During the modernization era for meat and poultry, how fast carcasses are moved across the slaughter floor is an issue that’s created controversies involving both food safety and worker safety.

Line speed, as it is called, is a current issue before multiple federal  Courts and Congress.

Dr. Mindy Brashears, Under Secretary of USDA for Food Safety, inherited the task of resolving modernization issues from the previous and current administrations. New inspection rules were first adopted for poultry in 2014 and followed by swine in late 2019.

Beef plants are also getting the option of filing for modernization waivers.

And while the line speed controversies have continued to boil, it has not resulted in much new information –until now. A new study finds increased line speed in young chicken slaughter establishments does not increase Salmonella contamination risks.

“From FSiS (Food Safety and Inspection Service) perspective, it does help us,” Brashears told Food Safety News.

Data was collected for 2018-2019 from 97 young chicken slaughter establishments to determine how differing line speeds impacted the frequency of positive Salmonella samples.

Dr. Louis Anthony (Tony) Cox, Jr., in association with the University of Colorado Denver, produced the study. Cox is an MIT-Harvard trained expert in statistics, regression analysis, and mathematics. Many National Academies, World Health Organization, EPA, USDA, and other agencies have named Cox to various projects, committees, and advisory boards.

In 2014, the New Poultry Inspection System (NPIS) gave the young chicken and turkey establishments a new option. Before NPIS, four online FSIS inspectors worked the line to spot unacceptable carcasses at a speed of 140 birds per minute(bpm) based on 35 bpm for each inspector.

Under NPIS, establishment employees are required to sort, wash and trim the poultry before it is presented on the line to a single FSIS inspector. It is supposed to be a faster, more efficient system.

Cox says the question is whether NPIS young chicken establishments can maintain process control at higher line speeds while keeping down microbial hazards such as contamination of carcasses with Salmonella.

Brashears says before NPIS was adopted in 2014, FSIS had some 20  years of data from its HIMP pilot program. It was sufficient to justify a line speed increase to 175 bpm.  “All that data told us it would be safe,” she said.

But, Brashears says because of the large number of concerned comments about line-speed, including many about worker safety, the agency backed off and kept the 140 bpm limit.

FSIS did allow the 20 establishments from its two-decade-long  HIMP pilot program to continue at 175 bpm under waivers. Safe, wholesome, and unadulterated production while meeting Salmonella reduction performance standards were also required for a waiver.

Beginning in early 2018, FSIS began offering line speed waivers to companies that were not in the original HIMP pilot. It required the poultry slaughter establishment to “incorporate measures into their food safety systems to maintain process control when operating at faster line speeds.”

To obtain line speed waivers, it required being in the NPIS for one year and meeting Salmonella performance standards. Not all establishments operated at 175 bpm even with waivers for various reasons.

The Public Health Information System (PHIS) was used to collect the data for the line speed study from on-site veterinarians.

As for the new study findings, it found that increased line speeds don’t increase risk or harm. “Current evidence seems to indicate, however, that the mix of changing conditions in production and slaughter –including accelerated line speeds–result in a product that is not contaminated more often than it was before line speeds were increased,” the study report says.

“The analysis presented here indicates that today’s establishments running at higher line speeds do not cause increased Salmonella risk under the conditions present during this study, ” it continues. “Although there have been useful clarification and much discussion of various sources of risk at higher line speed in regulatory, industry, and food safety circles in the decades since the NRC report, including discussions of occupational safety (Ronholm, 2018), to our knowledge this is the first study to provide recent survey data on today’s establishment addressing the issue of line speed and Salmonella contamination rates on chicken carcasses.”

The National Research Council or NRC called for line speed studies in a report 30 years ago.

The study was done with support from the Poultry Science Association Inc. for publication in Poultry Science.