1

Response to Comments Document 

for the 810.2000 Series Product Performance Guidelines

January (insert date), 2012

This document summarizes the comments received in response to the 810.2000 

Series Product Performance Guidelines for Sterilants, Disinfectants and Sanitizers, 

which were proposed on January 27, 2010, and provides the Agency’s responses to 

those comments. The following groups submitted comments to the docket, # EPA-OPPHQ-2009-0681. They are listed by their assigned docket designation.

0007 Keller and Heckman

0009 Public Employees for Environmental Responsibility

0010 Kimberly-Clark Corporation

0011 Ecolab

0012 The Clorox Company

0013 Patton Boggs LLP, Metrex Research, LLC

0014 Lonza, Inc.

0015 Consumer Specialty Products Association

1. General Comments (5)

1.1 Comment (0009, 0013):

Two commenters expressed concern over the non-binding nature of the 

guidelines. 

Agency Response: The guidelines are non-binding because they are guidelines 

and not regulations. However, the data requirements to which the guidelines 

relate are codified in the regulations.

1.2 Comment (0009):

The draft guidelines do not adequately consider the environmental and human 

health risks posed by antimicrobial pesticides.

Agency Response: These guidelines are intended to make recommendations on 

methods to be used in tests conducted to address the data requirements for 

product performance; these are not intended to address human health and 

environmental risks that could be posed by the use of antimicrobial pesticides. 

The data requirements for human health and environmental risks do and are in 

40 CFR Part 161.

1.3 Comment (0009):

The EPA has failed to adequately consider whether public health-related 

antimicrobial pesticides benefit average consumers.

Agency Response: The Agency has considered and understands the 

relationship between the use of antimicrobial pesticides and their benefit to 

average consumers. While the average consumer uses antimicrobial products to 
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reduce the number of germs in their household, the healthcare community also 

relies on antimicrobial pesticides as an important component of a comprehensive

infection control program. Antimicrobial pesticides, along with hand washing, 

isolation precautions and the use of barrier materials support the needs of 

infection preventionists in reducing the number of microorganisms on treated 

surfaces.

1.4 Comment (0007, 0011):

Two commenters stated the need for additional guidelines for commercial 

sterilants for aseptic packaging. One commenter provided language to go into 

the guidelines regarding the testing of products for aseptic packaging label 

claims. Further, one of the commenters “requests that EPA’s guidelines for 

product performances of public health uses of antimicrobial agents acknowledge

that validated testing acceptable to FDA also provides adequate assurance of 

commercial sterility for use in FDA regulated aseptic food processing operations.” 

Agency Response: The Agency will add the suggested language regarding test 

procedures and measures of success for products with label claims for aseptic 

packaging into a new section, designated as (j) in 810.2100 – Sterilants for Use 

on Hard Surfaces under the heading “Aseptic Packaging.” The Agency is aware 

and supports the Food and Drug Administration’s program for validating testing 

processes for commercial sterilants. 21 CFR Parts 108, 110, 113 and 114 deal 

with the packaging, compliance, good manufacturing practices, validation and 

other safety and control standards that food processors need to follow to ensure 

“commercial sterility” for aseptic packaging. However, this program does not 

relieve EPA of its statutory authority to regulate antimicrobial products (like 

commercial sterilants for aseptic packaging). EPA intends to develop additional 

guidance directed to aseptic packaging products, and sterilants intended for use 

in validated systems, in the near future.

1.5 Comment (0015):

The sections on “Data collection and reporting” and “Data for recommended 

methods” should be removed from 810.2100, 810.2200 and 810.2300 and placed 

in 810.2000 for consistency.

Agency Response: EPA disagrees with removing the sections on “Data 

collection and reporting” and “Data for recommended methods” from 810.2100, 

810.2200 and 810.2300, and placing the sections in 810.2000. Since each 

guideline is intended as a stand alone document, it is important to retain the 

sections on “Data collection and reporting” and Data for recommended methods” 

in each individual guideline.

2. Comments on 810.2000 Overview (24 comments)

2.1 Comment (0013, 0015):
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Previous guidelines: The Agency should make the 91B Non-Public Health

Guideline Series available on the EPA website and add citations to the guidelines 

for non-public health applications and for the interpretive instructions found in the 

Preamble of Subdivision G (e.g., Agency philosophy, waiver information, dose 

and effectiveness evaluations, instructions for adjuvants, geographic distribution 

of testing, study design, report content, test substance, application and 

equipment use). The Agency should update all non-public health guidelines.

Agency Response: The Agency will post the non-public health Guideline Series

91B on the Antimicrobials Division’s website. This posting will include a 

comparison that identifies the relevant sections in the 810 guidelines that match 

with the former 91A series numbers in Subdivision G. Most of the information 

cited in the Preamble of Subdivision G can be found within 810.2000. At this 

time, the Agency has no plans for updating the non-public health guidelines.

2.2 Comment (0015):

Test organisms should always be cited throughout the document with an 

identifier (e.g., ATCC number) where one is defined.

Agency Response: The Agency agrees and will add identifiers where they are 

missing.

2.3 Comment (0015):

The commenter requested a description (e.g., title, description of future content) 

for all sections labeled as “Reserved” and that these sections not be left open 

without clarification.

Agency Response: The term “Reserved” will be removed from the guidelines.

2.4 Comment (0015):

In appropriate places, replace “should” with “must” as the term “should” may 

leave the document open for too much interpretation.

Agency Response: At places in this guidance, the Agency uses the word 

“should.” Use of “should” with regard to an action means that the action is 

recommended rather than mandatory. Since these are guidelines and not 

regulations, the use of the word “must” instead of “should” is not appropriate.

2.5 Comment (0015):

The title for 810.2000 should be changed to “General Considerations for the 

Uses of Antimicrobial Agents” since it is positioned as an overview document 

describing how the Agency views all antimicrobial agents.

Agency Response: The Agency disagrees with the comment. The majority of 

information, with the exception of some of the definitions, in 810.2000, “General 
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Considerations for the Uses of Antimicrobial Agents” refers to public health uses 

of antimicrobial agents. 

2.6 Comment (0015):

The 810 guidelines are lacking a discussion on the emerging pathogen policy.

Agency Response: The emerging pathogen guidance deals with labeling of 

disinfectant products in emergency situations. The Agency does not believe the 

product performance guidelines are the appropriate document for discussing the 

emerging pathogen guidance, which can be found at 

http://www.epa.gov/oppad001/disinfection_hier.htm

2.7 Comment (0010, 0015):

Define the terms “Volatile” and “Non-volatile.”

Agency Response: The Agency agrees and will provide definitions for “volatile” 

and “non-volatile.”

2.8 Comment (0010, 0015):

The commenters support the Agency’s goals to periodically update the guidelines 

and adopt new quantitative methods. All updates must be vetted through a public 

notice and comment period and new methods must not be adopted without 

thorough validation. The level of stringency for new methods must be aligned 

with the stringency of historic methods. Adoption of new methods and criteria 

must not force widespread reformulation of products, which have been available, 

effective products registered for decades, to higher levels of active ingredient 

resulting in greater human and environmental safety concerns.

Agency Response: The Agency agrees that in general new methods should be 

validated prior to adoption, and public notice and comment should take place

before a method is accepted for use. The Agency also believes that as the stateof-the-science evolves and new information becomes available regarding 

disinfection principles, processes and test methods, new methods may not 

always align in stringency with historic methods. The Agency will uphold its 

responsibility to consider and adopt methods that are protective of public health.

Depending on the test results, the impact to an individual product would have to 

be assessed on a case-by-case basis.

2.9 Comment (0015):

New methods that have been approved through the internal protocol review 

process must be published on the EPA website until such a time as it can be 

added to these Guidelines.
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Agency Response: The Agency agrees that new methods approved through the 

internal protocol review process should be published on the EPA website. 

Methods that have previously been approved and newly approved methods will 

be posted to the Antimicrobials Division website. However, in some instances, 

scientific information has arisen that may change the Agency’s decision 

concerning a previously approved protocol. Such protocols will not be posted to 

the website or they will be removed if already posted.

2.10 Comment (0015):

Adoption of AOAC methods should not occur until the method has achieved final 

status.

Agency Response: The Agency disagrees with the comment. Methods that have 

achieved First Action by AOAC have been fully vetted and validated prior to 

acceptance by AOAC. Since these First Action methods have undergone 

validation, the Agency believes it is acceptable to adopt them for use. AOAC 

allows a two year period for methods to reach Final Action Status. Methods that 

do not reach final status may be delayed (depending on the nature of the 

comments) or repealed. In that case the Agency will need to decide whether to 

retain use of the method.

2.11 Comment (0015):

The assertion that all disinfectants are considered to be human health-related, 

whether or not control of infectious microorganisms as specifically claimed, is not 

correct.

Agency Response: The Agency agrees with the comment and has revised the 

section on public health claims to read: “An antimicrobial pesticide is considered 

to make a public health claim if the pesticide product bears a claim to control pest 

microorganisms that pose a threat to human health, and whose presence cannot 

readily be observed by the user, including but not limited to, microorganisms 

infectious to man in any area of the environment.”

2.12 Comment (0015):

Insert a place holder for mold remediation products.

Agency Response: As new guidelines are developed, the Agency will 

incorporate them into the 810 series. It is not necessary to add a place holder for 

each potential guideline.

2.13 Comment (0015):

Revise the title in Section (c) (2) (B) to include fungistatic products.
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Agency Response: The Agency agrees with the comment and will revise section 

(c)(2)(B) in 810.2000 to include fungistatic products.

2.14 Comment (0015):

Revise the sentence in Section (c) (2) (D) by changing the “or” to “and” so that it 

states, “. . . the Agency is requesting the submission of efficacy data to support 

these claims because these pathogens have animal health significance and the 

potential to infect humans.” Add a reference to a list of organisms that meet the 

criteria for which testing is required.

Agency Response: The Agency disagrees with the comment because the 

Agency would want to review the data in either case (significant animal health 

pathogen or the potential to infect humans) and has not made the suggested 

change to section (c)(2)(D) in 810.2000.

2.15 Comment (0015):

Commenter believes all definitions must agree with those definitions provided in 

FIFRA (e.g., antimicrobial pesticide, disinfectant, etc.). For those terms not 

defined in FIFRA, definitions consistent with those found in standard methods 

employed in testing antimicrobials should be used. Definitions for additional 

terms used in the Guidelines have been provided. The statement “For the 

purposes of these guidelines, slimicide claims are reserved for non-public health 

industrial label claims” is inappropriate.

Agency Response: The Agency has revised the definition for slimicide to remove 

the statement “are reserved for non-public health industrial label claims.” The 

Agency has determined this statement is not appropriate for the guidelines

because it deals with labeling and not tests that are recommended to support a 

label claim. Additional definitions for slime, volatile, non-volatile and revisions to 

the definition of a biofilm have also been made. Revisions have also been made 

to the definitions for sanitizer and disinfectant, however, the descriptors of these 

terms that are outlined in FIFRA section 4(i)(4)(C), which, by its own wording,

concerns only the reduction or waiver of fees for minor uses, were not used to 

define these terms.

2.16 Comment (0010, 0011, 0012, 0014 and 0015):

Several comments were made regarding testing formulations at the lower 

certified limit(s) (LCL) of the active ingredient(s). Most of the commenters agreed 

that formulations should be tested at the lower certified limit(s) of the active 

ingredient(s). However, for products that contain multiple actives, have inverse 

relationships (e.g., peracetic acid/peroxide), or the active is created in situ, 

producing batches with all the actives at the lower certified limits may be difficult 

or impossible to achieve. Suggestions for revised language were provided.
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Agency Response: The Agency agrees there may be situations where it may not 

be technically feasible to test at the exact LCL (e.g., reactive chemistries with a 

degradation profile, multiple active ingredients and formulations with inversely 

related active ingredients); a rationale should be provided to the Agency for 

approval of the testing that cannot be performed at the LCL. Efforts should be 

made to test as close to the LCL as possible. The suggested language from the 

commenter has been incorporated into 810.2000, section (e)(1)(v).

2.17 Comment (0015):

For the HBV, HCV and Norovirus studies, the fact that the data consistency 

controls found in the methods posted on the EPA web site are no longer required 

should be reflected in the 810.2000 guidance.

Agency Response: The Agency agrees with the comments and believes the 

data consistency controls are no longer needed for the HBV, HVC and Norovirus 

surrogate methods because sufficient data has been generated using these 

controls and shown that the data for these surrogates is consistent. The Agency

will remove the data consistency controls from these methods that use 

surrogates for HBV, HCV and Norovirus.

2.18 Comment (0010, 0013):

Two comments were made regarding the addition of an organic soil load in 

efficacy tests. One focused on the addition of organic soil to suspension based 

tests where the example given in the guidelines provides for the soil being added 

to the test substance. The commenter believes the soil load should be added to 

the test microorganism. The second commenter requests clarifying language be 

added, so that if the product requires pre-cleaning of the surface of gross debris 

before the use of the spray disinfectant or towelette, it is clear the EPA’s test 

method does NOT call for the addition of organic soil such as blood serum.

Agency Response: The Agency agrees with the first comment. For suspension 

based tests, the soil should be added to the test inoculum to achieve 5% of the 

test inoculum. The Agency also agrees that products requiring a pre-cleaning 

step do not call for the addition of organic soil in the test. The lack of the need for 

an organic soil when a pre-cleaning step is included on the label is also stated in 

Section (g)(3)(i) of the 810.2000 guidelines.

2.19 Comment (0015):

The Agency routinely accepts shorter time periods than are listed in methods. 

This section is worded in a way that makes it seem like registrants must seek 

Agency concurrence before conducting studies with shorter time periods. This is 

burdensome for both the Industry and the Agency when current policy allows 

time reductions on a routine basis.
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Agency Response: The Agency agrees with the comment. Section (g)(4) will be 

revised to state that shorter contact times than those listed in standard methods 

are allowed without obtaining Agency review prior to conducting the studies. Any 

resulting claims would reflect reduced contact time.

2.20 Comment (0015):

The proposed Guideline does not include any reference to use/reuse studies. 

While use/reuse is most commonly associated with reprocessing of medical 

equipment, an FDA regulated claim, there may be instances where use/reuse is 

indicated for EPA applications. Thus, registrants want to maintain the right to 

have this use on EPA regulated products.

Agency Response: The Agency does not envision situations where reuse of dirty 

disinfectant products would be appropriate. As stated in the comment, reuse is 

most commonly associated with reprocessing medical equipment and is 

therefore an FDA regulated claim. Therefore, references to reuse of disinfectant 

products will not be included in the guidelines.

2.21 Comment (0012, 0015):

Considering that neutralization is a key part of any antimicrobial study, a more 

detailed description of neutralization techniques and its importance should be 

highlighted in this document.

Agency Response: The Agency agrees with the comment and has revised 

section (h)(3) to provide a more detailed description concerning neutralization 

techniques.

2.22 Comment (0010):

The statement “The Agency reserves the option to perform its own tests for

validation of efficacy of products selected on a case-by-case basis” should be 

revised to read, “The Agency reserves the option to perform its own tests 

following the protocol submitted with the registration for validation of efficacy of 

products selected on a case-by-case basis.”

Agency Response: In general, the Agency agrees with the comment. When the 

protocol submitted for registration meets current recommended protocols, the 

Agency will use that same protocol when performing its own validation tests. If 

the protocol does not meet current agency standards, the Agency will use its own 

protocol to conduct validation studies on a product. The Agency will revise the 

statement to read, “The Agency reserves the option to perform its own tests, on a 

case-by-case basis, following the protocol submitted with the registration, if that 

protocol meets current agency standards. In all other cases, the Agency will 

conduct the validation studies using the current agency protocol.”
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2.23 Comment (0010, 0012 and 0015):

Several commenters requested clarifying information be added to the guidelines 

regarding the repeat testing of low level failures.

Agency Response: The Agency does not have a formal policy regarding the 

repeat testing of low level failures. The industry has historically repeated low 

level failures (e.g., 2 – 3 positive carriers out of 60 carriers) when the results from 

an analyst come under question or there is contamination in the system. The 

Agency believes the regulated industry is familiar with these limited instances 

where repeat testing should be conducted and that it is not necessary to include 

this information in the test guidelines.

2.24 Comment (0015):

The commenter recommends adding a section that describes what information 

should be included in a final report.

Agency Response: The Agency has already included a list of the information 

that should be included in a final report at the end of each test guideline. 

3. Comments on 810.2100 Sterilants (15 Comments)

3.1 Comment (0010):

The commenter believes it is inappropriate for the Agency to share developing 

methods with organizations outside of the Agency, and requests the following 

statement be deleted: “The Agency may consult with AOAC prior to accepting 

modifications to their standardized methods.”

Agency Response: The Agency disagrees with the comment. Methods that have 

been validated through a standard setting organization should not be changed 

without consultation with the standard setting organization. 

3.2 Comment (0010, 0015):

The commenters requested removal of the carrier count range (1 x 105– 1 x 106) 

for spore forming bacteria. If the carrier count range is retained, one commenter 

requested removal of the word “approximately” from the section on Bacillus 

anthracis.

Agency Response: The carrier count range needs to be retained so that a 

minimum spore count of at least 5 to 6 logs on each carrier is assured. The 

Agency agrees that the word “approximately” where in the proposal it modified 

the number of spore forming units per carrier is not needed because a finite 
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range is set for the number of spore forming units that should be achieved per 

carrier. The word will be deleted from the section on Bacillus anthracis.

3.3 Comment (0015):

The 810.2100 Guideline is missing information on the use of porous carriers as 

the more stringent test standard. In 810.2000, (g)(1) Type of Surface, a hard, 

porous carrier may be substituted for a non-porous carrier. The statement is as 

follows: “Since the use of a hard, porous surface would simulate the more 

stringent test condition, demonstrated efficacy on hard, porous surfaces would 

suffice to support an analogous claim for efficacy of the product on hard, nonporous surfaces as well.”

Agency Response: The Agency agrees with the comment and has added the 

language dealing with porous carriers from 810.2000 (g)(1) into the guideline 

under “General considerations.”

3.4 Comment (0010, 0015):

Official Methods of Analysis of AOAC International, Official Method 966.04 

Sporicidal Activity of Disinfectants test, Method II is limited to use for Bacillus 

subtilis (B. subtilis) spores dried on porcelain penicylinders. This method has not 

been validated for B. subtilis spores dried on suture loops or and Clostridium 

sporogenes dried on porcelain penicylinders and suture loops. Include Sporicidal 

Activity of Disinfectants Test, Method I in the recommended tests.

Agency Response: The Agency agrees with the comment and will include the 

Sporicidal Activity of Disinfectants Test, Method I among the recommended tests. 

However, it will be noted in the guidance document that Method I will no longer 

be applicable when AOAC issues First Action Status to the validated Method II 

for B. subtilis spores dried on suture loops, and for Clostridium sporogenes dried 

on porcelain penicylinders and suture loops. 

3.5 Comment (0015):

Include an explanation of the term “failures” under the section “Evaluation of 

Sterilant Success.”

Agency Response: The Agency agrees and has added an explanation of the 

term “failures” to the evaluation of success section.

3.6 Comment (0010, 0015):

The commenters are requesting independent validation testing for sterilant label 

claims be conducted in either a separate facility or in the same facility as the 

initial testing but with separate staff. This request is being made because there 

are a limited number of laboratories that have expertise in sporicidal testing.
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Agency Response: The Agency agrees with the comment. Independent 

validation testing for sterilant label claims may be conducted in the same facility 

as the initial testing so long as the study director, staff and QA auditor are not the 

same individuals who were involved in any way in the initial testing.

3.7 Comment (0015):

The commenter requests the removal of the term “interim guidance” under the 

section addressing testing against Clostridium difficile (C. difficile).

Agency Response: The Agency disagrees and will continue to use the term 

“interim” guidance until it believes the science issues under development 

surrounding testing for C. difficile have been adequately resolved.

3.8 Comment (0010):

The commenter requests clarification that the validation testing is not required for 

Clostridium difficile claims.

Agency Response: The Agency agrees and has added clarification that 

validation testing is not part of the recommended testing for C. difficile claims.

3.9 Comment (0010, 0015):

The commenters request the Agency clarify how to achieve a 90% spore purity 

limit.

Agency Response: There are several means to obtain a 90% spore purity limit, 

including using a physical process (e.g., HistoDenz) or chemical enzymatic 

digestions (e.g., lysozyme, trypsin).

3.10 Comment (0010, 0015):

Revise the Test procedure for C. difficile sporicides – quantitative testing to 

include the number of carriers to be used in each of the three recommended 

methods.

Agency Response: The Agency agrees and will include the number of carriers to 

be used for each of the three recommended methods.

3.11 Comment (0010):

Since no survivors are allowed in the qualitative test for C. difficile, the 

quantitative tests should be held to the same criteria.

Agency Response: The Agency disagrees with this comment. The performance 

standards for the qualitative test (which is a presence/absence test) are different 

from those of the quantitative test (which allows for survivors in order to facilitate 

calculating a log reduction).

3.12 Comment (0010):
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Include a section which addresses testing towelette products against C. difficile.

Agency Response: The Agency agrees and has added a section which 

addresses testing the use of towelette products against C. difficile.

3.13 Comment (0015):

The commenter requests the Agency provide a list of surrogate organisms to be 

used in testing for claims against Bacillus anthracis (B. anthracis).

Agency Response: EPA does not have a list of surrogate bacterial spores for use 

in testing for claims against Bacillus anthracis (B. anthracis). Because the 

susceptibility of spores to inactivation varies according to the antimicrobial 

chemical to which they are exposed, the strain of bacterial spore(s) that would be 

acceptable as surrogates to B. anthracis spores may vary. Accordingly, it is the 

responsibility of the registrant to provide data and/or a persuasive rationale as to 

why a particular bacterial spore strain should be an acceptable surrogate.

3.14 Comment (0015):

Define the statement “appropriate positive and negative controls should be 

employed”.

Agency Response: “Appropriate positive and negative controls” are those 

controls used in the method to demonstrate a valid test, including but not limited 

to; neutralization confirmation, sterility, purity, negative or inert substance, etc.

3.15 Comment (0015):

The commenter requests a rationale for how the target count of 1 x 107 spores

per carrier was determined and whether it has been collaborated and validated.

Agency Response: The target count of 1 x 107spores per carrier was 

determined to be necessary to demonstrate a 6log10 reduction in the quantitative 

test methods. It has been collaborated and validated in past studies that required 

a 6 log10 reduction as a performance criterion.

4. Comments on 810.2200 Disinfectants (12 Comments)

4.1 Comment (0015):

The commenter requests an upper limit be assigned to accompany the minimum 

mean log density for Staphylococcus aureus (S. aureus) and Pseudomonas 

aeruginosa (P. aeruginosa).

Agency Response: The Agency agrees with the comment and is currently 

working on establishing an upper limit to accompany the minimum mean log 

density for Staphylococcus aureus and Pseudomonas aeruginosa. This upper 

limit will be added to the guidelines once it is established.
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4.2 Comment (0015): 

Documents, references and methods cited in 810.2200 should be made 

publically available. For example: Sanitizer for Urinal and Toilet Bowl Water and 

In-tank Sanitizers, EPA Sanitizer Test, 1976 and any unpublished DIS/TSS 

documents.

Agency Response: The Agency agrees with the comment and will post the 

methods for In-tank sanitizers and other current Agency methods on the 

Antimicrobials Division’s website.

4.3 Comment (0015):

References to specific test methods should be modified to delete the edition 

number since it needs to be communicated to the user community that standard 

practice needs to be to use the most recent revision of the method.

Agency Response: The Agency agrees and will delete the edition numbers. The

guidelines will state that the reference is to the most current edition of the test 

methods.

4.4 Comment (0015):

The information provided allowing for the use of the Hard Surface Carrier Test 

needs to be further defined in the success criteria to include the carrier count 

requirements for each test organism.

Agency Response: The Agency agrees and will include the carrier counts for 

each test organism for the Hard Surface Carrier Test.

4.5 Comment (0015):

The mean log density for S. aureus is listed as at least 6.0 (corresponding to a 

geometric mean density of 1 x 106). Is this a requirement even though the 

corresponding test method is not a Final Action?

Agency Response: The Agency recommends a mean log density of at least 6.0 

(corresponding to a geometric mean density of 1 x 106) for Staphylococcus 

aureus. The Agency believes that any method that has achieved First Action 

Status has been fully vetted and validated by the AOAC and is, therefore, 

acceptable for use by the Agency.

4.6 Comment (0010):

Revise the sentence “In addition, per the 2009 revisions for the Use-Dilution 

Method, the mean log density...” to read “In addition, when testing with the 

AOAC Use-Dilution Method per the 2009 revisions, the mean log density...” This 

clarification is needed to communicate that the carrier count density requirements 

described are only applicable to testing with the AOAC Use-Dilution and 

therefore, do not apply to the other AOAC methods discussed in the section.
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Agency Response: The Agency agrees and will make the suggested clarification 

to the section describing the recommended method.

4.7 Comment (0015):

The Agency needs to define the total volume to be used for calculation of the 

appropriate use dilution used for testing of toilet bowl products. The current 

guidance requires the use of 96 fl oz as representative of a typical toilet. With the 

inclusion of low volume toilets in homes the total volume needs to be adjusted.

Agency Response: The Agency agrees and has added language to address the 

amount of water involved when dealing with low volume toilet bowls.

4.8 Comment (0015):

The inoculum employed for Fungicidal activity currently specifies a concentration 

of 1 x 104– 1 x 105conidia per carrier. This level has not been validated, 

collaborated or discussed through an SAP process. How was this level derived?

Agency Response: This level was derived through Agency discussions with 

commercial testing laboratories that provided data that the Agency reviewed and 

used to determine that 1 x 106conidia per carrier level was difficult to achieve.

4.9 Comment (0015):

The minimum carrier count and therefore success criteria for efficacy against 

additional organisms is not defined. The commenter requests the Agency provide 

guidance based on discussions with industry.

Agency Response: The minimum carrier count for additional organisms has 

always been expressed as no lower than 1 x 104in the DIS/TSS guidance 

document number 1, under the section addressing testing of additional 

microorganisms. 

4.10 Comment (0015):

The Multiple-Use Towelette language from previous guidance documents for 

testing towelettes should be added to the guideline.

Agency Response: The Agency disagrees with the comment because given the 

many towelette materials and label claims associated with this type of product, 

the Agency recommends a pre-registration meeting to discuss this product prior 

to registration.

4.11 Comment (0013):

EPA’s Test Method Does Not Address Towelette Size, but Should Do So.

Agency Response: The Agency disagrees with the comment because the 

amount of liquid in the towelette is more important than the actual size of the towelette. 
15

The towelette should be capable of dispensing enough liquid to keep the surface wet for 

the specified contact time listed on the label.

4.12 Comment (0013):

EPA’s Test Method Uses an Unrealistic Wiping Procedure

Agency Response: The Agency disagrees with the comment. The wiping 

procedure employed in the test is intended to simulate the back and forth motion of the 

towelette in actual use. The wiping is conducted on a stable surface similar to what 

would occur in practice.

5. Comments on 810.2300 Sanitizers (7 Comments)

5.1 Comment (0010):

The commenter states that virucidal testing should be allowed for all forms of 

sanitizing products. Virucidal activity is equally critical in food service applications 

as in healthcare and general disinfection uses. The FDA National Food Code 

(2009) states “Viruses such as Norovirus, hepatitis A and rotavirus are directly 

related to contamination from human feces. In most cases, however, 

contamination of food by viruses is the result of cross-contamination by ill food 

employees or unclean equipment and utensils.”

Agency Response: The Agency agrees there are instances where inactivation of 

viruses would be appropriate label claims for sanitizers. These determinations 

will be made on a case-by-case basis.

5.2 Comment (0010):

More detail of the key testing requirements for food contact surface towelettes is 

needed in the guideline.

Agency Response: The Agency agrees and has expanded the test information

guidance for food contact surface towelettes.

5.3 Comment (0010) (0015):

More detail of the key testing requirements for residual self-sanitizing (dry) is 

needed in the guideline.

Agency Response: The Agency agrees and has expanded the test information

guidance for residual self-sanitizing testing.

5.4 Comment (0015):

The name for Salmonella typhi (ATCC 6359) has been changed to Salmonella 

enterica (ATCC 6359).

Agency Response: Thank you for the correction. The Agency will make the 

change in the guidelines.
16

5.5 Comment (0015):

The ATCC numbers for the test microorganisms for in-tank sanitizers should be 

specified.

Agency Response: The Agency agrees and will provide the ATCC numbers for 

all test microorganisms recommended in the test guidelines.

5.6 Comment (0015):

Previous Agency guidance lists Salmonella typhi as the test organism for food 

contact testing of halide products. Table 1 of 810.2300 states test organisms are 

Salmonella typhi or Staphylococcus aureus. Is the intent to provide two options of 

test organisms?

Agency Response: Yes, the intent is to provide two options of test organisms 

since Salmonella typhi may be difficult to acquire from ATCC.

5.7 Comment (0015):

Sanitizers for Toilet and Urinal Bowl Water - Under the section describing the 

microbial counts of the treated bowl water, the Agency needs to define the three 

exposure intervals and provide clear guidance on how these were derived and 

what they equate to (e.g., duration, tablet lifespan, etc.).

Agency Response: The Agency has expanded this section to include the 

number of flushes, test days, and test weeks (duration) for the test. The intervals 

were derived when the protocol was first developed by the Agency and is 

intended to simulate flush activity in a normal household.