general, the NIOSH team concluded employees used good lifting practices, such as placing empty pallets under delivery pallets to achieve the desired lifting height.
After crunching the data, though, the NIOSH team found that the three lifting jobs do pose an elevated risk of injury. The team found molding jobs to be in a higher risk category than the other jobs due to the weight of the bundles, which are around 64 pounds.
Job Rotation Would Help if Volume Increases
Despite the risk of injury, BlueLinx has prevented back injuries and other injuries by the low frequency of lifting, good lifting techniques and other control measures. The NIOSH team also found that other activities that take place during the filling of an order such as paperwork actually reduce the workers' risk of injury because the activities give the workers adequate time for recovery between lifts.
The NIOSH investigators point out their evaluation took place during the winter, which is a slow time for business at the BlueLinx facility. With that in mind, NIOSH notes that the risk of injury might increase when the volume of orders increases.
"As a rule of thumb, the jobs studied will begin to increase in risk when and if lifting frequencies approach one or two lifts per minute on average, as opposed to less than one lift per 5 minutes or less, as was the case during the evaluation," the report says.
In such scenarios, NIOSH points out that rotating workers to non-lifting jobs would be "a practical measure for injury control."
Mechanical Lifts Might Be Necessary if Load Weights Increase
For the infrequent situations when lifted loads approach 51 pounds which, NIOSH asserts, is a weight that only can be safely lifted "under ideal conditions" NIOSH recommends control measures such as the use of mechanical lift assists, lowering of the weights handled and two-person lifting.
Overall, NIOSH recommends that BlueLinx:
- Reduce the weight of loads lifted, particularly in the molding area, as much as is feasible;
- Use lifting devices such as vacuum lifts or other mechanical assists for handling fixed-weight products such as boxes of nails and siding or heavy objects such as rolls of steel strapping and copper flashing;
- Continue to use safe lifting practices;
- Avoid lifting from below waist height or above shoulder height when picking objects directly from storage racks; and
- Keep work patterns and staffing levels that ensure order-picking remains an occasional lifting task (fewer than one lift per 5 minutes on average).
The entire report can be viewed at http://www.cdc.gov/niosh/hhe/reports/pdfs/2005-0318-3006.pdf.