[Federal Register Volume 87, Number 217 (Thursday, November 10, 2022)]
[Notices]
[Pages 67859-67861]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-24520]


-----------------------------------------------------------------------

DEPARTMENT OF AGRICULTURE

Agricultural Marketing Service

[Doc. No. AMS-FGIS-20-0061]


Mycotoxin Test Kit Design Specifications and Performance Criteria

AGENCY: Agricultural Marketing Service, USDA.

ACTION: Notice.

-----------------------------------------------------------------------

SUMMARY: The Agricultural Marketing Service (AMS) is announcing its 
decisions regarding proposed changes to its mycotoxin test kit 
performance criteria after evaluating public comments received during 
prior publications in the Federal Register (85 FR 82427 and 86 FR 
10531).

DATES: Applicable: November 10, 2022.

ADDRESSES: For access to the AMS mycotoxin test kit criteria, go to 
https://www.ams.usda.gov/services/fgis/standardization/tke.

FOR FURTHER INFORMATION CONTACT:  Thomas A. Weber, Analytical Chemistry 
Branch Chief, Technology and Science Division, Federal Grain Inspection 
Service, AMS, USDA, 816-702-3811; Telephone: (816) 702-3811, or Email: 
[email protected].

SUPPLEMENTARY INFORMATION: Mycotoxins are toxic chemicals produced by 
certain fungal species under favorable environmental conditions. Many 
countries \1\ have set maximum allowable concentration levels for 
specific mycotoxins in food and feed to ensure the safety of consumers. 
Mycotoxin levels are a critical factor in the trade of grain and 
quantitative mycotoxin testing is an integral part of buyer-seller 
contract specifications. Under the authority of the United States 
Grains Standards Act (7 U.S.C. 71-87k), as amended, and the 
Agricultural Marketing Act of 1946 (7 U.S.C. 1621-1627), as amended, 
AMS provides official mycotoxin testing services throughout the United 
States for domestic and export grains, oilseeds, and processed-grain 
commodities. Official testing services are provided for aflatoxins, 
deoxynivalenol, fumonisins, ochratoxin A, and zearalenone. Testing at 
field locations requires rapid, inexpensive, and accurate methods to 
effectively assess US grain quality. An essential part of ensuring the 
quality of official mycotoxin testing is the AMS test kit evaluation 
program, through which test kits are evaluated and certified for 
conformance to specific criteria. Only test kits having AMS 
certification are approved for official mycotoxin testing. AMS 
establishes the test kit performance criteria and periodically updates 
them to improve testing accuracy and to meet the official mycotoxin 
testing program's operational needs.
---------------------------------------------------------------------------

    \1\ Worldwide regulations for mycotoxins in food and feed in 
2003 [Online]. Food and Agriculture Organization of the United 
Nations, Rome, Italy, 2004. https://www.fao.org/3/y5499e/y5499e00.htm (accessed 5/24/2022).
---------------------------------------------------------------------------

    AMS requested comments from test kit manufacturers and other 
stakeholders on proposed changes to AMS mycotoxin test kit criteria 
through a notice that was published in the Federal Register at 85 FR 
82427 on December 18, 2020. The original 30-day comment period provided 
in the notice closed on January 19, 2021. Comments were received from 
ten stakeholders requesting an extension of the comment period. AMS 
reopened the comment period in the Federal Register at 86 FR 10531 on 
February 22, 2021, for 30 days to allow interested persons additional 
time to review and comment on the notice. The second comment period 
closed on March 24, 2021. A summary of the public comments, decisions, 
and future considerations follows.

Minimum Ranges of Conformance

    For each mycotoxin, AMS has established a minimum range of 
concentrations that must be covered in the test kit's scope and conform 
to AMS accuracy requirements. This range is referred to as the minimum 
range of conformance. AMS proposed to expand the minimum ranges for 
fumonisins, ochratoxin A, and zearalenone test kits to meet the current 
and anticipated future testing needs of the grain industry.
    AMS proposed expanding the current minimum range for fumonisins 
from 0.50-30 parts per million (ppm) to 0.50-100 ppm to provide testing 
up to the U.S. Food and Drug Administration's highest industry guidance 
level in corn and corn products. Comments were received from eleven 
stakeholders. Four stakeholders endorsed this proposal, while two of 
the four supported the change for corn only. Three stakeholders were 
against the change, because the grain has no market value at such high 
levels or because of the difficulty in sourcing large quantities of 
contaminated grains with 100 ppm fumonisins. Six stakeholders were

[[Page 67860]]

against this change due to the risk for increased variation in the test 
results and suggested instead that narrowing the ranges would reduce 
variability. Five of these stakeholders recommended that the evaluation 
of test kits at the 100-ppm level should be optional. AMS believes that 
there may be limitations in test kit calibration linearity and 
additional sample preparation steps that could lead to increased 
variation. As a result, AMS will not implement proposed change at this 
time. AMS will follow up with test kit manufacturers to further assess 
the risk of increased variation and its impact.
    To allow for expected testing variation below the maximum 
concentration levels of 5 parts per billion (ppb), required by a 
standard set by the Codex Alimentarius Commission, AMS proposed to 
expand the minimum range of concentrations for ochratoxin A from 5.0-
100 ppb to 1.0-100 ppb. AMS was interested in comments on whether the 
maximum limit should also be lowered from 100 ppb to 20 ppb, resulting 
in a narrower minimum range (i.e., 1.0-20 ppb). Comments were received 
from ten stakeholders. None of the stakeholders supported the AMS 
proposal to expand the minimum range. Five stakeholders asserted that 
the change would require test kits to be as accurate as the reference 
method, which they thought was an unreasonable expectation. However, no 
technical data was provided by the manufacturers to support that claim. 
Additionally, three stakeholders expressed concern that producing a 1.0 
ppb ochratoxin A reference material may be difficult. However, five 
stakeholders supported an alternative lower concentration limit of 2-3 
ppb and an upper limit of 20 ppb. AMS needs to gather and evaluate 
additional information from test kit manufacturers on their claim 
regarding the limitations of technology to quantify ochratoxin A at 
lower levels prior to setting a new limit. Therefore, AMS will not 
implement its proposed change at this time.
    International regulators, including the European Union, have 
established maximum concentration levels for zearalenone at 100 ppb in 
cereals and other grains. To allow for expected testing variation below 
this regulatory limit, AMS proposed to expand the minimum range of 
concentrations from 100-1000 ppb to 20-1000 ppb. Comments were received 
from ten stakeholders. None of the stakeholders supported the AMS 
proposal. Five stakeholders supported changing the lower limit to 50 
ppb, while two of the five also wanted an upper limit of 500 ppb. Four 
stakeholders requested that the required range of concentrations be 
narrower due to the potential for increased variability. AMS believes 
that there may be limitations in test kit calibration linearity and 
additional sample preparation steps that could lead to increased 
variation. As a result, AMS will not implement proposed change at this 
time. AMS will follow up with test kit manufacturers to further assess 
the risk of increased variation and its impact.

Evaluation of Mycotoxin Test Kit Accuracy

    AMS proposed to change the way the acceptable ranges for test 
results are calculated to align with the Horwitz-Thompson equation, 
which is an internationally accepted benchmark for evaluating 
analytical method performance. Comments were received from fourteen 
stakeholders. None of the stakeholders supported the AMS proposal. Four 
stakeholders were against the proposal because of perceived limitations 
of applying the Horwitz-Thompson equation to immunochemistry-based 
methods. Four stakeholders stated that the proposed acceptable ranges 
would result in more complex and longer test procedures, leading to 
higher variation. Six stakeholders stated that increasing the precision 
in test kit results would be most effective by minimizing the variation 
introduced by sample preparation, which includes grinding to a smaller 
particle size, adjusting the sample size, and using uniform sample 
extraction procedures. Seven stakeholders stated that narrowing the 
required concentration ranges would result in more accurate test 
results. AMS believes that the Horwitz-Thompson model should be the 
benchmark for the evaluation of mycotoxin test kits, since countries 
importing U.S. grain worldwide utilize standardized mycotoxin testing 
methods with performance characteristics that conform to this model. 
Providing mycotoxin test kits that meet this benchmark would increase 
the confidence of importing countries in AMS testing services, thereby 
facilitating exports of U.S. grain. However, AMS recognizes the 
concerns expressed through the comments received and will not implement 
the proposed changes at this time in order to further investigate how 
to incorporate the Horwitz-Thompson model into the mycotoxin test kit 
criteria.

Number of Readers

    Mycotoxin concentrations are determined by an electronic 
instrument, often referred to as a ``reader'' by test kit manufacturers 
and users. AMS has observed variation in test results during side-by-
side comparisons of identical reader models. In effort to increase the 
robustness of the evaluation, AMS proposed to use three separate 
readers during the evaluation process. Three readers were chosen as a 
practical number, because three analysts are participating in the 
evaluation and each could use a separate reader for expediency. 
Comments were received from five stakeholders, and all supported the 
AMS proposal to use three separate readers during the evaluation 
process. AMS will implement this requirement in the mycotoxin test kit 
program to account for variability in readers.

Test Kit Manufacturer Analysts

    AMS proposed to update the method performance criteria to allow up 
to two analysts from the test kit manufacturer to participate in the 
verification study conducted at the AMS laboratory. Comments were 
received from five stakeholders, all of whom supported this AMS 
proposal. AMS will implement this option in the mycotoxin test kit 
program to promote transparency in the verification process.

Extraction Method

    AMS proposed that the extraction method used for the primary 
grain(s) should be the same as that used for additional commodities. 
This change would provide evidence that the method can generate 
accurate results for both naturally contaminated and artificially 
fortified grains and commodities. Comments were received from five 
stakeholders. None of the stakeholders supported the AMS proposal. Two 
stakeholders recommended that naturally contaminated samples be 
required in the evaluation of additional commodities. AMS recognizes 
that artificially fortified samples do not truly represent naturally 
contaminated samples, and therefore, not the most robust method for 
evaluating test kit performance. AMS has allowed for artificially 
fortified samples due to the lack of the natural occurrence of specific 
mycotoxins in particular commodities. Requiring the use of naturally 
contaminated samples is anticipated to reduce the number of additional 
grains and commodities for which AMS can provide testing services. AMS 
will not implement the proposed change at this time in order to further 
engage industry stakeholders on the impacts associated with continuing 
to allow the use of artificially fortified samples versus

[[Page 67861]]

requiring naturally contaminated samples in evaluating test kit 
performance.

Other Comments

    Seven stakeholders made comments, which were beyond the scope of 
the changes proposed by AMS. These comments included recommendations to 
modify the minimum ranges of concentrations for aflatoxins and 
deoxynivalenol, to change the test kit certificate expiration period 
from three to five years, to revise the study design for the 
performance verification, to require all participants to use reference 
materials from one provider, and for AMS to provide guidance or 
recommendations on extraction procedures. AMS may engage stakeholders 
for further information about these recommendations and consider them 
in future program improvements.

Melissa Bailey,
Associate Administrator, Agricultural Marketing Service.
[FR Doc. 2022-24520 Filed 11-9-22; 8:45 am]
BILLING CODE 3410-02-P