Line speed is the term most often used for the maximum speed of the slaughter line on which animals are killed, bled out, and undergo internal organ removal. The speed is set by the USDA in the Code of Federal Regulations and is based on the number of animals that Food Safety and Inspection Services (FSIS) inspectors can effectively inspect for disease.[1,2]
In discussing line speeds, it is necessary to distinguish between the slaughter line (also called evisceration line) and the processing lines. The slaughter line usually feeds into multiple processing lines where workers debone and/or cut up the carcasses into pieces.[3] The USDA has no authority over processing line speeds, which are generally slower than slaughter line speeds, many of which are highly automated (in the poultry processing sector).[4] The agency regards the two processes as independent of each other.[5]
Livestock – 9 CFR § 310.1 Extent and time of post-mortem inspection; post-mortem inspection staffing standards
Poultry – 9 CFR § 381.69 Maximum line speed rates under the New Poultry Inspection System
National Chicken Council, Poultry Processing Line Speeds: An Infographic Overview, https://www.chickencheck.in/infographics/poultry-line-speeds/
U.S. Government Accountability Office (2017) Workplace Safety and Health: Better Outreach, Collaboration, and Information Needed to Help Protect Workers at Meat and Poultry Plants, GAO-18-12, p. 38. [“According to FSIS officials, FSIS does not regulate the speed of other lines, which may run slower than evisceration lines due to complex worker tasks.”]
USDA FSIS Modernization of Poultry Slaughter Inspection, 79 Fed Reg 49566, 49598. [“FSIS believes a key distinction should be made between processing line speed, inspection line speed, and daily production volume…The current poultry regulations and this final rule do not prevent industry from running a processing line faster or slower than the inspection line.”]
Slaughter line – First, live birds are manually unloaded from crates and hung on the shackles of the slaughter line. The processes that follow involve stunning, head cutting, scalding, de-feathering, and evisceration, which in the U.S. are largely automated.[1-3] The regulatory maximum slaughter line is 140 birds per minute (bpm), except for plants that have been given a waiver to operate at 175 bpm. Poultry operations are moving toward more automation that would allow for faster line speeds; one company currently markets evisceration equipment capable of processing 225 bpm.[4]
Processing Lines – Once the eviscerated birds have been chilled (to limit pathogen spread), they go to processing lines where they are cut into parts and packaged. Here, workers stand close to one another making rapid, repetitive cuts to the birds that quickly move on a conveyor belt.[5,6] The processing lines run at an average speed of ~37 birds per minute.[7]
Eruis Equipment (November 2022) 12 Steps for Chicken Slaughtering in a Slaughterhouse. https://www.slaughterhousemachine.com/12-steps-for-chicken-slaughtering-in-a-slaughterhouse
National Chicken Council, Poultry Processing Line Speeds: An Infographic Overview. https://www.chickencheck.in/infographics/poultry-line-speeds/ [Estimating 2% of plant employees work on the evisceration line.]
OSHA, Poultry Processing Industry eTool, Butting & Deboning. https://www.osha.gov/etools/poultry-processing/tasks/cutting-deboning/cutting#
Baader High Performance Evisceration manual. https://exhibitor-manual-004.s3.ap-south-1.amazonaws.com/Production/exb_doc/2016/17187/BRO_13_High_Performance_Evisceration_EN.pdf [Today, BAADER offers evisceration equipment capable of processing up to 13,500 birds per hour…” at p. 3]
Southern Poverty Law Center (2013) Unsafe at These Speeds, p. 11 [“The fast speed of the processing line also increases the risk of cuts and gashes for workers handling knives, scissors and saws. These workers often stand virtually shoulder-to-shoulder, putting them at risk of cutting not only themselves, but co-workers as well.”]
CDC (April 26, 2020) Meat and poultry processing workers and employers : interim guidance from CDC and the Occupational Safety and Health Administration (OSHA), p. 4. [The CDC recommended that poultry processing workers be separated “if feasible” by at least “six feet apart in all directions (e.g., side-to-side and when facing one another), when possible.”]
USDA FSIS (January 9, 2025) Poultry Processing Line Speed Evaluation Study, p. 91. [Report notes that line speeds at various stages of cut up lines ranged from ~34 to ~49 bpm, with the majority operating at ~37 bpm. The only exception was the area where birds were rehung on shackles direct from the chiller, with a line speed of 105 bpm.]
A recent study commissioned by the USDA found that 81% of all processing workers had an “unacceptably high MSD risk” regardless of slaughter line speed.[1]
Overall, the study did not conclude that slaughter line speed by itself was associated with MSD (musculoskeletal disorder) risk – not surprising given that poultry slaughter lines are highly automated. However, they did find that on the processing lines, “Piece rate, a proxy for job line speed and staffing levels, was statistically significantly associated with MSD risk. Job-specific line speeds and staffing levels are important drivers of MSD risk.”[2] Thus, if the “flow” of birds increases (i.e., faster slaughter lines delivering birds at a more rapid pace) and there is an insufficient number of processing workers to handle that flow, workers are at “increased risk for hand/wrist, upper extremity, and low back injuries.”[3]
Interviews with Workers – The study’s interviews with workers found that 40% reported experiencing moderate to severe upper extremity pain during the 12 months preceding the site visit. And of that group, 43% did not report their pain to their supervisor or company health provider.[4] “Although most workers could not tell if slaughter line speed affected the demands of their jobs, many felt that the pace of their jobs was too fast.”[5]
USDA FSIS (January 9, 2025) Poultry Processing Line Speed Evaluation Study, Harris-Adamson, C. et al., (Researchers, Univ. of California, San Francisco), p. 46. [This study was done to assess the impacts of increased slaughter line speeds on workers at 11 poultry operations where slaughter line speeds were running between 140 BPM and 175 BPM.]
Poultry Processing Line Speed Evaluation Study, p. 46. [Piece rates varied between plants and tasks, ranging from ~13 to over 40 pieces per minute. See, Table A.5.1.b, p. 75, and for definition of piece rate by job, see, Table 4.2.1, p. 18]
Poultry Processing Line Speed Evaluation Study, p. 58-59. [“However, none of the establishments appeared to have employed either in-house or external scientific research teams to document the ergonomic or respiratory exposures before and after the implementation of increased evisceration line speeds between 141 and 175 BPM.” An odd omission, given that the plants were given modified waivers for the express purpose of determining the impact of increased line speed on workers safety.]
Poultry Processing Line Speed Evaluation Study, p. 46.
Poultry Processing Line Speed Evaluation Study, p. 58.
Two seminal reports by the CDC (NIOSH) documented high numbers of MSD symptoms and MSDs in poultry workers due to the ergonomics hazards of the work.
CDC – In a report by Musolin et al., researchers found that 42% of workers had evidence of carpal tunnel syndrome. In both baseline and follow-up evaluations, 39% reported musculoskeletal symptoms of the hand or wrist, and 57% reported at least one musculoskeletal symptom (in other body parts).[1] The processing line was running at 35 bpm.
In another NIOSH study, 76% of workers had an abnormal nerve conduction test result, and 34% had evidence of carpal tunnel syndrome. MSD symptoms were also documented, with 58% of workers reporting symptoms in their hands or wrists and 64% reporting at least one MSD symptom in another body part.[2] The processing line was running at 40 bpm.
Worker Interviews – Human Rights Watch interviewed workers who reported that “rapid work speeds compound the highly repetitive, forceful movements required by meat and poultry slaughtering and processing work and increase the risk of developing musculoskeletal disorders.”[3] Workers said that they “perceived notable increases in line speeds throughout all departments of their plant since the company implemented the new inspection system…”[4]
The Southern Poverty Law Center found that 78% of workers surveyed in a poultry plant reported that increased line speed made them feel less safe, made their work more painful, and caused more injuries.[5]
Musolin, K., et al. (2014) U.S. Dept. of Health & Human Services, CDC, NIOSH, Evaluation of Musculoskeletal Disorders and Traumatic Injuries Among Employees at a Poultry Processing Plant, Report No. 2012-0125-3204, p. 5, and p. 26. [Report notes the processing line speed of 35 bpm (p. 2)]
Ramsey, J., et al., (2015) U.S. Dept. of Health & Human Services, CDC, NIOSH, Evaluation of Carpal Tunnel Syndrome and Other Musculoskeletal Disorders among Employees at a Poultry Processing Plant, Report No. 2014-00403232, p. 2. [Report notes the processing line speed of 40 bpm (p. 2)]
Human Rights Watch (2019) ‘When We’re Dead and Buried, Our Bones Will Keep Hurting’: Workers’ Rights Under Threat in US Meat and Poultry Plants, p. 50.
‘When We’re Dead and Buried, Our Bones Will Keep Hurting’: Workers’ Rights Under Threat in US Meat and Poultry Plants, p. 50.
Southern Poverty Law Center & Alabama Appleseed (2013) Unsafe at These Speeds: Alabama’s Poultry Industry and its Disposable Workers, p. 7. [This report documents many independent studies showing the correlation between the rates of repetition of a task and development of MSDs and cumulative trauma injuries. See also, Poultry Processing Worker Illnesses & Injuries]
In contrast with poultry slaughter, most of the killing, evisceration, and secondary processing of cattle and hogs is done manually. In a study of the impacts of increased line speed – referred to as “evisceration line speed” – on livestock slaughter workers, the USDA lists the numerous tasks in disassembling an animal without distinguishing which tasks are performed at “evisceration line speed” and which are performed “downstream of evisceration” which might imply a lesser speed.[1] It is evident, however, that nearly all of the tasks are still done manually on large, heavy animals.[2]
Although robotic technology has been developed, in the U.S. it is not yet common. This lack of automation “is evident if you visit a typical meat processing and production facility in the Western world, where you will find large numbers of workers performing a variety of highly repetitive tasks at remarkably high speeds.”[3]
Per USDA regulations, the maximum slaughter line speed for pigs is 1,106 head per hour (HPH), but a few pig slaughter plants have been given waivers to run them faster.[4] To date, there are no cattle slaughter plants given waivers to operate above the maximum slaughter line speed of 390 head per hour.[5]
USDA FSIS (January 9, 2025) Swine Processing Line Speed Evaluation Study, Harris-Adamson, C. et al., (Researchers, Univ. of California, San Francisco, p. 17. [“…a mix of jobs throughout the production process was included to fully evaluate the impact of evisceration line speed on processes upstream and downstream of evisceration.” And see, Table 4.2.1 p. 18]
Kim, J., et al., (2023). Robot Technology for Pork and Beef Meat Slaughtering Process: A Review. Animals, 13(4), 651, p. 2. [“In slaughterhouses that process red meat, carcasses are large, and equipment must be able to cope with the complexity and size of the work. Moreover, the characteristics of meat vary with species, breed, rearing conditions, feed diversity, carcass-splitting method, and
occurrences of abnormal anatomy.”]Mason, A., et al., (2023). Time for Change: The Case of Robotic Food Processing [Industry Activities]. IEEE Robotics & Automation Magazine, 30(2), 116–122, p. 116. [“However, the pace of automation in red meat processing has not kept up with other sectors.”]
USDA FSIS (January 9, 2025) Swine Processing Line Speed Evaluation Study, p. 17. [Report notes that some plants were operating up to 350 HPH faster.]
See, Slaughterhouse Line Speed Regulations
A recent study commissioned by the USDA found that 46% of evaluated workers were at high risk for musculoskeletal disorders (MSDs).[1]
The study found that slaughter line speed by itself was not associated with MSD risk. However, “Piece rate, a measure of work pace that accounts for job-specific line speed and staffing levels, was associated with a statistically significant increase in risk of injury across all establishments and was a better indicator of MSD risk than evisceration line speed.”[2]
Interviews with Workers – Of the workers interviewed, 42.8% reported moderate to severe upper extremity pain during the 12 months prior to the site visit. And of the workers who said they experienced any work-related pain, about one third did not report their pain to a supervisor or on-site nurse.[3] The researchers noted that “Pain was common among interviewed workers and was accepted by workers as part of the job.”[4]
USDA FSIS (January 9, 2025) Swine Processing Line Speed Evaluation Study, Harris-Adamson, C. et al., (Researchers, Univ. of California, San Francisco, p. 8. [This study was done to assess the impacts of increased slaughter line speeds on workers at six pig slaughtering operations.]
Swine Processing Line Speed Evaluation Study, p. 6.
Swine Processing Line Speed Evaluation Study, p. 70.
Swine Processing Line Speed Evaluation Study, p. 74.
CDC – In a study of 240 workers at a Michigan pork processing plant, NIOSH officials found that 32% of workers on the slaughter line had experienced work-related symptoms, pointing to upper body musculoskeletal disorders in the prior 12 months.[1] About 32% of all workers had hand activity levels and force above the ACGIH action limit, and 61% had hand activity levels and force at or above the ACGIH threshold limit, which is “considered unacceptable.”[2]
Some workers reported that “after a chain speed increase, it was harder to keep up with work, they had experienced more pain, and some job tasks had fewer people assigned.”[3]
Worker interviews – Other studies have found that rushing to keep up with line speed increases injuries, muscle pain, and a sense of higher risk and diminishing safety.[4,5] In a civil law suit involving hog slaughter, workers testified that when the speed of the line that carries stunned animals was increased, the kill floor workers had to keep pace. They reported that there is a higher risk that hog carcasses fall from the hooks and crush them and/or that they’re cut by other workers attempting to finish cuts on hogs that have already passed through their area.[6]
As clearly stated by a leading epidemiologist who conducted years of human health research in pork processing plants, “There is no doubt that increasing line speed will increase laceration injuries to workers. It doesn’t take a multiyear, prospective surveillance study of pork workers to prove that line speed causes injuries. One need only spend time inside the plants observing workers and production pressures to recognize that the intensely rapid pace of the work combined with ever present additional hazards including sharp objects, noise, temperature extremes, slippery floors, and crowded spaces already make for extremely hazardous conditions for workers.”[7]
Grant, M. P., et al., (2024) U.S. Dept. of Health & Human Services, CDC, NIOSH, Evaluation of Ergonomic Risks, Musculoskeletal Disorders, and Peracetic Acid Exposure Among Employees at a Pork Processing Plant in Michigan, p. 2. Note: This plant’s line speed (slaughter/evisceration line) was operating close to the regulatory maximum at an average speed of 1,100 hogs per hour. at p. 1]
Grant, M. P., et al., (2024), pp. 1-2. [Exposure levels above the (ACGIH) action limit are a warning sign that the exposure levels are getting too high. The ACGIH threshold limit value is the level above which a worker’s hand movement is considered unacceptable.]
Grant, M. P., et al., (2024), p. B-13.
Leibler, & Perry, M. J. (2017). Self-reported occupational injuries among industrial beef slaughterhouse workers in the Midwestern United States. Journal of Occupational and Environmental Hygiene, 14(1), 23–30, Table 1, p. 26. [“Rushing was identified as the cause of nearly 50% of injuries, and repetitive work as the cause of an additional 20% of injuries.”]
Lander, L., et al., (2012) A case-crossover study of laceration injuries in pork processing. Occupational and Environmental Medicine (London, England), 69(6), 410–416, Table 3, p. 412.
United Food & Commercial Workers Union v. US Dept of Agric., Case No. 19-cv-2660, 532 F. Supp. 3d 741 (D. Minn. 2021) [Testimony and affidavits before the court and cited in its decision, pp. 7-8]
Professor Melissa J. Perry, Professor of Environmental & Occupational Health (2018) Comment on Proposed Rule, Modernization of Swine Slaughter Inspection, 83 Fed. Reg. 4780. https://www.regulations.gov/document/FSIS-2016-0017-83467 (accessed 5/25/25)
There are no federal regulations of either slaughter or processing line speeds enacted to protect workers. Although OSHA can make recommendations, it has no authority to regulate line speeds.[1]
Both OSHA and FSIS have acknowledged that worker safety may be a concern when setting faster line speeds, and in 1994 they entered into a collaborative agreement to identify and report on safety issues.[2] But more than twenty years later, the GAO found that collaboration between the agencies had “improved little” since 2005 when it recommended that the two agencies strengthen their efforts.[3] And then in 2023, the GAO issued a damning report, stating, “we have seen little evidence of direct on-the-ground collaboration to help protect meat and poultry workers. Further, our discussions with OSHA worker safety inspectors and FSIS meat and poultry inspectors indicate little knowledge of the need to collaborate on worker safety.”[4]
The USDA, under the Trump administration, apparently referring to the two commissioned line speed studies released in early 2025, claims that “extensive research has confirmed no direct link between processing speeds and workplace injuries.”[5] This ignores the critically high levels of MSD risk uncovered in those and other reports, as well as the common sense conclusion that without significant workflow and staffing changes, higher slaughter line speeds can negatively impact worker safety.
U.S. Government Accountability Office (2017) Workplace Safety and Health: Better Outreach, Collaboration, and Information Needed to Help Protect Workers at Meat and Poultry Plants GAO 18-12, p. 38. [“The Occupational Safety and Health Administration (OSHA)— which is responsible for overseeing worker safety and health—does not play a role in regulating line speed, according to FSIS and OSHA officials.”]
USDA FSIS (2022) FSIS and OSHA Sign Memorandum of Understanding to Protect Workers and Enhance Training. https://www.fsis.usda.gov/news-events/news-press-releases/fsis-and-osha-sign-memorandum-understanding-protect-workers-and
U.S. Government Accountability Office (December 2017) GAO-18-12, p. 49.
U.S. Government Accountability Office (June 2023) Meat and Poultry Worker Safety: OSHA Should Determine How to Address Persistent Hazards Exacerbated by COVID-19, GAO-23-105104, p. 50.
USDA (March 17, 2025) Press Release: Secretary Rollins Takes Action to Streamline U.S. Pork and Poultry Processing. https://www.usda.gov/about-usda/news/press-releases/2025/03/17/secretary-rollins-takes-action-streamline-us-pork-and-poultry-processing
As of March 2025, there are 44 chicken plants participating in a USDA waiver program.[1]
There are 6 hog slaughter plants operating with increased line speeds as of March 2025.[2]
All the plants operating with faster than regulatory slaughter line speeds were part of a time-limited trial for the USDA to assess the impacts on worker safety. However, apparently in response to the two commissioned studies released in January 2025, “FSIS will no longer require plants to submit redundant worker safety data,” and the agency plans to formalize speed increases for these plants. It is unclear if additional slaughter plants will also be afforded waivers.[3]
USDA, FSIS (March 2025) Modernization of Poultry Slaughter Inspection https://www.fsis.usda.gov/inspection/inspection-programs/inspection-poultry-products/modernization-poultry-slaughter (accessed 5/24/25)
USDA FSIS (March 2025) Modernization of Swine Slaughter Inspection, NSIS Conversion Numbers https://www.fsis.usda.gov/inspection/inspection-programs/inspection-meat-products/modernization-swine-slaughter-inspection
USDA (March 17, 2025) Press Release: Secretary Rollins Takes Action to Streamline U.S. Pork and Poultry Processing. https://www.usda.gov/about-usda/news/press-releases/2025/03/17/secretary-rollins-takes-action-streamline-us-pork-and-poultry-processing