Amendment to the Enforcement Ordinance of the Food Sanitation Law and the 
Standards and Specifications fo r Foods and Food Additives.  
 
The government of Japan will designate Pol yvinylpyrrolidone as an authorized food 
additive. 
 Summary 
Under Article 10 of the Food Sanitation Law, food additives shall not be used 
marketed without authorization by the Mi nister of Health, Labour and Welfare 
(hereinafter referred as “the Minister”). In addition, when specific ations or standards 
are established for food additives based on Article 11 of the act and stipulated in the Ministry of Health, Labour and Welfare Noti fication (Ministry of Health and Welfare 
Notification No. 370, 1959), those additives sh all 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 establishe d under the Pharmaceutical Affairs and Food 
Sanitation Council has discussed the adequacy of the designation of Polyvinylpyrrolidone as food additives. Th e conclusion of the committee is outlined 
below.   Outline of conclusion  
The Minister, based on Article 10 of the Food Sanitation Law, should designate 
Polyvinylpyrrolidone, as food additives un likely to harm human health, and establish 
standard for use and compositional specificat ions, based on Article 11 of the law (see 
Attachment).     Attachment 
 
Polyvinylpyrrolidone 
Povidone  
ポリビニルピロリドン  
 
 
  
 
Standards for use 
Permitted for use only in foods not in conventional food form, like those in capsule or tablet form.   Compositional specifications 
Substance name  Polyvinylpyrrolidone 
Molecular formula    (C6H9NO) n 
Chemical name [CAS number]   Poly[1-(2-oxopyrro lidin-1-yl)ethylene]  [9003-39-8] 
Content  Polyvinylpyrrolidone , when calculated on the anhydrous basis, contains 
11.5–12.8% of nitrogen (N=14.01). 
Description   Polyvinylpyrrolidone  is a wh ite to pale yellow powder.   
Identification  Determine the infrared absorption spectrum of Polyvinylpyrrolidone , 
previously dried at 105 C for 6 hours, as directed in the Potassium Bromide Disk 
Method under Infrared Spectrophotometry, and compare with the Reference Spectrum. 
Both spectra exhibit absorptions having about the same intensity at the same 
wavenumbers.  
Purity  
(1) pH 3.0–7.0 (1.0 g, water 20 ml). 
(2) Viscosity   
Test Solution   Weigh accurately an amo unt, equivalent to 1.00 g of 
Polyvinylpyrrolidone  on the anhydrous basis , add water to dissolve, and make exactly 100 ml.  Allow the solution to stand for 60 minutes.  
Procedure  Measure the kinematic viscosity of the test solution and water at 25 C 
as directed under Method 1 in Viscosity, and determine K value by the following fomu1a. 
The K value is 90–108% of the labeled value.   
௥௘௟െ1
ܿ௥௘௟ሻଶ
ଶ 
c= the amount (g) of the sample, on th e anhydrous basis, in 100 ml of the test 
solution   
௥௘௟ = ratio of the kinematic viscosity of the test solution to the kinematic viscosity 
of water  
(3) Lead  Not more than 2.0 g/g as Pb. 
Test Solution  Weigh 2.0 g of Polyvinylpyrrolidone  in a platinum, quartz, or 
porcelain crucible or a quartz  beaker. Moisten the sample entirely with sulfuric acid, 
heat on a hot plate by increasing the te mperature gradually until the sample is 
carbonized and white fumes are no longer evolved. Place it in an electric furnace, heat 
by increasing the temperature gr adually, and incinerate at 500–600 C.  To the residue, 
add 10 ml of diluted hydrochloric acid (1 in 4), and evaporate on a water bath to dryness. 
To the residue, add a little amount of dilute d nitric acid (1 in 100), and dissolve while 
heating. After cooling, add d iluted nitric acid (1 in 100) to make exactly 10 ml.  
Control Solution  Measure exactly 1 ml of the Lead Standard Stock 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 10 ml. 
Procedure  Proceed as directed under Method 1 in the Lead Limit Test.     
(4) Aldehyde  No t more than 500 g/g as acetaldehyde. 
Test Solution  Weigh accurately about 1 g of Pol yvinylpyrrolidone , and dissolve in 
potassium pyrophosphate–hydrochloric acid bu ffer (0.05 mol/L, pH9. 0) to make exactly 
100 ml. Stopper tightly, heat at 60 C for 60 minutes, and cool to room temperature.  
Standard Solution  Weigh 0.100 g of freshly distille d acetaldehyde, and dissolve in 
4C water to make exactly 100 ml. Allow to stand at 4 C for about 20 hours. Take 
exactly 1 ml of this solution, add potassi um pyrophosphate–hydrochloric acid buffer 
(0.05 mol/L, pH 9.0) to  make exactly 100 ml.   
Procedure  Place 0.5 ml each of the test solution, standard solution, and water in 
separate cells, and add exactly 2.5 ml of potassium pyrophosphate–hydrochloric acid 
buffer (0.05 mol/L, pH9.0) and 0.2 ml -nicotinamide adenine di nucleotide TS in each 
cell. Stir them well, stopper tigh tly, and allow to stand at 22  2C for 2–3 minutes. 
Measure the absorbances (A T1, AS1, and  AB1) of these solutions at 340 nm against water as reference. To each soluti on, add 0.05 ml of aldehyde dehydrogenase TS, stir, stopper, 
and allow to stand at 22  2C for 5 minutes. Measure the absorbances (A T2, AS2, and  
AB2) of these solutions in the same manner. Determine the amount of aldehyde by 
formula:  
Amount	of	aldehyde	 ሺμg/gሻൌ		 
1000
Anhydrous	basis	weight	 ሺgሻ	of	the	sample	஻ଵሻ
஻ଵሻ 
(5) 1-Vinyl-2-pyrrolidone  Not more than 10 g/g as 1-vinyl-2-pyrrolidone. 
Test Solution  Weigh accurately about 0.25 g of Polyvinylpyrrolidone , and 
dissolve in methanol (1 in 5) to make exactly 10 ml.  
Standard Solution  Weigh exactly 0.050 g of 1-vinyl-2-pyrrolidone, add 
methanol to dissolve, and make exactly 100 ml. Measure exactly 1 ml of this solution, add methanol to make exactly 100 ml .  Measure exactly 5 ml of the second 
solution, and add methanol (1 in 5) to make exactly 100 ml.  
Procedure  Analyze 50 l-potions 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 1-vinyl-2-pyrrolidone for the test solution and the 
standard solution, and determine its amount by the formula: 
Amount	ሺμg/gሻ	of	1െvinylെ2െpyrrolidone  =  
2.5
Anhydrous	basis	weight	ሺgሻ	of		the	sampleൈA୘
Aୗ 
Operating Conditions  
Detector: Ultraviolet spectrophot ometer (wavelength 254 nm).  
Column: A stainless steel tube of about 4 mm internal diameter and about 25 
cm length.   
Column packing material: 5- m octylsilanized silica gel for liquid 
chromatography. 
Guard column: A column with the same in ternal diameter as the main column, 
packed with the same material as the main column.   
Column temperature: A cons tant temperature around 40 C.  
Mobile phase: A 4:1 mixture of water/methanol.  
Flow rate: Adjust so that the retention time of 1-vinyl-2-pyrrolidone is about 10 
minutes.  
Column selection: Use a column that is capable of eluting 1-vinyl-2-pyrrolidone 
and vinyl acetate in that order and whose separation rate is not less than 2.0 
when 50 l of the solution prepared as directed below is chromatographed according to the above operating conditions. When the test is repeated 6 
times according to the above operatin g conditions, the relative standard 
deviation of the peak areas of 1-viny l-2-pyrrolidone is not more than 2%.  
Preparation of the solution  Dissolving 0.010 g of Polyvinylpyrrolidone  
and 0.5 g of vinyl acetate in 100 ml of methanol. To 1 mL of this solution, add methanol (1 in 5) to make 100 ml.  
Rinse of guard column: After testing , run the mobile phase through the guard 
column in reverse direction to testing operation at the above flow rate for 
30 minute.   
(6) Hydrazine  
Not more than 1 g/g as hydrazine.  
Test Solution  Transfer about 2.5 g of Polyvinylpyrrolidone, w eighed accurately,  
into a 50-ml centrifuge tube, add 25 ml of  water, and dissolve by stirring. Add 500 l 
of a solution (1 in 20) of salicylaldehyde in methanol, shake, and heat in a water 
bath at 60 C for 15 minutes. After cooling, add 2.0 ml of toluene, stopper, and shake 
vigorously for 2 minutes. Centrifuge, and us e the upper layer as the test solution.  
Standard Solution  Weigh 0.090 g of salicylaldazine, and dissolve in toluene to 
make exactly 100 ml. To exactly measured 1 ml of this solution, add toluene to make exactly 100 ml.   
Procedure  Analyze 10- L portions of the test solution and the standard 
solution by thin-layer chromatography, using methanol solution (2 in 3) as the 
developing solvent. Use a thin-layer plate coated with fluoresc ent dimethylsilanized 
silica gel for thin-layer chromatography as the solid support and then dried at 110ºC 
for 1 hour. Stop the development when th e solvent front has ascended to a point 
about 15 cm above the original line, and air-dry the plate. Examine under ultraviolet light (around 365 nm).  A spot from the test solution appears at the 
position corresponding to the spot from the standard solution. The fluorescence of 
the spot from the test solution is not mo re intense than that produced by the spot 
from the standard solution.      
Water   Not more than 5.0% ( 0.5g, Direct Titration).     
Residue on Ignition   Not more than 0.1% (1 g, 600  50C) 
Assay (1) Apparatus  Use hard-glass apparatu s, as illustrated below. Ground-glass 
may be used for joint parts.  Before use, all rubber parts used for the apparatus should 
be boiled in sodium hydroxide solution (1 in 25) for 10–30 minutes and then in water for 
30–60 minutes, and finally rinsed thoroughly with water.  
 A: Kjeldahl flask. 
B: Steam generator (filled with water 
containing 2 to 3 drops of sulfuric acid, and boiling chips to prevent bumping). 
C: Spray trap. D: Water supply funnel. E: Steam generator. F: Injection funnel for alkali solution. G: Rubber tube with pinch cock. H: Small hole (the diameter is almost the 
same as the internal diameter of the tube). 
J: Condenser (with the lower end cut 
diagonally). 
K: Absorption flask.  
 
(2) Procedure   
Transfer about 0.1 g of Polyvinylpyrrolidone,  accurately weighed, in Kjeldahl flask 
A, and add 5 g of a powdered mixture of 33 g of potassium sulfate, 1 g of cupper(II) sulfate pentahydrate, and 1 g of titanium(IV) oxide. Wash down the sample adhering to 
the neck of A with a small amount of f water, and then pour 7 ml of sulfuric acid down 
the inside wall of A. Heat A gradually until the solution in the flask exhibits a clear yellow-green color and the inside walls of fl ask A are free from carbonized material, and 
heat for another 45 minute. After cooling,  add 20 ml of water carefully, and cool. 
Connect A to the distillation apparatus, washed by passing steam through it. To 
absorption flask K, add 30 ml of boric acid so lution (1 in 25) and 3 drops of bromocresol 
green–methyl red mixture TS, and add an adequate amount of water to immerse the lower end of condenser J in the solution. Add 30 ml of sodium hydroxide solution (2 in 5) through funnel F, carefully wash down with 10 ml of water, and immediately close the 
pinch cock attached to rubber tube G. Dist ill with steam until 80–100 ml of distillate is 
obtained. Lower absorption K so that the lower end of J comes above the solution, and rinse the end of J with a small amount of wa ter. Titrate with 0.025 mol/L sulfuric acid. 
The endpoint is when the color of the solution changes from green through slightly grayish blue to slightly grayish red-violet . Separately, perform a blank test to make 
necessary correction.    Each ml of 0.025 mol/L sulfuric acid =0.7003 mg of N     （Unit: mm ）  
Reagents  
 
Aldehyde Dehydrogenase  A white powder. Enzyme activity equivalent to not less than 
2 units per milligram.   
Enzyme activity determination   
(i) Sample solution  Dissolve about 20 mg of Aldehyde Dehydrogenase, 
accurately weighed, in 1 ml of water, add an  ice-cold solution of bovine serum albumin 
(1 in 100) to make exactly 200 ml.  
(ii) Procedure  Dissolve 20.0 mg of -nicotinamido  adenine dinucleotide in water 
to exactly 1 ml. Add 0.20 ml of this solution , 0.10 ml of pyrazole solution (17 in 2500), 
and 0.10 ml of the sample solution to 2.50 ml of pyrophosphate buffer (pH9.0) , stir, 
stopper tightly, and allow to stand at 25  1C for 2 minutes. To this solution, add 0.10 
ml of acetaldehyde solution (3 in 1000), st ir, and stopper. Every 30 seconds, measure 
the absorbance at 340 nm as directed under  Ultraviolet-visible Spectrophotometry, 
and calculate a change ( ΔA) in absorbance per minute from the straight line region of 
the absorbance-straight curve, and determin e the enzyme activity by the formula 
given below. One unit is an amount of enzyme that oxidizes 1 mol of acetaldehyde per 
minute when enzyme activity measurement is done using the operating conditions 
given in the procedure. 
 ሻof	aldehyde	dehydrogenase  
ൈ200
ൈ0.10ൈ1000	 
 
Aldehyde Dehydrogenase TS  Dissolve an amount equivalent to 70 units of aldehyde 
dehydrogenase in 10 ml of water. Prepare fresh before use.  Bovine Serum Albumin   A substance obtained from cattle serum. It contains not less 
than 95% of albumin.   Dimethylsilanized Silica Gel for Thin-l ayer Chromatography (fluorescent)  Use 
dimethylsilanized silica gel that has been produced exclusively for thin-layer chromatography and to which a fluorescent agent is added.   
Dithiothreitol  C
4H10O2S2  Crystals.  
Melting point  42–43C 
 -Nicotinamido Adenine Dinucleotide   C 21H27N7O14P2  [-NAD＋ , K9802.] 
 
-Nicotinamido Adenine Dinucleotide TS   Dissolve 0.04 g of -Nicotinamido Adenine 
Dinucleotide in 10 ml of water. Prepare fresh before use. 
 Potassium Pyrophosphate  K
4O7P2   A white crystalline powder. Very soluble in water.  
Melting point  1109C.  
 
Potassium Pyrophosphate–Hydrochloric Acid Buffer (0.05 mol/L, pH9.0)  Dissolve 0.83 
g of potassium pyrophosphate in 40 ml of water. To this solution, add 1 mol/L hydrochloric acid to adjust its pH to 9. 0, and add water to make 50 ml. Adjust the 
temperature to 22  2C before use.  
 
Pyrazole   C
3H4N2  White to pale yellow crystals or crystalline powder. 
Melting point  67–71C. 
 
Pyrophosphate buffer (pH9.0)   Weigh 3.3 g of p otassium pyrophosphate, 15 mg of 
dithiothreitol, and 40 mg of disodium ethylenediaminetetraacetate dehydrate, add 
water to dissolve them, and make 70 ml. Ad just the pH to 9.0 with citric acid 
monohydrate (21 in 100), and add water to make exactly 100 ml. Prepare fresh before 
use.  Salicylaldazine   C
14H12N2O2 
Melting point  213–219 C. 
Purity  Dissolve 0.09 g of Salicylaldazine in toluene to make 100 ml. To  exactly 
measured 1 ml of this solution, add toluen e to make exactly 100 ml. When the resulting 
solution is analyzed as directed under Pu rity (6) for Polyvinylpyrrolidone, any spot 
other than the main spot does not appear.  
 
Titanium(IV) Oxide   TiO 2  [K8703]  
 1-Vinyl-2-pyrrolidone   C
6H9NO  A clear liquid.  
Purity  Analyze 0.5- l portions of 1-Vinyl-2-pyrrolidone by gas chromatography 
using the operating conditions given below. Measure the peak areas of the components 
contained, and determine 1-vinyl-2-pyrrolidone as directed under the Peak Area Percentage Method in the Flavoring Substanc es Tests. Its concentration shall be not less than 99.0%. The detection sensitivity must be adjusted so that the peak height of 
1-vinyl-2-pyrrolidone obtained from a 0.5- l portion of the sample is about 70% of its full 
scale.   
Operating conditions  
Detector: Flame-ionization detector 
Column: A silicate glass capillary tube (0.53 mm internal diameter and 30 m 
length) coated with a 1.0 m thick layer of polyethylene glycol for gas 
chromatography. 
Column temperature: Maintain the temperature at 80 C for 1 minute, raise it to 
190C at a rate of 10 C/minute, and m aintain for 20 minutes.   
Inlet temperature: 190 C. 
Carrier gas: Helium. 
Flow rate: Adjust so that the peak of 1-vinyl-2-pyrrolidoe appears about 15 minutes 
after injection. 
 
Infrared Reference Spectrum  
Polyvinylpyrrolidone