QB/T 2738-2023Evaluating methods for antibacterial and bacteriostatic efficacy of daily chemical products (English PDF)

4.6 Reagents that require sterility, such as distilled water, phosphate buffer, culture

medium, bovine serum albumin, standard hard water, neutralizer, etc., shall be sterilized or filtered.

4.7 Before using sterile equipment and reagents, check whether the container or

packaging is intact. If damaged, it shall not be used.

4.8 Sterile equipment and reagents in use shall not be exposed to the air for a long time.

4.9 When pipetting or inoculating, the mouth of the test tube and the agar plate shall be close to the flame to prevent contamination.

4.10 All used contaminated equipment shall be immediately placed in a container containing disinfectant, to prevent contamination of the surrounding environment and clean items.

6.1 Bactericidal test determination method

The bactericidal test determination method in the document is used to evaluate the antibacterial effect of the product.

6.2 Bacteriostatic test determination method

The bacteriostatic test determination method in the document is used to evaluate the bacteriostatic effect of the product.

6.3 Indicator microorganisms for inspection

The test bacteria in Table 1 shall be selected and tested according to the product implementation standard or the scope of application of the instructions. Other strains can also be added as test strains according to the product usage requirements.

6.4 Action concentration

It is carried out according to the standard requirements clearly stated on the product. If it is not clearly stated, QB/T 2850 shall be implemented.

6.5 Action time

It is carried out according to the standard requirements clearly stated on the product. If it is not clearly stated, QB/T 2850 shall be implemented.

6.6 Colony count

Count according to the provisions of GB 4789.2.

6.7 Result report

The test result report is a written expression of the test conditions and results. The result report shall at least include.

7.1 Classification of test methods for antibacterial and bacteriostatic efficacy of

daily chemical products

See Table 2 for the classification of test methods for antibacterial and bacteriostatic efficacy of daily chemical products.

7.2 Bactericidal effect test method for daily chemical products (suspension

quantitative method)

7.2.1 Equipment

The main equipment is.

7.2.2 Reagents

7.2.3 Neutralizer identification test

7.2.3.1 General

In order to accurately evaluate the killing effect of the sample on microorganisms, it is required to select an appropriate neutralizer in the sterilization test. The selected neutralizer can not only stop the inhibitory and killing effect of the antibacterial wash on microorganisms in time, but also the reaction product of the neutralizer itself and the sample (i.e., the neutralization product) has no inhibitory or killing effect on microorganisms, has no adverse effect on the culture medium.

7.2.5 Calculation formula

The sterilization rate is calculated according to formula (2); the result is expressed as a percentage (%), with two decimal places.

7.3 Bacteriostatic effect test method for daily chemical products (suspension

quantitative method)

7.3.1 Equipment

Same as 7.2.1.

7.3.2 Reagents

Same as 7.2.2.

7.3.3 Bacteriostatic test operation steps

7.3.3.1 Dilute the test bacteria suspension (7.2.2.5) with PBS solution appropriately;

the required concentration is as follows. take 0.1 mL and drop it into 5.0 mL control sample solution (PBS); the number of recovered bacteria is 1��104 CFU/mL ~ 9��104

CFU/mL.

7.3.4 Calculation formula

The bacteriostatic rate is calculated according to formula (9); the result is expressed as a percentage (%), with 2 decimal places retained.

7.3.5 Error evaluation

Same as 7.2.6.

7.3.6 Evaluation of product bacteriostatic effect

Fill the test results into Table 7 to evaluate the bacteriostatic effect of the product. When the bacteriostatic rate is not less than 90%, it indicates that the product has a strong bacteriostatic effect under this condition; when the bacteriostatic rate is not less than

50% and less than 90%, it indicates that the product has an bacteriostatic effect under this condition.

7.4 Test method for antibacterial or bacteriostatic effect of fabric detergents

(simulation method)

7.4.5 Operation steps of bactericidal or bacteriostatic test

7.4.5.1 Place 2 pieces of bacterial carrier (7.4.4.4) between the 6th and 7th layers of cloth strips of the rotating bracket; place the third piece between the 7th and 8th layers of cloth strips.

7.4.5.2 Aseptically place the rotating unit (bracket, cloth strip, contaminated carrier)

into the glass jar containing the test sample and cover it. Fix the glass jar on the shaker;

roll and rotate to wash until the set time (i.e., the action time of antibacterial and bacteriostatic tests); remove the glass jar.

7.5 Bacteriostatic effect test method for daily chemical products (bacteriostatic

ring method)

7.5.1 Principle

The bacteriostatic agent is continuously dissolved and diffused through agar, to form different concentration gradients to show its bacteriostatic effect. The size of the bacteriostatic ring is used to determine whether it has bacteriostatic ability.

7.5.2 Equipment

7.5.3 Reagents

7.5.4 Bacteriostatic test operation steps

7.5.4.1 Preparation of bacteriostatic tablets

For liquid bacteriostatic test samples, take sterile dry filter paper pieces; add 20 ��L of bacteriostatic test sample solution of actual use concentration to each piece; then place the filter paper piece flat in a clean sterile plate; open the cover and place it in a constant temperature oven (36 �� 1) ��C to dry, or place it at room temperature to dry naturally to prepare for use. For solid bacteriostatic test samples, directly make a round piece (block) with a diameter of 5 mm and a thickness of no more than 4 mm, to prepare for use.

7.6 Test method for bacteriostatic effect of human skin cleaning products

(retention method)

7.6.1 Principle

This test simulates skin conditions suitable for bacterial growth, reproduction and possible infection; uses a randomized, double-blind, paired comparison method to detect the retention antibacterial effect of human skin cleaning products on human skin, over a certain period of time.

7.6.2 Equipment

7.6.3 Reagents

7.6.3.1 Culture medium (commercial qualified commercial culture medium). Tryptone

soy broth medium (TSB), Tryptone soy agar medium (TSA).

7.6.3.2 0.03 mol/L phosphate buffer (same as 7.2.2.3).

7.6.3.3 70% ~ 75% alcohol.

7.6.3.4 Sheep blood.

7.6.3.5 Fatty alcohol polyoxyethylene ether.

7.6.3.6 External antibiotic ointment.

7.6.4 Samples

The test products are divided into 25 groups according to the sequence number. Each group has 2 samples, one is the test sample prepared according to the specified action concentration, whilst the other is the control sample without bacteriostatic agent.

7.6.5 Bacteriostatic test operation steps

7.9 Bacteriostatic effect test method for bacteriostatic daily chemical products

(carrier immersion quantitative method)

7.9.1 Equipment

Same as 7.2.1.

7.9.2 Reagents

Same as 7.2.2.

7.9.3 Preparation of bacterial carrier

Same as 7.8.3.

7.9.4 Bacteriostatic test operation steps

7.9.4.1 Dilute the test sample with sterile standard hard water to the specified

concentration (soap products are diluted with distilled water).

8 Stability test method for antibacterial and bacteriostatic efficacy of daily chemical products

8.1 Test conditions

8.1.1 Natural retention sample. Place the original packaged sample at room temperature

(15 ��C ~ 30 ��C) and sample it for the time specified in the product instructions, for sterilization or antibacterial performance determination.

8.1.2 Accelerated test. Place the original packaged sample in a (54 �� 2) ��C constant temperature box for 14 days, or in a (37 �� 2) ��C constant temperature box for 90 days, or in a 40 ��C ~ 45 ��C constant temperature box for 180 days, or in a 40 ��C ~ 45 ��C constant temperature box for 270 days; conduct a bactericidal or bacteriostatic performance test.

8.2 Test method

Use the corresponding method in Table 2.

8.3 Evaluation standard

8.3.1 After the product is naturally retained, its bactericidal rate or bacteriostatic rate reaches the specified index value; the bactericidal or bacteriostatic effect of the product is valid for the natural retention time.

8.3.2 After the product is placed in a (54 �� 2) ��C constant temperature box for 14 days, its bactericidal rate or bacteriostatic rate reaches the specified index value; the bactericidal or bacteriostatic effect of the product is valid for one year.

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