Most Chicken Slaughterhouse Workers At High Risk For Injury

In recent years, the United States Department of Agriculture (USDA) has granted waivers allowing chicken slaughterhouses to increase their evisceration line speeds up to 175 birds per minute. This has raised concerns for the well-being of workers, who must perform highly repetitive and forceful motions that are known to cause debilitating musculoskeletal disorders such as carpal tunnel syndrome. Beyond physical injuries, workers in these facilities are also exposed to airborne chemicals like peracetic acid, an antimicrobial agent that can cause respiratory irritation and other health issues.

To investigate these concerns, the USDA funded a large-scale study to assess how evisceration line speeds affect worker safety. The research aimed to understand the relationship between line speed and the risks of both musculoskeletal disorders and respiratory symptoms from chemical exposure.

Researchers from the University of California, San Francisco conducted a cross-sectional study between November 2023 and April 2024 involving 1,047 workers across 11 U.S. poultry processing plants. These facilities operated at various line speeds, from 140 to 175 birds per minute. The study team used a comprehensive approach, gathering data through worker surveys, medical interviews, and direct ergonomic assessments using video analysis and wearable sensors that measured muscle exertion and wrist movements. They also measured airborne peracetic acid concentrations in various work areas.

Workers were about 38 years of age on average. Most were men (54.5%), born outside of the U.S. (52%), identified as Black or African American (36%) or Hispanic (37%), and had a primary language other than English (52%).

Surprisingly, the study found that the overall evisceration line speed of a plant was not directly associated with a worker’s risk of developing a musculoskeletal disorder. Instead, the critical factor was the individual worker’s “piece rate” — the number of chickens or chicken parts they were required to handle per minute. The researchers discovered that some establishments with faster overall line speeds mitigated the risk by adding more staff to a specific job or slowing down that individual station, which kept the piece rate from increasing.

However, this doesn’t mean the work is safe. The study revealed a staggering level of danger across the board: regardless of the line speed, 81% of workers were found to be at an unacceptably high risk for a musculoskeletal disorder. This indicates that the combination of forceful exertion and rapid repetition required for their jobs is inherently hazardous.

This risk translated into widespread suffering. Across all plants, 40% of workers reported experiencing moderate to severe work-related pain in the past year. The study also found that 70% of workers experienced “break-in pain” when they first started their jobs, and for nearly a quarter of them (24%), that pain never went away. This constant pain took a heavy toll: of those affected, 27% struggled to maintain their work pace or quality, 38% had considered changing lines or quitting, and 21% had taken time off from work.

The problem of pain is compounded by a culture of underreporting. The study found that 44% of workers who experienced work-related pain didn’t report it to a supervisor or company healthcare provider. Medical interviews revealed that many workers felt pain was just “part of the job” and didn’t report it for fear of being unable to maintain their pay or losing their jobs.

In addition to physical injuries, the study also identified significant chemical hazards. While airborne peracetic acid concentrations weren’t linked to line speed, one in five jobs sampled had exposure levels exceeding the recommended short-term safety limit. These unsafe exposures were found at nearly half (45%) of the establishments studied. Overall, about 17% of all participants reported experiencing respiratory symptoms in the last 12 months.

One of the study’s main limitations is the “healthy worker survivor effect.” The poultry processing plants had an extremely high employee turnover rate — an average of 86% in 2023 among the facilities that provided data. This means that the study likely sampled workers who were healthy enough to endure the conditions, while those who left their jobs due to injury weren’t included. Therefore, the study’s alarming findings may actually be an underestimate of the true level of harm experienced by workers.

This report provides powerful, data-driven evidence of the immense human cost embedded in the industrial chicken industry. It shows that focusing on headline-grabbing “line speeds” alone can be misleading. The true danger lies in the relentless pace and physical demands placed on individual workers.

The finding that over 80% of workers face an unacceptably high risk of injury, regardless of the overall line speed, paints a damning picture of the entire system. For animal advocates, this research reinforces the message that the systems that exploit and harm farmed animals are often the same systems that exploit and harm people.

The data on worker pain, fear of reporting, and chemical exposure can be used to build broader coalitions and strengthen campaigns that call for systemic change. The report’s recommendations — such as reducing musculoskeletal disorder risk by increasing staff and slowing down individual job tasks — show that safer conditions are possible but require a fundamental shift away from prioritizing productivity above all else. This evidence can help advocates argue for a more just and compassionate food system for all beings involved.

This summary was drafted by a large language model (LLM) and closely edited by our Research Library Manager for clarity and accuracy. As per our AI policy, Faunalytics only uses LLMs to summarize very long reports (50+ pages) that are not appropriate to assign to volunteers, as well as studies that contain graphic descriptions of animal cruelty or animal industries. We remain committed to bringing you reliable data, which is why any AI-generated work will always be reviewed by a human.