MSU Extension Agrifood Safety

Environmental monitoring (EM) isn’t looking for things that harm the environment like you might find in the MAEAP program. Rather, this activity involves the routine monitoring for microbial pathogens through testing surfaces where you might be likely to find them.

Because it isn’t easy to do, EM is often performed for farms with packhouses or coolers by private microbiological labs. An environmental monitoring program is invaluable for farms doing regularly scheduled sanitation cleaning in buildings and equipment. EM is even useful for farms doing as-needed cleaning for meeting the Produce Safety Rule, which does not require sanitizer use, but calls for food contact surfaces to be free of visible filth - a term encompassing dirt, mold and plant residues that can trap harmful bacteria.

Environmental monitoring should only be done on non-food contact surfaces adjacent to locations where food is handled. This is because a positive result on food contact surfaces might result in an FDA recall. Three types of environmental monitoring and what they test for are listed below:


Total Aerobic Plate Count (APC)

What does it measure: An APC test measures the number of living bacteria that grow on whatever surface you are testing. These are all bacteria that grow when oxygen is present. These bacteria overwhelmingly do not make people sick. Bacteria that cause foodborne illness, if present, will also be counted as part of all the bacteria.


Adenosine Triphosphate (ATP) Luminometer test

What does it measure: Every living cell uses an enzyme called adenosine triphosphate (ATP) to generate energy. As cells are destroyed through the cleaning process, this enzyme gets smeared over all surfaces. When you’ve cleaned the surface well, the ATP is largely removed too.


Listeria Species (spp.) test

What does it measure: There are a lot of different types of listeria out in the world. Some don’t cause human health issues. Some, like Listeria monocytogenes, will make a person very sick or even kill them. A Listeria spp. test measures the presence of any Listeria species around on the surfaces tested.