SN/T 5706-2023 English PDF (SNT5706-2023)

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SN/T 5706-2023: (Microbiological testing methods for cosmetics Escherichia coli testing)
SN/T 5706-2023
SN
ENTRY-EXIT INSPECTION AND QUARANTINE INDUSTRY
STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 71.100.70
CCS Y 42
Cosmetics microbiology - Detection of escherichia coli
ISSUED ON: DECEMBER 29, 2023
IMPLEMENTED ON: JULY 01, 2024
Issued by: General Administration of Customs of PRC
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Method summary ... 4
5 Equipment and materials ... 4
6 Culture medium and reagents ... 5
7 Inspection procedure ... 5
8 Result report ... 6
Appendix A (Normative) Main culture medium and reagents ... 7
Cosmetics microbiology - Detection of Escherichia coli
1 Scope
This document describes the qualitative test method for Escherichia coli in cosmetics.
This document is applicable to the test of Escherichia coli in cosmetics.
2 Normative references
The contents of the following documents constitute essential clauses of this document
through normative references in the text. Among them, for dated references, only the
version corresponding to the date applies to this document; for undated references, the
latest version (including all amendments) applies to this document.
SN/T 5075 Specification for sample preparation for microbiological inspection of
cosmetics
3 Terms and definitions
There are no terms and definitions that need to be defined in this document.
4 Method summary
This method uses the activity of β-glucuronidase in Escherichia coli, which can
decompose 5-bromo-4-chloro-3-indole-β-D-glucuronide and form blue-green colonies
on trypsin bile salt X-glucuronide agar plates, for qualitative testing.
Note: This method is not applicable to a small number of β-glucuronidase-negative Escherichia
coli, such as O157.
5 Equipment and materials
In addition to the conventional sterilization and culture equipment of the microbiology
laboratory, other equipment and materials are as follows.
5.1 Constant temperature incubator: 36 °C ± 1 °C.
5.2 Constant temperature device: 48 °C ± 2 °C.
5.3 Refrigerator: 2 °C ~ 8 °C.
5.4 Homogenizer or emulsion disperser (speed above 1000 r/min).
5.5 Electronic balance: Sensitivity 0.1 g.
5.6 Sterile conical flask: 250 mL or 300 mL.
5.7 Sterile pipette: 10 mL (with 0.1 mL scale).
5.8 Sterile culture dish: Diameter 90 mm.
5.9 Sterile homogenizing bag or homogenizing cup.
5.10 Sterile inoculation loop: 10 μL (about 3 mm in diameter).
5.11 pH meter or precision pH test paper.
5.12 Quality control strains: Escherichia coli ATCC25922 or CGMCC 1.2385 or
equivalent strains as positive control; Citrobacter freundii ATCC 43864 or CICC 10296
or equivalent strains as negative control.
6 Culture medium and reagents
6.1 Soybean casein lecithin Tween 80 (SCDLP) liquid culture medium: According to
A.1.
6.2 Tryptone bile X-glucuronide (TBX) agar: According to A.2.
7 Inspection procedure
7.1 Inspection procedure for Escherichia coli in cosmetics
The inspection procedure for Escherichia coli in cosmetics is as shown in Figure 1.
Appendix A
(Normative)
Main culture medium and reagents
A.1 Soybean casein lecithin Tween 80 (SCDLP) liquid culture medium
A.1.1 Ingredients
Casein peptone: 17.0 g
Soybean protein peptone: 3.0 g
Sodium chloride: 5.0 g
Potassium hydrogen phosphate: 2.5 g
Glucose: 2.5 g
Lecithin: 1.0 g
Tween 80: 7.0 g
Distilled water: 1000 mL
A.1.2 Preparation method
First, heat and dissolve lecithin in a small amount of distilled water. Then mix with
other ingredients. Heat and dissolve, 90 mL per bottle. Sterilize at 121 °C for 15 min.
Note that the oscillation shall be performed to mix the Tween 80 precipitated at the
bottom layer thoroughly. Cool it to about 25 °C to prepare for use. The pH of the
sterilized culture medium at 25 °C is 7.2 ± 0.2.
A.2 Trypsin bile salt X-Glucuronide (TBX) agar
A.2.1 Ingredients
Trypsin: 20.0 g
Bile salt No.3: 1.5 g
5-Bromo-4-chloro-3-indole-D-glucuronide (BCIG): 75.0 mg
Agar: 8.0 g ~ 18.0 g
Distilled water: 1000 mL
A.2.2 Preparation