Clean Bottles Don't Stay Clean
During a routine sanitation audit on a dairy farm I always include checking a nursing bottle and nipple carried on the milk feeding cart. I use a luminometer to pick up the presence of bacteria (see note below on this tool). This dairy is using an ATP value of 100 as an upper threshold for acceptable cleanliness.
The audits in March and June showed these values respectively:
Bottle: 0 and 83
Nipple: 0 and 7
At the September audit the values were:
What is going on here?
As a result of very high ATP values last year a sanitizing protocol was being followed before each feeding. The bottle was filled with a warm strong bleach solution at the beginning of each feeding. It was dumped out before using or if not used dumped out at the end of the feeding routine.
With a change in personnel this sanitizing protocol was discontinued. The "clean" equipment sat unused for a full week before I checked the bottle and nipple.
The lesson here is that "clean" equipment does not stay clean.
[I use the Hygiena SystemSure Plus unit (luminometer) to do adenosine triphosphate (ATP) monitoring. The ATP test is a process of rapidly measuring organic matter including actively growing microorganisms through the detection of adenosine triphosphate. An ATP monitoring system can detect the amount of potential microbial contamination that remains after cleaning a surface (for example, calf feeding equipment).
Thresholds used in the food processing industry are less than10 RLU for direct food contact surfaces and less than 50 RLU for environmental surfaces. I often use a reading of 100 RLU as realistic on-farm upper threshold for calf feeding equipment.]