ATLANTA and SAN FRANCISCO - When University of California San Francisco (UCSF) officials were contracted by the U.S. Department of Agriculture (USDA) to conduct research on line speeds at pork and poultry processing facilities, they knew exactly who to ask for additional support: researchers from the Safety, Health, and Environmental Services (SHES) division at Georgia Tech.
A program housed in Tech's Enterprise Innovation Institute, SHES offers occupational safety, health, and environmental (OSHA) consulting and training services to manufacturers across the country and has worked extensively examining food-processing workers' exposure to chemicals.
UCSF needed a partner with specific scientific expertise regarding employee exposure to a chemical used to limit bacterial growth during pork processing. SHES' prior working relationship with UCSF also proved beneficial. In 2021, SHES industrial hygienist Brandon Philpot was the primary investigator (PI) for a collaborative project with a group from the UC system to develop safety training for workers fabricating engineered stone countertops.
"UC San Francisco's School of Medicine was so impressed with our team's work, they came back to us for this much larger project," said Jenny Houlroyd, Ph.D., manager of occupational health services at SHES. "We're trying to build meaningful relationships and leverage expertise across institutions."
Study Parameters
The study was initiated when the USDA's Food Safety and Inspection Service division contracted with third-party experts to investigate whether increases in poultry and swine evisceration line speeds affected worker safety.
A secondary aspect of the study looked at the potential for an increase in worker exposure to peracetic acid (a food-safe chemical applied to surfaces in certain food-processing applications) when processing line speeds are increased.
"The study's designers believed that ergonomics was the driving factor in worker safety, but they were unsure if by slaughtering and processing more animals per day, workers were also applying more peracetic acid," said Houlroyd. "This is what the SHES team was asked to measure."
In addition to tapping Georgia Tech's expertise in industrial hygiene, UCSF brought in several other schools in the University of California system, primarily UC Berkeley, to assist with research.
Scope of SHES' Role
"Our work with UC started in July 2024 and was completed in January 2025," said Houlroyd, who served as the project's PI and UC liaison.
Conducting the field research were SHES industrial hygienists Philpot, Sean Castillo, and Bob Hendry, as well as SHES OSHA Training Institute Education Center manager Hilarie Warren. The group traveled to six pork processing plants across the U.S. over 11 weeks.
Although the preferred method for industrial hygiene and worker exposure is to chart direct exposure to the workers themselves, the study did not allow employees to wear chemical monitors on the processing line for safety reasons.
"Our on-site sampling included putting on a variety of wearable monitors on ourselves," Hendry said. "We'd then go to the various work areas in the plant where peracetic acid was used, stand next to the workers, and take readings."
Each SHES team member upheld consistent sampling standards, but they were stationed at different sites. As a result, Castillo said, "It was up to us to use professional judgment to evaluate where the areas of concern were. We had to make sure we were very organized so that if I was at one site one week and Bob came out the next week, we could replicate our data almost one-to-one."
Importance of Worker Interviews
The USDA study received Institutional Review Board (IRB) approval, which is needed if researchers interact with human subjects. Houlroyd noted that because the USDA study was considered formal research, IRB approval was necessary.
Although conducting worker interviews was not a requirement of their participation, the SHES team set up a special room where they interviewed employees on ergonomic issues and musculoskeletal disorders.
"We were able to take the load off from our collaborators and, in doing so, speed up their process so that they could finish their research earlier," said Castillo.
Philpot stressed the importance of worker interviews to the study. "The process was good for collecting background information on what the employees were going through, day in and day out, to see if there's anything that we could do to help their situation."
By putting workers at ease, he and his teammates were able to gain their trust and listen to their concerns. "They could actually see that we cared about what's going on," Philpot said.
According to Houlroyd, "One of the reasons the UC group loved Brandon and Sean and Bob so much is that we've had so much experience doing interviews, we were quick to jump into that role and help them. Our team knows that there is dignity in all labor, so we approach workers with respect. We meet the workers where they are, and we speak to them not as an academic, but human to human."
Study Results
Acting Secretary of Labor Julie Su reported that the USDA study found that faster line speeds did result in an increased risk of injuries, but that this risk "could be mitigated with other controls, specifically having more workers on the line and having effective ergonomic plans."
The results of the peracetic acid research conducted by SHES, however, were inconclusive. "Was there more exposure at the faster line speed?" asked Houlroyd. "We found one plant where it was true, but it wasn't consistently true at all the plants, so it was determined that there should be more research."
Regardless, she welcomed the chance to strengthen collaborative ties with the UC system and celebrated the meticulous and compassionate work conducted by SHES.
"I am so grateful for this team for traveling to remote locations in our country and spending 11 weeks in slaughterhouses," said Houlroyd. "I had no doubt that we could do it, and we did it well."
