Biofilm in food manufacturing doesn’t trigger a failed inspection on its own. You can’t always see it. It doesn’t smell. But in food and pharmaceutical manufacturing facilities, biofilm is one of the most persistent and dangerous forms of microbial contamination, and it’s the one that conventional chemical sanitation programs are least equipped to handle.
What biofilm is and how it forms
Biofilm is a structured community of microorganisms, bacteria, mold, yeast, that attach to surfaces and encase themselves in a self-produced matrix of proteins, polysaccharides, and extracellular DNA. That matrix is called the extracellular polymeric substance, or EPS. It acts as a shield.
Biofilm in food manufacturing forms on virtually any surface given the right conditions: moisture, organic material, and time. The highest-risk zones are:
- Drains, drain channels, and floor-wall junctions
- Equipment surfaces and gaskets in CIP (clean-in-place) systems
- Water lines, recirculation loops, and cooling towers
- Porous surfaces including conveyor belts, rubber gaskets, and grouted floors
- HVAC condensate pans and ductwork
Once established, biofilm doesn’t just sit there. It periodically sheds cells into the surrounding environment, including onto product contact surfaces, into water streams, and into the air. Those shed cells are a continuous source of contamination even when routine sanitation is being performed consistently.
Why chemical sanitation struggles with biofilm
Biofilm doesn’t fail sanitation audits because it isn’t there. It fails them because it’s in places the chemistry never reaches, and when it is reached, the EPS matrix neutralizes the disinfectant before it can act.
Standard chemical disinfectants, peracetic acid, chlorine dioxide, quaternary ammonium compounds, are effective against planktonic (free-floating) bacteria. Against biofilm in food manufacturing environments, they face two fundamental problems.
Problem 1: Penetration
The EPS matrix is physically and chemically resistant to many disinfectants. Studies have shown that biofilm-embedded bacteria can require concentrations of chemical disinfectant 100 to 1,000 times higher than planktonic bacteria to achieve the same kill level. At the concentrations used in operational sanitation programs, concentrations that are safe for equipment and food contact surfaces, many disinfectants simply cannot penetrate established biofilm.
Problem 2: Resistance development
Repeated exposure to sub-lethal concentrations of chemical disinfectants creates selection pressure. The bacteria that survive each sanitation cycle are the ones best adapted to that chemistry. Over time, this produces populations that are increasingly resistant to the disinfectants being applied, a phenomenon well-documented in both food manufacturing and healthcare settings.
The practical result: facilities that have been running the same chemical rotation for years are often seeing diminishing returns from their sanitation programs without understanding why.
Where ozone changes the equation
Ozone addresses both problems.
Gaseous ozone penetrates porous surfaces, reaches into cracks and crevices, and contacts the organic material in the biofilm matrix directly. Its oxidative mechanism doesn’t rely on chemical diffusion through a protective layer. Ozone reacts on contact, breaking down the EPS matrix and destroying the bacterial cells within it.
Aqueous ozone, dissolved ozone in water, delivers this same oxidative action in liquid form, making it highly effective for CIP system sanitation, water line treatment, and targeted surface applications where gaseous ozone isn’t the right tool.
Critically, ozone cannot generate resistance. Its mechanism of action, non-selective oxidative destruction of cell walls and DNA, is a physical process, not a chemical one that bacteria can adapt to. There is no documented case of microbial resistance to ozone. There never will be.
The detection problem
One of the most challenging aspects of biofilm in food manufacturing for QA teams is that it doesn’t always show up on routine swabs. Standard ATP bioluminescence testing and traditional plate counts are designed to detect planktonic contamination. Biofilm-embedded bacteria can return a clean swab result while a thriving biofilm community persists beneath the surface.
This is why facilities can pass routine microbiological testing and still experience periodic contamination events, positive environmental monitoring results, or unexplained product quality failures. The biofilm is there. The standard testing protocol just isn’t finding it.
Effective biofilm management requires testing that specifically targets surface biofilm, not just ambient contamination, and a disinfection approach that addresses the matrix, not just the cells floating above it.
Building a biofilm control strategy
A comprehensive approach to biofilm in food manufacturing and pharma facilities generally involves three components:
- Assessment: identifying high-risk zones, understanding current sanitation program gaps, and establishing a baseline of where biofilm is present
- Mechanical disruption: physical removal of established biofilm through high-pressure washing, scrubbing, or CIP protocols, necessary before disinfection can be fully effective
- Chemical-free oxidative treatment: applying gaseous or aqueous ozone to destroy the biofilm matrix and the organisms within it, without the resistance risk or residue concerns of traditional chemistries
HS Ultra works with food and pharma facilities on all three components. The goal isn’t to replace your existing sanitation program. It’s to close the gap that chemical sanitation alone can’t address.
If your facility has persistent environmental monitoring positives, recurring Listeria or Salmonella findings, or simply hasn’t had a third-party evaluation of your biofilm risk profile, an HS Ultra facility assessment is a practical starting point. We identify the gaps, document the baseline, and propose a targeted solution.
