Evaluation of Repeatability of Surface ATP Test Devices at Different Environmental Temperatures

Introduction: The hygiene of food contact surfaces is critical to ensure the safety and quality of foods. The use of surface ATP hygiene monitoring systems is widespread and provides food business operators with rapid, measurable and cost effective tests. This enables them to take corrective actions in a timely manner and improve surface hygiene. Therefore, it is essential that the ATP hygiene monitoring system provides accurate and reliable results.   

Purpose: To evaluate the repeatability of seven brands of surface ATP test devices and luminometers at different environmental temperatures, in order to assess performance differences, and whether repeatability varies at different temperatures. 

Methods: The performance of the luminometers and ATP test devices was evaluated at 5°C, 10°C, 20°C and 35°C using an environmental chamber. All devices were tested by pipetting 10µl of a 4 x 10^–9 M ATP solution onto the mid-section of the swab/sponge bud of each device. Testing was completed following the instructions provided by the device manufacturer. The repeatability was assessed by calculating the Coefficient of Variance (%CV). 

Results: Ten repeat samples at each temperature for all manufacturers were obtained to evaluate the repeatability. The results suggest that only one of the seven devices had consistently repeatable results (%CV < 20) at all temperatures studied.  

Significance: There are considerable differences between the repeatability performances of the brands; it is essential that hygiene monitoring systems provide a repeatable result to ensure consistency and accuracy of results. Effective and accurate surface assessment can be used for optimization of sanitation procedures and continual improvement.