If you work in food growing, food processing, or food distribution, there are many concerns to consider about the presence of pathogens and contaminants in the same environment as your product. This presentation answers frequently asked questions about establishing a pathogen environmental monitoring program for your facility.

1. How to Establish a
Pathogen Environmental
Monitoring (PEM) Program
By Ivy Cho
ivyc@abcr.com

2. Questions to ask
• What are the environmental
sources of spoilage organisms?
• Where is the presence of
foodborne pathogens or their
indicators in the environment
and on the equipment?
• How effective are the cleaning
and sanitation practices?
• How frequent should the
cleaning and sanitation be
practiced?

3. Facility environment
• Pathogens can enter as raw materials,
ingredients, pests, or by people.
– Persist in niches and hot spots and moves
through the facility by traffic flow, dust,
and condensation
Perfect recipe for
contamination!

4. Microbiological concerns
• Pathogens
– Salmonella spp.
– Listeria spp.
– E. coli 0157:H7
• Indicator organisms:
non-
pathogenic, indicat
ors for
contamination
– Aerobic plate count
– Coliforms
– E. coli

5. PEM zoning concept – Zone I
• Zone I: direct or indirect product
contact surfaces after the lethality
or microbial reduction step and
before the
product is
sealed in the
primary
package

6. PEM zoning concept – Zone II
• Zone II: non-
product
contact sites
adjacent to
Zone I

7. PEM zoning concept – Zone III
• Zone III: non-
product contact
sites adjacent to
Zone II, areas of
cross-
contamination
risk

8. PEM zoning concept – Zone IV
• Zone IV:
areas remote
from Zone I

9. PEM zoning concept examples
Zone I – slicers, conveyors,
peelers, strip tables,
utensils, work tables, racks,
employee hands, pumps,
hoppers, fillers
Zone II – exterior of
equipment, refrigeration
units, framework, equipment
housing
Zone III – phones, air return covers, hand
trucks, forklifts, walls, floors, drains
Zone IV – cafeteria, locker rooms, halls, warehouse, loading dock

10. Sampling methods for PEM
• The use of proper sampling methods is
crucial for ensuring reliable and
defensible data.
– Surface sampling: sponges and swabs
– Product residue scraping and dust
samples
– Water and rinse samples
– Air samples

11. Establish your baseline
• Investigational sampling is
intensive to establish a
baseline.
– It is not uncommon to sample
25-50 target areas in each
zone everyday for a
month.
• By determining the baseline counts, it will be
established what is unacceptable and acceptable
under normal operating conditions.
• Move to routine sampling; rotate sites and test each
site 4 times a year.

12. Sampling Diagram
Minimum
Zone Sampling site Microbiological analyses sampling Number of
frequency samples
I Direct product Indicator organisms Weekly Line
contact site and pathogens under dependent
special situations
II non-product Pathogens Weekly 10-15
contact sites
adjacent to Zone I
III non-product Pathogens Weekly 10-15
contact sites
adjacent to Zone II,
areas of cross-
contamination risk
IV areas remote from Pathogens Monthly 5-10
Zone I

13. How valuable is a PEM program?
• It is more dependable and concrete to
monitor the environment than to depend
on finished product testing only.
– Can help identify and eliminate harborage
niches and hot spots.
– Can demonstrate food safety competence
to visitors (auditors, buyers, regulators).
– Verifies that sanitation, GMP’s, and pre-
requisite programs are working in
competence.

14. Related information
Video instructions on how to perform environmental sampling
The dos & don'ts of environmental sampling
Video instructions on how to sample water & ice
How to sample for laboratory water testing

15. Questions?
For additional
information, please
contact us at
352.372.0436 or visit our
website at abcr.com