Key insights
- EPA MB-40 is used to evaluate residual antimicrobial efficacy of antimicrobial coatings after abrasion cycles
- This test is applicable for antimicrobial coatings used on hard, non-porous surfaces
- EPA MLB SOP MB-40 supports EPA residual antimicrobial surface claims.
- This test simulates real-world use by introducing mechanical abrasion and chemical exposure cycles.
- MB-40 uses Staphylococcus aureus and Pseudomonas aeruginosa as mandatory test organisms. Viruses can be included for label claim support.
- To pass EPA MB-40 test, products must achieve a minimum of 3 log reduction
Summary
EPA MLB SOP MB-40, is recommended by the U.S. Environmental Protection Agency (EPA) Office of Pesticide Programs (OPP), is a test method that evaluates residual antimicrobial efficacy of surface coatings applied to hard, non-porous surfaces. The method assesses whether antimicrobial coatings continue to reduce bacteria and viruses after repeated chemical exposure and mechanical abrasion.
What is EPA MLB SOP MB-40?
EPA MLB SOP MB-40 is a standard test that evaluates whether antimicrobial activity of surface coatings, films and non-porous surfaces persists after simulated wear and cleaning by introducing defined abrasion cycles.
The method replicates realistic use conditions by inducing abrasion and chemical exposure prior to challenging the treated surface with microorganisms. It generates data that helps manufacturers support residual antimicrobial claims for coated surfaces.
Why was EPA MLB SOP MB-40 test method developed?
- Increasing need for residual protection – Traditional disinfectants deliver immediate microbial reduction but may not provide continued protection between routine cleaning cycles
- Supporting EPA residual efficacy claims – MB-40 was introduced to assess whether antimicrobial coatings continue to reduce microbial contamination after repeated use and cleaning
- Replicating real-world surface conditions – The method incorporates mechanical abrasion and chemical exposure to simulate realistic use conditions
Why do residual antimicrobial claims require specialized testing?
Residual antimicrobial technologies differ significantly from conventional disinfectants as they are intended to continue reducing microbial contamination after application and repeated use. Demonstrating such performance needs a special durability-focused efficacy test.
Healthcare facilities, public transportation spaces, commercial buildings and consumer environments are now in need of residual antimicrobial technologies. To ensure the performance of residual antimicrobial technologies, stringent testing and validation methods are required that demonstrates that antimicrobial performance persists even after exposure to wear, abrasion and cleaning. EPA MLB SOP MB-40 provides this durability-focused evaluation by following controlled abrasion procedures.
Products commonly tested under EPA MLB SOP MB-40
EPA MLB SOP MB-40 is applicable to:
- Hard, non-porous surfaces ( ex – Stainless steel) coated with antimicrobial agents
- Residual antimicrobial surface coatings and films used on environment contact surfaces
This test is not intended for porous surfaces (such as textiles) unless protocol modifications are approved by EPA.
Test organisms used in EPA MLB SOP MB-40
The mandatory organisms used by EPA MLB SOP MB-40 test method are
- Pseudomonas aeruginosa
- Viruses
EPA MLB SOP MB-40 test method procedure
Coating Application
- Stainless steel carriers are coated with the antimicrobial product and untreated carriers are used as controls
Abrasion
- The carriers are abraded using alternating wet and dry abrasions.
- An independent dry abrasion treatment is also performed
Microbial Challenge
- After abrasion and treatment, the carriers are inoculated with test microorganisms and soil load and allowed to interact for specified contact time
Neutralization
- At the end of contact time, neutralization is performed to stop antimicrobial activity.
Results
- Surviving microorganisms are recovered and quantified.
Understanding the abrasion cycles in EPA MLB SOP MB-40
EPA MLB SOP MB-40 test method uses alternating wet and dry abrasion cycles designed to simulate the wear and tear that antimicrobial surfaces experience during normal use.
coated surfaces are often exposed to touching, wiping, cleaning, and various environmental conditions. This exposure can affect the coating performance over time. The abrasion cycles are used to assess whether the coating continues to provide antimicrobial protection after such exposure.
Typically, the test includes a combination of wet and dry abrasion procedures:
- Wet abrasion cycles
- Dry abrasion cycles
MB-40 provides a more realistic assessment of residual antimicrobial efficacy by exposing the treated surface to repeated abrasion cycles before microbial challenge. Passing criteria for EPA MLB SOP MB-40
The product must achieve a minimum of 3 log (99.9%) reduction in microbial growth within the specified contact time under pre-defined test conditions.
EPA MLB SOP MB-40 vs other test methods
| Parameter | EPA MLB SOP MB-40 | EPA MLB SOP MB-41 | EPA Protocol #01-1A | PAS 2424:2014 |
| Purpose/claim | Residual antimicrobial efficacy for a period of 1 week | Continuous antimicrobial reduction claims | 24-hour residual self-sanitizing efficacy | 24-hour residual bactericidal and yeasticidal efficacy |
| Mandatory test organisms | Staphylococcus aureus, Pseudomonas aeruginosa and Viruses | Staphylococcus aureus, Pseudomonas aeruginosa and Viruses | Staphylococcus aureus + Klebsiella pneumoniae or Enterobacter plus optional bacteria | P. aeruginosa, S. aureus, E. coli, Enterococcus hirae, K. pneumoniae (bacteria) and Candida albicans (yeast) |
| Scope of products | Residual antimicrobial surface coatings and films applied to hard, non-porous surfaces | Hard, non-porous copper surfaces and copper-containing materials | Antimicrobial products intended for use on inanimate, hard, non-porous, non-food contact surfaces | Antimicrobial treated articles and surfaces, including coatings and materials |
| Passing criteria | ≥ 3 log reduction (99.9%) | ≥ 3 log reduction (≥ 99.9%) | ≥ 3 log reduction (≥ 99.9%) | ≥ 3 log reduction (≥ 99.9%) |
For more details check –
- EPA MLB SOP MB-41 – Standard Method for the Evaluation of Antimicrobial Activity of Hard, Non-porous Copper-containing Surface Products
- EPA #01-01A – Standard Method for the Evaluation of Residual Self-Sanitising Activity of Dried Chemical Residues on Hard, Non-Porous Surfaces
- PAS 2424: 2015 – Quantitative Surface Test for Antimicrobial Efficacy of Disinfectants (Bactericidal and/or Yeasticidal) on Hard Non-porous Surface
How to prepare for EPA MLB SOP MB-40?
Before you submit a product for MB-40 testing, manufacturers should verify that the coating is ready for application, durability evaluation, and microbial efficacy assessment.
Define the product and intended claims
Clearly identify:
- Product name and formulation
- Type of antimicrobial coating
- Intended use surface
- Residual antimicrobial claims to be supported
Provide application instructions
The coating should be applied according to the manufacturer’s recommended directions. Important details include:
- Application method
- Coverage rate
- Drying or curing conditions
- Recoat requirements (if applicable)
Submit representative samples
Provide sufficient product samples from the final commercial formulation. The samples should represent the product that will be marketed and registered.
Prepare supporting documentation
Testing laboratories may require:
- Product technical data sheets
- Application instructions
- Proposed label claims
Work with an experienced testing laboratory
Because MB-40 includes specialized abrasion procedures, neutralization validation, and microbial recovery steps, partnering with a laboratory experienced in antimicrobial efficacy testing can help ensure the study is conducted according to EPA requirements.
Regulatory importance of EPA MLB SOP MB-40
EPA MLB SOP MB-40 is an important standard recommended by the U.S Environmental Protection Agency (EPA ) Office of Pesticide Programs (OPP) to manufacturers seeking support for residual antimicrobial claims. Without data from the test method, such claims may not be substantiated during EPA review. The method provides scientifically validated evidence to regulatory bodies by demonstrating that antimicrobial performance is maintained after simulated wear and cleaning, ensuring that product claims reflect real-use conditions.
Need EPA MLB SOP MB-40 testing?
At Microbe Investigations Switzerland (MIS), Our expert microbiology team helps you choose the right test method for your product, and provides robust EPA MLB -40 testing services, generating reliable and reproducible results. To discuss your testing needs, contact our experts today
FAQs
What is EPA MLB SOP MB-40?
EPA MLB SOP MB-40 is a standardized test method used to evaluate the residual antimicrobial efficacy of surface coatings after simulated wear and abrasion
Does MB-40 test immediate disinfectant efficacy?
No, it evaluates residual antimicrobial performance after durability challenges.
Is EPA MLB SOP MB-40 required for EPA registration?
It is generally expected when manufacturers want to make residual antimicrobial surface coatings claims.
What is a residual antimicrobial claim?
A residual antimicrobial claim states that a surface continues reducing microorganisms after application and after exposure to routine use conditions.
What is the difference between MB-40 and MB-41?
EPA MLB SOP MB-40 evaluates the residual antimicrobial coatings claims while MB-41 focuses to assess the long-lasting antimicrobial performance of copper and copper alloy surfaces.
Why are wet and dry abrasion cycles used?
They simulate realistic cleaning activities and physical wear experienced by coated surfaces.
Can MB-40 evaluate antiviral coatings?
Yes, the method can be adapted to include viruses when supported by the intended product claims
What surfaces are suitable for MB-40 testing?
The method is primarily used for hard, non-porous coated surfaces such as stainless steel
How long does MB-40 testing typically take?
Typical turnaround time is 4-5 weeks.
