Authorization for Use as Food Additive (Azoxystrobin and Chlorous Acid Water)  
 
 
The government of Japan is to designate Azoxystrobin and Chlorous Acid Water as 
authorized food additives. 
 
Summary  
Under Article 10 of the Food Sanitation Law, food additives shall not be used or 
marketed without authorization by the Minister of Health, Labour and Welfare. When 
compositional specifications or standards for use or manufacturing are established for 
food additives based on Article 11 of the law, those additives shall not be used or 
marketed unless they meet the standards or specifications.  
 
In response to a request from the Minister, the Committee on Food Additives of the Food 
Sanitation Council that is established under the Pharmaceutical Affairs and Food 
Sanitation Council has discussed the adequacy of the designation of Azoxystrobin and 
Chlorous Acid Water as food additives. The conclusion of the committee is outlined 
below.  
 
 
Outline of conclusion  
The Minister should, based on Article 10 of the Food Sanitation Law, designate 
Azoxystrobin and Chlorous Acid Water as food additives unlikely to harm human health, 
and establish compositional specifications and use standards for these substances based 
on Article 11 of the law (See Attachments 1 and 2). 
  Attachment 1 
Azoxystrobin 
 
 
 
 
 
Standard for use  
Azoxystrobin can be used in citrus fruits (excluding unshū oranges) only. 
It shall not remain more than 0.010 g/kg as azoxystrobin.  
 
Compositional specifications  
Substance name   Azoxystrobin      
Molecular formula   C 22H17N3O5 
Mol. Weight   403.39 
Chemical name [CAS number]    
Methyl ( E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate   
[131860-33-8] 
Content  Azoxystrobin contains not less than 95.0% of azoxystrobin (C 22H17N3O5). 
Description   Azoxystrobin occurs as a white to yellow-red, odorless powder.      
Identification    
Determine the infrared absorption spectrum of Azoxystrobin as directed in the 
Paste Method under Infrared Spectrophotometry. It exhibits absorption bands at  
wavenumbers of about 2230 cm-1, 1625 cm-1, 1587 cm-1, 1201 cm-1, 1155 cm-1, 840 cm-1.   
Purity    
(1) Melting point   114–119ºC. 
(2) Lead   Not more than 2.0 mg/g as Pb. 
Test Solution  Weigh 2.0 g of Azoxystrobin, and transfer it into a platinum, quartz, 
or porcelain crucible; or a quartz beaker. Add diluted sulfuric acid (1 in 4) to moist the 
whole of it, and heat on a hot plate while gradually increasing temperature until white 
fumes are no longer emit evolved. Add diluted sulfuric acid (1 in 4) again if necessary, 
and heat until the sample is carbonized. Place a lid on the crucible (or beaker), and heat in an electric furnace while gradually increasing temperature, and ignite at 500 –600ºC 
until the content is incinerated. Add 10 ml of diluted hydrochloric acid (1 in 4) to the 
residue, and evaporate on a water bath to dryness. Add a small amount of diluted nitric 
acid (1 in 100), heat to dissolve it, and cool. Add diluted nitric acid (1 in 100) to make 
exactly 100 ml.     
Control Solution   Measure exactly 1 ml of Lead Standard Solution, and add water 
to make exactly 100 ml. Measure exactly 4 ml of this solution, and add diluted nitric 
acid (1 in 100) to make exactly 100 ml. 
Procedure   Proceed as directed in Method 1 in the Lead Limit Test. 
Water Content  Not more than 0.50% (2.0 g, Direct Titration). 
Assay   Weigh accurately about 0.05 g each of Azoxystrobin and azoxystrobin for assay. 
Dissolve each in acetonitrile to make exactly 100 ml. Use them as test solution and 
standard solution respectively. Aanalyze 10 ml portions of the test solution and the 
standard solution by liquid chromatography using the operating conditions given below. 
Measure the peak areas (A T and A S) of azoxystrobin for the test solution and the 
standard solution. Calculate the azoxystrobin content by the formula: 
Content (%) of azoxystrobin (C 𝑑𝑑H𝑑𝑑N𝑑O𝑑) = 
Weight (g) of azoxystrobin for assay 
Weight (g) of the sample×A𝑑
A𝑑× 100  
Operating conditions 
Detector: Ultraviolet spectrophotometer. 
Column: A stainless steel tube of 4.6 mm internal diameter and 15 cm length. 
Column packing material: 5- mm octadecyl silanized silica gel for 
liquidchromatography.     
Column temperature: 40ºC. 
Mobile phase: A 9:11 mixture of acetonitrile/water. 
Flow rate: Adjust so that the retention time of azoxystrobin is about 15 minutes. 
 
 
Regents and Solutions  
1,4-BTMSB- d4  C12H18D4Si2  Deuterated 1,4-bis(trimethylsilyl)benzene whose  
traceability to the International System of Units is ensured. 
Azoxystrobin for Assay   C 22H17N3O5  A white powder. 
Content   Not less than 99% of azoxystrobin (C 22H17N3O5).  
   Identification  Determine the infrared absorption spectrum of Azoxystrobin as 
directed in the Paste Method or Potassium Bromide Disk Method under Infrared 
Spectrophotometry. It exhibits absorption bands at about 2230 cm-1, 1625 cm-1, 1587 cm-1, 1201 cm-1, 1155 cm-1, 840 cm-1.   
 
Melting point  115–119ºC. 
Assay   Weigh accurately about 20 mg of Azoxystrobin for Assay and about 4 mg of 
1,4-BTMSB- d4, and add 2 ml of deuterated acetonitrile to dissolve them together. 
Transfer the resulting solution to an NMR tube of 5 mm in external diameter, stopper 
tightly, and measure 1HNMR spectra using a spectrometer at a proton resonance 
frequency of 400 MHz or more. Assuming the signal of 1,4-BTMSB- d4 as  0.23 ppm, 
when the signal intensities around  3.40–3.80 ppm,  6.43 ppm, and  8.28 ppm are 
designated as A 1 (corresponding to 6 hydrogens), A 2 (corresponding to 1 hydrogen), and 
A3 (corresponding to 1 hydrogen), respectively, confirm that each of (A 1/6)/A 2, (A1/6)/A 3, 
and A 2/A3 is 1.0.  Then, assuming the signal intensity of 1,4-BTMSB- d4 as 18.00, when 
the sum of A 1, A2, and  A3,  the sum of the number of hydrogens, and the purity of 
1,4-BTMSB- d4 are designated as I, N, and P(%), respectively,  determine the content of 
azoxystrobin by the following formula. If the signal from Azoxystrobin for Assay is 
overlapped with the signal from a contaminant, do not use its signal area intensity for 
the assay. 
  
Content (%) of azoxystrobin (C 𝑑𝑑H𝑑𝑑N𝑑O𝑑) = 
Weight (mg) of 1,4 ̵̵̵̵ ̵BTMSB ̵𝑑𝑑 × I × P 
Weight  (mg)ofthe sample ×  N× 1.781  
 
Operating conditions  
Spinning:  Off. 
13C decoupling: Present.  
Acquisition time: 4 seconds.  
Spectral range: At least 20 ppm including between −5 ppm and 15 ppm. 
Flip angle: 90º. 
Delay time: 64 seconds. 
Dummy scans: Not less than 1.  
Number of accumulation: Not less than 8.  
 
Deuterated acetonitrile  C2D3N  Use deuterated acetonitrile produced exclusively for 
NMR spectral measurement.  
 
  
 Attachment 2 
 
Chlorous Acid Water 
 
 
Standard for use  
Chlorous Acid Water can be used in polished rice, legumes/pulses, vegetables (excluding 
mushrooms), fruits, seaweed, fresh fish and shellfish (including fresh whale meat), 
fresh meat (livestock and poultry including wild animals), processed meat, and 
processed whale meat as well as their products in a preservable state that were 
obtained by adding appropriate treatments such as salting or drying.* The maximum 
use amount shall be 0.40 g/kg of water for dipping or spraying of each commodity.  The 
Chlorous Acid Water used shall be decomposed or removed before the completion of the 
final food.  
* The products in a preservable state are not intended to be distributed as is, and the 
Chlorous Acid Water is used in products in a desalted or reconstituted state.  
 
Standard for manufacturing  
Sodium chloride used as a manufacturing material shall be sodium chloride specified in 
the Japanese Pharmacopoeia or sodium chloride that meets the requirements specified 
in the monograph for sodium chloride in the Japanese Pharmacopoeia. 
 
Compositional specifications  
Substance name:  Chlorous Acid Water  
Definition:  Saturated sodium chloride solution with hydrochloric acid is electrolyzed 
under acidic condition in an electrolytic cell without a septum (“electrolytic cell without 
a septum” refers to a cell consisting of an anode and a cathode not separated by a 
septum) to obtain an aqueous solution. The resulting solution is strongly acidified with 
sulfuric acid to generate chloric acid, which is converted into chlorous acid water with 
addition of hydrogen peroxide water.    
Content:  Chlorous Acid Water  contains not less than 4.0 −6.0% of chlorous acid  
(HCLO 2 = 68.46). 
Description:   Chlorous Acid  Water occurs as a light yellow-green to yellow-red 
transparent liquid having a chlorine odor. 
Identification:   
(1) To 5 mL of a solution of Hypochlorous Acid Water (1 in 20), add 0.1 mL of potassium permanganate solution (1 in 300). A red-purple color is produced, which 
changes to light yellow on the addition of 1 mL of diluted sulfuric acid (1 in 20).  
(2) A solution of Chlorous Acid Water (1 in 20) exhibits absorption maxima at 
wavelengths of 258–262 nm and 346–361 nm.  
(3) The color of potassium iodide-starch paper changes to blue in Chlorous Acid 
Water and then fades.  
Purity:    
(1) Lead  Not more than 1.0 mg/g as Pb. 
Test Solution   To 5.0 g of Chlorous Acid  Water, add 2 mL of nitric acid ad 20 mL of 
hydrochloric acid, and evaporate on a water bath to dryness. To the residue, add diluted 
nitric acid (1 in 150) to make 10 ml.  
Control Solution   Dilute 1.0 mL of Lead Standard Solution with diluted nitric acid 
(1 in 150) up to 20 mL.  
Procedure  Proceed as directed in Method 1 in the Lead Limit Test.            
(2) Arsenic No more than 1.0 mg/g as As 2O3 (2.0 g, Medthod 2, Apparatus B). 
Assay:    
Sample Solution   Weigh accurately about 5 g of Chlorous Acid  Water, and add 
water to make exactly 100 mL. Transfer the resulting solution into a gas washing bottle, 
and blow nitrogen gas into the bottle until the solution is colorless. Use this as the 
sample solution. Place exactly 20 mL of the sample solution in an iodine-flask, add 10 
mL of diluted sulfuric acid (1 in 10), and then add 1 g of potassium iodide. Immediately 
put a stopper tightly on the flask, and shake well. Pour 5 mL of potassium iodide TS in 
the upper part of the flask without removing the stopper, and allow to stand for 15 
minutes in a dark place. Loosen the stopper to pour potassium iodide TS into the flask, 
immediately stopper tightly, and shake well. Titrate free iodine with 0.1 mol/L sodium 
thiosulfate. Add 5 mL of starch TS as the indicator when the color of the solution 
changes to light yellow. Perform a blank test to make a necessary correction.  
Each mL of 0.1 mol/L sodium thiosulfate =1.711 mg of HCLO 2