Microbiological Test of Toys

The materials of toys that require microbiological testing are as follows:
Category A: Baby products and face paints or cosmetics that are likely to be used in the eye area.
Category B: Other products (liquids, toothpastes, pastes, gels, powders), cosmetics and cosmetic products.
Category C: Bird feather products.

1．Colony-Forming Units (CFU) refer to the total number of bacterial colonies in a unit volume.
cfu/mL refers to the total number of bacterial colonies contained in each milliliter of the sample.
cfu/g refers to the total number of bacterial colonies contained in each gram of the sample.    

2．A medium is an artificially prepared nutrient for the growth and maintenance of microorganisms, plant and animal tissues. It generally contains water, nitrogen sources, inorganic salts (including trace elements), carbon sources, growth factors (vitamins, amino acids, bases, antibiotics, pigments, hormones, serum, etc.).

Due to different raw materials used in the preparation, different usage requirements, and slightly different storage and preservation methods. Generally, after being heated or absorbing moisture, the medium is easily contaminated by bacteria or decomposes and deteriorates. Therefore, the medium must be stored in a moisture-proof, light-proof and cool place. For some media that require strict sterilization (such as tissue culture media), for long-term storage, they must be placed in a refrigerator at 3-6°C. Since liquid media are not easy to be stored for a long time, they are all made into powders.

The limit requirements for USP61+62 microbiological testing of general toy products refer to: ASTM-F963-17 Section 8.4.1 Material Cleanliness, Category B products.
Category A: Baby products and face paints or cosmetics that are highly likely to be used in the eye area.
Category B: Other products (liquids, pastes, putties, gels, powders), cosmetics and toiletries.
Category C: Bird feather products.

• Testing Method: Test for Specified Microorganisms
• Sampling Method:
  Samples must be taken according to the specified sampling method. 2-3 samples should be taken from each batch of samples and tested separately.
• Pretreatment:

1. If the sample requires a certain antibacterial activity, it should be neutralized or removed as much as possible.
2. If a surfactant is used in the sample pretreatment process, its non-toxicity to microorganisms and its compatibility with the neutralizer or inactivator used should be confirmed, and its effectiveness and no impact on the growth and survival of microorganisms should be demonstrated.

8．Testing Principle: Under the experimental conditions (temperature, time, medium 《test bacterial solution》), the provided test sample itself is used to check whether there are specific microorganisms in the sample by the test for specified microorganisms; that is, it is fully proven that it will not inhibit the growth of possible microorganisms.
Therefore, when preparing the sample, formal experimental operations and experimental conditions that meet the requirements are required, and the diluted sample should be inoculated into the corresponding medium containing (microbial) culture.

9．Testing Conditions: Prepare the test sample, and use a method suitable for the physical properties of the sample for sample treatment. The treatment procedure shall not change the initial number and types of microorganisms in the sample to obtain a solution or suspension that can be used for the testing operation.

10．Improvement Method before Testing: Appropriate high-temperature sterilization, ultraviolet sterilization, and addition of preservatives.