Tag Archives: ISO

Consumer buying apple

Foundation FSSC Launches 24000 Scheme for Social Management Systems

By Food Safety Tech Staff
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Consumer buying apple

The Foundation FSSC, the independent nonprofit owner of the FSSC 22000 Scheme, a complete certification scheme for Food Safety Management Systems that is aligned with the ISO Management System and ISO Harmonized Structure, has launched the FSSC 24000 certification scheme for Social Management Systems.

FSSC 24000 is based on the internationally recognized, independent management system standard PAS 24000 developed by BSI. It helps organizations make a greater social impact, improve their overall labor-related social performance and contribute to Sustainable Development Goals (SDGs) beyond those related to food safety only.

In a statement announcing the new Scheme, the Foundation FSSC stated, “The Foundation FSSC, alongside our stakeholders, wants to make a social impact and contribute to the SDGs. Globally, problems related to human rights seem to be increasing rather than decreasing. Through the FSSC 24000 Scheme, we strive to improve labor relationships, health and safety at work, and work and business ethics with a management system approach that drives continuous improvement on key social issues.”

FSSC 24000 is an audit- and certification Scheme for social management systems that aligns with the ISO Management System approach. It helps organizations improve their management system, protect their brands, drive business impact and contribute to the SDGs as determined by the United Nations.

The PAS 24000 standard and the FSSC 24000 documents are free to download through the FSSC website.

 

lightbulb, innovation

Upcoming Webinar Highlights How Standards Support the Food Supply Chain

By Food Safety Tech Staff
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lightbulb, innovation

Join Food Safety Tech and food safety leaders from BSI for a 60-minute webinar on “Food Safety & Quality: How Standards Support the Food Supply Chain” on Monday, December 13. Sponsored by Intelex, the complimentary event will educate attendees about key standards in ensuring food safety and quality in the supply chain—including ISO 22000, ISO 9001 and the new cold chain logistics standard, ISO 23412:2020, which addresses indirect, temperature-controlled refrigerated delivery services. Featured speakers are Sara Walton, sector lead (food) – standards at BSI, and Amanda McCarthy, chair of AW/90, quality systems for food industry at BSI. The event begins at 12 pm ET. Register now!

Arun Apte, CloudLIMS
In the Food Lab

Is Your Food Testing Lab Prepping for an ISO/IEC 17025 Audit?

By Arun Apte
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Arun Apte, CloudLIMS

With the increasing globalization of the food industry, ensuring that products reaching consumers are safe has never been more important. Local, state and federal regulatory agencies are increasing their emphasis on the need for food and beverage laboratories to be accredited to ISO/IEC 17025 compliance. This complicated process can be simplified and streamlined through the adoption of LIMS, making accreditation an achievable goal for all food and beverage laboratories.

With a global marketplace and complex supply chain, the food industry continues to face increasing risks for both unintentional and intentional food contamination or adulteration.1 To mitigate the risk of contaminated products reaching consumers, the International Organization for Standardization (ISO), using a consensus-based approval process, developed the first global laboratory standard in 1999 (ISO/IEC 17025:1999). Since publication, the standard has been updated twice, once in 2005 and most recently in 2017, and provides general requirements for the competence of testing and calibration laboratories.2

In the recent revision, four key updates were identified:

  1. A revision to the scope to include testing, calibration and sampling associated with subsequent calibration and testing performed by a laboratory.3
  2. An emphasis on the results of a process instead of focusing on prescriptive procedures and policies.4
  3. The introduction of the concept of a risk-based approach used in production quality management systems.2
  4. A stronger focus on information technologies/management systems, specifically Laboratory Information Management System (LIMS).4

As modern-day laboratories reduce their reliance on hard copy documents and transition to electronic records, additional emphasis and guidance for ISO 17025 accreditation in food testing labs using LIMS was greatly needed. Food testing laboratories have increased reliance on LIMS to successfully meet the requirements of accreditation. Food and beverage LIMS has evolved to increase a laboratory’s ability to meet all aspects of ISO 17025.

ISO 17025 requirements
Figure 1. A schematic representation of some of the requirements of ISO/IEC 17025:2017 compliance. (Figure courtesy CloudLIMS)

Traceability

Chain of Custody
A key element for ISO 17025 accredited laboratories is the traceability of samples from accession to disposal.5 Sometimes referred to as chain of custody, properly documented traceability allows a laboratory to tell the story of each sample from the time it arrives until the time it is disposed of.

LIMS software allows for seamless tracking of samples by employing unique sample accession numbers through barcoding processes. At each step of sample analysis, a laboratory technician updates data in a LIMS by scanning the sample barcode, establishing time and date signatures for the analysis. During an ISO 17025 audit, this information can be quickly obtained for review by the auditor.

Procurement and Laboratory Supplies
ISO 17025 requires the traceability of all supplies or inventory items from purchase to usage.6 This includes using approved vendors, documentation of receipt, traceability of supply usage to an associated sample, and for certain products, preparation of supply to working conditions within the laboratory. Supply traceability impacts multiple departments and coordinating this process can be overwhelming. A LIMS for food testing labs helps manage laboratory inventory, track usage of inventory items, and automatically alerts laboratory managers to restock inventory once the quantity falls below a threshold level.

A food LIMS can ensure that materials are ordered from approved vendors only, flagging items purchased outside this group. As supplies are inventoried into LIMS, the barcoding process can ensure accurate storage. A LIMS can track the supply through its usage and associate it with specific analytical tests for which inventory items are utilized. As products begin to expire, a LIMS can notify technicians to discard the obsolete products.

One unique advantage of a fully integrated LIMS software is the preparation and traceability of working laboratory standards. A software solution for food labs can assist a technician in preparing standards by determining the concentration of solvents needed based on the input weight from a balance. Once prepared, LIMS prints out a label with barcodes and begins the supply traceability process as previously discussed.

Quality Assurance of Test and Calibration Data

This section of ISO 17025 pertains to the validity of a laboratory’s quality system including demonstrating that appropriate tests were performed, testing was conducted on properly maintained and calibrated equipment by qualified personnel, and with appropriate quality control checks.

Laboratory Personnel Competency
Laboratory personnel are assigned to a specific scope of work based upon qualifications (education, training and experience) and with clearly defined duties.7 This process adds another layer to the validity of data generated during analysis by ensuring only appropriate personnel are performing the testing. However, training within a laboratory can be one of the most difficult components of the accreditation process to capture due to the rapid nature in which laboratories operate.

With a food LIMS, management can ensure employees meet requirements (qualifications, competency) as specified in job descriptions, have up-to-date training records (both onboarding and ongoing), and verify that only qualified, trained individuals are performing certain tests.

Calibration and Maintenance of Equipment
Within the scope of ISO 17025, food testing laboratories must ensure that data obtained from analytical instruments is reliable and valid.5 Facilities must maintain that instruments are in correct operating condition and that calibration data (whether performed daily, weekly, or monthly) is valid. As with laboratory personnel requirements, this element to the standard adds an additional layer of credibility that sample data is precise, accurate, and valid.

A fully integrated software solution for food labs sends a notification when instrument calibration is out of specification or expired and can keep track of both routine internal and external maintenance on instruments, ensuring that instruments are calibrated and maintained regularly. Auditors often ask for instrument maintenance and calibration records upon the initiation of an audit, and LIMS can swiftly provide this information with minimal effort.

Figure 2. A preconfigured food LIMS to manage instrument calibration and maintenance data. (Figure courtesy of CloudLIMS)

Measurement of Uncertainty (UM)
Accredited food testing laboratories must measure and report the uncertainty associated with each test result.8 This is accomplished by using certified reference materials (CRM), or known spiked blanks. UM data is trended using control charts, which can be prepared using labor-intensive manual input or performed automatically using LIMS software. A fully integrated food LIMS can populate control data from the instrument into the control chart and determine if sample data analyzed in that batch can be approved for release.

Valid Test Methods and Results
Accurate test and calibration results can only be obtained with methods that are validated for the intended use.5 Accredited food laboratories should use test methods that are current and contain embedded quality control standards.

A LIMS for food testing labs can ensure correct method selection by technicians by comparing data from the sample accession input with the test method selected for analysis. Specific product identifiers can indicate if methods have been validated. As testing is performed, a LIMS can track time signatures to ensure protocols are properly performed. At the end of the analysis, results of the quality control samples are linked to the test samples to ensure only valid results are available for clients. Instilling checks at each step of the process allows a LIMS to auto-generate Certificates of Analysis (CoA) knowing that the testing was performed accurately.

Data Integrity
The foundation of a laboratory’s reputation is based on its ability to provide reliable and accurate data. ISO 17025:2017 includes specific references to data protection and integrity.10 Laboratories often claim within their quality manuals that they ensure the integrity of their data but provide limited details on how it is accomplished making this a high priority review for auditors. Data integrity is easily captured in laboratories that have fully integrated their instrumentation into LIMS software. Through the integration process, data is automatically populated from analytical instruments into a LIMS. This eliminates unintentional transcription errors or potential intentional data manipulation. A LIMS for food testing labs restricts access to changing or modifying data, allowing only those with high-level access this ability. To control data manipulation even further, changes to data auto-populated in LIMS by integrated instrumentation are tracked with date, time, and user signatures. This allows an auditor to review any changes made to data within LIMS and determine if appropriate documentation was included on why the change was made.

Sampling
ISO 17025:2017 requires all food testing laboratories to have a documented sampling plan for the preparation of test portions prior to analysis. Within the plan, the laboratory must determine if factors are addressed that will ensure the validity of the testing, ensure that the sampling plan is available to the laboratory (or the site where sampling is performed), and identify any preparation or pre-treatment of samples prior to analysis. This can include storage, homogenization (grinding/blending) or chemical treatments.9

As sample information is entered into LIMS, the software can specify the correct sampling method to be performed, indicate appropriate sample storage conditions, restrict the testing to approved personnel and provide electronic signatures for each step.

Monitoring and Maintenance of the Quality System

Organization within a laboratory’s quality system is a key indicator to assessors during the audit process that the facility is prepared to handle the rigors that come with accreditation.10 Assessors are keenly aware of the benefits that a food LIMS provides to operators as a single, well-organized source for quality and technical documents.

Document Control
An ISO 17025 accredited laboratory must demonstrate document control throughout its facility.6 Only approved documents are available for use in the testing facility, and the access to these documents is restricted through quality control. This reduces the risk of document access or modification by unauthorized personnel.

LIMS software efficiently facilitates this process in several ways. A food LIMS can restrict access to controlled documents (both electronic and paper) and require electronic signatures each time approved personnel access, modify or print them. This digital signature provides a chain of custody to the document, ensuring that only approved controlled documents are used during analyses and that these documents are not modified.

Software, LIMS
Figure 3. A software solution for food labs helps manage documents, track their revision history, and ensure document control. (Figure courtesy of CloudLIMS)

Corrective Actions/Non-Conforming Work
A fundamental requirement for quality systems is the documentation of non-conforming work, and subsequent corrective action plans established to reduce their future occurrence.5

A software solution for food labs can automatically maintain electronic records of deviations in testing, flagging them for review by quality departments or management. After a corrective action plan has been established, LIMS software can monitor the effectiveness of the corrective action by identifying similar non-conforming work items.

Conclusion

Food and beverage testing laboratories are increasingly becoming accredited to ISO 17025. With recent changes to ISO 17025, the importance of LIMS for the food and beverage industry has only amplified. A software solution for food labs can integrate all parts of the accreditation process from personnel qualification, equipment calibration and maintenance, to testing and methodologies.11 Fully automated LIMS increases laboratory efficiency, productivity, and is an indispensable tool for achieving and maintaining ISO 17025 accreditation.

References

  1. Spink, J. (2014). Safety of Food and Beverages: Risks of Food Adulteration. Encyclopedia of Food Safety (413-416). Academic Press.
  2. International Organization for Standardization (October 2017). ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories. Retrieved from: https://www.iso.org/files/live/sites/isoorg/files/store/en/PUB100424.pdf
  3. 17025 Store (2018). Transitioning from ISO 17025:2005 to ISO/IEC 17024:2017. Standards Store.
  4. Perry Johnson Laboratory Accreditation (2019). An Overview of Changes Between 17025:2005 and 17025:2017. ISO/IEC 17025:2017 Transition. https://www.pjlabs.com/downloads/17025-Transition-Book.pdf
  5. Analytical Laboratory Accreditation Criteria Committee. (2018). AOAC INTERNATIONAL Guidelines for Laboratories Performing Microbiological and Chemical Analyses of Food, Dietary Supplements, and Pharmaceuticals, An Aid to Interpretation of ISO/IEC 17025. Oxford, England: Oxford University Press.
  6. Cokakli, M. (September 4, 2020). Transitioning to ISO/IEC 17025:2017. New Food Magazine.
  7. ISO/IEC 17025:2017. General requirements for the competence of testing and calibration laboratories.
  8. Bell, S. (1999). A Beginner’s Guide to Uncertainty of Measurement. Measurement Good Practice Guide. 11 (2).
  9. 17025Store (2018). Clause 7: Process requirements. Standards Store.
  10. Dell’Aringa, J. (March 27, 2017). Best Practices for ISO 17025 Accreditation: Preparing for a Food Laboratory Audit (Part I). Food Safety Tech.
  11. Apte, A. (2020). Preparing for an ISO 17025 Audit: What to Expect from a LIMS?
Karil Kochenderfer, LINKAGES
FST Soapbox

GFSI at 20 YEARS: Time for a Reboot?

By Karil Kochenderfer
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Karil Kochenderfer, LINKAGES

The marketplace has experienced dramatic changes that were barely on the horizon 20 years ago—by that, I mean mobile phones, Instagram, Facebook, climate change, consumer transparency, globalization, novel new products delivered to your doorstep and now COVID-19, too.

I write from a perspective of both pride and concern. I had the privilege of representing GFSI in North America and helping the organization expand beyond Europe as new food safety laws were implemented in both the United States and Canada.

Questionable Utility of Multiple, Redundant and Costly Certifications

However, I also sympathized with small and medium food companies that struggled with minimal resources and food safety expertise to understand GFSI and then to become certified not once, but multiple times for multiple customers. GFSI’s mantra, “Once Certified, Accepted Everywhere,” was far from their GFSI reality…or, frankly, the reality of many food companies. My concern was not insignificant. The food industry is populated by a majority of small businesses, each seeking that one big break that could possibly, maybe open up access to retail shelves. Their confusion about being audited and certified to one standard was significant. Certification to multiple and redundant standards presented a daunting and costly endeavor for these start-ups. I heard their anxiety in their voices as I served as GFSI’s 1.800 “customer service rep” in North America for years.

Karil Kochenderfer will present “GFSI at 20 Years: Time for a Reboot?” during the 2020 Food Safety Consortium Virtual Conference Series | Her session takes place on December 17Transparency

In the 20 years since GFSI was established, the world has become much more transparent. Today, entire industries operate on open, international, consensus-based ISO management standards in far bigger and more complex sectors than the food sector (e.g., the automotive, airline and medical device sectors). And, in the 20 years since GFSI was established, an ISO food safety management system standard has been developed that is now used widely throughout the world with more than 36,000 certifications (i.e., ISO 22000).

Auditing and certifying a facility to a single, international, public standard would enhance GFSI transparency. It also would help to hurdle government concerns related to the lack of public input into the development of private standards, enabling private certifications like GFSI to be used efficiently as a compliance tool—a benefit to both government and food interests and to consumer health, safety and trade.

New Technologies

Many new technologies, such blockchain, artificial intelligence, sensors and the Internet of Things are being heralded widely now as well, particularly for businesses with complex supply-chains like those in like the fast-moving food and retail sectors. The benefits of these technologies are predicated on the use of a common digital language…or standard. Multiple and diverse standards, like GFSI, complicate the use of these new technologies, which is why FDA is examining the harmonizing role of standards and data management in its proposed New Era of Smarter Food Safety.

Sustainable Development

Today, food safety often is managed in tandem with other corporate environment, health and safety programs. The Consumer Goods Forum, which oversees GFSI, should take a similar approach and merge GFSI with its sustainability, and health and wellness programs to help CGF members meet their existing commitments to the United Nations’ Sustainable Development Goals (SDGs) and to encourage others to do the same. Here, once again, adoption of a single, transparent ISO standard can help. Adoption of ISO 22000 as the single and foundational standard for GFSI makes it easy to layer on and comply with other ISO standards—for example, for the environment (ISO 14000), worker protection (ISO 45001), energy efficiency (ISO 50001) and information/data security (ISO 27001)— and to simultaneously meet multiple SDGs.

Globalization

As I write, the COVID pandemic rages. It may re-align global supply chains and set back global trade temporarily, but the unprecedented rise in consumer incomes and corresponding decrease in poverty around the world attests to the importance of the global trade rules established by the World Trade Organization (WTO). Among these rules is a directive to governments (and businesses) to use common standards to facilitate trade, which uniquely recognizes ISO standards as well as those of Codex and OIE. When trade disputes arise, food interests that use ISO 22000 are hands-down winners, no questions asked. So, why use many and conflicting private standards?

Supply Chain Efficiency

Finally, ISO 22005, part of the ISO 22000 family of food management standards, also is aligned with GS1 Standards for supply-chain management, used throughout the food and retail sectors in North America and globally to share information between customers and suppliers. GS1 is most well known for being the administrators of the familiar U.P.C. barcode. The barcode and other “data carriers” provide visibility into the movement of products as well as information about select attributes about those products—including whether they have been certified under GFSI. Both GS1 and ISO GS1 standards are foundational to the new technologies that are being adopted in the fast-moving food, consumer products, healthcare and retail sectors both in the United States and globally. That alignment puts a spotlight on safety, sustainability, mobility, efficiency and so much more.

Focus Less on the Change, More on the Outcome

My proposal will surely set tongues in motion. Proposals to switch things up generally do. Disruption has become the norm, however, and food businesses are prized for their agility and responsiveness to the endless changes in today’s fast-moving marketplace. Still, ISO and Codex standards already are embedded in the GFSI benchmark so what I’m proposing should not be so disruptive and no one scheme or CPO should benefit disproportionately. And, less differentiation in the standard of industry performance will compel scheme or certification owners to shift their focus away from compliance with their standards and audit checklists to working with customers to truly enhance and establish “food safety-oriented cultures.” If they do, all of us emerge as winners.

The New Normal?

Around us new food businesses are emerging just as old businesses reinvent theirs. Trucks now operate as restaurants and athletes deliver dinner on bicycles. For a long time, we’ve operated businesses based on 20th century models that don’t resonate in the 21st century world. Are we at an inflection point, with both small and large businesses paying for costly and inefficient practices that no longer apply, and is it time for GFSI to change?

I welcome your thoughts. I truly do. Better, let’s discuss on a webinar or video call of your choosing. I look forward to connecting.

Submit questions you want Karil to answer during her session at the 2020 Food Safety Consortium Virtual Conference Series in the Comments section below.

Newer Regulations Clarify Food Microbiology Parameters for Labs

By Jacob Bowland
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Accuracy and validity of food test results hinge on purified water and annual water testing.

Laboratory-grade water literature is well documented among the large life science water manufacturers. General levels of resistivity, total organic carbon (TOC), particles and bacteria in water classify into Types 1, 2, or 3, with Type 1 having the most stringent requirements. Each type is useful for a different application depending on the procedure:1,2,3

  • Type 3. Generic applications where water will not come into contact with analytes during the procedure
  • Type 2. Standard applications such as media and buffers
  • Type 1. Critical applications such as GC, MS, HPLC analyzers4

Achieving high-quality water requires purification through a polishing step such as deionization (DI), reverse osmosis (RO), ultraviolet light (UV), filtration or distillation, which removes specific impurities.3,5

This classification system gets muddled, as different agencies have their own standard that examines different end-point analysis and levels:

  • ISO (International Organization for Standards)
  • CLSI (Clinical and Laboratory Standards Institute)
  • ASTM (American Society for Testing & Materials)
  • USP (United States Pharmacopoeia)2,5

With all these standards and testing in place, many labs assume that their installed DI water supply is clean, yet in reality, the water in general would be closer to Type 3 rather than the required Type 1. 

The problem with using lower quality water in food testing labs is that the accuracy and validity of tests will be compromised. Many of the analyzers requiring Type 1 water would recognize contamination from lower quality water, creating difficulty in identifying actual contamination or yielding false positives. False positives can result due to microorganism contamination in the water that is amplified through the testing procedure. In addition, dirty water can damage expensive machinery, because tools in the laboratory that are designed for a high-purity water supply can malfunction when less-pure water is used. For example, a system with microfilters can become rapidly clogged with lower quality water, introducing the possibility of flooding when tubing bursts, if left unnoticed.

Newer regulations in regards to ISO 11133:2014, along with ISO 17025:2005, provide clarity on food microbiology water parameters for the laboratory. ISO 11133:2014 “Microbiology of food, animal feed and water–Preparation, production, storage and performance testing of culture media” describes how water for culture media must be purified. The purification recommended is distilled, demineralized, DI, or RO, and stored in an inert container. To verify purity, labs must regularly test the water to assure microbial contamination is kept to a minimum. Regarding 17025:2005, which refers to food microbiology requirements for accreditation, there should be daily, weekly and monthly testing of the laboratory’s water source to verify required quality for microbiological water. Daily testing examines resistivity of water; monthly testing examines the water’s chlorine levels and aerobic plate counts; yearly testing examines heavy metals in the water. Therefore, accuracy and validity of food test results critically revolve around producing purified water and annual water testing.

Bibliography
1. Veolia. (n.d.). Water Quality. Retrieved from: http://www.elgalabwater.com/water-quality-en-us
2. Puretec Industrial Water. (n.d.). Laboratory Water Quality Standards. Retrieved from: http://puretecwater.com/laboratory-water-quality-standards.html
3. Millipore. (n.d.). Water in the Laboratory. Retrieved from: http://www.emdmillipore.com/US/en/water-purification/learning-centers/tutorial/OPab.qB.IxUAAAE_MkoRHe3J,nav
4. Denoncourt, J. (2010). Pure Water. Retrieved from: http://www.labmanager.com/lab-design-and-furnishings/2010/09/pure-water?fw1pk=2#.VRrT7fnF-Cn
 5. The National Institutes of Health. (2013). Laboratory Water, It’s Importance and Application. Retrieved from: http://orf.od.nih.gov/PoliciesAndGuidelines/Documents/DTR%20White%20Papers/Laboratory%20Water-Its%20Importance%20and%20Application-March-2013_508.pdf

Jacob Bowland is Product Manager at Heateflex and Steven Hausle is Vice President of Sales and Marketing at Heateflex.

 

Thomas R. Weschler, Founder and President, Strategic Consulting, Inc (SCI)

High False Positive Rates for Pathogen Food Safety Testing

By Thomas R. Weschler
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Thomas R. Weschler, Founder and President, Strategic Consulting, Inc (SCI)

This article looks at proficiency testing (PT) for pathogen analysis, and the recent finding by the the American Proficiency Institute (API) of a 6.6 percent false-negative rate on food safety PT samples (14-year average for the 1999-2012 period).

While at IAFP this year, I met with Heather Jordan, who directs food PT programs at API. The proficiency testing programs are used at many food labs in conjunction with lab accreditation programs. Proficiency testing is done at food plant labs (FPLs) and corporate labs, as well as at food contract testing labs (FCLs) as a way to demonstrate quality results in their food micro and chemistry testing.

More proficiency testing but less proficiency?

In fact, the use of PTs is increasing in food labs, which is probably tied in part to the push for lab accreditation by FSMA and non-government groups like GFSI. Yet it seems to me that the current use of PTs doesn’t go far enough to enable an FPL or FCL to demonstrate overall laboratory competency, and gain or maintain accreditation (ISO 17025).

In most labs, PTs are done just a few times a year. And really, they test the competency of the lab technician and protocols used in analyzing the PT samples. They are not a holistic measure of the lab and its ability to consistently generate quality results on every test run by every operator in the lab.

In a previous life I ran a group of environmental testing labs, which also are required to run PT samples during the year. From this experience, I know that lab personnel are aware that PTs are in-house: The sample-receiving group logs them in, and then alerts management. As a result, the best operators usually are assigned to run the PTs. This kid-glove treatment is not representative of day-to-day practices and processes. If we really want to validate and accredit the proficiency of an entire lab, shouldn’t every operator be tested on all protocols in use?

Plus, if labs know when they are running PT samples, and likely have their best operators running them, shouldn’t there be few, if any, false-negative or false-positive results? Surprisingly, that’s not what the API research found…

API study: Performance accuracy for food pathogens remains problematic

In a retrospective study, “Pathogen Detection in Food Microbiology Laboratories: An Analysis of Proficiency Test Performance,” API analyzed the results from 39,500 food proficiency tests conducted between 1999 and 2012 to see how U.S. labs are doing in detecting or ruling out contamination of four common food pathogens.

Over the 14-year period, “False negative results ranged from 3.3 percent to 14.0 percent for E. coli O157:H7; 1.9 percent to 10.6 percent for Salmonella spp; 3.4 percent to 11.0 percent for L. monocytogenes; and 0 percent to 19.8 percent for Campylobacter spp.” Most concerning is that while both false positive and false negative rates were down in the last year of the study, the cumulative false negative rate for the 14-year period was 6.6 percent.

As we know, false positive results (in which a sample that does not contain pathogens is incorrectly shown as positive) are a nuisance. But false negative test results—which fail to detect true pathogenic organisms in the sample—are not unacceptable.

Tom-Weschler-False-Negatives-Sep-2014

The cumulative average false positive rate was 3.1 percent, less than half of the false negative rate for the same period.

The objective of the study—and, I would think, of proficiency testing in general—is to demonstrate improvement in lab performance year over year. The results of the API report concluded to the contrary, however: “Performance accuracy for food pathogens remains problematic with the recent cumulative trend showing a slight decrease for false positive and false negative results.”

Clearly if false negatives happen in proficiency programs, they happen in the course of regular testing at food labs. I’m told that many FCLs and FPLs rely on other parts of their QA systems to make sure testing is being conducted properly. Even so, the documentation of ongoing and unacceptably high false negative rates in PT testing is a big concern for everyone. It also points to a number of follow-on questions:

  • Would the false negative and false positive results be even higher if every technician, rather than the best operator, performed the analysis?
  • PT samples are created in only a couple of sample matrices. Would results be even worse if performed on the myriad of sample matrices present in the food industry?
  • What are the performance results among all of the pathogen methods available? Are some methods better than others when measured in real world conditions? Do the more complex protocols of some pathogen diagnostic systems result in poorer PT performance results?
  • Would PT results and, even more important, lab proficiency improve if the frequency of PTs increased, and were required of every technician involved with real food samples?
  • How can proficiency testing be used to isolate problem areas, whether in the pathogen diagnostic method or the competency of lab operators and processes?
  • And finally, is the performance data different between food contract labs and food plant labs? And are all FCLs are equal, or are some more able to deliver quality results?