What Is ASTM E1115 Surgical Hand Scrub Efficacy?
ASTM E1115 – officially the “Standard Test Method for Evaluation of Surgical Hand Scrub Formulations” – is an active, in vivo microbiological method that measures how well a surgical hand scrub or surgical hand antiseptic reduces the resident bacterial flora naturally present on human skin. It’s a different approach than disinfectant testing, which relies on inoculated challenge organisms: E1115 instead works with each volunteer’s own existing skin flora, giving formulators a direct, clinically grounded read on how a product will actually perform in the operating room. ASTM International has kept the standard current over the years, reviewing and reapproving it periodically, and it remains a recognized benchmark for surgical scrub efficacy rather than a document that’s been withdrawn or superseded.
Testing itself involves qualified human subjects – volunteers who show a sufficiently high baseline bacterial count on their hands and who’ve avoided antimicrobial products for a defined period beforehand. After researchers collect a baseline sample using the standardized glove-juice recovery technique, subjects perform the test scrub procedure, and researchers resample their hands right away to quantify how quickly the product reduces microbial counts. One hand is then gloved and resampled several hours later, which lets researchers evaluate the formulation’s persistent, or residual, antimicrobial activity under surgical gloves. This property matters enormously for products used during lengthy procedures. There’s also an optional multi-day cumulative protocol available, useful for determining whether repeated daily use builds additional long-term protection.
Manufacturers lean on ASTM E1115 data throughout product development, for label claims, and in regulatory submissions, including those addressing FDA requirements for healthcare antiseptic products. Infinita Lab connects formulators and healthcare product manufacturers with accredited laboratories experienced in running this human-subject study under proper ethical and quality oversight.
Applications and Benefits of ASTM E1115 Surgical Hand Scrub Efficacy Testing
Scope
ASTM E1115-11 defines procedures to measure the reduction of microbial flora on human hands using surgical scrub formulations under controlled conditions. It evaluates immediate, persistent, and cumulative antimicrobial effects after single or repeated applications.
- Sets out an in vivo protocol for evaluating antimicrobial hand scrub formulations intended for surgical use.
- Covers surgical scrub products such as antiseptic soaps, sponge-brush systems, and other leave-on or rinse-off surgical hand preparations.
- Relies on each subject’s own naturally occurring resident skin flora as the baseline microbial population, rather than an artificially inoculated challenge organism.
- Volunteers must meet a minimum baseline bacterial load on their hands before testing begins.
- Subjects need to refrain from using antimicrobial soaps, sanitizers, or antiseptic products for a defined period leading up to the study.
- The standardized glove-juice sampling technique is used to recover and quantify viable bacteria from the hands at each time point.
- Both the immediate reduction in bacterial counts right after scrubbing and the persistent, or residual, effect measured several hours later under a surgical glove are evaluated.
- An optional cumulative-use protocol, run over multiple consecutive days, can characterize sustained-use performance.
- Trained microbiological personnel and a controlled clinical testing environment are required to keep sampling valid and reproducible.
- It’s distinct from ASTM E1174, which evaluates healthcare personnel handwash formulations against an artificially applied transient organism rather than resident skin flora.
Applications
- Supports research and development of new surgical hand scrub and surgical hand antiseptic formulations.
- Generates efficacy data that substantiate product label claims for immediate and persistent antimicrobial activity.
- Helps build a data package for regulatory submissions tied to healthcare antiseptic drug products.
- Useful for comparing a new or reformulated surgical scrub against a currently marketed or reference product.
- Validates manufacturing or formulation changes to confirm antimicrobial performance hasn’t slipped.
- Informs hospital procurement and infection-control decisions with objective, standardized efficacy data.
- Differentiates a surgical scrub product from healthcare personnel handwash products by demonstrating sustained under-glove protection.
Benefits
- Delivers clinically meaningful, human-subject data instead of relying solely on in vitro or surrogate testing.
- Captures both fast-acting and long-duration antimicrobial performance within a single coordinated study.
- Draws on a nationally recognized ASTM protocol that regulators, customers, and partners readily accept.
- Helps manufacturers spot formulation strengths and weaknesses before committing to larger-scale clinical or regulatory programs.
- Backs up marketing and technical claims with a defensible, standardized test method.
- Lowers downstream regulatory risk by generating efficacy evidence aligned with recognized healthcare antiseptic expectations.
Our ASTM E1115 Testing Procedure
Subject Selection
Select healthy volunteers with no recent antimicrobial exposure.
1Baseline Sampling
Collect their initial hand microbial counts.
2Product Application
Apply surgical hand scrub as per the specified time and dosage
3Data & Reporting
Calculate log reductions and report results.
4ASTM E1115 Test Parameters and Requirements
| Parameter | Details |
|---|---|
| Test Objective | Efficacy of surgical hand scrub formulations |
| Test Type | In vivo antimicrobial evaluation |
| Test Subjects | Human volunteers |
| Measurement | Log₁₀ microbial reduction |
| Sampling | Standard hand sampling method |
| Outcome | Quantitative efficacy data |
- Biosafety Cabinet – Gives technicians a controlled, contamination-free space for handling and processing bacterial samples.
- Incubators – Hold the controlled temperature conditions needed for accurate recovery and growth of bacterial colonies from hand samples.
- Autoclave / Sterilization Equipment – Keeps sampling gloves, media, and other glove-juice recovery materials sterile before use.
- Colony Counting Equipment – Enumerates viable bacterial colonies recovered from each sample, feeding the quantitative log-reduction analysis.
- Calibrated Timers – Keep scrub duration and sampling intervals consistent across every subject and timepoint.
- Sterile Sampling Gloves and Diluents – Make the standardized glove-juice technique possible for recovering bacteria from the hands.
- Data Recording and LIMS Systems – Capture subject, timepoint, and colony-count data so log-reduction calculations and reporting stay audit-ready.
Equipment and Instrumentation Used for ASTM E1115 Testing
What You Receive: Test Report, Data, and Certification
- A detailed final study report covering the test protocol, subject demographics, and the product formulation tested.
- Quantitative bacterial recovery and log-reduction data spanning the baseline, immediate, and persistence time points.
- An analysis comparing immediate versus residual antimicrobial performance to characterize both fast-acting and sustained protection.
- Cumulative-use performance data, when the optional multi-day protocol is part of the study design.
- A summary suited to regulatory submissions, technical files, or internal formulation decisions.
- Guidance on interpreting the results against applicable healthcare antiseptic efficacy expectations.
ASTM E1115 Surgical Hand Scrub Efficacy FAQs
ASTM E1115-11 evaluates how effectively surgical hand scrub formulations reduce microbial flora immediately after use and maintain antimicrobial activity over time, ensuring sustained protection and minimizing infection risks during surgical procedures.
Human skin provides realistic biological conditions, including natural flora and variability, which cannot be replicated in vitro. This ensures accurate assessment of antimicrobial performance under real-world usage conditions.
Log reduction quantifies the decrease in microbial population on a logarithmic scale. Higher log reductions indicate greater antimicrobial effectiveness, directly reflecting the product’s ability to control microbial contamination.
Yes, ASTM E1115-11 enables direct comparison of antimicrobial efficacy between different surgical scrub formulations under standardized conditions.
Persistent activity ensures continued antimicrobial protection during long surgical procedures, reducing the likelihood of microbial contamination over time.
ASTM E1115 evaluates surgical hand scrub formulations by measuring bacterial reduction immediately after use and their persistent antimicrobial effect, typically after 6 hours.
ASTM E1838 measures the effectiveness of handwash and handrub products by testing their ability to reduce infectious viruses on adult fingerpads.
ASTM E1153 evaluates sanitizers on hard, nonporous, non-food-contact surfaces by measuring the reduction of specified bacteria on treated surfaces compared with untreated controls.
Why Choose Infinita Lab for Surgical Hand Scrub Efficacy Testing
When your Surgical Hand Scrub Efficacy results have to hold up - for compliance, a customer audit, or an engineering decision - ASTM E1115 accuracy and an unbiased third-party report matter more than price. Infinita Lab routes your ASTM E1115 surgical hand scrub efficacy testing to ISO/IEC 17025-accredited U.S. partner labs with hands-on method experience, so you get defensible data, transparent reporting, and turnaround times built around your project deadline - not ours.
Looking for an Accredited Partner for ASTM E1115 Surgical Hand Scrub Efficacy Testing?
Send query us at hello@infinitalab.com or call us at (888) 878-3090 to learn more about our services and how we can support you.
