Key insights
- ASTM D7907 evaluates surface bactericidal performance of medical examination gloves
- The method measures bactericidal activity on both the outer or inner surface of the glove.
- ASTM D7907 testing can be conducted under both clean and soiled contamination conditions
- It is applicable to gloves with antimicrobial treatments or bactericidal additives
- Under ASTM D7907, results are quantitatively expressed as log reduction in bacterial counts
- ASTM D7907 is widely used to support antibacterial regulatory claims
Summary
ASTM D7907 is a standard test method that evaluates the surface bactericidal efficacy of medical examination gloves with antimicrobial properties. The method measures bacterial reduction under controlled laboratory conditions, providing quantitative log reduction data. ASTM D7907 helps manufacturers in validating antibacterial performance claims with scientifically generated evidence.
What is ASTM D7907?
ASTM D7907 is a quantitative test used to evaluate the bactericidal efficacy of medical examination gloves that are incorporated with antibacterial treatments, coatings or additives. This method measures the reduction of viable bacteria on either the inner or outer glove surface after a defined contact period.
The standard includes two separate test methods:
- Method A – Testing without organic contamination
- Method B – Testing with an organic load to simulate soiled conditions
Why antibacterial gloves require specialized testing?
Medical examination gloves are an important barrier inhibiting contamination. However, gloves claiming antibacterial activity must demonstrate that they reduce bacterial growth.
Traditional glove performance tests do not measure antimicrobial performance. Hence, specific test methods such as ASTM D7907 are developed to determine whether antibacterial treatments effectively reduce viable bacteria on glove surfaces.
Bactericidal vs antibacterial activity
The terms antibacterial and bactericidal describe different biological effects.
Antibacterial activity – It is a broad term that describes the ability of a material to inhibit or reduce or interfere with bacterial growth. An antibacterial product usually does not kill bacteria but prevents them from multiplying
Bactericidal activity – This term specifically refers to the ability of the material to kill bacteria. A bactericidal product reduces the number of viable bacterial cells in a measurable quantity.
ASTM D7907 evaluates bactericidal efficacy by quantifying the reduction of bacteria recovered from treated glove surfaces compared with untreated controls.
Why ASTM D7907 testing required for antibacterial face masks
In hospital settings, doctors and staff frequently are vulnerable to contract microbial infections.
Hence, testing the efficacy of such products is critical to confirm their claims and ensure safety of end users.
ASTM D7907 testing is specially designed to help manufacturers to to understand if their face masks stand up to their performance claims and provide optimum protections.
ASTM D7907 test helps –
- Verify antibacterial claims under standard conditions
- Comparing different antimicrobial technologies
- Support product development
- Generate data for regulatory submission
- Differentiate products in a market
Products that can be tested under ASTM D7907
ASTM D7907 is particularly applicable to medical examination gloves, they include:
- Nitrile examination gloves
- Latex examination gloves
- Vinyl (PVC) examination gloves
- Neoprene examination gloves
- Synthetic polymer gloves
- Silver-coated gloves
- Antimicrobial-treated gloves
- Gloves containing embedded antibacterial additives
Why do untreated controls matter?
Untreated or control samples of gloves are are important in ASTM D7907. The control acts as the baseline against which antibacterial performance is measured. Without a control, it would be impossible to evaluate bacterial reduction from the antimicrobial treatment or from natural bacterial decline during the test period.
Mandatory test microorganisms in ASTM D7907
- Pseudomonas aeruginosa (ATCC 9027)
- Staphylococcus aureus (ATCC 6538P)
- Enterococcus faecalis (ATCC 33186)
- Klebsiella pneumoniae (ATCC 4352)
ASTM D7907 method A vs method B
| Parameter | Method A | Method B |
| Organic load | No | Yes |
| Contamination challenges | Clean conditions | Soiled conditions |
| Test suspension | Saline or phosphate buffered saline | Saline or phosphate buffered saline with organic load |
Step-by-step ASTM D7907 test procedure:
- For method A, Bacteria are prepared in a saline solution without any organic load
- For method B, bacteria are prepared in a saline solution containing organic load
- The bacterial suspension is applied to both treated and untreated glove samples.
- Samples are covered to maintain direct contact between bacteria and the glove surface
- The gloves are exposed to the bacteria for a specific contact time
- After exposure, any bactericidal activity is neutralized and surviving bacteria are recovered
- Recovered bacteria are cultured and counted
- The bacterial counts from treated and untreated samples are compared to determine bactericidal activity
Understanding log reduction results
In ASTM D7907, results are evaluated by calculating the log reduction in bacterial counts on treated and untreated glove samples. Higher log reduction values indicate stronger bactericidal surface activity.
What is log reduction?
Log reduction is used to compare bacterial populations before and after treatments
| Log reduction | percentage |
| 1 log | 90% |
| 2 log | 99% |
| 3 log | 99.9% |
| 4 log | 99.99% |
| 5 log | 99.999% |
Factors that influence ASTM D7907 results
- Type of antimicrobial technology used – Type of antimicrobial agents used in face mask material can significantly impact results. Different antimicrobial agents such as Silver-based additives, quaternary ammonium compounds (QACs) or similar may vary in their efficacy against bacterial strains. a.
- Contact time – Bactericidal performance of face mask depends upon the exposure period between product sample and microbes. Short or Longer exposure periods can result in misleading data on bactericidal performance.
- Organic soil load – ASTM D 7906 testing uses the dirty conditions to better understand product performance which can also interfere with product efficacy.
- Product material – Material and surface characteristics can affect how antibacterial agents are distributed and surface interaction of bacteria
- Concentration of active ingredient – Higher concentration of antibacterial additives improve performance. However, efficacy also depends on the formulation and release mechanism.
- Environmental conditions – Temperature and humidity affect both bacterial survival and antibacterial activity during testing
- Storage and aging – Antibacterial efficacy of gloves may change over time depending on storage conditions and shelf life of the products
ASTM D7907 limitations
While it is highly significant for evaluating bactericidal glove performance, it has limitations:
- It evaluates only vegetative bacteria
- Does not evaluate fungicidal, virucidal properties
- Uses controlled laboratory conditions that may not represent every real-world use scenario
Why choose MIS for ASTM D7907 testing?
At Microbe Investigations Switzerland (MIS), we provide specialized ASTM D7907 bactericidal efficacy testing to evaluate the antibacterial performance of medical gloves. Our experienced microbiology team conducts testing under controlled laboratory conditions, quantifying bacterial reduction against relevant challenge organisms and delivering accurate, reproducible results that support product development, quality assurance, and regulatory requirements.
Contact our experts to discuss ASTM D7907 testing requirements.
FAQs
1. Is ASTM D7907 applicable to nitrile gloves?
Yes, It is applicable to nitrile, latex, vinyl, neoprene, and other medical examination gloves.
2. Does ASTM D7907 evaluate antiviral activity?
No, ASTM D7907 only evaluates bactericidal efficacy
3. Can both the inner and outer glove surfaces be tested?
Yes, the method can evaluate bactericidal activity on either the inner or outer surface of medical examination gloves
4. Is ASTM D7907 mandatory for antibacterial glove claims?
It is not mandatory but is widely recognized as the industry standard for supporting antibacterial glove claims
5. Can ASTM D7907 data support regulatory submissions?
Yes, the data can be used as supporting evidence for antibacterial performance claims and regulatory documentation
6. What is the difference between ASTM D7907 and AATCC 100?
ASTM D7907 is specifically designed for medical examination gloves, whereas AATCC 100 is commonly used to evaluate antibacterial finishes on textile materials
7. What does log reduction mean in ASTM D7907?
Log reduction represents the decrease in viable bacterial counts on treated gloves relative to untreated controls. Higher log reductions indicate greater bactericidal efficacy.
8. Can ASTM D7907 evaluate silver-coated gloves?
Yes. Silver-coated gloves and other antimicrobial-treated gloves can be evaluated using ASTM D7907 if they are intended as medical examination gloves.
9. Does ASTM D7907 evaluate bacterial transfer between surfaces?
No, the method measures bacterial reduction on glove surfaces and does not directly evaluate bacterial transfer between contaminated and clean surfaces
