Guidance on efficacy requirements for biocides: Planning your test product and testing
On this page
- Formulation-specific testing
- Replicating the formulation
- Replicating the physical form and method of application
- Testing efficacy
- Acceptable test methods
- Sourcing test organisms
- Antibiotic resistance
- Batch replication, microbial counts and performance standards
- Repeat testing and re-testing
- Confirmatory data requirements
- Efficacy data reporting
Formulation-specific testing
The efficacy information you include in your application should:
- be specific to the formulation at in-use concentration
- with the exception of dyes and/or fragrances under or equal to 1% weight per weight (w/w)
- indicate the following for biocides that are diluted from a concentrated formulation:
- type of diluent used
- how the dilution was prepared
- level of water hardness used in the test, expressed as the amount of calcium carbonate (CaCO3) present
- indicate the concentration of the active ingredient(s) for each batch tested and if any were aged or stressed, for how long and under what conditions
- be specific to the proposed physical form and method of application, for example:
- towelettes should be tested using towelette methods
- sprays should be tested using spray methods
- indicate the name or identification number of the formulation
- indicate the breakdown of formulation
- have tests showing that your specific biocide is able to meet the performance criteria to support the proposed claims
- have tests that reflect the recommended conditions for use that are on your biocide's label
The method you use to test efficacy should be relevant to the:
- label claims and target micro-organisms
- settings in which the biocide is intended to be used
- achievable contact times for the proposed use
- the biocide is able to evenly coat all of the surface for the entire contact time without re-application to achieve efficacy
- the contact time should be 10 minutes or less for non-immersion biocides and less time for volatile formulations
For biocides that come in different dilutions, you may use the same in-use formulation and methods of application to develop efficacy information to support your application.
Replicating the formulation
- Your test formulation should be representative of your biocide. For example, it should have the same:
- ingredients and in-use concentrations (the breakdown of formulation should be included with your application)
- diluent use (if applicable)
- activator use (if applicable)
Ingredients
The ingredients used in the test sample should be the same as those in the proposed biocide. The only differences that we accept without confirmatory data are differences in dyes and/or fragrances under or equal to 1% w/w. Other alternative formulations should be supported by confirmatory efficacy data.
The test product you use to test efficacy for each sample or batch should be formulated at the lower certified limits (LCL) for all representative micro-organisms within each microbial category. LCLs (described in Table 1) are calculated using the biocide's labelled nominal active ingredient concentrations.
As there are potential difficulties associated with generating test samples exactly at the LCL, we accept testing up to, and not above, its upper limit.
Nominal concentration (N) of active ingredients | LCL | Upper limit for LCL |
---|---|---|
N less than or equal to 1% | N minus 10% N | LCL plus 2% LCL |
N greater than 1% and less than or equal to 20% | N minus 5% N | LCL plus 1% LCL |
N greater than 20% and less than or equal to 100% | N minus 3% N | LCL plus 0.6% LCL |
Testing against representative test organisms in each microbial category should be done using your biocide's LCL, as shown in Table 1. If you want your biocide to have a narrower LCL (approved by us), you should provide quality information such as stability data that supports the proposed limits.
Refer to quality requirements for biocides for more information and contact us to discuss the acceptability of using narrower LCL prior to testing.
Additional micro-organisms that are not considered representative micro-organisms for a microbial class can be tested at or below the nominal concentration. Refer to Table 2 for examples of:
- common microbial categories when determining which micro-organisms can be tested at or below the nominal concentration
- representative micro-organisms that must be tested at the LCL
For more information on efficacy data requirements for other microbial categories, refer to the following sections in this guidance:
- hard-surface disinfection and sanitization
- soft-surface disinfection and sanitization
- other types of claims
- confirmatory data
Microbial categories on hard or non-porous surfaces | Representative test organisms to be tested at LCL |
---|---|
Bacteria disinfection |
S. aureus (ATCC 6538) and 1 of either P. aeruginosa (ATCC 15442) Footnote 1 or S. enterica (ATCC 10708) |
All other non-spore forming bacteria disinfection claims can be tested at or below the nominal concentration. P. aeruginosa should be tested at LCL for hospital disinfectantsFootnote 1 |
|
Broad-spectrum virucideFootnote 2 |
Testing against any small non-enveloped virus from the following families:
|
Viruses |
Hardest-to-kill virus on the labelFootnote 3 |
All other virus disinfection claims can be tested at or below the nominal concentration. |
|
Fungicide |
T. interdigitale (ATCC 9533) |
Specific fungi |
If your biocide is a general fungicide, then testing at LCL is only required for T. interdigitale. Except for C. auris, additional fungal claims can be tested at nominal concentration. In the absence of a general fungicide claim, specific fungi claims should be tested at the LCL. |
Food contact surface sanitization |
S. aureus (ATCC 6538) and E. coli (ATCC 11229) for non-halide biocides S. aureus (ATCC 6538) or S. enterica (ATCC 6539) for halide biocides |
All other food contact surface sanitization claims can be tested at or below nominal concentration. |
|
Non-food contact surface sanitization |
S. aureus (ATCC 6538) and 1 of either K. pneumoniae (ATCC 4352) or K. aerogenes (ATCC 13048). |
All other non-food contact surface sanitization claims can be tested at or below nominal concentration. |
|
Mycobactericide |
M. bovis (ATCC 35743) or M. terrae (ATCC 15755), depending on the test method. |
Specific mycobacteria |
If your biocide is a general mycobactericide, then testing at the LCL is only required M. bovis or M. terrae. Additional mycobacteria can be tested at or below the nominal concentration. In the absence of a general mycobactericide claim, all specific mycobacteria claims should be tested at the LCL. |
Sporicide |
B. subtilis (ATCC 19659) and C. sporogenes (ATCC 3584) |
Specific spores |
All spore claims should be tested at the LCL |
Abbreviation: ATCC: American Type Culture Collection |
|
|
You should provide a certificate of analysis for the tested batches indicating the initial level of the active ingredient(s) to demonstrate that testing has been done at the appropriate concentration. If you use a method that cannot differentiate between active ingredients in a formulation, you should submit analytical testing for the combined ingredients (for example, quaternary ammonium compounds (QACs)). The LCL can be determined for the sum of these ingredients. Within your application, you should provide a description of how you calculated the LCLs tested.
To test your biocide at the LCL, you may either produce a test batch with an active ingredient at the LCL or dilute your biocide with water. Biocides that may be reactive or less stable in water may be diluted with a primary solvent already present in the formulation. Avoid using emulsifiers or surfactants as diluents even if they're present in the formulation, as these may alter the biocide's efficacy.
Biocides in a solid physical form (powder or tablets) should be diluted with more water than indicated on the label to achieve an in-use concentration at LCL. For example, before efficacy testing:
- dilute a 10 g tablet containing 50% active ingredient with an indicated use at 0.5% w/w (1 tablet diluted in 1 L of water) to an LCL level of 0.485% w/w (N minus 3%, 20% less than N less than or equal to 100%) with 1.04 L
Sometimes it may not be feasible to test a biocide formulated at the LCL range described in Table 1. If this is the case, provide a rationale in your efficacy summary to support why your efficacy testing was not conducted at the exact lower limits.
If it is not possible to dilute the biocide, you may choose other ways to test at the LCL, for example, testing:
- batches past the shelf life or
- a biocide that has been stored at accelerated stability test conditions and duration
For more information on acceptable accelerated stability conditions, consult:
Diluent or activator use
If your biocide is to be diluted or activated (or both) before using, your test formulation should be representative of the biocide's labelled directions for use. This means it should, for example:
- use the same diluent (distilled tap or hard water, for example) or activator
- have the same dilution ratio
All micro-organisms in the same microbial category (bacteria, viruses, fungi) should be tested at the same level of water hardness. Hard water tolerance levels may differ with the level of antimicrobial activity claimed for a biocide. Unless your biocide label says otherwise, we recommend using water with a minimum hardness of 200 ppm (parts per million), expressed as the amount of calcium carbonate (CaCO3) present in your testing. Refer to the most recent version of the AOAC Germicidal and Detergent Sanitizing Action of Disinfectants test (Official Method 960.09) or the Standard Operating Procedure (SOP) MB-30 : Preparation of hard water and other diluents for preparation of antimicrobial products for guidance on the preparation of synthetic hard water. The acceptable range for hard water is -10% to +5% of the target hardness (for example, an AOAC hard water target of 400 ppm CaCO3 could have a hardness range of 360 to 420 ppm CaCO3).
If your biocide indicates efficacy claims specifically in hard water for any of the microbial categories, testing should be conducted with water at a higher hardness level for all micro-organisms within that microbial category. For example, if your biocide makes claims of food contact surface sanitization efficacy in 400 ppm (parts per million) of hard water, all micro-organisms for that claim should be tested with 400 ppm water.
We may allow you to use distilled water as a diluent in your test product if you provide an acceptable justification. An example would be if the devices used in testing are sensitive to calcium carbonate buildup. If this is the case, your biocide label should indicate to dilute with distilled water.
Replicating the physical form and method of application
The method of application and conditions of use for your test product and your biocide should be the same. This applies to biocides with the following physical forms and methods of application:
- biocides applied as liquids
- towelette biocides
- reusable biocides
- biocides for soft surfaces
- diluted or activated biocides
- vapour, mist, gas, dry gas or charged spray biocides
Liquid biocides
Immersion, mopping or using a cloth or sponge are methods of application that involve evenly applying a sufficient amount of a liquid biocide to a surface. Biocides with these methods of application can be tested using immersion methods, such as the "use dilution method" for bacteria.
Liquid biocides that are intended to be sprayed on a surface should be using spray methods such as the "germicidal spray test" for bacteria.
Non-volatile biocides are expected to evenly cover a treated surface for the entire contact time. Biocides that have both spray and non-spray applications may be tested using an immersion method.
Volatile biocides (for instance, biocides that readily evaporate into the atmosphere, such as biocides containing isopropyl alcohol or ethanol as an active ingredient, for example) should be tested using spray methods. This is because immersion methods do not accurately simulate the way in which volatile biocides perform on environmental surfaces. Alternatively, a wetness test showing that the surfaces remain thoroughly wet for the entire contact time may be submitted to support the use of immersion methods for volatile biocides.
Conduct a spray test on your biocide. If it evenly covers the surface of the carrier for the entire contact time, then a spray method can be used for efficacy testing.
Recommendations for conducting wetness determinations are specified in the testing efficacy section of this guidance. Contact us if you want to verify wetness determination approaches before initiating your testing.
Towelette biocides
If your biocide is a single-use pre-saturated or impregnated towelette, you should use the towelette to test the biocide's efficacy. Your test method should include detailed procedures for:
- wiping the surface of inoculated test carriers with the towelette and
- sub-culturing the carriers after the specified contact time
You can also use the liquid expressed from a towelette to conduct your testing. In your application include analytical data on the concentration levels of the active ingredients in the expressed liquid.
To test with a towelette, use 1 towelette to treat either:
- 10 carriers or
- 1 carrier with a surface area equal to 10 1-by-1-inch (2.54-by-2.54-centimetres) per carrier set per batch
Each carrier should be wiped back and forth up to 3 times, for a total of 6 passes, before moving to the next carrier. A pass is defined as moving from 1 side of the carrier to the other with a single motion. The contact time begins after 6 passes.
For disinfectant claims against bacteria, mycobacteria and fungi, we recommend either of the following test methods:
- Modified AOAC 961.02 Germicidal Spray Products as Disinfectants or
- ASTM E2362 Standard practice for evaluation of pre-saturated or impregnated towelettes for hard surface disinfection
We recommend the ASTM E1053 method for virucidal claims. Use 1 towelette to wipe 1 test carrier.
You can bridge data from a liquid biocide for the same biocide in towelette form using confirmatory data. All representative micro-organisms in each microbial category should be tested using the biocide in towelette form. If the towelette biocide has the same efficacy claims as the biocide in liquid form, you can bridge data if you:
- provide a certificate of analysis for the liquid used to saturate the towelettes and the liquid expressed from the towelettes to show that the active ingredient is delivered to the target surface and does not bind to the towelette material
- use the same towelette material for the tests
Extended-use and reusable biocides
You should provide data to support your biocide's effectiveness at the end of its shelf life:
- after being diluted or activated beyond 24 hours
- when reused for a certain number of days
For example, a biocide that is used for a certain number of days for immersion application after repeated soaking of contaminated instruments.
The data should reflect simulated use, soiling and dilution as applicable.
Vapour or gas biocides
If your biocide is a vapour, mist or gas, you should test your biocide under similar conditions and settings (for example, simulated-use testing). This includes the type and size of the areas the biocide is for use in. Examples of vapour or gas biocides include those:
- used in a fogging or misting machine
- applied by a specific device
When testing vapour or gas biocides, be sure that all key parameters for efficacy are monitored throughout the use area and reflect the labelled conditions, such as:
- temperature
- contact time
- relative humidity
- active ingredient concentration
When planning your testing, you should:
- use appropriate controls
- demonstrate the biocide's efficacy on surfaces that have a mild to moderate soil load
- for example, 5% fetal bovine serum
- describe how you monitor and determine the disinfection process is effective
- determine and test the total mass of vapour, mist or gas released into the area and the maximum volume of space that can be disinfected
- demonstrate that the active ingredient concentration is maintained throughout the entire area and for the duration of the contact time that is indicated on the label
- place carriers in different parts of the room to demonstrate that the vapour, mist or gas will reach all parts of the room, including:
- every corner
- various locations on the wall faces
- centre of the floor
- underneath horizontal surfaces
- various heights, including the maximum height specified in the fogging system instructions
For guidance on the test method for vapour or gas biocides, consult:
- Protocol for room sterilization by fogger application (US Environmental Protection Agency)
Testing efficacy
In addition to replicating your biocide's formulation, physical form and conditions of use, you should use the same conditions and parameters as the referenced test method (unless test method does not prescribe the conditions and parameters). Conditions and parameters include:
- use-dilution
- contact time
- number of carriers
- water hardness level
- temperature being used
- organic burden level (soil load)
- type of carriers (for soft, porous surfaces)
The number of carriers should be based on the most recent version of the test method being referenced.
All micro-organisms should be tested in similar conditions to how the biocide will be used. If the biocide will not be used in a conventional way, test modifications or alternative test methods may be needed to support the efficacy of the biocide for its proposed use. Contact us to discuss the appropriate alternative test methods or modifications for your biocide.
Contact time
Your efficacy testing should use the same (or a shorter) contact time as the time indicated on your proposed biocide label.
Note: Any change in contact time in efficacy testing may be restricted by the limitations of the test method or the proposed method of application. For instance, an exposure period greater than 10 minutes for a biocide that will likely evaporate from a treated hard surface within 10 minutes. Shorter contact times may be required for some uses where the 10-minute contact time is not achievable.
Your biocide should meet the performance standard set for the test method and target micro-organism within a 10-minute contact time. Exceptions may be given to biocides that direct users to immerse objects in the solution for a specified time.
You will not be able to propose contact times above 10 minutes unless either:
- your biocide is meant for immersion application
- you provide a wetness test showing the biocide will not evaporate in 10 minutes
Contact us for a pre-submission meeting if you require a longer contact time.
For liquid or spray biocides with volatile active ingredients, you can determine the maximum contact time by testing your biocide's evaporation over the proposed contact period using a wetness test.
For spray-only biocides, do not use a test method that immerses your test organism in the biocide fluid. Immersion does not accurately represent the way biocides perform on surfaces. Instead, use 1 of the following test methods:
- AOAC 961.02
- ASTM E1053
- ASTM E1153 (modified for a spray application)
You may use an immersion test method for non-volatile biocides that are applied by both spray and non-spray methods. Volatile formulations should be tested using spray methods as this accurately represents the way volatile biocides perform on surfaces.
For biocides in towelette form, you may use a wetness test to determine the maximum contact time. This test will:
- assess the amount of liquid left on the surface treated (wiped) when used according to the label
- for example, surface remains evenly wet before the end of the contact period
- determine the contact time you should use in your efficacy testing
We recommend that you refer to the US EPA's 810.2100 product performance test guideline for information on how to conduct visual and gravimetric wetness determinations. While the US EPA's recommendations are specific for testing against C. difficile and C. auris claims for towelette products, you may conduct wetness determination testing for other target microorganisms.
Contact us if you want to verify wetness determination approaches before initiating your testing.
Temperature
Your efficacy testing should have the same temperature conditions as those indicated on your biocide's label. Otherwise, conduct your test between 18°C and 25°C, including the steps to:
- confirm neutralization
- expose carriers to the test substance
Neutralization
Neutralization inactivates your test product's antimicrobial activity. For all efficacy testing, follow procedures to neutralize your biocide at the end of all contact times. This will prevent residual effects in the subculture medium.
Confirm how you will neutralize the product when you test for efficacy or as required by the test method. The neutralization procedure should align with your test method.
You may neutralize your biocide by:
- physical means
- filtration, dilution, secondary subculture
- chemical means
- adding sodium thiosulfate to the diluent
If you are unable to validate the neutralizers used for all biocide tests against micro-organisms (except for viruses) using standard test methods, refer to the:
Organic burden
If your biocide will be used in light to moderate amounts of soil without a pre-clean, your organic soil load should be:
- a minimum of 5% v/v (volume-per-volume) blood or animal serum or
- the amount and type required by the test method (for example, 3-part soil)
Examples of these types of biocides are:
- a 1-step cleaner and disinfectant
- a 1-step cleaner and sanitizer
If your biocide will be used on surfaces where the presence of soil is likely even with a pre-clean, you should conduct your efficacy testing with the same representative organic burden as above. - Examples of these types of biocides are:
- fogging and misting biocides for whole room treatments
- used to treat all room surfaces, including hard-to-reach places that may not be possible to pre-clean
- residual sanitizers and disinfectants
- biocides for use on soft surfaces, such as:
- sanitizers
- disinfectants
- laundry biocides
- pre-soak treatments
- carpet treatments
- biocides for use against C. difficile and C. auris
Contact us if you want to deviate from these approaches for organic burden
Acceptable test methods
In general, Health Canada recognizes biocide test methods and protocols published by international standards organizations or other regulators. You should use the current official version of the test method.
You may not apply requirements from different test methods unless you have a suitable rationale for doing so. An example would be modifying test methods commonly recommended by other regulators or international organizations to test alternate organisms or product forms.
You should follow all prescribed information outlined for the test method you use. If the method does not outline certain information (for example, microbial count or performance criteria), you should meet the requirements outlined in this guidance.
In general, we recognize efficacy test methods published by:
- Association of Official Analytical Collaboration (AOAC) International
- American Society for Testing and Materials (ASTM) International
- Australian Therapeutic Goods Administration's Guideline for the evaluation of sterilants and disinfectants (TGA)
- European Chemical Agency's (ECHA) Guidance on the Biocidal Products Regulations: Volume II – Efficacy (Parts A, B, C)
- European Committee for Standardization
- Organisation for Economic Co-operation and Development's (OECD) Quantitative test method for hard surface disinfectants
- US Environmental Protection Agency's (US EPA) 810.2000, 810.2100, 810.2200, 810.2300 and 810.2400 product performance guidelines
- includes additional stand-alone methods, procedures and guidance documents for surface disinfectants
Note: When using European (EN) test methods, phase 1 test methods are only considered acceptable as secondary supporting evidence of efficacy. While they cannot be used solely to support a proposed claim and are not accepted for biocide authorization, they can be used to help develop a proposed biocide. You should conduct all testing using at least 2 batches and phase 2 test methods.
Sourcing test organisms
Your efficacy testing for each microbial category claimed on your biocide's label should use representative test organisms.
We recommend that you use test organisms available for purchase through the American Type Culture Collection (ATCC). You may use micro-organism stocks purchased from other suppliers if they:
- meet quality assurance standards (for example, characterization, preservation, purity, etc.) and
- are appropriate for the chosen efficacy test method
Antibiotic resistance
If you claim that your biocide is effective against micro-organisms that are resistant to antibiotics (for example, Methicillin-resistant Staphylococcus aureus, MRSA), you should provide scientific data to support this. When preparing this scientific data, you should:
- use the specific micro-organism mentioned on your biocide's label in the test
- test for antibiotic resistance when you test for efficacy
If you claim that your biocide is effective against strains that are resistant to antibiotics, you should provide confirmation of this. Confirmation tests include:
- quality control procedures used to verify results
- method of preparation before testing (for example, transfer history)
- results of testing (including the numerical values of all antibiotics tested)
- method of preservation or storage (for example, refrigerated agar slants, cryogenic beads)
- method to confirm the identity (for example, resistance verification, biochemical test, Gram stain, morphology)
- scientific method used (for example, Kirby-Bauer, disc agar diffusion, gradient agar diffusion, automated minimum inhibitory concentration (MIC) procedures)
Examples of relevant numerical values of antibiotics are:
- zone sizes for manual tests
- the MIC for automated tests
- comparison to a standard clinical or national standards interpretations of such tests (for example, standards from the Clinical & Laboratory Standards Institute (CLSI))
Batch replication, microbial counts and performance standards
To show that efficacy results are reproducible and statistically sound, you should have:
- separately compounded batches for testing
- carriers for each batch tested against the same micro-organism, as required by the method
- replicates for each batch tested for each carrier used, as required by the method
Find more information, consult:
- hard-surface disinfection and sanitization
- soft-surface disinfection and sanitization
- other types of claims
The microbial count of a sample (inoculum counts or carrier counts) determines the microbial challenge level for the test. For a test result to be valid, the microbial levels should be within the prescribed limits for the test method.
The way you determine the microbial count should be in line with the test method. For suspension test methods, you should determine the microbial count of the sample. For carrier test methods, you should determine the microbial counts on untreated dried control carriers.
In general, it is acceptable if the microbial counts exceed the prescribed levels outlined in the test requirements as long as the biocide meets the prescribed performance criteria.
Repeat testing and re-testing
Repeat test: subsequent testing using the same test conditions.
Re-test: subsequent testing using one or more modified test conditions.
A biocide may fail to meet the performance standard required for the efficacy claim due to contamination, laboratory error, control failure or not meeting the prescribed carrier count. We recommend that you follow the US EPA's 810.2000 product performance test guideline to help you determine whether you need to repeat testing of, or retest, the biocide and if so, how.
If a laboratory test indicates that the failure is due to a false positive, you may repeat the test for that particular batch.
If you decide to repeat the test, you do not need to use:
- a different laboratory
- different laboratory personnel
- for example, study director, technical staff, quality assurance auditor
You may conduct up to 2 repeat tests for each type of control failure. You do not need to conduct repeat testing for carrier population controls that are greater than the acceptance criteria (unless otherwise specified in the test methods).
If the issue has not been resolved after 2 repeat tests, a re-test may be conducted.
Failure due to contamination
Contaminants are micro-organisms that are not the test organism in the study. Contamination in the test system may invalidate the assay.
Use 1 of the following methods to identify the contaminant and presence or absence of the test organism:
- Gram staining
- colony morphology
- biochemical assays
If contamination happens again, the laboratory may consider a quality plan to correct the issue. Quality plans can include mitigation strategies such as:
- replacing the stock tube
- purchasing a new lyophilized stock
- performing a facility or equipment cleaning
Failed repeat testing
If you repeated the test and your results continue to fail to meet performance standards, you may wish to conduct a different test by changing the test conditions. This will affect your labelled claim for your biocide. Examples of changes include:
- removing soil load
- using a higher concentration
- using an increased contact time
Confirmatory data requirements
You may use confirmatory data with reduced batch replication requirements to support situations that may affect your biocide's efficacy, such as:
- formulation variations
- major changes to formulants (for examples, refer to Table 2: Examples of types of changes)
- bridging liquid biocide data for a towelette biocide
- different conditions of use for your biocide
- for example, adding a new contact time or changing the concentration of use
We accept reduced batch replication requirements for confirmatory data for:
- formulation variations
- major changes to formulants (for examples, refer to Table 2: Examples of types of changes)
- different conditions of use for your biocide
For more information, visit:
- hard-surface disinfection and sanitization
- soft-surface disinfection and sanitization
- other types of claims
Formulation variations
If you include formulation variations in your application, make sure they are substantially similar to the basic formulation.
All variations should be supported by a single benefits (efficacy) package and label text to demonstrate that they:
- meet every label claim
- have physical and chemical properties that are within product specifications
- are as safe as the basic formulation
- do not negatively affect the stability and quality of the biocide
When proposing formulation variations, you should include both:
- confirmatory data to demonstrate the alternate formulation is as effective when there are major changes to formulants (for examples, refer to Table 2: Examples of types of changes) and
- a scientific rationale to demonstrate the formulation has the same efficacy, safety and quality
The confirmatory data that you include in the application should:
- have the same or more stringent testing conditions
- be produced using the same lower certified limit (LCL) as your basic formulation
- include data according to the batch replication requirements against each representative test organism for each microbial category on your biocide's label
For more information, visit the:
- hard-surface disinfection and sanitization
- soft-surface disinfection and sanitization
- other types of claims
You do not need to provide confirmatory efficacy data when:
- only the concentration of a fragrance or dye is increased, substituted or decreased in a formulation and either:
- the concentration of fragrances does not exceed 1% of the total formulation, expressed as a percentage on a weight-per-weight basis (% w/w) or
- the total percentage of changes in dyes does not exceed 1% of the total formulation, expressed as % w/w
Contact us if you want to verify whether submission of confirmatory data is required.
For more information, consult:
Towelette biocides
Confirmatory testing allows you to bridge additional specific claims approved for your liquid biocide to the same biocide in towelette form. This confirmatory data should include the representative test organisms for each microbial category claimed on the label of your towelette biocide and be tested using towelettes. If acceptable, you do not need efficacy data to support all other additional claims.
When conducting confirmatory testing, you should:
- use the same testing conditions (same contact time, soil load, temperature) or more stringent conditions
- an example of more stringent conditions would be to include soil for a towelette test if the original test did not include soil
- meet the batch replication requirements outlined in this guide for the representative test organisms for each microbial category claimed on your label
Efficacy data reporting
The efficacy data submitted for your biocide should be presented in a report format and should include the information outlined in the following sections.
Laboratory information
You should include information on the laboratory that performed your efficacy testing. This information should include the:
- name(s) of the person(s) responsible for the test
- name and address of the testing laboratory or organization
- signed statement of compliance with good laboratory practice
- dates on which the study was started, completed, terminated or discontinued
You should also include a testing laboratory analysis or certificate of analysis (CoA) for each batch tested. This analysis should include the:
- laboratory signature
- testing laboratory name
- analysis method (may reference the method description)
- manufacturing and analysis dates (before testing for efficacy)
- analysis results (concentration of each active ingredient, with conversion table included when ppm of concentration is indicated)
Test product description
When describing your test product and the formulation used in each batch test, you should include the following:
- in-use concentration(s) tested
- formulation of the tested product
- physical form of the product
- for example, liquid, spray, solid or powder, towelettes
- description of how you calculated the lower certified limits tested
- product name or identification number and the number of batches tested
- concentration of the active ingredient(s) for each batch tested and details on how long and under what conditions for ingredients that were aged or stressed
- for biocides that are diluted from a concentrated formulation:
- type of diluent used
- how the dilution was prepared
- level of water hardness used in the test, expressed as the amount of calcium carbonate (CaCO3) present
Organisms used
You should provide the following information on the test organisms you used:
- names
- source (stock supplier)
- identity of the specific strain
- for example, the American Type Culture Collection identifier
If you used viruses in your testing, you should also include:
- source and strain of the host cell line
- methods used to standardize the culture
- any special methods (for example, use of columns) to increase the virus titer and reduce the cytotoxicity of the residual disinfectant
Methodology
The methodology section of your summary should include:
- an overview of the statistical plan, when applicable
- statistical assumptions for analyzing the data
- any deviations or modifications made to the standard test parameters or methodologies
- complete testing protocols, if you used alternate test methods we did not recommend (for in-use or simulated-use testing)
- rationale to support re-testing, with all reported passing and failing data
If the test method you chose includes multiple options for materials or procedures, include a description of each option you used in your testing. This could include information on the:
- growth media
- drying time for inoculated carriers
- neutralization confirmation and subculture media, secondary sub-culturing
You should also include a description of the recovery procedure (for example, removal of the micro-organisms from the carrier), including the specific assay procedure. Details on the enumeration procedure used should include:
- diluents
- replication
- subculture media
- incubation time and temperature conditions
Test methods
For each test method used, indicate the:
- purpose of the study
- number of batches tested
- title of the efficacy study
- test method and protocol
- host cell line source and strain for ASTM E1053 testing
- study identification number
- initial inoculums of the test organisms
- number and type of carriers or replicates
- test exposure conditions, such as:
- contact time
- temperature
- relative humidity
- type and level of soil load
If you used alternate test methods we did not recommend, you should also include a description of the materials and procedures.
Controls
You should include control data to establish validity, for example:
- purity control
- viability control
- infectivity assays
- cytotoxicity controls
- carrier sterility control
- carrier population control
- antimicrobial resistance, if applicable
You should also include data that confirms neutralization, which means:
- the neutralizing agent does not have any antimicrobial activity and
- all subculture techniques used prevent residual carryover of the active ingredients
The following counts are required to validate a test:
- inoculum counts (for suspension tests), or
- based on determinations in parallel between the inoculated untreated diluent carrier counts (control) and treated carrier counts (for carrier-based assays)
Results
You should include the following efficacy information:
- raw data for each replication
- numerical test results (in a table)
- scientific literature references
- a conclusion indicating if the biocide meets the specific performance criteria for the test method used
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