il-june-18

AN UPDATE ON
THE PRODUCE
SAFETY RULE
By Melissa Partyka
In November 2016, the U.S. Food and Drug
Administration (FDA) finalized the Produce Safety Rule,
which includes an Agricultural Water Provision (AWP)
requiring that growers identify, inspect, and monitor their
irrigation water supplies for indicator E. coli. Compliance
for all aspects of the rule was set to begin in January 2018.
However, in March 2017 the FDA made an announcement
that it was reviewing the AWP after increasing pushback and
confusion over some of the finer points of the provision. In
the end, it kept the criteria the same but pushed the timeline
for compliance out an additional 4 years and continued to
emphasize the possibility of refinement as more science
becomes available. Therein lies the rub.
Most people recognize that monitoring the water
supplies that come into direct contact with fresh produce is
a good idea. The problem that the FDA has encountered,
one echoed by the scientific community, is that there
are currently not enough data available to create a truly
science-based standard for irrigation water. That does
not mean that the regulation of water has no basis in
science, but rather that the science of irrigation water has
lagged behind that of other water types, like drinking or
swimming. Why is that? Because research is hard and
expensive and takes a considerable amount of time before
concrete answers may be had, if any ever are. Further,
funding for research is frequently driven by demand, and
until recently, the demand for research linking microbial
contamination of irrigation water supplies to the risk of
human illness in the United States has been low. However,
as outbreaks of illness associated with consumption of
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fresh produce have increased, so too has public awareness
of produce production environments, placing irrigation
supplies in the crosshairs.
The microbial quality of irrigation water supplies is
at the heart of the matter. Most bacterial, protozoal, and
viral pathogens that have been associated with foodborne
outbreaks are readily dispersed via water, so surface water
distribution networks can spread localized sources of
pathogens across large areas. If a grower’s irrigation source
is contaminated, pathogens may be broadcast throughout
a field, creating contact with many pieces of produce, and
eventually resulting in an outbreak. These, among other
qualities, make water a perfect vehicle for pathogens,
making their regular monitoring beyond a good idea, but
a necessity. The problem is deciding what to monitor for,
which forces the underlying question: What makes people
sick? The answer is: Many things! However, pathogens
are relatively rare, and monitoring for a rare thing is
not only time consuming but also expensive. So many
agencies choose to monitor for indicator organisms that
occur in high concentrations inside human and animal
guts. To protect the public, standards are frequently set
at concentrations associated with human illness. For
example, the standards in the AWP come from the
U.S. Environmental Protection Agency and state that
approximately 36 in 1,000 people exposed to water with
an average generic E. coli concentration of 126 colonyforming
units/100 milliliters are likely to become ill. It does
not say guaranteed, nor does it say ill with what. This
estimation is the result of decades of research and is still
IRRIGATION LEADER
PHOTOS COURTESY OF FLICKR/U.S. FOOD AND DRUG ADMINISTRATION AND MELISSA PARTYKA.