Cleaning boosts sanitizer performance against foodborne pathogens
Sept. 30, 2026
By John Lovett
University of Arkansas Division of Agriculture
Fast Facts
- Food safety study ranks sanitizers on produce packing house food-contact surfaces
- Dry environments should not be considered low risk simply because water is limited
- Cleaning before sanitizing improved pathogen reduction by nearly 6 percentage points
(1,084 words)
Download PHOTOS of Kristen Gibson
SIDEBAR: What produce packing house research can teach you about your cutting board
FAYETTEVILLE, Ark. — Cleaning food-contact surfaces before sanitizing can achieve nearly 100 percent pathogen removal, according to a two-year study that also found foodborne bacteria and viruses can survive for days on materials commonly used in produce-packing facilities.
The findings can help growers and packers reduce contamination risks before produce reaches consumers, said Kristen Gibson, leader of the study and a professor of food safety and microbiology for the University of Arkansas Division of Agriculture’s research arm, the Arkansas Agricultural Experiment Station.
In addition to stainless steel, many produce packers also use porous materials such as unfinished wood, high-density foam and rubber. The study, funded by the Center for Produce Safety, measured the effectiveness of sanitizing these “unconventional” food-contact surfaces after being cleaned with soap and water.
“People hear ‘clean before you sanitize’ all the time, but this work demonstrates why that step is so important,” Gibson said. “If organic material remains on a surface, sanitizers may not work as effectively. The type of surface and the sanitation strategy both matter.”
Gibson is also director of UADA’s Center for Food Safety and part of the department of food science in the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas.
The data collected showed that cleaning before sanitizing improved pathogen reduction by nearly 6 percentage points, increasing average reductions from 93.81 percent with sanitizer alone to 99.75 percent with cleaning and sanitizing.
“The difference may seem small, but it is significant,” Gibson said. “It is the difference between tens and hundreds of bacteria removed.”
The research also showed that viruses can persist on surfaces for extended periods depending on the temperature, which she said was “critical to understand in establishing effective sanitation programs.”
Looking beyond stainless steel
To better understand real-world conditions, the research team visited 15 packing houses of varying sizes across the United States to document commonly used materials and sanitation practices.
The facilities handled crops ranging from leafy greens and root vegetables to apples, grapes, tomatoes and corn. Researchers visited facilities in Arkansas, Florida, Michigan, North Carolina and Washington and conducted virtual interviews with produce safety educators, including those with land-grant university extension services.
The extension educators identified high-density foam as the greatest food safety concern. The material is commonly used to cushion produce as it moves between processing steps.
Back in the lab, Gibson and her team tested how well viral and bacterial pathogens survived on the different surfaces.
The bacterial pathogens included listeria, salmonella and Shiga toxin-producing E. coli, or STEC. Viral pathogens included Tulane virus, a surrogate virus to mimic human noroviruses, and Aichivirus A, a human picornavirus that causes gastroenteritis.
The industrial sanitizers included a peracetic acid and hydrogen peroxide solution, isopropyl alcohol and quaternary ammonium compounds, and chlorine dioxide.
Survival for each pathogen was monitored over seven days at two temperatures: 27 degrees Celsius (80.6 degrees Fahrenheit) and 21 degrees Celsius (69.8 degrees Fahrenheit).
Dry contamination can be deceptive
One finding that stood out for Gibson involved dry contamination.
In addition to testing cleaning and sanitizer treatments in the lab with liquid droplets containing microorganisms, the researchers also tested a dry contamination scenario by using a sand-based medium to mimic dust and debris that may accumulate in packing facilities.
Bacterial pathogens introduced in dry conditions often persisted as long as, and sometimes longer than, those introduced in wet conditions. Although the pathogens were not multiplying, they could remain viable on surfaces for extended periods.
“The driving factor for bacterial persistence varied by bacterial type but was primarily dependent on how the bacteria were cultured — nutrient-rich versus nutrient-deprived conditions — and temperature,” Gibson said. “Wet versus dry was also a factor but not always significant.”
The results suggest that dry-packing environments should not automatically be considered low risk simply because water is limited and underscore the need for routine sanitation even in dry facilities, Gibson added.
No one-size-fits-all sanitizer
The treatments evaluated for the control of foodborne pathogens included cleaning alone, each sanitizer alone, and cleaning followed by each sanitizer. Soapy water and a brush were used to clean the surfaces for 30 seconds followed by a 30-second rinse.
Cleaning with soapy water followed by sanitizing was the most effective treatment, achieving an average 99.75 percent reduction in pathogens across all surface types.
- A peracetic acid-based sanitizer performed well across wood, rubber and high-density foam, producing average reductions of 99.7 percent even when used without a preceding cleaning step.
- Chlorine dioxide, a strong oxidizing agent, was the least effective on all food-contact surfaces when used alone. However, its effectiveness improved dramatically when paired with cleaning, achieving a 99.68 percent reduction in pathogens.
- On wood surfaces, cleaning alone was insufficient for effective bacterial reduction. When combined with cleaning, the sanitizers reduced pathogens on wood by at least 99 percent. When not cleaned, the peracetic acid-based and isopropyl alcohol-based sanitizers performed best on wood.
- On wood and rubber surfaces, researchers observed no significant differences among sanitizer treatments.
- While the foam supported longer persistence of foodborne pathogens, the recovery efficiency was significantly different than the other surfaces so no direct comparison was possible.
For packing houses that use foam, rubber and wood as food-contact surfaces, Gibson said the study’s results highlight the need for more frequent evaluation of whether these surfaces can be effectively cleaned and sanitized.
“We were able to reduce contamination under controlled laboratory conditions,” Gibson said. “But what we did isn’t always practical in an operating packing house.”
Practical guidance for growers
The research provides additional evidence that produce packers should use hygienically designed, nonporous food-contact surfaces whenever possible and carefully evaluate sanitation frequency, especially in facilities that operate seasonally or rely on difficult-to-clean materials, Gibson said.
For smaller packing operations with limited staff and resources, Gibson said the findings can help close knowledge gaps and support food safety decisions that protect both consumers and produce markets.
“This project was really about providing data that growers and packers can use,” Gibson said. “The more we understand how pathogens behave in these environments, the better we can prevent contamination before it happens.”
Gibson will present findings from the research during a Center for Produce Safety webinar on Oct. 27 titled “Sanitation of Nonconventional Food-Contact Surfaces.”
About the researchers and funding support
Center for Food Safety members who took part in this project with Gibson included Md. Ashrafudoulla, Ph.D., Sahaana Chandran, Ph.D., Lucy Carreon, Kafui Kwamikorkor, Juan Moreira, Ph.D., Meagan Moseley, Hanyi Shi, Ph.D., and Matthew Vawter.
The Center for Produce Safety provided support for this research under award number 2024CPS03.
To learn more about ag and food research in Arkansas, visit aaes.uada.edu. Follow the Arkansas Agricultural Experiment Station on LinkedIn and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.
About the Center for Produce Safety
The Center for Produce Safety (CPS) is a 501(c)(3), U.S. tax-exempt, charitable organization dedicated exclusively to advancing produce safety. CPS provides the produce industry and government with open access to actionable information, empowering stakeholders to continually improve practices and reduce food safety risks.
About the Division of Agriculture
The University of Arkansas Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.
The Division of Agriculture is one of 22 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on three system campuses.
Pursuant to 7 CFR § 15.3, the University of Arkansas Division of Agriculture offers all its Extension and Research programs and services (including employment) without regard to race, color, sex, national origin, religion, age, disability, marital or veteran status, genetic information, sexual preference, pregnancy or any other legally protected status, and is an equal opportunity institution.
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Media Contact:
John Lovett
U of A Division of Agriculture
Arkansas Agricultural Experiment Station
(479) 763-5929
jlovett@uada.edu