Listeria Prevention in Dairy Processing: Why Proactive Sanitation Matters

For dairy processors, controlling Listeria monocytogenes is an ongoing operational challenge. The pathogen can persist in processing environments, contaminate equipment and food-contact surfaces, and create serious risks for ready-to-eat products.

In 2026, the FDA placed renewed emphasis on dairy safety, identifying cheese aging practices, small ice cream producers, and queso manufacturers as areas for additional education, evaluation, and prevention efforts.

Subsequent contamination investigations reinforced the importance of that focus.

What Recent Listeria Incidents Reveal

In June 2026, the FDA investigated a multistate Listeria outbreak associated with soft cheese. In September, the agency issued a warning letter to an ice cream company describing recurring environmental Listeria findings and shortcomings in the facility's preventive controls.

These cases illustrate a persistent problem in food manufacturing: contamination risks aren't always resolved through routine cleaning alone.

Listeria can survive in refrigerated environments and persist in difficult-to-clean areas of processing equipment. Once established, contamination can become an ongoing challenge without effective sanitation, environmental monitoring, and corrective action.

For dairy processors, the objective is to identify and control these risks before they affect finished products.

Why Continuous Prevention Matters

An effective sanitation program extends beyond scheduled cleaning.

It requires understanding where contamination can occur, verifying that controls are working, and responding quickly when monitoring identifies a problem.

The FDA emphasizes preventive controls, sanitary equipment design, environmental monitoring, and documentation as important components of food safety management.

For facilities producing cheese, ice cream, and other ready-to-eat dairy products, these practices are especially important because contamination may occur after a product's primary microbial reduction step.

Where Ozone Can Support Dairy Sanitation

Ozone is a powerful oxidizing agent with established antimicrobial applications in food processing and water treatment.

Depending on the facility and intended use, appropriately designed ozone systems may provide an additional means of microbial control in process water or selected sanitation applications.

One advantage of ozone is that it decomposes into oxygen rather than leaving a persistent ozone residual. This makes it worth evaluating in processing environments where chemical residues and product quality are important considerations.

Research has also examined ozone's effectiveness against Listeria and microbial biofilms. However, results depend on concentration, contact time, surface conditions, and the presence of organic material.

Ozone is not a replacement for validated sanitation procedures, environmental monitoring, or preventive controls. It is a potential additional tool within a comprehensive food safety program.

Building a Stronger Sanitation Strategy

The most effective approach to pathogen control begins with evaluating the entire processing environment.

That includes equipment design, cleaning procedures, water quality, microbial monitoring, and the ability to document treatment performance.

For dairy processors considering ozone, the first step is identifying applications where it could provide measurable benefits and determining how treatment effectiveness would be validated.

Ozone International works with food processors to evaluate ozone treatment opportunities within existing operations, including system integration, monitoring, and ongoing service.

For dairy facilities reviewing their sanitation programs, the goal is straightforward: strengthen preventive controls before contamination becomes a recall.

Links

‍