Surface Sampling and the Detection of Contamination

Cross-contamination is an increasingly important risk factor in food safety. Cleaning and disinfection regimens are essential components in its prevention but need to be validated, monitored, and verified. This in turn requires the implementation of protocols for surface sampling and the assessment of residual contamination. Visual assessment although widely used, in isolation, is ineffective but can be useful as part of an integrated approach. Microbial and nonmicrobial methods of sampling and testing are compared. Nonmicrobial assessment methods, especially ATP, are effective at monitoring residual surface soil. Traditional specific, and nonspecific, microbial methods indicate residual microbial contamination but not surface soil. Recent advances in molecular microbial methods and bioluminogenic tests are discussed. There is no single ideal surface test method and how, when, and where to sample are discussed within the framework of suggested guidelines, an integrated approach, and the use of trend analysis.