2

(4) other comments and changes. A revised label table along with complete appendices 

accompanies this document and reflect the changes to the RED. 

Attachments: 

• Pyrethrins Revised Label Table 

• Appendix A: Uses Supported for Reregistration 

• Appendix B: Generic Data Requirements Table 

• Appendix C: Technical Support Documents 

• Appendix D: Database Citations 

• Appendix E: EPA’s Acute Toxicity Batching 

• Appendix F: Supplement for PDCI Special Study for Arthropods: Pests of Public 

Health Importance and Structural Pests 
3

SRRD’s Response to Public Comments to the 

Pyrethrins Reregistration Eligibility Decision 

I. Public Health Uses 

Comment: The Delaware Mosquito Control Section (DMCS) of the Division of Fish and 

Wildlife, Delaware Department of Natural Resources and Environmental Control 

commented that the environmental hazard statement, which appears on wide area public 

health pyrethrins products, is not applicable to public health uses of pyrethrins. Further, 

the DMCS proposed adding the following statement to the label: “if used in accordance 

with the label, pyrethrins pose no unreasonable risk to human health, aquatic organisms, 

wildlife, or the environment.” The Maryland Mosquito Control Section submitted similar 

comments. 

SRRD Response: The environmental hazard statement (EHS) for adult mosquito control 

programs is in accordance with EPA’s Pesticide Registration (PR) Notice 2005-1 (link: 

http://www.epa.gov/PR_Notices/pr2005-1.pdf), “Labeling Statements on Products Used 

for Adult Mosquito Control.” After considerable public input and discussions with 

stakeholders the Agency has adopted this language for all products used in wide area 

adult mosquito control, not just the labels for products with pyrethrins. Therefore, the 

environmental hazard statement will not be removed or revised to include the suggestion 

above for pyrethrins products used for wide area adult mosquito control. 

Comment: The DMCS commented the following part of the EHS, “(w)hen applying as a 

wide area mosquito adulticide, do not apply over bodies of water (lakes, rivers, 

permanent streams, natural ponds, commercial fish ponds, swamps, marshes or 

estuaries), except when...weather conditions will facilitated movement of applied 

material away from the water in order to minimize incidental deposition into the body of 

water,” should be advisory, not mandatory, since pyrethrins will cause very little to no 

adverse effects to non-target organisms. The Maryland Mosquito Control Section 

submitted similar comments. 

SRRD Response: See response above. 

Comment: The DMCS also stated that the bodies of water identified in the 

environmental hazard statement need to be better defined. The Maryland Mosquito 

Control Section submitted similar comments. 

SRRD Response: See response above. 

Comment: The group Beyond Pesticides commented that pyrethrins are toxic to bees, 

and the protection of pollinators should be the highest priority for EPA. 

SRRD Response: EPA supports protecting pollinators, especially bees. The pyrethrins 

are toxic to bees, and so EPA has required bee hazard statements to be added to all 

products containing pyrethrins applied outside when bees would be present. The original 
4

pyrethrins RED only required the bee statement for professionally applied products, but 

as a result of this comment, this bee statement is also being added to all residential 

products applied outdoors as well. The bee hazard language states: 

“This product is highly toxic to bees exposed to direct treatment on 

blooming crops or weeds. Do not apply this product or allow it to drift to 

blooming crops or weeds while bees are actively visiting the treatment 

area.” 

Comment: AMCA recommended that the label language included for mosquito control 

be changed to clarify the restrictions over bodies of water and that they be moved from 

the Environmental Hazards section to the Directions for Use section of the label. 

SRRD Response: The label statements pertaining to bodies of water for adult mosquito 

control programs are in accordance with the PR Notice 2005-1, Labeling Statements on 

Products Used for Adult Mosquito Control. The Agency is adopting this language on all 

products used for wide area adult mosquito control, not just the labels for products with 

pyrethrins. Therefore, the label statements will not be revised for pyrethrins products 

used for wide area adult mosquito control. 

Comment: AMCA requested that the droplet size restrictions for mosquito misting 

systems be explicitly distinguished from droplet size restrictions for agricultural 

applications. 

SRRD Response: The droplet size information for these two very different types of 

applications is clearly separated in the label table. In addition, EPA encourages 

registrants to separate labels with use for wide area mosquito abatement from labels with 

other uses, as explained further in PR Notice 2005-1. 

II. Outdoor Use 

A. Water Contamination Comments 

Comment: The California Stormwater Quality Association (CASQA) recommended the 

Agency clarify the additional application restrictions for outdoor residential products on 

the label table intended to prevent run-off of pyrethrins into urban sewers and streams. 

CASQA stated the language would more fully meet this intent if modified as stated in the 

comments. 

SRRD Response: Since the pyrethrins RED was finalized, the Agency has finalized PR 

Notice 2008-1 that allows registrants to voluntarily change their environmental hazard 

statements on residential products so users will be able to better understand how to apply 

consumer products to minimize environmental hazards. The statements included in this 

PR Notice are similar to the language that was required in the pyrethrins RED, and the 

intention is the same for both statements, to help consumers use these products correctly 

in order to minimize environmental risks. Therefore, the pyrethrins RED labeling will be 
5

updated to require the same environmental hazard statements for residential products that 

are included in PR Notice 2008-1. 

Comment: CASQA also stated that professional products for urban use (i.e., products for 

landscaping, rights of way, etc.) should have stewardship language on their labels. CASQA 

included labeling suggestions in their comments. The CA Regional Water Quality Control 

Board, San Francisco Bay Region submitted similar comments. 

SRRD Response: The Agency agrees that pyrethrins products for professional use 

should have language on the labels to prevent the run-off of pyrethrins residues down 

storm drains. Therefore, in addition to the revisions made to the Environmental Hazards 

statements, the following statements have been added to the amended pyrethrins label 

table for end use products primarily intended for occupational use by commercial pest 

control operators. 

Products labeled for use around or near floor drains or sewer drains:

 “Do not apply directly into sewers or drains, or to any area like a gutter 

where drainage to storm sewers, water bodies, or aquatic habitat can 

occur.” 

Comment: The County Sanitation Districts of Los Angels County and the California 

Stormwater Quality Association (CASQA) commented that environmental hazard statements, 

similar to the required outdoor environmental hazard statements, be added to all indoor 

products. The reasons are that there is potential exposure to pyrethrins down the drain after 

using pet shampoos, discharging of water used to clean surfaces that were treated with 

pyrethrins, and washing materials that have been treated with pyrethrins in a washing 

machine. The Sanitation Districts and CASQA believe toxicity statements should be added to 

indoor use products, along with statements about consulting with the local sewage treatment 

agencies for uses that may result in a discharge down-the-drain, and how to dispose of water 

containing pyrethrins. 

SRRD Response: Through various labeling initiatives (some discussed in the Section IV 

below), OPP hopes to reduce the overall amount of pyrethrins discharged into both storm 

water and sewage drainage systems. However, at this time, the Agency does not believe 

additional aquatic environmental hazard statements, similar to the environmental hazard 

statements on outdoor products, is appropriate on indoor use products since local sewage 

treatment plants may not be equipped to deal with many consumer calls. 

B. Outdoor Residential Misting System Comments 

Comment: MGK Company submitted various comments on the label language for 

outdoor residential misting systems. Many of the comments supported or provided more 

rationale for the language that EPA is requiring. One comment was concerned with 

people being able to access their misting systems if emergencies occur. 
6

SRRD Response: EPA is requiring reservoir tanks to be locked, mainly to ensure 

children or others who may tamper with the devices are not exposed to the tank of 

pesticide. Homeowners who install these systems should have a mechanism for turning 

off the misting systems in case of an accident. However, the requirement to keep systems 

locked still applies to help ensure others are not exposed to the pesticide in the tank. 

Comment: The New York State Department of Pesticide Management commented about 

adding other label language for mosquito misting systems that would ensure applications 

were efficacious by setting temperature limits and requiring the product to be agitated 

periodically. They also requested that buffer zones be added to labels. 

SRRD Response: The Agency has not required language for the misting systems that 

may influence the efficacy of the system, since each system and chemical may have a 

different set of requirements. EPA has required labeling so these systems may be used in 

a manner that does not cause unreasonable adverse effects to humans or the environment. 

If registrants or system manufactures have specific requirements for their systems in 

order for them to work effectively, they must add them to either the end use product, or 

the misting device system, whichever is more appropriate. EPA has not set buffer zones 

for these misting systems, but there is label language that requires all nozzles to spray 

toward the target area. 

Comment: Valent BioSciences commented that the statement, “not for use in outdoor 

residential misting systems,” should not be required for all products since it implies that 

the product was once registered for use in these systems and could be misleading.

SRRD Response: This label language is a part of EPA’s goal to ensure that only 

pesticides that have been evaluated for use in misters are used in misters. EPA has 

included this statement on the label of products not approved for use in misters to prevent 

any improper use in residential misting systems, since Section 2(ee) of FIFRA, permits 

the use of any application methods that are not specifically prohibited by the pesticide’s 

labeling. 

C. Other Labeling Comments 

Comment: Valent BioSciences recommended revising the last sentence of the 

environmental hazard statements to delete references to other precautions, since that is a 

separate part of the label.

SRRD Response: The suggested change has been made and updated in the revised 

version of the label table. 

Comment: Valent BioSciences recommended that the statements for outdoor residential 

use be revised to state “application equipment” instead of “applicator” in the Directions 

for Use Section. 
7

SRRD Response: The outdoor residential statements have been updated with the 

language from the new Pesticide Registration Notice 2008-1, which includes language 

similar to that which Valent suggests. 

Comment: Valent BioSciences recommended that the “User Safety Recommendations” 

section of the labeling should not be included for household consumer products. They 

commented that these statements should only be required on products if the acute toxicity 

profile of the formulation shows they are warranted. 

SRRD Response: The User Safety Recommendations have been removed from the label 

table since the statements could vary depending on the results of the acute toxicity data. 

III. Registration Review of Pyrethroid Chemicals 

Comment: The California Stormwater Quality Association (CASQA) and the CA 

Regional Water Control Board, San Francisco Bay stated concerns that the pyrethroids 

are not scheduled for Registration Review until 2010, and mitigation would not occur 

until 2011. They state that this puts municipalities in an untenable position because they 

must comply with the Clean Water Act immediately. CASQA requested Registration 

Review be initiated immediately for the pyrethroids, or a special review be initiated. 

Additionally, according to the Water Board, pyrethroids are anticipated to be the cause 

of impaired water bodies, listed on the 2008 303(d) list. 

SRRD Response: The Permethrin, Resmethrin, Cypermethrin, Pyrethrins, Piperonyl 

Butoxide, and MGK-264 Reregistration Eligibility Decisions were signed in 

Spring/Summer 2006, and decisions for non-food pyrethroids, including allethrin 

stereoisomers, tetramethrin, and sumethrin, were completed in 2008. Therefore, the 2010 

date for Registration Review to begin for the pyrethoid, pyrethrins, and synergists (PPS) 

group of chemicals allows time for the risk mitigation and label changes identified in 

these REDs to be incorporated. Further, in the recent PPS REDs, the Agency identified 

a number of limitations in the reregistration of these chemicals, such as no 

urban/residential model available to assess potential ecological risks from residential 

uses; and an inability to assess (or compare) ecological impacts from PPS chemicals as a 

group because a large majority of the pyrethroids were registered after 1984. 

In order to address these limitations and allow the registration review risk assessments to 

be more refined, there are several on-going efforts to prepare for registration review of 

the PPS chemicals including: determine whether the pyrethroids share a common mode 

of action; revise spray drift language for pyrethroid agricultural labels; identify a model 

and appropriate scenarios for use in urban run-off modeling; compile detailed use and 

usage information about the PPS chemicals, both agricultural and residential uses; and 

identify data needs. Additionally, the Agency is coordinating with the California 

Department of Pesticide Regulation (CDPR), which is currently conducting its 

reevaluation of pyrethroids. The reevaluation includes calling in new and additional data, 

which will be useful to the Agency’s Registration Review process of the PPS chemicals 

which begins in 2010 for some chemicals. Therefore, the Agency does not believe it 
8

would be prudent to initiate the Registration Review of the PPS chemicals any earlier 

than currently scheduled. 

Comment: CASQA and the CA Regional Water Control Board, San Francisco Bay 

stated that OPP needs to initiate development of an urban run-off model as soon as 

possible. An empirical model should be used opposed to the mechanistic model OPP 

typically uses. 

SRRD Response: The Agency recognizes the need to identify a screening-level model 

for urban pesticide uses and has begun to discuss the state of urban modeling and the 

potential avenues for future advances internally and with stakeholders. Improvements in 

the resolution of GIS databases may allow better representation of the impervious and 

pervious portions of a typical urban landscape. For example, as it becomes more clear 

which uses are most likely to lead to transport of pyrethroids to surface water, the 

conceptual model of how urban transport should be simulated will be more focused. 

Comment: CASQA commented that U.S. EPA may be generating a “Data Call-In” (DCI) 

for pyrethroids to provide data for future pyrethroids reviews. They appreciate that U.S. EPA 

recognizes that data critical to managing risks from pyrethroids is currently not available 

and that EPA intends to require that pyrethroid manufacturers provide the needed data. 

Among data needed for pyrethroids water quality management, CASQA believes the 

following information is high priority: data to support urban runoff modeling, application 

instructions, and aquatic sediment data. In addition, the California Department of Pesticide 

Regulation (DPR) has initiated a data call in process for pyrethroids called “re-evaluation”. 

CASQA anticipates that this process will generate a substantial amount of information that 

would be useful to U.S. EPA. CASQA recommends that U.S. EPA coordinate with DPR in 

developing the DCI. CASQA asks U.S. EPA to request, obtain, and review all data submitted 

to DPR. CASQA stands ready to provide formal support for U.S. EPA’s request to review 

data submitted to DPR. 

SRRD Response: The Agency appreciates the recommendation provided by the CASQA, 

and is in the process of planning for the pyrethroid Registration Review process. As part of 

the initial phase of registration review a preliminary work plan will provide an opportunity 

for stakeholders to comment on the anticipated data the Agency will require in order to 

complete a risk assessment. Since this will be the first chance to evaluate all of the 

pyrethroids, pyrethrins, and synergists at once it will be a good opportunity to call in data 

necessary to assess the chemicals together. The Agency also recognizes that it needs to gain 

a better understanding of the residential and urban application of pyrethroids, to identify an 

urban run-off model, and more aquatic sediment data. The Agency is continuing to 

coordinate with the CDPR, and the two organizations have continued to share data and 

reviews on these chemicals. 

Comment: CASQA stated U.S. EPA has taken important steps toward protecting water 

quality throughout its various reregistration processes. However, CASQA stated that U.S. 

EPA needs to better integrate surface water quality protection into its pesticide registration 

and regulatory review programs. CASQA stated that coordination between U.S. EPA offices 

in reviewing pesticide ingredients is essential to Clean Water Act implementation; it also 

provides an appropriate method of meeting the Federal Insecticide, Fungicide, and 
9

Rodenticide Act’s goal of preventing unreasonable adverse impacts from pesticide use. The 

CA Regional Water Control Board, San Francisco Bay submitted similar comments. 

SRRD Response: The Office of Pesticide Programs (OPP) agrees that coordination is 

essential between OPP and the Office of Water. In its effort to plan for the upcoming 

registration review of the pyrethroid case of chemicals, OPP has initiated discussions with 

OW to address issues that affect both Offices. 

Comment: The CA Regional Water Control Board, San Francisco Bay Region included 

steps to be taken in the near term in their comments to the Agency. The steps include 

OPP completing a cumulative environmental risk assessment for pyrethroids; completing 

an alternatives assessment that considers both low risk and non-pesticide alternatives; 

completing a cluster assessment for problematic outdoor urban insecticide application; 

and assessing whether urban uses of pyrethroids pose unreasonable risks, taking into 

account the above information and the cost of non-compliance with the Clean Water Act. 

SRRD Response: The Agency appreciates the suggestions provided by the CA Regional 

Water Board, San Francisco Bay Region. As stated above, OPP is in the process of 

planning for the registration review of pyrethroids, pyrethrins, and synergists chemicals. 

As part of its planning effort, OPP is working closely with CA DPR as it conducts its 

reevaluation of pyrethroids, as well as coordinating with EPA’s Office of Water. As the 

planning progresses, OPP will continue to discuss these issues and the feasibility of the 

various assessments with the Water Board and other stakeholders. 

Comment: Various comments from the California Regional Water Quality Control Board, 

California State Water Resources Control Board, and the County Sanitation Districts of LA 

County state that additional data should be called in to help assess the potential ecological 

risks from residential use of pyrethrins, and other compounds.

SRRD Response: The Agency appreciates the recommendation provided in the 

comments and is in the process of planning for the pyrethroid registration review process, 

which includes PBO. The Agency also recognizes that it needs to gain a better 

understanding of the residential and urban uses of this group of chemicals, to identify an 

urban run-off model, and evaluate more aquatic sediment data. The Agency is 

coordinating with the CDPR, and the two organizations have been sharing data and 

reviews when possible. 

IV. Other Comments and Changes 

Comment: The Agency received comments from Beyond Pesticides about including the 

effects of synergists in all applicable exposure scenarios for both human health and 

ecological impacts. The comment states: “EPA did not consider the possible effects of 

these chemicals in combination.” 

SRRD Response: The Agency has completed risk assessments and Reregistration 

Eligibility Decisions (REDs) for the pyrethrins, and two synergists commonly found in 

products with pyrethrins, including piperonyl butoxide (PBO) and MGK-264. The 
10

synergist active ingredients were evaluated separately because evidence indicates that 

these chemicals do not effectively act as a synergist in mammals. For example, PBO 

inhibits microsomal enzymes in insects and evidence indicates that enzyme inhibition in 

mammals is transient and occurs at high doses. Additionally, the Agency requires and 

reviews product specific data that would take into account effects of the combined 

ingredients for a number of studies, including acute toxicity, efficacy, and product 

chemistry. The Agency has included these studies in the Data Call-Ins (DCIs) for 

products containing these active ingredients. 

Other Labeling Changes: 

• Due to the proposed revocation of tolerances for food stored in bags, all directions 

for use on “food stored in bags” have been removed from the label table and 

Appendix A. 

• A ventilation statement requiring ventilation for at least 2 hours for total release 

foggers was added that was similar to other ventilation statements required for 

other chemicals with a similar use. If registrants provide data to support different 

ventilation periods this time duration may be changed on a case-by-case basis. 

• The label table included with the Pyrethrins RED in 2006 was quite lengthy and 

could be confusing to read. In an effort to simplify and clarify the label changes, 

all of the rates that are being supported by the Pyrethrin Joint Venture, and were 

used in the risk assessments are included in Appendix A only. Only changes that 

are specifically included as risk mitigation in Chapter 4 of the RED will be listed 

in the label table. 

• A letter from the Pyrethrin Joint Venture was received on January 21, 2009 

requesting changes to three rates used in the risk assessments. 

o The PJV requested the space spray rate used for food handling 

establishments be changed from 0.00033 lbs ai/1000 cubic feet to 0.0033 

lbs ai/1000 cubic feet. Since this rate was already included in the Phase 3 

risk assessment and was only changed at the request of the registrant at the 

end of the RED process, and there are no risk concerns with this rate 

change, the space spray rate for food handling establishments will be set at 

0.0033 lbs ai/1000 cubic feet. The space spray rate for residential areas 

will remain at 0.00033 lbs ai/1000 cubic feet. 

o The PJV requested that the metered release rate be changed from 0.00046 

lbs ai/1000 cubic feet to 0.0046 lbs ai/1000 cubic feet. The Agency 

identified risks of concern for some metered release scenarios in the RED 

and required a rate reduction. In subsequent conversations with the PJV 

they agreed to keep the space spray rate at 0.00046 lbs ai/1000 cubic feet. 

o The PJV requested that the post-harvest application rate be changed from 

0.0001 lbs ai/1000 cubic feet to 0.001 lbs ai/ 1000 cubic feet and supplied 

a data reference supporting the rate. The Agency has reviewed the study 
11

and agrees the maximum rate may be change to 0.001 lbs ai/1000 cubic 

feet. 

• A letter from Wellmark to Valent Biosciences was forwarded to EPA on January 

5, 2007. The letter requested a clarification on the rate used in the risk assessment 

for pet sprays. 

o The Agency had assumed the maximum amount of pyrethrins in a pet 

spray product was 0.01% ai. After reviewing the data and considering the 

new rate (ORE Review D347780, Aggregate Review D347781), the 

Agency is allowing pet spray products to be formulated up to 0.20% ai. 

• In the 2006 RED some label language was developed for metered release systems 

indoors (for barn or industrial type areas), and for outdoor residential misting 

systems. Although the risk assessments were complete, some additional uses that 

did not fit into these two categories were brought to the Agency’s attention after 

the RED. In order to provide a complete set of label instructions for the other 

kinds of systems being developed, additional labeling is included in this 

Amendment for metered release devices in outdoor areas, and for indoor misting 

systems that may be used in commercial barns, stables, and animal quarters.