ATP or IAQ Meter for Healthy Buildings
An ATP meter is used by cleaning companies to spot-check the work of the cleaners. Special attention is given to the bathrooms and eating areas. ATP (Adenosine Triphosphate) is the enzyme of living matter, particularly bacteria. So, the ATP meter is testing, not directly for bacteria, but the byproduct of bacteria. So, ATP testing is an indirect way to measure for the presence of bacteria. These are then calculated in CFU's', meaning Colony Forming Units.
What an ATP does not measure is the presence of virus. I see some companies offering ATP testing as proof of the sanitizing process. But, ATP meters are testing for bacteria, not virus.
What we can assume is that if the sanitizing process kills of the bacteria, it is likely killing the virus as well. This is helpful, but not a direct test for things like the coronavirus.
ATP testing is helpful in a quality control fashion, but it is a spot check that test several 4" square areas as a sample of the whole job.
I feel it is best to rely on the EPA registered claims of the product and trained workers to do the sanitizing. Products like Decon Five deliver a hospital-grade sanitizing treatment without adding to the chemical bioload of the building. See: http://www.DeconFive.com
An IAQ meter is quite effective at finding the other real threat to worker. A sick or toxic building has been a common concern prior to COVID-19, and should not be a neglected issue now. IAQ or VOC meters test for Volatile Organic Compounds which are the results of chemicals and materials used inside the building. The major VOC is formaldehyde (HCHO) that is found in most buildings. Formaldehyde is well-known as a primary factor in Sick Building Syndrome. There are many more VOCs, but formaldehyde is most prevalent.
When sanitizing with products like bleach, the gas given off by bleach is another VOC, making the sanitized building worse for air quality. In fact many cleaning products add to the bioload of the building. In time, the accumulation of the chemicals, pollutants, toxins, and pesticides can and will create a hostile condition in the building. This is when workers start to complain, take more sick leave, or incur more medical costs.
Sick and toxic building also reduce productivity because of headaches, fatigue, and brain fog.
When given a choice, ask for an Indoor Air Quality (IAQ) check of the building's air. We know how to sanitize for germs, but few firms know how to sanitizing the building and deliver a healthy building. See: http://www.FiveWaySanitized.com.