Sanitation Programs for Low-Moisture Ready-to-Eat Foods: How to Prevent and Respond to Pathogen Contamination Events

Does "dry" really mean "safe," or does it just mean the risk is harder to see?

For years, many food manufacturers treated low-moisture foods as relatively low-risk products. After all, products like spices, cereals, powders, nut butters, and powdered beverages are shelf-stable and do not support rapid microbial growth the same way high-moisture foods do.

FDA's draft guidance, released in January 2025 and reopened for comment in May 2025, highlights a growing concern: pathogens can survive in low-moisture ready-to-eat (LMRTE) environments when sanitation controls are weak. The guidance supports compliance with 21 CFR Part 117, and for powdered infant formula, 21 CFR Part 106.

Contamination can spread through dust, airflow, equipment niches, employee movement, or contaminated ingredients long before a product test detects the issue. As a result, food manufacturers need proactive sanitation programs that help prevent, detect, and respond to contamination before it leads to recalls or outbreaks.

Why Low-Moisture Foods Still Carry Serious Pathogen Risks

FDA defines low-moisture foods as products with a water activity (aw) of 0.85 or below. While this environment limits microbial growth, it does not eliminate the ability of pathogens like Salmonella to survive.

That distinction is noteworthy. In dry processing environments, pathogens can persist for extended periods in:

• Equipment niches
• Cracks and harborage points
• Dust accumulation
• Poorly cleaned zones
• Airflow systems
• Dry residues left behind after production

Unlike refrigerated or wet environments where spoilage may become visible, contamination in low-moisture facilities often remains hidden. Facilities may continue operating normally while pathogens silently move through the environment.

This is why FDA strongly emphasizes environmental monitoring and preventive sanitation controls instead of relying solely on end-product testing.

Recent Contamination Events Show the Risk Is Real

Recent recalls and outbreak investigations continue to demonstrate how serious contamination risks can become in dry food environments.

Pistachio Cream Salmonella Outbreak

In 2025, a multistate Salmonella outbreak linked to pistachio cream products triggered recalls after contaminated retail and import samples tested positive.

Moringa Powder and Supplement Recalls

Multiple recalls involving moringa powder products and dietary supplements were also tied to Salmonella contamination in 2025–2026.

Dry Ingredient Contamination

Investigations involving powders, supplements, and shelf-stable ingredients repeatedly showed the same pattern:

• Contamination survived in dry environments
• Pathogens spread through facility conditions
• Contamination was often discovered late in the process

These incidents reinforce a critical lesson for food safety teams: low-moisture contamination events rarely begin with the finished product. They usually begin inside the environment itself.

What FDA's Draft Guidance Is Really Emphasizing

It promotes a broader sanitation strategy that integrates:

• Sanitation controls
• Environmental monitoring
• Hazard analysis
• Preventive controls
• Corrective actions
• Root cause investigations
• Verification activities

FDA describes environmental monitoring as a "seek and destroy" approach, meaning facilities should actively search for pathogens in the environment, identify contamination sources, and eliminate them before product contamination occurs.

Core Elements of an Effective Sanitation Program

1. Hygienic Facility and Equipment Design

Strong sanitation programs begin with hygienic design. Equipment and facility layouts should minimize:

• Hard-to-clean areas
• Residue buildup
• Moisture accumulation
• Inaccessible harborage points

Even small cracks, ledges, hollow rollers, or poorly designed equipment joints can become long-term contamination reservoirs in dry facilities.

2. Controlled Dry Cleaning Practices

In low-moisture environments, introducing unnecessary water can increase contamination risk rather than reduce it. For that reason, dry cleaning methods are often preferred where practical, including:

• Vacuuming
• Dry wiping
• Scraping
• Controlled dry sanitation tools

When wet cleaning becomes necessary, facilities must ensure moisture is tightly controlled, affected areas are thoroughly dried, and sanitation verification occurs before production resumes. Residual moisture in a dry facility can create ideal conditions for pathogen survival and spread.

3. Personnel Practices and Movement Control

People can unintentionally transfer contamination throughout a facility long before anyone realizes a problem exists. That is why zoning and personnel control remain critical in low-moisture plants. Important controls include:

• Hygienic zoning
• Controlled traffic flow
• Gowning procedures
• PPE discipline
• Restricted movement between raw and high-care areas

Without strong movement controls, contamination can spread across production zones even when cleaning procedures appear effective.

4. Sanitation Verification and Documentation

A sanitation program is only effective if the facility can prove it is working consistently. Verification activities should include:

• SSOP documentation
• Sanitation logs
• Cleaning schedules
• Pre-operational inspections
• Verification records
• Corrective action documentation

In low-moisture operations, documented evidence is just as important as execution itself.

Environmental Monitoring as a Preventive Tool

Environmental monitoring is one of the most important tools in low-moisture facilities because it helps identify contamination before it reaches the product.

Zoning Approach: Zone 1 to Zone 4

A zone-based sampling approach gives structure to the program. Food-contact surfaces, near-product areas, and more distant environmental locations should all be considered in a risk-based way. That allows teams to understand whether contamination is isolated or spreading through the facility.

Trend Analysis and Early Risk Detection

A single positive result is important, but trend analysis is what turns environmental monitoring into a real warning system. Repeated positives in the same area can point to equipment issues, poor sanitation execution, or a hidden source of contamination. FDA specifically highlights the value of using monitoring data to identify weak points and improve sanitary conditions over time.

Linking Monitoring Data to Action

This is where many programs fall short. Data is useful only when it leads to action. That action may include:

• Intensified cleaning
• Equipment inspection
• Disassembly
• Retraining
• Deeper root cause investigation
• A review of sanitation frequency or plant layout

Why Product Testing Alone Is Not Enough

1. Limitations of Finished Product Testing

Finished product testing does have value, but it should not be the only line of defense. Contamination in low-moisture foods may be low-level and unevenly distributed, which means a sample may miss the problem entirely.

2. False Sense of Security

A plant may see clean product results while the environment might still hold the pathogen. That is why FDA places greater weight on preventive sanitation, environmental monitoring, and corrective action than on product testing alone.

3. Smarter Approach: Preventive & Predictive Controls

The strongest programs combine preventive controls with predictive thinking. In practical terms, that means using sanitation, zoning, monitoring, and trend data together so risks are caught earlier and corrected faster. FDA's current guidance strongly supports this kind of layered approach.

What to Do During a Pathogen Contamination Event

Step 1: Contain the Situation Immediately

When contamination is suspected:

• Stop affected production
• Isolate impacted areas
• Document findings immediately
• Prevent further movement through the facility

Step 2: Conduct a Structured Root Cause Investigation

The purpose of a root cause investigation is not just to identify where contamination was detected, but to understand why the pathogen survived, how it spread, and what allowed it to persist within the facility. A structured investigation should evaluate:

• Facility and equipment conditions, including harborage points, airflow, and dust movement
• Operational factors such as employee movement, ingredient handling, sanitation execution, and recent process changes
• Maintenance and environmental conditions, especially any moisture introduction in dry areas

Most importantly, investigations should rely on evidence — environmental monitoring results, sanitation records, maintenance logs, and recurring sampling trends should all support the final findings and corrective actions.

Step 3: Assess Potentially Affected Product

Products manufactured since the last validated sanitation break may need to be placed on hold while the investigation continues. Traceability becomes critical at this stage. Facilities should be able to quickly identify:

• Affected lots
• Ingredient sources
• Sanitation windows
• Downstream distribution exposure

Step 4: Implement Corrective Actions

FDA emphasizes that corrective actions must go beyond superficial cleaning. If contamination reaches food-contact surfaces, remediation should include:

• Thorough cleaning
• Sanitization
• Verification activities
• Reassessment of sanitation procedures

Facilities may also need to redesign equipment, adjust sanitation frequency, improve zoning, reduce dust movement, or strengthen moisture controls.

Step 5: Verify Effectiveness

A corrective action is only successful if the contamination issue truly disappears. Verification activities should confirm:

• Sanitary conditions were restored
• The contamination source was eliminated
• Preventive controls are functioning effectively

Repeated positives in the same area usually indicate the underlying root cause was never fully addressed.

Continuous Improvement and Digital Tools

Continuous Improvement and Program Reanalysis

Facilities should reassess programs whenever:

• Contamination trends shift
• Equipment changes occur
• Operational processes change
• Recurring positives emerge
• Major corrective actions are implemented

The strongest food safety cultures treat sanitation, monitoring, investigation, and corrective action as daily operational disciplines, not emergency responses.

How Digital Tools Strengthen Sanitation and EMP Programs

Manual logs and spreadsheets can work for simple tasks, but they make trend visibility and follow-up harder as complexity grows. A digital EMP platform can help teams schedule monitoring, flag misses, record corrective actions, and analyze recurring patterns more efficiently. That matters in low-moisture facilities, where speed and traceability can shape the entire response.

With a system like Smart EMP, the workflow becomes more structured:

• Automated monitoring schedules
• Real-time alerts
• Trend analysis
• Corrective action tracking
• Better audit readiness

Conclusion

Low-moisture ready-to-eat foods may look stable, but stability is not the same as safety. The draft guidance released in early 2025 makes it clear that plants that want to stay ahead need sanitation programs that are proactive, evidence-based, and ready to respond before contamination becomes a crisis.

Don't wait for a positive result to tell you the system is weak. Build the system so it finds the weakness first.

Book a demo today, to see how Smart EMP can help strengthen your sanitation and environmental monitoring program.