N.15 – Trouble shooting in environmental monitoring


The major routes of contamination can be broadly classified as surfaces, water, people and air.

Each time that “ALERT LEVEL” and “ACTION LEVEL” are reached, the person responsible for environmental monitoring should know what action must be taken.

The reported troubleshooting guide taken from the Document Guide Line No.20 – Effective

Microbiological Sampling of Food Processing Environments – by C. & C. gives some useful hints.


– Is the problem real? How much confidence do you have in the microbiological evidence and the detection techniques used?

– What is the scale of the problem? Has more than one sample been taken, is the problem within a batch, between batches or across a product range?

– Has the process or recipe been changed? What is it written in the protocol?

– Has the problem occurred before and was it solved? Any evidence in the available protocol?

– Are any single raw material implicated?

– Are environmental microbiological reduction processes in control? Were HVAC System, air filtration, boot-washing, hand-washing, sanitation program recently monitored?

– Where is product contamination first encountered? Once a product becomes contaminated, the product itself will spread the contamination downstream

– When during the production batch is product first contaminated? Contamination at the beginning of production is related to raw materials, failures of microbiological control process or gross environmental contamination levels. Contamination arising late in the production batch is usually related to inadequate sanitation program, leaving residues on surfaces. This may also indicate that production runs are too long in terms of product safety and quality

– If sampling indicates that an equipment surface is the contamination source, is the equipment dismantled for inspection? A close co-operation is necessary between the Production Manager and the Bacteriology Laboratory Manager

– Is the causative organism unusual?


GuideLine No.20 – Effective Microbiological Sampling of Food Processing Environments

Troubleshooting – C&C – 1999.