United States Department of Agriculture 

Agricultural Marketing Service 

Federal Grain Inspection Service 

Directive 9180.84 May 1, 2019 

NATIONAL FALLING NUMBER QUALITY ASSURANCE PROGRAM 

Contents 

PURPOSE............................................................................................................. 2 

POLICY ................................................................................................................. 2 

REPLACEMENT HIGHLIGHTS............................................................................. 2 

BACKGROUND..................................................................................................... 3 

PROCEDURES ..................................................................................................... 3 

TROUBLESHOOTING .......................................................................................... 6 

INQUIRIES............................................................................................................ 6 

ATTACHMENTS ................................................................................................... 6 

The U.S. Department of Agriculture (USDA) prohibits discrimination in its programs 

on the basis of race, color, national origin, sex, religion, age, disability, political 

beliefs, and marital or familial status. (Not all prohibited bases apply to all programs.) 

Persons with disabilities who require alternate means for communication of program 

information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET 

Center at (202) 720-2600 (voice and TDD). 

To file a complaint, write to the USDA, Office of Civil Rights, Room 326-W, 1400 

Independence Avenue, SW, Washington, DC 20250-9410, or call (202) 720-5964 

(voice and TDD). USDA is an equal employment opportunity employer. 

Distribution: FGIS, OSP, Industry Originating Office: TSD, ACB 
PURPOSE 

 

 

 

This directive establishes the policies and procedures for operation of the Federal Grain 

Inspection Service (FGIS) National Falling Number Quality Assurance Program 

(NFQAP). 

POLICY 

All official service providers of falling number testing will follow this directive. The 

effective date of this directive is May 1, 2019. 

REPLACEMENT HIGHLIGHTS 

This directive supersedes FGIS Program Directive 9180.84, Falling Number National 

Quality Assurance Program, dated April 23, 2014. The following, significant changes 

were made: 

• Adobe Acrobat is required to open and view the attachments for this directive.

• Updated the format to be consistent with FGIS Administrative Directive 3010.2;

• Changed the monitoring sample submission rate to at least one sample per

instrument per week regardless of whether the instrument was used for an official

inspection that week;

• Required validation of new instruments or those that have undergone significant

repair prior to use;

• Corrected the percentage associated with the confidence range for the action

limits to 99.7 percent;

• Corrected the number of results expected outside the action limits to one out of

333;

• Changed shipping procedure so that Technology and Science Division (TSD) is

charged for all shipping of inspection monitoring samples; Federal offices no

longer use their own funding code or UPS account code;

• Changed contact for inquiries to the Falling Number Program, Analytical

Chemistry Branch;

• Updated attachment 1, Sample Submission Form.

FGIS Directive 9180.84 May 1, 2019 

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BACKGROUND 

The falling number (FN) method is an indirect measurement of the amount of alphaamylase activity in wheat. High alpha-amylase activity is associated with the natural 

germination process that results in the breakdown of starch and ultimately in sprouting of 

the wheat kernel. High alpha-amylase activity adversely affects the end-use quality of 

wheat, and as a result, assessment of this factor is important in the domestic and 

international trade of wheat. 

The FN result is the time in seconds required for the instrument to mix the sample with a 

plunger, release the plunger, and allow it to fall through the hot aqueous mixture. A high 

FN indicates a high viscosity of the mixture and low alpha-amylase activity. A low FN 

indicates a low viscosity of the mixture and high alpha-amylase activity. 

FN is the most widely accepted method of evaluating alpha-amylase activity and has 

been standardized by American Association of Cereal Chemists International (AACCI 

56-81.03), International Association for Cereal Science and Technology (ICC 107/1), and 

International Organization for Standardization (ISO 3093-2009). 

FGIS, along with the official agencies it supervises, provides approximately 40,000 FN 

inspections each year following FGIS Program Directive 9180.38. 

In 2014, FGIS established a national quality assurance program for official FN testing to 

provide information on measurement uncertainty and improve the quality of official FN 

testing. The program is administered by TSD and consists of several components, 

including proficiency testing, inspection monitoring, training, and instrument validation. 

The components of this program act synergistically to promote consistently accurate 

official FN testing services to the wheat industry. 

PROCEDURES 

a. Check Sample Program 

There will be two annual check sample distributions to evaluate all instruments used 

for official FN inspections. TSD will send blind samples (both ground and unground) 

with a cover letter giving specific instructions to follow for testing the samples and 

reporting the results. A summary report will be provided to each service point 

following each distribution. 

FGIS Directive 9180.84 May 1, 2019 

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b. Inspection Monitoring Program 

Submit at least one sample per instrument per week regardless of whether the 

instrument was used for an official inspection that week. Complete a sample 

submission form for each sample (attachment 1). 

NOTE: Backup or seasonal instruments must complete the validation process 

(section 5.c of this directive) prior to reinstatement for official falling number 

determinations. 

NOTE: Report actual FN results even if results are above 400 seconds. 

The work week is Sunday through Saturday. For the week ending on Saturday, the 

samples should be mailed to TSD on the following Monday, but no later than 

Wednesday. For samples to be run by FN service points will need to collect an 

additional 650-gram quantity of wheat before the removal of dockage. 

Service points should submit at least 650 grams (before the removal of dockage), 

seal the sample in a 6-mil plastic bag, and mark the sample number on each bag 

using an indelible marker. All field offices and official agencies should ship samples 

using UPS 2nd Day Air service and charge shipping costs to TSD. Please contact 

TSD to obtain the UPS account code. 

Mail samples to: 

Falling Number Program 

USDA FGIS NGC 

Technology and Science Division 

10383 N. Ambassador Drive 

Kansas City, MO 64153-1394 

The results will be communicated to each service point using the following example 

spreadsheet and chart. 

FGIS Directive 9180.84 May 1, 2019 

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All State Grain Inspection 

Falling Number Instrument Model 1700 

Serial Number 1234567 

Date TSD 

All 

State 

Difference 

Relative 

Difference 

% 

Relative 

Difference 

Sample 

ID Inspected 

TSD 

Analysis FN FN 

2662 8/02/2013 8/05/2013 335 340 5 0.015 1.493 

2994 8/09/2013 8/14/2013 335 341 6 0.018 1.791 

3488 8/16/2013 8/21/2013 375 360 -15 -0.040 -4.000 

670 8/23/2013 8/26/2013 401 390 -11 -0.027 -2.743 

1897 8/30/2013 9/02/2013 433 430 -3 -0.007 -0.693 

3353 9/06/2013 9/08/2013 429 416 -13 -0.030 -3.030 

• The blue lines represent the 95 percent confidence range and serve as the 

warning limits (WL). Service points should examine the result with current and 

historical results to determine if this result can be accepted. No more than 1 out 

of every 20 samples should be observed outside the warning limits, but inside the 

action limits. 

• The red lines represent the 99.7 percent confidence range and serve as the action 

limits (AL). Service points should examine the result with current and historical 

results to determine if this result can be accepted. No more than 1 out of every 

FGIS Directive 9180.84 May 1, 2019 

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333 samples should be observed outside of the action limits. Corrective action 

should be taken when results are outside these limits. 

• Each service point is responsible for taking the appropriate corrective action when 

FN readings are outside of these limits. 

c. Validation of New or Repaired Instruments 

New instruments or instruments that have undergone significant repair must be 

validated prior to use for official FN certification. 

Contact TSD to arrange for reference material to be sent for testing. 

TSD will send 150 grams of reference material with a mean FN of 250–350 seconds 

to the lab’s point of contact. 

Perform six FN tests and report the results to TSD using attachment 2. The 

worksheet automatically corrects for barometric pressure, reports on an “as-is” 

moisture basis, and compares the measured value to the reference value. 

To be considered validated for official use, the mean of the six tests must be within 

7.00 percent of the reference value and the relative standard deviation of no more 

than 3.00 percent. 

NOTE: It is recommended that the operator practice with their own sample 

prior to attempting the validation using the reference material. 

TROUBLESHOOTING 

Refer to attachment 4 of FGIS Program Directive 9180.38 for aid in troubleshooting of 

FN results. 

INQUIRIES 

Direct inquiries regarding this directive to the Falling Number Program, Analytical 

Chemistry Branch at 816-891-0401 or FGISFallingNumber@usda.gov. 

ATTACHMENTS 

Open the attachment navigation pane on the left of the display. Double click on an 

attachment to open it. The attachments can be saved locally for use. 

Attachment 1: Sample Submission Form 

Attachment 2: Instrument Validation Worksheet 

FGIS Directive 9180.84 May 1, 2019 

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