Chlorine Dioxide and Dry Steam in Food Processing: The Clean Break That Resets Pathogen Risks

Sometimes, incremental cleaning isn’t enough. That’s when food and beverage processors need what Jared Torgeson, vice president at PureLine Solutions, calls a “clean break.”

Torgeson discussed the benefits of using chlorine dioxide, an FDA- and USDA-approved sanitizer for food facilities, during the recent QA webinar “Chlorine Dioxide: Reset the Pathogenic Environment,” sponsored by PureLine Solutions.

Chlorine dioxide appeals to food and beverage facility operators as a sanitizing agent in part because it leaves no residue behind. It also delivers a 6-log reduction in pathogens such as Listeria and Salmonella — two of the most common culprits behind foodborne illness.

“From floor to ceiling, wall to wall, every single surface is going to be decontaminated within the treatment area,” Torgeson said.

Because chlorine dioxide is a true gas, it diffuses evenly and penetrates cracks, seams and harborage sites.

“As long as air can get to it, gas is going to get to it,” said Torgeson.

This type of environmental decontamination isn’t meant for daily sanitation. Instead, chlorine dioxide in food processing is used as a corrective action when standard methods can’t eliminate persistent positives, or as part of a preventive strategy in high-risk areas.

“Chlorine dioxide is not designed to replace everyday sanitation,” said Torgeson. “It’s designed to reset the environment and provide a clean break.”

Four rules for a pathogenic reset.

Consider the following guidelines when conducting a pathogenic reset:

1. Start clean. Gas won’t tunnel through grime. “Surfaces must be clean and free of residue before the treatment,” said Torgeson.
2. Verify with science. Effective programs validate results through adenosine triphosphate (ATP) testing, APC (aerobic plate count) and biological indicators containing six logs of resistant spores. “All of our swabs are sent to a third-party lab, so you have independent validation of a successful treatment,” said Torgeson.
3. Check material compatibility. While chlorine dioxide is broadly safe, Torgeson noted that “the only oxidation you would ever see would be on mild, unpainted steel,” and even then, the discoloration is cosmetic. Being aware of this ahead of time helps facilities prevent surprises and maintain confidence in the treatment.
4. Control environmental conditions. Temperature: Chlorine is more effective above 41°F; freezers are ideally shut down. “Coolers, not necessary [to shut off],” said Torgeson.
   • Humidity: Higher humidity enhances efficacy; dry air requires a higher dose.
   • Light: UV degrades gas molecules, so lights are typically kept low.

Chlorine dioxide benefits.

Typical chlorine dioxide treatments take 8–12 hours, Torgeson said — often less than the downtime required for full manual disassembly and wipe-downs of processing equipment.

According to Torgeson, chlorine dioxide in food processing offers several other advantages for food and beverage sanitation programs:

• Bacteria cannot develop resistance to chlorine dioxide. “Some sanitizers kill 99% or 99.9%, leaving the most stubborn, hardest-to-kill bacteria organisms left behind, creating superorganisms over time,” he said. “That's never going to be the case with chlorine dioxide.”
• The gas is ideal for dry clean-only areas. “Dairy plants, spices or any applications you can’t get wet — chlorine dioxide treatments don’t introduce any moisture into the environment,” said Torgeson.
• Chlorine dioxide oxidizes biofilm, not only destroying the hard-to-remove, glue-like substance, but preventing it from forming in the first place, penetrating the slime to kill microorganisms.
• There’s no extra clean-up involved once the treatment is complete. “There is no post-rinse required after sanitation,” said Torgeson.

“[Chlorine dioxide] is designed to reset the environment and provide a clean break.” —Jared Torgeson

Cleaning with dry steam.

Where chlorine dioxide resets a facility’s pathogenic environment, dry steam targets equipment and surfaces with precision, less water and the same benefit of no chemical residue.

Sean Westerwelle, national enterprise accounts director at Steamericas, discussed the benefits of sanitizing with dry steam in food and beverage processing environments during the August QA webinar “Cleaning Smarter: Dry Steam Sanitation for Safer, More Sustainable Food Production,” sponsored by Steamericas.

“It’s not just water and chemical savings,” Westerwelle said of dry steam sanitation. “It’s the increased productivity and reduced cleaning times.”

What makes steam ‘dry?’

It comes down to moisture content, said Westerwelle. Boilers hold temperatures around 340° F, creating steam that behaves “more like hot air than wet or water,” he explained. That high heat instantly inactivates pathogens without oversaturation.

“It's so hot that at the flash point, you generally don't have to worry about a buildup of moisture on the surface,” Westerwelle said.

Steam is validated to kill pathogens including Listeria, Salmonella and E. coli, and it’s also been used to reduce allergen proteins, said Westerwelle.

Where to use dry steam.

Westerwelle listed some of the ideal environments for using dry steam sanitization:

• Conveyors and belts: Automated or pneumatic nozzles allow one operator to manage multiple belts at once.
• Sanitize-in-place (SIP): “Steam tenting” encloses equipment in plastic sheeting to raise temperatures without disassembly. “You’re wrapping it … to keep that steam captured or concentrated so that you can increase the temperature of the entire device,” said Westerwelle.
• Sensitive equipment: Electronics, guards, motors and belts can be sanitized without corrosion or damage, said Westerwelle.
• Drains and floors: Persistent biofilms in wet areas respond to high-heat disruption, he said.

Allergens and biofilms.

Westerwelle stressed that allergens are physical contaminants, not just microbial hazards.

“It’s not as much about just hitting it with heat,” he said. “It’s a physical problem.”

Dry steam can lift proteins from pores and seams, making them easier to wipe or vacuum away, Westerwelle said.

Biofilms, meanwhile, succumb to thermal inactivation. High heat breaks down the protective matrix and ruptures cells, said Westerwelle.

Dry steam benefits.

Traditional wash-down methods rely on volume — more water, more chemicals, more people. Each has costs and risks, said Westerwelle:

• Water: Oversaturation increases slip hazards, lengthens dry times and leads to wastewater handling.
• Chemicals: Residues require extra rinsing; exposure creates safety risks. “Any time we have to be around chemicals, mixing chemicals, trying to get it right, there’s all those chances, those risks in there,” Westerwelle said.
• Labor: Adding workers doesn’t always guarantee better quality. “Are we really optimizing for quality, or are we just throwing more people at it?” Westerwelle asked.

By contrast, dry steam allows one worker to manage multiple stations, he said. One bakery cited reduced water use from 1,200 gallons to just 24 gallons per conveyor belt cleaning, with cleanup time dropping from hours to minutes, Westerwelle shared.

“Steam can be the last step if you’d like it to be,” Westerwelle said — especially in allergen or pathogen cleanup workflows.

Dry steam safety and setup.

As with any high-energy system, dry steam requires proper safeguards, said Westerwelle:

• PPE: Gloves, safety glasses and long sleeves protect operators. “Don’t spray yourself with it,” he said.
• Water quality: Steamers need soft water (5–40 ppm). How do they respond to hard water? “Not well,” said Westerwelle, adding that it can cause scale buildup and increased downtime. “That’s the very short answer.”
• Power and accessories: Ensure appropriate voltage and choose attachments that match cleaning needs, from handheld steam guns to automated belt cleaners.

“The goal is to let steam do all the heavy lifting for you.” —Sean Westerwelle

Integrating advanced cleaning methods into fsqa programs.

Both sanitization methods have clear roles. Gas-based chlorine dioxide treatments are used for corrective resets, post-contamination interventions and high-risk zones. Dry steam sanitation is best suited for routine precision cleaning, allergen control, drain biofilm disruption and sensitive equipment sanitation.

The strongest programs often combine both: periodic clean breaks to reset environments, plus ongoing steam applications to keep equipment and surfaces safe.

For FSQA leaders, the following principles apply, regardless of method:

1. Pre-clean before you sanitize. Whether gas or steam, start with surfaces free of visible soils.
2. Design for access. Sanitary design and accessibility reduce harborage and overspray.
3. Validate every step. ATP, APC, biological indicators and allergen swabs provide confidence and audit documentation.
4. Document and trend. Data isn’t just compliance — it shows when resets are needed and when processes succeed.
5. Train for safety and consistency. Operators must understand not just how to run equipment, but why it matters.

Reaching further, cleaning smarter.

In today’s food facilities, FSQA professionals face twin pressures: keeping pathogens and allergens out while meeting sustainability goals and facing labor constraints. Gas treatments and dry steam sanitation provide complementary answers — one to reset the environment with a validated clean break, and the other to clean smarter with less water, fewer chemicals and more precision.

As Westerwelle put it, “The goal is to let steam do all the heavy lifting for you.” And when sanitation demands a true reset, Torgeson’s reminder holds: “Chlorine dioxide in food processing is not designed to replace everyday sanitation. It’s designed to reset the environment and provide a clean break.”

Together, these approaches offer FSQA teams more than compliance. They provide confidence that when production starts, it starts clean — every surface, every shift.

Editor’s Note: Information for this article was taken from two recent QA magazine webinars: “Chlorine Dioxide: Reset the Pathogenic Environment,” sponsored by PureLine Solutions, and “Cleaning Smarter: Dry Steam Sanitation for Safer, More Sustainable Food Production,” sponsored by Steamericas. Both webinars are available to watch in full on qualityassurancemag.com/tag/webinars.