Solution:
Photocatalyst coating is a ‘hygienic surface protection.’ coating technology. It protects surfaces from microbes like bacteria, fungi, parasites, germs, etc. They were basically launched to prevent the growth of microbes and dirt on surfaces they were used on. The photocatalyst coating not only kill bacteria cells, but also decompose the cell itself. The titanium dioxide photocatalyst has been found to be more effective than any other antibacterial agent, because the photocatalytic reaction works even when there are cells covering the surface and while the bacteria are actively propagating. The endotoxin produced at the death of cell is also expected to be decomposed by photocatalytic action. Titanium dioxide does not deteriorate and it shows a long-term anti-bacterial effect. Generally speaking, disinfections by titanium oxide is three times stronger than chlorine, and 1.5 times stronger than ozone.
Applications in the antimicrobial coatings market consist of mold remediation, indoor air quality, construction, medical, textiles, and others.
Test Report of Antimicrobial
Date: October 29th, 2004
Client: Kon Corporation
Laboratory: Kyoto Biseibutsu Kenkyusho (Kyoto Microorganism Research Center)
The test result is certified by the Japanese Ministry of Health Labor and Welfare Hygiene 650th.
Address: 16-2 Kubo-cho, Kamikazan Yamashina-ku, Kyoto 607-8464
Examiner: Ryosuke Matsuura
- Supplied test product: TiO2 photocatalyst ceramic tiles
- Test purpose: Evaluation of Antimicrobial power
- Test method: Film contact method on optical irradiation
An antimicrobial power was determined by “Film contact method on optical irradiation” of SIAA(Society of Industrial-Technology for Antimicrobial Articles)
The bacteria suspention was then to make an initial count of 100000 CFU/ml with a 1/500 Nutrient Broth(diluted with sterilization water 500 times).
The bacteria suspention was onto a sample and film cover on the bacteria suspention.
The sample was incubated at 20 to 25 degrees centigrade while shading. After 24 hours, the number of live bacteria was counted. - Bacteria: Escherichia coli NBRC-3972, Staphylococcus IFO-12732
Bacteria test result on coated tile with TiO2
| Type of bacteria |
Titanium Dioxide | Immediately after illumination (number/ml) |
24 hours later (Group 1) |
24 hours later (Group 2) |
Average |
|---|---|---|---|---|---|
| E. coli | TPX-85 | 3.5 x 105 | < 10 | < 10 | < 10 |
| None | 3.5 x 105 | 5.0 x 106 | 6.1 x 106 | 5.6 x 106 | |
| ST. auresu | TPX-85 | 3.5 x 105 | < 10 | < 10 | < 10 |
| None | 3.5 x 105 | 6.1 x 104 | 6.7 x 104 | 6.4 x 104 |
Tested by Kyoto Microorganism Research Center
| Test Result | Escherichia coli | |
|---|---|---|
| Initial State |  |
 |
| 24 hours after |  |
 |
| Test Result | Staphylococcus aureus | |
|---|---|---|
| Initial State |  |
 |
| 24 hours after |  |
 |
Test Procedure:
- Pipette 0.2mg of bacteria suspension on a test porcelain tile and a resin plate (50mm×50mm size)
- The test substrates are covered with a piece of polyethylene film.
- Light of 500 LUX exposes the test glass for 24 hours. The test needs to be conducted in an environment where temperature is a constant 35℃.
- Count the number of survived bacteria
- In order to convert the number of bacteria in 1 ml, use SCDLP culture medium and measure the number on the test materials by a pour-plate culture way.
| Type of Bacteria |
Titanium Dioxide | Immediately after illumination (number/ml) |
24 Hours later (number/ml) |
% Killed |
|---|---|---|---|---|
| E. coli | Coated | 1.1 x 106 | < 10 | 99% |
| None | 1.1 x 106 | 1.8 x 107 | – | |
| MRSA | Coated | 4.4 x 105 | < 10 | 99.9% |
| None | 4.4 x 105 | 9.9 x 105 | – | |
| P.aeruginosa | Coated | 2.2 x 105 | < 10 | 99.9% |
| None | 2.2 x 105 | 2.6 x 106 | – |
Tested by food inspection center of Osaka hygienic food association
The product of Green Millennium is not registered with the US EPA as a pesticide product and makes no antimicrobial claims to the general public.
