| ATP surface cleanliness |
ATP stands for Adenosine Tri-Phosphate. ATP is the energy currency of living cells. All living cells contain it. ATP may be present on surfaces either as cells or in released form. Substances that contain ATP include food, recently active cells, and actively living cells. Housedust may also contain ATP. The relative level of ATP present on a surface is an indicator of the general "cleanliness" of a surface. |
| "Cleanliness" versus "contamination" | While high ATP levels may correlate with contamination, this is not always the case, as "contamination" can also take non-biological forms. "Contamination" simply means presence of particles on a surface, it does not refer to the physical, chemical, radiological, viable or other nature of particles on a surface. A low level of ATP detectable on a surface is an indicator of the general "cleanliness" of a surface, but does not mean a surface is devoid of all contamination. A low level of ATP detectable on a surface can mean that decontamination may have made a difference/ improvement to the state of cleanliness of the surface. |
| "Caution" | A caution should be interpreted as a fail, as recommended by the meter and swab manufacturers. However, if a caution is achieved on a retest of a surface that formerly yielded a fail, then the caution may represent an improvement in surface cleanliness. |