Food / Hygiene

Just how clean is clean? Before the advent of adenosine triphosphate (ATP) testing, public health inspectors frequently cited food contact surfaces for not being clean to the sight and touch. Now an ATP testing meter provides a quantifiable answer to the question of cleanliness in a matter of seconds.

So what exactly is ATP? ATP is a molecule found in all organic matter, living or dead, including plants, animals and cells. The detection of ATP on a visibly clean surface indicates the presence of biological microorganisms too small for the human eye to see. Microorganisms such as bacteria, viruses and fungi (mold) can present a risk to human health and safety.

ATP testing was developed in the late 1980s and early 1990s. Early ATP test kits were big, heavy and complex, so sanitarians struggled to both carry and use the kits routinely in the field. However, as electronics technology became streamlined over time, so did ATP testing technology. Today's ATP testing meters are portable handheld devices designed for quick and easy assessments of surface hygiene. Results are presented in relative light units (RLUs), as the ATP testing meter measures the light produced by a reaction between the ATP and luciferase. Luciferase is a naturally occurring firefly enzyme used as a reagent in ATP testing. For convenience, the luciferase often comes in a single-use pen-sized container complete with a swab. Generally, low levels of total ATP indicate a more sanitary surface, as ATP is found in microbiological material and proper cleaning, sanitization and sterilization practices should eliminate most microbial residue.

While ATP tests are conducted during health inspections, food service and food processing facilities are encouraged to take a proactive stance on food hygiene. Regular ATP testing should be an integral part of any food hygiene monitoring program, including but not limited to a Hazard Analysis and Critical Control Point (HACCP) system.

According to the United States (US) Food and Drug Administration (FDA), "a hazard is defined as a biological, chemical or physical agent that is reasonably likely to cause illness or injury in the absence of its control." Therefore, bacteria on a food contact surface would constitute as a hazard. An effective surface sanitization process would constitute as a control. To document proper implementation of this control, the staff at PCE Instruments recommends using an ATP testing meter that records date- and time-stamped measuring results. An ATP testing meter with data-recording or data-logging functionality saves time by automating the documentation process.

In addition to food industry applications, ATP testing has applications in the medical industry. ATP testing is performed in pharmaceutical laboratories to avoid cross-contamination. ATP testing also is conducted in hospitals and other healthcare facilities to prevent the spread of disease.

An ATP testing meter can be used for detecting and measuring biological matter on surfaces as well as in water. A first-generation ATP testing meter is typically used on surfaces, while a second-generation ATP testing meter is designed for use in water and wastewater. Thus, an ATP testing meter is a useful tool in almost any industry where hygiene control is crucial.

Using this brief introduction to hygiene and ATP testing, it should be possible for you to identify the right measuring tool to meet your needs. However, if you have any questions, please don't hesitate to contact us at or +44 (0) 2380 987 035 for PCE Instruments UK, or or +1 (561) 320-9162 for PCE Americas Inc.