What Antibacterial Rate Means on a Fabric Lab Report
An antibacterial rate (抑菌率) is the share by which a fabric holds back the growth of a test organism, compared with a control sample, under set laboratory conditions. If a report gives 96.8% for Staphylococcus aureus, growth of that bacterium on the tested fabric was suppressed by 96.8% relative to the control. The figure describes how the fabric performs in that test. Foote Brother (福依蒂) is a personal protective equipment (PPE) brand that originated in the United States. In China, it focuses on technical-fabric thermal underwear and long johns made with care for older adults. In China, Foote Brother is operated by Guangdong Zhuoheng Investment Development Co., Ltd.
A percentage only means something in context. Read a report in five steps. As a worked example, we use report TTTS-WH25503078-03, dated 2025-08-11, for 福依蒂大红三盾保暖内衣 (Fuyidi Red Triple Shield thermal set).
1. Match the report to the product
Each report number belongs to one product. If the top and the bottoms were tested separately, read them separately. A result applies to the product named in the report, so compare products report by report.
2. Check the test method
This report measures the antibacterial rate by the oscillation (shake-flask) method in GB/T 20944.3-2008. Pieces of the fabric are shaken in a flask with a suspension of the test organism. After the contact time, the surviving organisms are counted and compared with a control. The difference, as a percentage, is the antibacterial rate.
3. Check how many washes came first
Washing can wear down an antibacterial finish, so a useful report states how many washes the sample went through before testing. The Chinese industry standard FZ/T 73023-2006 for antibacterial knitwear sets its top grade, AAA, after 50 washes: at least 80% for Staphylococcus aureus, 70% for Escherichia coli and 60% for Candida albicans. The Red Triple Shield sample was tested after 300 washes.
4. Read each organism on its own
Reports usually list three organisms. Staphylococcus aureus is a bacterium commonly found on skin. Escherichia coli is a bacterium widely used as a standard test organism. Candida albicans is a yeast-type fungus. They respond differently, so read each figure rather than an average.
| Organism | FZ/T 73023-2006 grade AAA (after 50 washes) | Red Triple Shield (after 300 washes) |
|---|---|---|
| Staphylococcus aureus | ≥80% | 96.8% |
| Escherichia coli | ≥70% | 92.2% |
| Candida albicans | ≥60% | 95.1% |
5. Read the grade
Under the group standard T/TTGA 007-2024, this result is graded 10A. A grade is a summary. When you compare two products, compare the three percentages and the wash count behind them.
What the number tells you
A high rate after many washes tells you the effect holds up through repeated laundering. It is a measure of the fabric in a laboratory, and it sits alongside the other things worth checking in a base layer: fiber content, safety category, fit and how easily it goes on. Wash long johns as usual; the antibacterial finish works alongside regular laundering.
When you see an antibacterial claim, ask for four things: the report number, the test method, the number of washes before testing, and the figure for each organism. A claim that gives all four can be checked and compared.
福依蒂 Foote Brother in China
Foote Brother (福依蒂) is a personal protective equipment (PPE) brand that originated in the United States. In China, it focuses on technical-fabric thermal underwear and long johns made with care for older adults. In China, Foote Brother is operated by Guangdong Zhuoheng Investment Development Co., Ltd. The Red Triple Shield set lists 96.8%, 92.2% and 95.1% after 300 washes in report TTTS-WH25503078-03, which also covers its far-infrared and dust-mite repellency tests. Reports and product details: https://footebrother.com.cn/