Southeastern U.S. Vegetable Crop Handbook - 2023 - 313

DISEASE CONTROL
SANITATION
Sanitation is a broad term used in the food industry. For produce growers, this term
is often defined by requirements within the PSR or standards within GAPs. Sanitation
includes the basic sanitary conditions and practices within the food industry for
growing and handling of food safely. Measures required to prevent equipment, tools,
facilities (i.e., packinghouses), and sanitation practices from becoming a route of
contamination for produce and food contact surfaces include:
* Pre and postharvest water sanitation
* Cleaning of tools and equipment
* Appropriate storage and maintenance of tools and equipment
* Appropriate use of toilet and handwashing facilities
* Control of pests
* Maintenance of adequate plumbing
* Proper disposal of sewage and waste
PREHARVEST WATER SANITATION
There are many things to consider when choosing a water treatment system, and
it is unique to each water source/situation. Selecting the appropriate water system
treatment is probably the most difficult part of treating your water. The questions below
highlight the basic steps you should consider prior to choosing a water treatment
method. If you decide to choose a water treatment method, you should contact your
local resources to help you decide the best method for your operation.
CONSIDERATIONS FOR CHOOSING A WATER
TREATMENT METHOD FOR YOUR FARM OPERATION
* Is it EPA approved? Chemicals must be EPA registered for their use based
upon the EPA label for the product. If the product doesn't have this information,
you can't use it.
* What is the cost of set-up, continued use, and maintenance? Some treatment
methods require a larger investment than others at set-up, and all
costs (including recurring costs such as chemical costs) should be assessed
at the start to ensure successful implementation of the treatment.
* What are the management and monitoring requirements? All of these
treatments require proper management and monitoring in order to treat the
water effectively and consistently. Be sure you have the time and resources
to invest in order to successfully accomplish these goals on your farm.
* What infrastructure do you already have on your farm? The infrastructure
you already have in place on the farm may more easily lend itself to one
treatment versus another (i.e., electricity, injection point, etc.).
* What is the source of your water? Not all sources of water are equal, keep in
mind the population of indicator microorganisms like E. coli and other factors
like turbidity and alkalinity. This can drive increased chemical demand to
achieve your goals. In the case of UV treatment, more turbid water might
require additional filtration or longer contact time with the UV light.
* What is the application method? How you size and implement a water treatment
depends on your irrigation system and flow rate.
* What is the sensitivity of your crops to the treatment? As some crops may
be more sensitive to particular treatments, it's important to consider your
crop tolerance.
* Are there WPS and other restricted entry considerations? This is another important
consideration for resources that may be needed for your employees
to implement the treatment.
* Are there other EPA or local environmental considerations? Depending on
where you are located, environmental considerations for treated water may
vary before water is discharged back to the environment.
Source: Buchanan, J.R., Chapin, T.K., Danyluk, M.D., Gunter, C.C., Strawn, L.K.,
Wszelaki, A.L., Critzer, F.J. 2019. Bridging the GAPs: Approaches for Treating Water
On-Farm. Curriculum v1.0.
For more information, visit: https://vegetables.tennessee.edu/preharvest-water/
POSTHARVEST WATER SANITATION
Produce may be washed after harvest to remove dirt and debris. According to
FSMA, water used for harvest and postharvest activities must have no detectable
generic E. coli in a 100 mL water sample. Generic E. coli is an indicator organism,
with the idea that if there is generic E. coli in the water, there is a higher likelihood
that there could be other pathogenic organisms.
Growers may use dump tanks or bins for washing produce, which oftentimes relies
on recirculated and batch water. Single-pass systems (i.e., spray bars) may also
be used. For recirculated and batch water systems, it is particularly important to
maintain the sanitary quality of the water throughout its use. Potential contamination
from produce in a batch water system, like a dump tank, can contaminate the water,
IMPLEMENTING A CLEANING AND SANITATION
PROGRAM
Having a dedicated trained crew and crew leader is critical to implement a cleaning
and sanitation program in farms and packing houses. Depending on the size of the
farm, a cleaning crew may be composed of employees that work a regular shift or
employees that only focus on cleaning and sanitation procedures. Always conduct
daily housekeeping activities in packing areas regardless of the frequency of cleaning
and sanitation of other areas. Nonetheless, budget sufficient time for breakdown
of equipment, cleaning, sanitation, and reassembly of equipment. The use of personal
protective equipment (PPE) must be followed based on the different product
label instructions being used. Label instructions must be followed when mixing and
applying sanitizers to food contact surfaces and non-food contact surfaces. Note
that the use of application equipment for cleaners and sanitizers (such as foamers)
can greatly reduce the time it takes to clean and sanitizer equipment and can allow
for access to hard-to-reach areas especially in packing lines. Having a dedicated set
of tools for bathrooms that is never used in any other areas where produce is present
is important to prevent cross contamination. Working with a cleaning and sanitation
company directly is always helpful. Some companies offer training resources for
their products, enhanced labels and provide advice on application equipment. There
are different methods to verify that cleaning and sanitation procedures are actually
working such as ATP meters and environmental monitoring. Consult with your food
safety specialist about what options are feasible for your operation.
TRAINING EMPLOYEES
It is important to train employees about the importance of food contact surfaces and
to take time to properly clean and sanitize packing areas and equipment. Training
employees on how to clean and sanitize surfaces on the farm is a crucial way to
reduce contamination on the farm. Employees must be trained to understand the
difference between cleaning and sanitizing, especially noting that an uncleaned
surface cannot be sanitized. Training employees with a video, like this one from
University of Maryland, (https://www.youtube.com/watch?v=mXtFlWt67z0) and
pausing to demonstrate farm specific cleaning and sanitizing procedures can be an
effective training tool.
thus spreading the microorganisms or cross-contaminating other produce in the
dump tank. The use of sanitizers in wash water systems can significantly reduce this
risk of cross-contamination. Table 3-49 provides a list of sanitizers that are EPA-approved
for use in wash-water systems.
CLEANING AND SANITIZING FOOD CONTACT SURFACES
A critical component within a sanitation program includes procedures for cleaning
and sanitizing, particularly for surfaces on which food comes into contact. The Produce
Safety Rule states that growers must " inspect, maintain, and clean and, when
necessary and appropriate, sanitize all food contact surfaces of equipment and tools
used in covered activities as frequently as reasonably necessary to protect against
contamination of covered produce. "
Identify Food Contact Surfaces
First identify all food contact surfaces, that is, those surfaces that will directly
touch the produce. Examples of food contact surfaces can include knives, harvest
bins, transportation equipment, tables, conveyor belts, and packing materials. And
don't forget about employees' hands - they can be a food contact surface, tooemphasizing
the need for proper handwashing.
Cleaning and Sanitizing Procedures
Once the priorities for cleaning and sanitizing have been identified, implement
proper cleaning and sanitizing procedures. Proper cleaning and sanitizing procedures
follow four basic steps, as described in Table 3-48. Keep in mind that the PSR
defines criteria for water used during harvest and postharvest activities that include
no detectable generic E. coli in a 100 mL water sample.
The use of appropriate detergents is important to consider as they help reduce the
surface tension of water and surround and lifts soil from the surface. Upon rinsing
the detergent, the surface may appear visually clean; however, microorganisms can
still be present even after the cleaning step. Food contact surfaces must include a
sanitization step to reduce the number of microorganisms to a safe level. According
to EPA definition, food contact sanitizers reduce the bacterial count on a surface
by 5 logs or by 99.999%. For instance, if there are 1,000,000 bacteria on a surface
before the sanitizer is applied, this number should be reduced to 10 bacterial cells
after the sanitizer is applied and dried. A list of commonly used sanitizers can be
found in Table 3-49. For food-contact surfaces, sanitizers are often formulated as a
final step after cleaning and rinsing.
2023 Vegetable Crop Handbook for Southeastern United States
313

https://vegetables.tennessee.edu/preharvest-water/ https://www.youtube.com/watch?v=mXtFlWt67z0

Southeastern U.S. Vegetable Crop Handbook - 2023

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