Performance Standards for Salmonella
on Carcasses and on Raw Ground Product
Talking points prepared for delivery by Philip Derfler,
Deputy Administrator, Office of Policy, Program Development and
Evaluation, before the National Advisory Committee on Microbiological
Criteria for Foods, Washington, DC, May 7, 2001.
Hello. Mr. Billy has introduced you to
pathogen reduction, HACCP, and performance standards. In my remarks, I
will provide you with some more details about the performance standards
that FSIS has adopted. In particular, I will talk about the performance
standards for Salmonella on carcasses and on raw ground product.
I will discuss three key aspects of these performance standards:
1) why FSIS chose Salmonella as the target organism for
2) how FSIS arrived at the levels in the performance standards; and
3) how FSIS ensures compliance with the performance standards.
- Please keep in mind that FSIS has in place, or has proposed, Salmonella
performance standards for other product classes, such as for certain
cooked meat products. These standards have a very different function,
and were designed in a very different way, than those about which I will
be speaking. Today, I will talk only about the Salmonella standards
for the carcasses and raw ground products. Those standards are the ones
involved in the questions that the Agency is asking you to address.
So --- Why Salmonella was chosen as the target for pathogen
These four factors make clear that FSIS chose Salmonella as its
target because it would provide a ready indication of whether SSOPs and
HACCP were succeeding in controlling and reducing pathogens.
How were the levels in the Salmonella performance standards
The Pathogen Reduction/HACCP systems final
rule sets pathogen reduction performance standards for Salmonella
that must be met by all slaughter plants and all plants that produce raw
ground products. There are separate performance standards for carcasses
of cattle (one for steers/heifers and one for cows/bulls), for market hog
carcasses; and for young chickens. There are also pathogen reduction
performance standards for ground beef, ground chicken, and ground turkey.
The pathogen reduction performance standards for Salmonella
are based on FSIS data collection efforts, which are referred to as
"baseline studies." There was a separate baseline study for
each product category. The Agency used the results of these baseline
studies to provide a national estimate for each product category of the
percentage of product that contains Salmonella. In the final rule,
FSIS concluded that these national estimates of Salmonella
prevalence were the best available data on which to establish Salmonella
- So the performance standards have been set based on the national
estimates of Salmonella prevalence. For example, the standard for
ground beef is 7.5% because the results of the baseline study support a
national estimate that 7.5% of ground beef contains Salmonella.
The performance standards are not, however directly translatable into
an enforceable measure. After developing the standards, the Agency sought
to design a sampling approach for determining whether an establishment is
meeting the applicable standard. The Agency decided to measure individual
plant performance using a series of sample sets. FSIS defined sample sets
based on two parameters: The number of test results in the set and the
maximum number of positives that can occur with there still being
As for the former factor, FSIS decided that the set size should be
greater than 50, so that in doing sampling, FSIS would be measuring
process control over time. As for the number of positives, FSIS set these
numbers so that establishments that are operating at the performance
standard, that is, at the national prevalence level, would have an 80%
probability of passing the set. The preamble to the final rule explained
that. FSIS decided to choose the 80% level based on a balancing of three
factors: The need to prevent establishments from failing to meet the
standard based on chance results, the need to ensure that plants that
were not meeting the standard would be readily detected, and the need to
give plants an incentive to perform beyond what would be minimally
- Given the decisions to use a set size over 50 and an 80% probability
of passing at the standard, the number of samples to be taken and the
number of positives to achieve the standard in a set were determined
using binomial probability distribution. To explain how this
distribution works would take a statistician, but for the performance
standard for ground beef it means that even though the standard is 7.5%,
a plant will be considered to meet the standard if, of 53 samples that
are to be taken, 5 or less are positive.
- The approach that FSIS used in setting the performance standards
results in the levels of performance that establishments must achieve
varying from product class to product class. This fact has led some to
complain about inequities in the standards; for example, that broilers
can be 20% positive for Salmonella and pass, while steers and
heifers can only be 1.0% positive to pass. The standards are consistent
however, because, what is required is the same for all establishments.
They must achieve at least the baseline level of performance for the
product classes that they produce.
It is important to note that the Salmonella
performance standards are not based on a quantitative assessment of the
risk posed by any particular incidence of contamination, nor on a
determination of a "safe" incidence or level. In other words,
the levels are not based on how much Salmonella it takes to make
a person sick. There is not an adequate scientific basis for making such
The Salmonella performance standards
are instead based on the public health judgment that reducing the
percentage of product with Salmonella will reduce the risk of
foodborne illness, and that what it is important for an establishment to
demonstrate is that it is able to control the occurrence of pathogens in
its product; that is, that it is able to consistently produce product
that meets the performance standard.
Data collected in 2000 indicate that
Salmonella prevalence in each of the product categories subject to
performance standards has dropped since HACCP implementation, and that,
overall, 90% of all plants tested are meeting the standards.
- Despite these encouraging results, there has been some concern
within industry that the standards are too stringent. The Agency?s
response to these concerns is this: It is feasible for all
establishments to meet or exceed the baseline prevalence of
contamination with Salmonella, particularly if they maintain
sanitary conditions under their Sanitation Standard Operating Procedures
and operate in accordance with adequate, validated HACCP systems. This
fact is strongly supported by the results of the testing that FSIS has
done, which, as I stated, show that most establishments are meeting the
How does FSIS enforce performance standards?
It is important to point out that
establishments must meet the Salmonella performance standard not
on a lot-by-lot basis, but consistently over a period of time. In other
words, the standards for raw product are not used to judge whether
specific lots of product are adulterated under the law. Rather, the
standards are intended to be a basis on which to evaluate the adequacy of
an establishment?s HACCP system for controlling and reducing hazards,
including pathogenic bacteria on raw products.
FSIS determines an establishment?s
compliance with the Salmonella performance standard by taking the
appropriate number of samples, generally at the rate of one per day,
testing each sample for Salmonella, and determining whether the
number of positives is above the maximum permitted for that product.
The Agency?s goal is to achieve pathogen
reduction by ensuring that all slaughter and raw ground establishments
meet the performance standards established by FSIS. Enforcement is based
on a two-part testing program: ongoing testing, which includes all
establishments at regular intervals irrespective of performance, and
targeted testing, focused on establishments that have been unable to meet
If ongoing or targeted testing in an
establishment evidences that the performance standard is not being met,
then FSIS will decide whether to conduct follow-up testing on the basis
of several factors.
FSIS initiates another set of tests
immediately at all establishments with test results that significantly
exceed the standard.
If an establishment has Salmonella
test results marginally above the limit and takes corrective action, FSIS
will decide that immediate follow-up testing is not necessary. If, on the
other hand, that establishment were not to take meaningful corrective
action, or if it took no action at all, then FSIS would immediately
institute another series of tests, despite the fact that the results were
only marginally above the standard.
If the establishment fails the second
targeted series of tests, then it is required to reassess its HACCP plan
for the tested product and to modify the plan as necessary to achieve the
Salmonella performance standard.
If the establishment fails to reassess its
HACCP plan or to make the modifications in its plan that the reassessment
suggests, or if it fails the third series of targeted tests, FSIS will
give the establishment notice that it intends to suspend inspection
services. If entered, the suspension would remain in effect until the
establishment comes forward with a credible plan for modification of its
HACCP plan that will likely enable it to meet the performance standard.
I would like to close by reiterating what I
think are some of the most important points to remember about the Salmonella
performance standards for carcasses and raw ground product.
First, the standards are based on what FSIS
concluded were the best data available on the prevalence of Salmonella
in raw products. The standards were established based on FSIS' public
health judgment that reducing the percentage of carcasses and of ground
product with Salmonella will reduce the risk of foodborne illness.
Second, we know that the Salmonella
performance standards are achievable because they are based upon a
nationwide baseline survey of what establishments were achieving prior to
HACCP implementation. In fact, the overwhelming majority of plants have
been able to meet or exceed the standards since they were implemented.
Third, the Salmonella standards are not for use in judging a
specific product, but instead they are used to evaluate the performance
of an establishment.
Finally, as Mr. Billy said, there is reason to believe that the Salmonella
standards are working. Salmonella levels are down in the products
for which standards have been set, and there is at least the suggestion
in the CDC FoodNet data that foodborne illness is down as well.
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