NIOSH Evaluates Ergonomics at Michigan Pork Processing Plant

Employees at a pork processing plant in Michigan were at risk for musculoskeletal disorders when NIOSH evaluated the plant in 2021 and 2022, according to a recently published health hazard evaluation (HHE) report. At the request of plant management, NIOSH staff members performed a virtual walkthrough and visited the plant twice. Workers’ hands moved at rates at or above ACGIH’s Threshold Limit Value for hand activity levels and force in 61 percent of the job tasks evaluated, according to the report. OSHA logs showed that the rate of upper body musculoskeletal disorders (MSDs) at this plant were higher than the overall rate reported for the animal slaughtering and processing industry, and about one-third of employees involved in harvesting tasks—in which hogs are killed and eviscerated—had experienced work-related symptoms of upper body MSDs in the preceding 12 months. Most of the reported musculoskeletal injuries involved the hand or wrist. The NIOSH evaluators also detected peracetic acid, acetic acid, and hydrogen peroxide at locations near a spray cabinet used for sanitation.

The HHE describes recommendations for reducing workers’ risk for MSDs, starting with assessing job tasks to reduce repetition, force, and awkward postures and applying ergonomic interventions. These interventions include decreasing the speed at which work is performed and increasing the number of employees assigned to a task. Implementing a job rotation plan may reduce risk for MSDs, as employees who do repetitive work with their hands move to jobs that use other parts of their bodies. Other recommendations include increasing the number of breaks employees take to reduce the time they spend doing continuous work, providing adjustable stands at workstations, and creating a workplace ergonomics team.

The plant could also take steps to improve monitoring for MSDs and training employees in injury prevention. For example, the NIOSH evaluators found that the plant provided training on how to report symptoms and concerns in English and Spanish, but employees also spoke many other languages. The HHE recommends that the plant ensure all employees are trained on how to recognize, prevent, and report musculoskeletal symptoms specific to their job tasks. The employer should identify any policies and procedures that discourage employees from reporting illnesses and injuries and taking medical leave, take steps to improve recordkeeping, and regularly review data.

Although sampling by NIOSH did not find levels of peracetic acid, acetic acid, or hydrogen peroxide that would have required personal exposure monitoring, the HHE recommends several engineering and administrative controls to reduce exposures. For instance, the HHE advises management to move the cart where employees placed disposable plastic aprons and other non-cloth apparel during break times away from the peracetic spray cabinet, as NIOSH evaluators had observed these items accumulating liquid from the cabinet.

Plant management are also advised to address some other health and safety issues identified by the NIOSH evaluators. Some employees had experienced cough or shortness of breath potentially caused by ammonia exposures and others did not wear hearing protection correctly or in areas where it was required. To address these concerns, the report recommends that employees receive training in their preferred languages.

The report may be downloaded as a PDF from NIOSH’s HHE report archive.