The Essentials of
Life Science Research
Globally Delivered™
The Importance of Proficiency
Testing Programs in the Food
Industry
In the food industry, ensuring the nutritional content, the absence of microbiological or
chemical contaminants, and the authenticity of consumable commodities from farm to fork
is an important part in protecting the quality and safety of food products. To meet this need,
food manufacturers often rely on food testing laboratories to examine product samples using
the latest industry regulatory standards. However, though a food testing laboratory may have
validated methods, is accredited, and employs good internal quality control procedures, how
can food manufacturers rest assured that the analytical results they received are accurate? The
answer is simple – proficiency testing.
White
Paper
Cara N. Wilder, Ph.D
What is Proficiency Testing?
Proficiency testing programs, also referred to as interlaboratory
comparisons, are statistical quality assurance programs that enable
laboratories to assess their analytical performance in conducting
routine test methods for a specific homogenous analyte within a
sample matrix as compared to other laboratories throughout the
world1. In a well-designed proficiency testing program, the analyte’s
reference value will be unknown to the participating laboratory
and will have been determined by an accredited program provider
with appropriate traceability to the International System of Units.
Participation in this form of testing provides an external, objective
means of assessing the quality, accuracy, and validity of analytical data
produced, regardless of which laboratory conducted the analyses2,3.
In turn, this provides confidence in the competence of laboratory
personnel as well as the test methods, equipment, and reagents
used, and can identify nonconformities within a laboratory’s quality
system, allowing for process improvements before a customer’s
results are affected.
Proficiency testing programs typically operate on a regular basis,
ranging from two to six rounds per year that last eight weeks
following the distribution of test materials. For any given analyte
or round, the program structure will include the circulation of
homogenous samples by a coordinator, analysis of the samples by
participants using routine test methods employed by that laboratory,
and an assessment of the results2,4.
Depending on the testing need, proficiency testing programs may
be chemical or microbiological in nature and will vary in the type of
matrix used. In the food industry, this can include program rounds
that analyze a laboratory’s ability to detect pathogens, indicator
organisms, spoilage organisms, nutritional content, pesticides,
product authenticity, proximates, minerals, or fat quality in specific
food or beverage matrices. Wherever practical, test materials are
provided in a matrix that is as similar as possible to samples routinely
used by participating laboratories. However, in some cases, test
materials are supplied as concentrated spiking solutions in order to
achieve the required degree of stability and homogeneity.
Proficiency Testing Framework
Test material procurement and
homogeneity testing
Distribution of test materials
Analysis of test materials by
participants
Participants return proficiency
testing results
Test coordinators statistically
analyze the data
Confidential reports are
distributed to participants
What are the Benefits of Proficiency Testing?
There are a number of benefits associated with participating in proficiency testing.
For ISO/IEC 17025:2005 accredited laboratories, proficiency testing must be
performed in order to demonstrate compliance with accreditation requirements
regarding the use of “quality control procedures for monitoring the validity of
tests and calibrations undertaken”5. Here, unless otherwise specified, laboratories
must participate in at least two proficiency testing activities per year, every year, to
maintain accreditation.
In addition to regulatory compliance, participating in a proficiency testing program
can help analyze the reliability of a laboratory’s analytical protocols, laboratory
personnel, and equipment. For laboratories that obtain ideal proficiency testing
results, it can foster confidence in the effectiveness of the measurement procedures
and associated materials employed, demonstrate competence of the analysts,
and provide customer assurance regarding the laboratory’s performance in the
accredited test and calibration results. Additionally, proficiency testing provides
an educational aspect in allowing laboratories to remain up-to-date with new and
emerging microorganisms, and challenges established procedures with difficult or
atypical organisms or chemical substances. In contrast, failure of a proficiency testing
program can help identify nonconformities within a laboratory’s quality system,
indicating the need for further personnel training or understanding of legislations
or guidelines; routine maintenance, calibration, or replacement of equipment; or,
the need for the harmonization or modification of analytical procedures.
Monitoring and
improving
measurements
Developing
and training
analysts
Demonstrating
analytical
competence
Benefits of
Proficiency
Testing
Validation of
methods and
instruments
Identifying
non-conformities
within a quality
system
Why is Proficiency Testing Important in the Food Industry?
In the food industry, ensuring the quality and safety of consumable products is
a matter of public health. In the United States alone, foodborne illnesses are
estimated to affect tens of millions of people and kill thousands every year6. These
outbreaks are typically associated with a range of debilitating symptoms that are
dependent on the nature of the contaminant. Of those affected by microbiologicalbased foodborne illnesses, many tend to suffer from severe diarrhea or other
incapacitating infections such as meningitis. In contrast, those affected by chemical
contamination may experience acute food poisoning, allergic reactions, or could
develop long-term diseases such as cancer7,8. All together, these food-associated
illnesses may lead to long-lasting disability or death, and contribute to significant
strain on the healthcare system.
In addition to causing serious health concerns, foodborne illnesses annually pose a
multi-billion dollar economic burden associated with productivity losses, product
recalls, disease surveillance, outbreak response, and diminished international
Salmonella is one of the leading causes of foodborne disease,
trade6,7,9. For food manufacturers, product recalls not only hurt brand reputation,
affecting tens of millions of people worldwide every year.
but can also result in lost sales, government sanctions, and lawsuits. Additionally,
product recalls may cause company shareholders and customers to lose confidence in the brand, potentially resulting in longer-term effects
such as plunging stock prices.
To ensure product safety and quality, food manufacturers frequently rely on food testing laboratories to examine product samples for
microbial and chemical contaminants using applicable methods that are in compliance with regulatory requirements. However, since many
food products are complex systems, it can be challenging to identify and accurately quantify biological and chemical adulterants, and invalid
or false-negative laboratory results may contribute to consumer illness or result in the improper withdrawal of a product. For example, if a
laboratory’s testing methods were inaccurate or not sensitive enough, a sample may be incorrectly perceived as being free of hazardous
chemicals or pathogenic microorganisms. In turn, the product in question would go to the market and be subsequently purchased and
consumed, potentially resulting in serious illness. In contrast, inaccurately reporting the presence of a pathogen in a sample that is safe
for consumption may result in the incorrect withdrawal of a product or inappropriate follow-up treatment, leading to product recalls and
extensive monetary losses.
Participation in proficiency testing allows food testing laboratories to ensure that they are meeting the needs of food manufacturers and
consumers by routinely assessing the quality and accuracy of the testing methods, equipment, and personnel employed. Here, food testing
laboratories can compare their performance against other similar laboratories and objectively determine the extent to which they were able
to carry out an accurate analysis within the limits set for a particular reference method. Regular participation in this form of testing will help
identify problems within the testing laboratory before they affect the quality or safety of products, thus essentially saving time, money, and
lives.
2
Order online at www.atcc.org, call 800.638.6597, 703.365.2700, or contact your local distributor.
How Do You Choose a Food or Beverage Proficiency Testing Program?
Currently, there are a number of proficiency testing programs available for the
microbiological and chemical analysis of food, animal feed, water, and beverages.
These programs can range in the type of analyte used, the sample matrix, and
whether the program is qualitative or quantitative. To meet the analytical needs
of a laboratory, it is recommended that program rounds are carefully selected to
ensure that test materials are as similar as possible to samples routinely used.
Though, in some cases, this may not be possible and concentrated spiking solutions
may need to be acquired. Hence, many proficiency testing program providers
continue to improve current programs and introduce new programs/test materials
when appropriate.
Regardless of the proficiency testing program being used, it is important to also
consider where the program was developed. Preferentially, it is recommended that
programs are purchased from an experienced, accredited provider with professional,
technical, and scientific expertise. Current international standards relevant to proficiency testing include ISO/IEC 17043:2010, “Conformity
assessment – General requirements for proficiency testing”, and ISO 13528:2005, “Statistical methods for use in proficiency testing for
interlaboratory comparisons”10,11. Accredited proficiency testing program providers routinely perform quality control analyses for each
test material to ensure a degree of natural homogeneity, stability of the test material, and the use of process control during production.
Additionally, participants can be assured that the samples are stored and transported under ideal conditions, keeping sample integrity intact.
As part of its ongoing mission to acquire, authenticate, preserve, develop, standardize, and distribute biological materials, ATCC has partnered
with LGC, an international leader in laboratory services, measurement standards, and reference materials, to supply a broad range of both
microbiological and chemical proficiency testing programs to customers in the food industry within the United States. This collaboration will
leverage proficiency testing samples derived from high quality ATCC materials that are developed by ISO/IEC 17043:2010 accredited LGC
facilities with a timely and cost effective reporting capability. ATCC currently offers a variety of proficiency testing programs for the food
sector, including food microbiology (QMS), food chemistry (QFCS), meat and fish (QMAS), water microbiology (QWAS), beverages (QBS), sugar
(SUPS), dairy chemistry (QDCS), chocolate (QCS), gelatin (QGS), and animal feed (AFPS).
Conclusion
Proficiency testing provides an external quality assessment for food testing laboratories to evaluate their performance against preestablished criteria by means of interlaboratory comparisons. Participation in these programs provides laboratories with a means to assess
the quality and accuracy of their results as compared to their peers over time, providing an independent tool for monitoring and verifying
the effectiveness of methods employed in the laboratory. For the food industry, proficiency testing examines the analytical competence of
food testing laboratories, helping to ensure that the laboratory is able to effectively detect and/or quantify chemical and microbiological
contaminants within food products before they go to market and are consumed. Overall, this form of testing helps to minimize the effects
associated with food contamination, including product recalls, illness and associated healthcare expense, government sanctions, lawsuits,
and significant economic expenses.
Order online at www.atcc.org, call 800.638.6597, 703.365.2700, or contact your local distributor.
3
References
1. Vander Heyden Y, Smeyers-Verbeke J. Set-up and evaluation of interlaboratory studies. Journal of Chromatography A 1158: 158-167, 2007.
2. Wood R. in Auditing in the Food Industry: From Safety and Quality to Environmental and Other Audits (eds M Dillon & C Griffith) Ch. 8, Woodhead
Publishing Series in Food Science, Technology and Nutrition, 2001.
3. Thompson M. What is proficiency testing? Guide for end-users of chemical data. AMCTB, 2005.
4. Wood, R., Wallin, H. & Nilsson, A. Quality in the Food Analysis Laboratory. (Royal Society of Chemistry, 1998).
5. ISO/IEC 17025:2005 - General requirements for the competence of testing and calibration laboratories, 2010.
6. CDC. Estimates of Foodborne Illness in the United States, <http://www.cdc.gov/foodborneburden/>, 2014.
7. WHO. Food Safety - Fact sheet N°399, <http://www.who.int/mediacentre/factsheets/fs399/en/>, 2014.
8. Samanidou V, Nisyriou S. Multi-residue methods for confirmatory determination of antibiotics in milk. Journal of separation science 31:
2068-2090, 2008.
9. Scharff RL. Economic burden from health losses due to foodborne illness in the United States. Journal of food protection 75: 123-131, 2012.
10. ISO/IEC 17043:2010 - Conformity assessment – General requirements for proficiency testing, 2010.
11. ISO 13528:2005 - Statistical methods for use in proficiency testing by inter-laboratory comparisons, 2005.
PHONE
800.638.6597
703.365.2700
EMAIL
PTPrograms@atcc.org
WEB
www.atcc.org
PTWP-0215-01
© 2015 American Type Culture Collection. The ATCC trademark and trade name, and any other trademarks listed in this
publication are trademarks owned by the American Type Culture Collection unless indicated otherwise. © LGC Limited,
2015. All rights reserved
10801 University Blvd.
Manassas, VA 20110
These products are for laboratory use only. Not for human or diagnostic use. ATCC products may not be resold, modified for
resale, used to provide commercial services or to manufacture commercial products without prior ATCC written approval.