Determination of Cleaning and Sanitization Efficacy
The FDA Food Safety Modernization Act (FSMA) of 2011 rule on Sanitary Transportation of Human and Animal Foods one of seven foundational rules proposed to create a modern, risk-based framework for food safety.1 A key requirement of the rule is that vehicles and transportation equipment design, maintenance, and storage must be appropriate to prevent the food from becoming unsafe during transportation operations.2 FDA expects shippers and carriers to develop and implement written procedures that ensure vehicles and equipment are maintained in appropriate sanitary conditions. This assurance necessitates attention to the adequacy of cleaning and sanitation procedures.
A relevant question would be: How is adequacy of cleaning and sanitization determined?
A measure of cleaning and sanitization efficacy is the recovery of contaminants after cleaning and sanitization are conducted according to the documented procedures. Contaminant recovery is determined by sampling. There are two general types of sampling that have been found acceptable: direct surface sampling and use of rinse solutions. The most desirable is the direct method of sampling the surface of the equipment.3
Table 1. Direct Sampling Methods
Advantages of direct sampling are that areas hardest to clean and which are reasonably accessible can be evaluated, leading to establishing a level of contamination or residue per given surface area. Additionally, residues that are "dried out" or are insoluble can be sampled by physical removal.
Rinse Sampling is commonly utilized in a Clean-In-Place (CIP) system. A fixed volume of the sampling liquid, for example, water for injection systems (WFI) is passed at a designated temperature through the spray device to cover all internal surfaces of the equipment and collecting that rinse solution in a suitable collection vessel as it exits the drain valve in the manufacturing vessel. Two advantages of using rinse samples are that a larger surface area may be sampled, and inaccessible systems or ones that cannot be routinely disassembled can be sampled and evaluated. A disadvantage of rinse samples is that the residue or contaminant may not be soluble or may be physically occluded in the equipment. It is important to determine that a direct measurement of the residue or contaminant has been made for the rinse water when it is used to validate the cleaning process.
If the validation test fails, a re-test should be performed. If the test fails a second time, a diagnosis of both the method of cleaning and the method of testing is required.
Table 2. Sampling of Surfaces by Swabbing
1. KEY REQUIREMENTS: Final Rule on Sanitary Transportation of Human and Animal Food https://www.fda.gov/downloads/Food/GuidanceRegulation/FSMA/UCM494118.pdf