Silver-containing Inorganic
Antibacterial Agents
Silver-containing Inorganic
Antibacterial Agents
Antibacterial Performance
MBC Test Method
【Evaluation Method】
MBC (Minimum Bactericidal Concentration) refers to the lowest concentration of an antibacterial agent required to kill bacteria. In this test, bacteria are exposed to various concentrations of the agent and
then cultured to determine the minimum concentration at which no bacterial growth is observed.
【Evaluation Criteria】
The lower the MBC value, the more effective the product is against microorganisms.
Minimum bactericidal concentration of Apacider (unit: μg/ml)
| Bacterial Species ＼ Grade | AW | AK |
|---|---|---|
| Staphylococcus aureus | 3.25 | 3.25 |
| Escherichia coli | 3.25 | 1.56 |
* The above values are representative and not guaranteed.
Film Contact Method (JIS Z2801)
【Evaluation Method】
Film Contact Method is used to evaluate the number of bacteria present on the surface of
antibacterially treated products (including intermediate products) such as plastics, metals, and
ceramics.
This method is specified as a standard test for antibacterial performance under JIS Z 2801:2010.
【Evaluation Criteria】
Antibacterial Activity Value
The antibacterial activity value indicates the difference in the logarithmic number of viable bacteria
obtained after culturing bacteria on the surfaces of antibacterially treated and untreated products.
A product is considered to exhibit antibacterial effectiveness when the antibacterial activity value is
2.0 or greater.
SBR Rubber Sheet
In the case of SBR rubber sheets inoculated with 0.3%, 0.5% or 1.0% of Apacider AK respectively, an antibacterial activity value of 4.1 against Staphylococcus aureus and 6.1 against Escherichia coli was observed at concentrations of 0.3% or higher.
SBR Rubber Sheet
| Test Sample | Staphylococcus aureus | Escherichia coli | ||
|---|---|---|---|---|
| Viable Count (CFU) | Antibacterial Activity Value | Viable Count (CFU) | Antibacterial Activity Value | |
| No additive | 1.5 × 10 5 | － | 1.5 × 10 7 | - |
| AK 0.3% | Not detected | 4.1 | Not detected | 6.1 |
| AK 0.5% | Not detected | 4.1 | Not detected | 6.1 |
| AK 1.0% | Not detected | 4.1 | Not detected | 6.1 |
*The above test was conducted in accordance with JIS Z 2801:2000.
PP Plate
In the case of PP plates inoculated with 0.5% of Apacider AW or AK respectively, the antibacterial activity values for AW were 4.6 against Staphylococcus aureus and 6.1 against Escherichia coli, while those for AK were 4.7 and 6.2, respectively.
PP Plate
| Test Sample | Staphylococcus aureus | Escherichia coli | ||
|---|---|---|---|---|
| Viable Count (CFU) | Antibacterial Activity Value | Viable Count (CFU) | Antibacterial Activity Value | |
| No additive | 3.2 × 10 4 | － | 1.0 × 10 6 | － |
| AW 0.5% | Not detected | 4.6 | Not detected | 6.1 |
| AK 0.5% | Not detected | 4.7 | Not detected | 6.2 |
ABS Plate
In the case of ABS plates inoculated with 0.5% of Apacider AW or AK respectively, the antibacterial activity values for both AW and AK were 4.3 against Staphylococcus aureus and 6.1 against Escherichia coli.
ABS Plate
| Test Sample | Staphylococcus aureus | Escherichia coli | ||
|---|---|---|---|---|
| Viable Count (CFU) | Antibacterial Activity Value | Viable Count (CFU) | Antibacterial Activity Value | |
| No additive | 1.3 × 10 4 | － | 9.8 × 10 5 | － |
| AW 1.0% | Not detected | 4.3 | Not detected | 6.1 |
| AK 1.0% | Not detected | 4.3 | Not detected | 6.1 |
PE Plate
In the case of PE plates inoculated with 0.5% of Apacider AW or AK respectively, the antibacterial activity values for AW were 4.7 against Staphylococcus aureus and 5.7 against Escherichia coli, while those for AK were 4.1 and 6.2, respectively.
PE Plate
| Test Sample | Staphylococcus aureus | Escherichia coli | ||
|---|---|---|---|---|
| Viable Count (CFU) | Antibacterial Activity Value | Viable Count (CFU) | Antibacterial Activity Value | |
| No additive | 1.7 × 10 4 | － | 1.0 × 10 6 | － |
| AW 0.5% | Not detected | 4.7 | Not detected | 5.7 |
| AK 0.5% | Not detected | 4.1 | Not detected | 6.2 |
PE Film
In the case of PE film inoculated with 1.0% of Apacider AW, the antibacterial activity values were 3.2 against Staphylococcus aureus and 4.7 against Escherichia coli.
PE Film
| Test Sample | Staphylococcus aureus | Escherichia coli | ||
|---|---|---|---|---|
| Viable Count (CFU) | Antibacterial Activity Value | Viable Count (CFU) | Antibacterial Activity Value | |
| No additive | 3.5 × 10 4 | － | 1.1 × 10 6 | － |
| AW 1.0% | 1.9 × 10 | 3.2 | 2.2 × 10 | 4.7 |
Next, as a representative example of the test results shown in the table above, photographs of the antimicrobial test results using PP plates are shown below.
PP Plate
In the case of PP plates inoculated with 0.5% of Apacider AW or AK respectively, no bacterial colonies of Staphylococcus aureus or Escherichia coli were observed.
In contrast, in the case of PP plate without antibacterial agent, both bacterial species formed colonies that spread across the entire surface of the culture medium.
PP Plate
| Staphylococcus aureus | |
|---|---|
| No additive | AW 0.5％ |
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| No additive | AK 0.5％ |
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* Test conducted by BOKEN Quality Evaluation Institute
| Escherichia coli | |
|---|---|
| No additive | AW 0.5％ |
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| No additive | AK 0.5％ |
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*Test conducted by BOKEN Quality Evaluation Institute