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Note for Guidance for Food Contact Materials
Page 62 of 126
shake the flask and make the volume up to the neck of the flask. Adjust the pH of the
solution to 7.5 + 0.1 with 0.2 M sodium hydroxide (NaOH). Make the volume up to the
mark with water and shake thoroughly to mix.

4 APPARATUS
NOTE: An instrument or item of apparatus is listed only where it is special, or made to a particular
specification, usual laboratory equipment being assumed to be available.

4.1
Glass vials, 100 ml or 125 ml, with crimp-on type PTFE/silicone rubber septa.

4.2
Crimping and decapping pliers.

4.3
Device for mechanical agitation of the simulant, e.g. a flask shaker, or a magnetic stirrer
bar for use with a stirrer plate, situated in a cabinet or water bath controlled to a
temperature of 37 + 1C.

5 SAMPLES
NOTE: The test substance should be of similar purity as the substance used in food contact materials.

5.1
Preparation of stock solutions
Weigh out the required weight of the test substance to the nearest 0.1 mg into a 10 ml
volumetric flask and dissolve in a suitable dispersing solvent such as one listed in
section 3.1.10. Make the volume up to the mark, and shake the flask thoroughly to mix.
NOTE: The solvent selected must completely dissolve the test substance and must not chemically react
with it.
The final concentration of solvent (other than water) in the digestive fluid simulant should
not exceed 0.1% (v/v).
The concentration of the test substance in the digestive fluid simulant should be selected
such as to enable determination of the substance down to 5% of the amount added to the
simulant. Anyhow, that concentration should not be lower than the maximum likely
human intake predicted from migration studies.

6 PROCEDURE

6.1 Hydrolysis
equation
Set out the hydrolysis equation, using the following model expression:
PC => HP-1 + HP-2 (+ HP-3 +..... HP-N), in which:
PC = parent constituent
HP = hydrolysis product