"Visually Clean" Is Not Enough: What New Research Means for Allergen Cleaning Validation
"Visually Clean" Is Not Enough: What New Research Means for Allergen Cleaning Validation
If you work in food safety, food manufacturing or food service, you will likely have seen "visually clean" used as a monitoring criterion in cleaning procedures and HACCP plans. It describes what a person can see on a surface after cleaning. The problem is that what you can see and what is actually on that surface are not always the same thing, particularly when allergens are involved.
New research published through the Allergen Bureau has made that distinction very concrete, and the findings have direct implications for how food businesses approach allergen control.
What the research looked at
The study examined how effectively common cleaning methods remove allergen residues from typical kitchen surfaces including stainless steel, plastic, ceramic and wood. Allergens tested included egg, wheat (gluten), sesame and almond. Cleaning methods compared were manual wash-rinse-sanitise procedures and mechanical warewashing at both high and low temperatures.
What it found
Mechanical warewashing consistently outperformed manual cleaning across most food types. For operations that rely heavily on manual cleaning of allergen-contact equipment, this is a finding worth examining.
Sticky, high-fat foods like tahini and almond butter proved particularly difficult to remove. Even when surfaces appeared visually clean, allergen residues were often still detectable. Pre-cleaning steps and multiple wash cycles improved outcomes but did not always eliminate residues completely.
The most significant finding for food service and food manufacturing operations is the recontamination pathway. The study identified that allergenic material can transfer through shared wash water onto items that were otherwise clean. This is a cross-contact risk that can sit inside your cleaning process, undetected, if your cleaning approach has not been validated.
Why this matters for HACCP and allergen control
Allergen management is an area of increasing scrutiny for food businesses across Australia. Whether you are certified to SQF, ISO 22000 or another GFSI-recognised standard, or whether you are working toward certification, your allergen control program needs to be built on more than documented procedures.
This is where the distinction between three related but different things becomes important.
A cleaning procedure tells you what actions will be taken. It documents the steps, the chemicals, the contact times and the method. What it does not tell you is whether those actions are actually sufficient to remove allergens from your specific surfaces, with your specific equipment, for the specific foods used in your facility.
Cleaning validation is the process of demonstrating that your cleaning procedure is capable of reducing allergen residues to an acceptable level under defined conditions. Validation needs to reflect your actual operation: the food matrices involved, the surface types, the equipment and the cleaning method. A procedure validated for one allergen and surface type cannot automatically be assumed to work for another.
Cleaning verification confirms that the validated procedure has been correctly followed and has achieved the expected result during routine operations. Verification is your ongoing evidence that the system is working.
If "visually clean" is the primary monitoring criterion for allergen cleaning in your operation, without validated procedures behind it, this research provides a clear evidence base for why that needs to be reviewed.
What food safety consultants and auditors are looking for
As a food safety consultant and HACCP consultant working with food businesses across Australia, allergen cleaning validation is an area I see flagged regularly during audits. The expectation under SQF, ISO 22000 and broader food safety management system requirements is not simply that a cleaning procedure exists. It is that there is documented evidence the procedure works for the specific conditions in which it is applied.
For internal auditors, this is a useful area to examine during your own program reviews. Check whether your cleaning validation records reflect your current product mix and equipment. Check whether any changes to ingredients, suppliers or equipment have triggered a revalidation. And check whether your monitoring criteria, including any use of "visually clean," are appropriate for the level of allergen risk in your operation.
The practical step forward
Review your allergen cleaning procedures with validation in mind. If they have not been validated, or if validation was done under conditions that no longer reflect your current operation, that is worth addressing before your next certification audit.
If you need support developing or reviewing allergen cleaning validation as part of your food safety management system, Pinnacle Management Systems works with food businesses across Australia on practical, evidence-based HACCP and allergen control programs.
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