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Docket Number EPA-HQ-OPP-2009-0336

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Table of Contents

Contents

I. Introduction.......................................................................................................................... 4

II. Scientific Assessment .......................................................................................................... 6

A. Human Health Assessment ........................................................................................................ 6

1. Risk Conclusions ................................................................................................................. 7

2. Human Incidents.................................................................................................................. 7

3. Tolerances............................................................................................................................ 7

B. Environmental Assessment ....................................................................................................... 7

1. Environmental Fate and Exposures ..................................................................................... 7

2. Ecological Assessment......................................................................................................... 7

3. Characterization of Ecological Risk .................................................................................... 8

4. Ecological Incidents............................................................................................................. 9

5. Risk Conclusions ................................................................................................................. 9

C. Benefits Assessment................................................................................................................. 10

D. Endangered Species Assessment ............................................................................................. 10

E. Endocrine Disruptor Screening Program.................................................................................. 11

III. Proposed Interim Registration Review Decision............................................................... 12

A. Risk Mitigation and Regulatory Rationale ........................................................................ 12

B. Proposed Interim Registration Review Decision............................................................... 13

IV. Next Steps and Timeline.................................................................................................... 13

A. Interim Registration Review Decision............................................................................... 13

B. Implementation of Mitigation Measures............................................................................ 13

Appendix A: Summary of Proposed or Completed Actions Taken for DTEA-HCl ................... 14

Appendix B: DTEA-HCl Label Table ......................................................................................... 15
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I. Introduction

This document is the Environmental Protection Agency’s (EPA or the agency) Proposed Interim 

Registration Review Decision for 2-(decylthio)ethanamine hydrochloride (herein referred to as 

DTEA-HCl) and is being issued pursuant to 40 CFR sections 155.56 and 155.58. A registration 

review decision is the agency's determination whether a pesticide meets, or does not meet, the 

standard for registration in the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The 

agency may issue, when it determines it to be appropriate, an interim registration review decision 

before completing a registration review. Among other things, the interim registration review 

decision may require new risk mitigation measures, impose interim risk mitigation measures, 

identify data or information required to complete the review, and include schedules for 

submitting the required data, conducting the new risk assessment and completing the registration 

review. Further information and additional documents on DTEA-HCl, PC code 128963, case 

5029, can be found in EPA’s public docket (EPA-HQ-OPP-2009-0336) at www.regulations.gov.

FIFRA, as amended by the Food Quality Protection Act (FQPA) of 1996, mandated the 

continuous review of existing pesticides. All pesticides distributed or sold in the United States

(U.S.) generally must be registered by the EPA based on scientific data showing that they will 

not cause unreasonable risks to human health or to the environment when used as directed on 

product labeling. The registration review program is intended to make sure that, as the ability to 

assess and reduce risk evolves and as policies and practices change, all registered pesticides 

continue to meet the statutory standard of no unreasonable adverse effects. Changes in science, 

public policy, and pesticide use practices will occur over time. Through the registration review 

program, the agency periodically reevaluates pesticides to make sure that as these changes occur, 

products in the marketplace can continue to be used safely. Information on this program is 

provided at http://www2.epa.gov/pesticide-reevaluation.

In 2006, the Agency implemented the registration review program pursuant to FIFRA section 

3(g) and will review each registered pesticide every 15 years to determine whether it continues to 

meet the FIFRA standard for registration.

DTEA-HCl is a liquid, organic industrial biocide commonly known by the trade name DTEA. 

There is one manufacturing-use and one end-use product registration of DTEA-HCl. The 

manufacturing-use product, Antimicrobial DTEA Technical (99.8%), is registered for 

formulation of pesticide products for use in re-circulating cooling water systems. These systems 

include evaporative condensers, heat exchange water systems, commercial and industrial cooling 

towers, influent systems such as flow-through filters and lagoons, industrial water scrubbing 

systems and brewery pasteurizers. The end-use product contains 15% DTEA-HCl and is 

registered for use to control bacterial, fungal, and algal slimes. 

DTEA-HCl was first registered in 1993 but it is not marketed in the U.S. While exposures 

described in the assessment presented in this document are not occurring at this time and are 

theoretical, the agency assumes that DTEA-HCl could be used at some time in the future. 

Therefore, the risk assessment covers any potential future exposure should the product be sold, 

distributed, and used in the U.S. Since DTEA very rapidly dissociates from DTEA-HCl in 

aqueous solution, this assessment focused on DTEA. As explained herein, EPA believes that
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exposure to registered uses of DTEA-HCl will not result in unreasonable adverse effects to nontarget aquatic and terrestrial organisms provided that label amendments are adopted. 

Pursuant to 40 CFR section 155.50, EPA formally initiated registration review for DTEA-HCl. A 

Reregistration Eligibility Decision (RED) was not issued by the agency for DTEA-HCl as it was 

registered after 1984. The following timeline highlights significant events that have occurred 

during the registration review of DTEA-HCl:

- Publication of DTEA-HCl Summary Document, including the Preliminary Work Plan 

(PWP), for DTEA-HCl was issued in September 2009 for a 60-day public comment 

period. 

- Final Work Plan (FWP) for DTEA-HCl was posted December 16, 2009 after public 

comments were addressed. 

- Generic Data Call-In notice (GDCI) for DTEA-HCl was issued August 17, 2011. Since 

the final work plan (FWP) was posted, the agency’s practice for evaluating ecological 

risks from recirculating cooling process water systems expanded to include evaluation of 

sediment exposure pathways and bioaccumulation up the aquatic food chain to terrestrial 

wildlife. Therefore, not all the data needed to address these exposure pathways was 

anticipated to be needed in the FWP. 

- The 2-(Decylthio)Ethanamine Hydrochloride (DTEA-HCl), Human Health and 

Ecological Preliminary Risk Assessment for the Registration Review dated September 

30, 2013 was posted for a 60-day public comment period. One comment was received 

from Crop Life America (CLA) during the comment period. The comment is 

summarized and responded to below.

The agency anticipates publishing the 2-(Decylthio)Ethanamine Hydrochloride (DTEA-HCl)

Proposed Interim Registration Review Decision by March 2016 in docket number EPA-HQOPP-2009-0336 for a 60-day public comment period.

Additional information on DTEA-HCl can be found in EPA’s public docket, EPA-HQ-OPP2009-0336, accessed at www.regulations.gov.

Comment Received from Crop Life America (CLA)

Comment: Crop Life America commented that the preliminary risk assessment (PRA) for the 

registration review of DTEA-HCl largely relied on screening level estimates of exposure 

compared to a threatened and endangered (listed) species level of concern (LOC). CLA further 

stated that screening tiers indicate whether a potential risk exists, but additional refinements to 

reduce uncertainties would indicate whether a risk of concern actually exists. CLA stated that it 

would be premature to evaluate what, if any, risk mitigation options may be suitable until a risk 

assessment including all additional data gathering and refinement has been completed to indicate 

what the risks actually are.

Response: EPA has reviewed the comments from Crop Life America (CLA) on the preliminary 

risk assessment for DTEA-HCl and plans to address many of the concerns raised by CLA as part 
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of the implementation plan for assessing the risks of pesticides to threatened and endangered 

(listed) species based on the recommendations of the April 2013 National Academy of Sciences 

(NAS) report. EPA will address concerns specific to DTEA-HCl in connection with the 

development of its final registration review decision for DTEA-HCl.

In November 2013, the EPA, along with the Services and the USDA, released a summary of 

their joint Interim Approaches for assessing risks to endangered and threatened (listed) species 

from pesticides. For further information on how the agency intends to assess risks to endangered 

species from the use of DTEA-HCl please see section D of this document. The Interim 

Approaches were developed jointly by the agencies in response to the National Academy of 

Sciences’ (NAS) recommendations and reflect a common approach to risk assessment shared by 

the agencies as a way of addressing scientific differences between the EPA and the 

Services. The NAS report outlines recommendations on specific scientific and technical issues 

related to the development of pesticide risk assessments that EPA and the Services must conduct 

in connection with their obligations under the ESA and FIFRA. 

The joint Interim Approaches were released prior to a stakeholder workshop held on November 

15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013 

Pesticide Program Dialogue Committee (PPDC) and State-FIFRA Issues Research and 

Evaluation Group (SFIREG) meetings. The agencies also held a stakeholder workshops in April 

2014 and October 2014, allowing additional opportunities for stakeholders to comment on the 

Interim Approaches. Additional workshops are planned to enhance stakeholder involvement. As 

part of a phased, iterative process for developing the Interim Approaches, the agencies will also 

consider public comments on the Interim Approaches in connection with the development of 

upcoming Registration Review decisions. The details of the joint Interim Approaches are 

contained in the white paper “Interim Approaches for National-Level Pesticide Endangered 

Species Act Assessments Based on the Recommendations of the National Academy of Sciences 

April 2013 Report,” dated November 1, 2013. 

Once the agencies have fully developed and implemented the scientific methods necessary to 

complete risk assessments for endangered and threatened (listed) species and their designated 

critical habitats, these methods will be applied to subsequent analyses for DTEA-HCl as part of 

completing this registration review. 

II. Scientific Assessment 

A. Human Health Assessment

A summary of the agency’s human health risk assessment is presented below in support of the 

registration review of DTEA-HCl. For detailed discussions of all aspects of the human health 

assessment, see the 2-(Decylthio)Ethanamine Hydrochloride (DTEA-HCl), Human Health and 

Ecological Preliminary Risk Assessment for the Registration Review located in the public docket 

at EPA-HQ-OPP-2009-0336.

Based on the label requiring closed-loading, no quantitative occupational human health risk 

assessment was conducted as the label requirement minimizes occupational exposure. For the 

human health risk assessment, no dietary risk assessment is necessary because dietary (food and 
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drinking water) exposures are expected to be minimal based on use patterns and water treatment.

Additionally, any discharged DTEA-HCl is expected to become diluted in the receiving water 

body.

1. Risk Conclusions

DTEA-HCl is currently not marketed or used in the U.S. and therefore, all estimated exposures 

are theoretical. However, if DTEA-HCl is marketed and used in the future in the U.S., EPA 

believes that risks to human health from the use of DTEA-HCl are expected to be minimal based 

on current label language that minimizes exposure. 

2. Human Incidents

There is no human incident information in the agency’s incident data system (IDS) from 1993 to 

2015 since DTEA-HCl is currently not marketed or used in the U.S.

3. Tolerances 

No tolerance or exemption from tolerance has been established by EPA for DTEA-HCl.

B. Environmental Assessment

A summary of the agency’s environment risk assessment is presented below in support of the 

registration review of DTEA-HCl. DTEA-HCl is diluted to concentration of 15% and formulated

to treat water systems. In the past the cooling tower use was considered an “indoor use” and 

exposure to non-target organisms was not expected. Under the 40 CFR158W codified in 2013, 

this use is now subject to an evaluation to determine if exposure to non-target organisms is 

occurring and if so, to determine appropriate mitigation. For detailed discussions of all aspects of 

the ecological risk assessment, see the 2-(Decylthio)Ethanamine Hydrochloride (DTEA-HCl), 

Human Health and Ecological Preliminary Risk Assessment for the Registration Review located 

in the public docket at EPA-HQ-OPP-2009-0336.

1. Environmental Fate and Exposures

In solution, DTEA-HCl is persistent under abiotic conditions at pH 5, 7, and 9. Its solubility is 

low in water. The Henry’s law constant value indicates that DTEA-HCl has a moderate tendency 

to volatilize from water surfaces to air. Its half life in air is about 3 hours, and it is not likely to 

persist in air. It is immobile on soil surfaces, and sludge surfaces. It is not ready biodegradable. 

Its Log Kow is high which indicates that it is likely to be bioaccumulative. The dissipation 

pathway appears to be binding to soil/sediments and therefore, the possibility of adverse effects 

on benthic organisms exists.

2. Ecological Assessment

According to the product label, there are two methods of treatment for control of bacteria, fungi, 

and algae in recirculating cooling water systems: (1) intermittent or slug method and (2) 

continuous feed method. For both methods of treatment, the label specifies application rates of 

Antimicrobial DTEA-HCl 15% for both initial treatment of fouled systems and maintenance 
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treatment. Maintenance treatments can range from 0.5 to 25 fluid ounces of product per 1000 

gallons of water for the intermittent or slug method of application and 0.5 to 2 fluid ounces of 

product per 1000 gallons of water for the continuous feed method. Initial treatment of fouled 

systems can range from 6 to 41 fluid ounces of product for both intermittent/slug and continuous 

feed methods.

Potential exposures and risks to DTEA-HCl from releases of blowdown water from recirculating 

cooling towers to surface water were examined for the following circumstances: 

• maintenance treatments versus initial treatments for fouled systems; 

• large-size versus moderate-size recirculating cooling towers; 

• high-end versus average case scenarios from E-FAST, EPA’s model that provides 

screening level estimates of the concentration of chemicals released to air, surface 

water, landfills, and from consumer products; and 

• wastewater treatment versus no wastewater treatment prior to discharge of 

blowdown water to surface water.

In the case where no treatment of blowdown water is assumed, the industrial releases module of 

E-FAST is run assuming no removal. In the case where it is assumed that blowdown water 

undergoes wastewater treatment prior to discharge, the industrial releases module of E-FAST is 

run assuming 93% removal based on activated sludge sorption isotherm data that indicate that 

from 93 to 98% of DTEA-HCl is removed during wastewater treatment via sorption to activated 

sludge. Surface water concentrations are estimated based on the distribution of plant flows and 

stream flows from the Steam Electric Power Plants SIC code. Model results are expressed as 

days per year of exceedance of concentrations of concern (COC) for aquatic organisms 

downstream of recirculating cooling towers.

3. Characterization of Ecological Risk 

Risks to Freshwater Organisms based on Maintenance Treatments Scenarios

There are exceedances of COC for aquatic organisms for the average case scenarios examined at 

the lowest environmental release for moderate-size cooling towers of 0.03 kg/site/day (0.5 ppm)

when wastewater treatment is assumed. However, the only COC exceeded is that for endangered 

freshwater invertebrates (1.7 ppb), and that exceedance is only for one day of 360 days per year 

of release.

For the average case scenarios, estimated DTEA-HCl concentrations in sediments (0.004 to 

0.216 mg/kg-sediment) under a range of organic carbon levels do not exceed the chronic DTEAHCl NOAEC (No Observed Adverse Effect Concentration) values for benthic organisms (0.77 to 

8.4 mg/kg-sediment) indicating no chronic risks assuming waste water treatment prior to 

discharge. 

For the large cooling tower, high end scenarios, estimated DTEA-HCl concentrations in 

sediments (11.2 to 613 mg/kg-sediment) under a range of organic carbon levels exceed the 

chronic NOAEC values for benthic organisms indicating the potential for chronic effects to the 
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aquatic benthic organisms under the maximum label use rate. For the no wastewater treatment 

scenario prior to discharge, the risks are indicated to be greater.

Risk to Freshwater and Estuarine/Marine Organisms Based on Initial Treatments of a Fouled 

System Scenarios

For the purpose of assessing exposures to aquatic organisms from initial treatment applications, 

it is assumed that environmental releases of DTEA-HCl to surface water via cooling tower 

blowdown water occur for one day.

Potential risks for freshwater aquatic organisms have been identified. Additionally, the agency 

has no toxicity data for estuarine/marine organisms to show that they would be less sensitive to 

exposure to DTEA-HCl than freshwater organisms. In the absence of data, EPA assumes that the 

use and release of DTEA-HCl to estuarine and marine systems would result in risks of concern 

for estuarine and marine aquatic organisms. 

Risks to Piscivorous Birds and Mammals: Maintenance Use with Wastewater Treatment Prior to 

Discharge

Quantitative acute risk cannot be calculated for birds because the acute oral LD50 is greater than 

the highest residue level tested. Further, on a dietary basis the potential DTEA-HCl residues in 

the upper trophic level are more than 10 times lower than the residue levels tested. Therefore, it 

is unlikely that acute levels of concern (LOCs) for listed and nonlisted birds will be exceeded.

4. Ecological Incidents

DTEA-HCl is currently not marketed or used in the U.S. For the period from 1993 to 2015, there 

is no ecological incident information on this product in the agency’s incident database.

5. Risk Conclusions 

There are several uncertainties associated with the ecological risk assessment. On the hazard 

assessment, EPA made conservative assumptions based on the lack of definitive toxicity data on 

benthic organisms, estuarine and marine organisms, aquatic plants and chronic data for birds.

Risks to non-target birds and mammals are expected to be minimal. There is a potential risk to 

birds that consume fish that are exposed to releases from large towers treated at the maximum 

treatment rate without wastewater treatment prior to release. 

There are potential risks to all aquatic organisms from releases of cooling tower waters including 

releases of water which has been treated in a wastewater treatment facility prior to release. 

Aquatic invertebrates and algae are more sensitive to DTEA-HCl than are freshwater fish, but all 

aquatic organisms would be affected if a release occurs. Maintenance treatments which result in 

daily releases (360 days/year) are expected to result in greater risks than initial treatments that 

result in single (one time) release. 
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Benthic organisms would be exposed to DTEA-HCl as it sorbs to sediment. Chronic risks are 

estimated for treatments of large towers and high rates with no chronic risks for benthic 

organisms from moderate size towers treated at low rates. 

C. Benefits Assessment

Although DTEA-HCl is registered in the U.S., it has not been marketed. There is no benefits 

assessment for this product. 

D. Endangered Species Assessment

Consistent with EPA's responsibility under the Endangered Species Act (ESA), the Agency

will evaluate risks to federally listed species from registered uses of pesticides in accordance

with the Joint Interim Approaches developed to implement the recommendations of the

April 2013 National Academy of Sciences·(NAS)report, Assessing Risks to Endangered

and Threatened Species from Pesticides. The NAS report1 outlinesrecommendations on

specific scientific and technical issues related to the development of pesticide risk 

assessments that EPA and the Services must conduct in connection with their obligations

under the ESA and FIFRA. EPA will address concerns specific to DTEA-HCl in connection

with the development of its final registration review decision for DTEA-HCl.

In November 2013, EPA, the U.S. Fish and Wildlife Service, National Marine Fisheries

Services (the Services), and the U.S. Department of Agriculture released a white paper

containing a summary of theirjoint Interim Approaches for assessing risks to listed species

from pesticides. These Interim Approaches were developed jointly by the agencies in

response to the NAS recommendations, and reflect a common approach to risk assessment

shared by the agencies as a way of addressing scientific differences between the EPA and the

Services. Details ofthe joint Interim Approaches are contained in the November 1,2013

white paper, Interim Approachesfor National-Level Pesticide Endangered SpeciesAct

Assessments Based on the Recommendations of theNational Academy of Sciences April

2013 Report.

Given that the agencies are continuing to develop and work toward implementation of the

Interim Approaches to assess the potential risks of pesticides to listed species and their

designated critical habitat, the ecological risk assessment supporting this Proposed Interim

Registration Review Decision for DTEA-HCl does not contain a complete ESA analysis,

including effects determinations for specific listed species or designated critical habitat. 

While the agencies continue to develop a common method for ESA analysis, the preliminary

risk assessment for the registration review of DTEA-HCl describes the level of ESA analysis

completed for this particular registration review case. This assessment will allow EPA to

focus its future evaluations on the types of species where the potential for effects exists, once

the scientific methods being developed by the agencies have been fully vetted. Once the

agencies have fully developed and implemented the scientific methods necessary to complete

risk assessments for listed species and their designated critical habitats, these methods will

 1 http://www.nap.edu/catalog.php?record_id=18344
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be applied to subsequent analyses of DTEA-HCl as part of completing this registration

review.

E. Endocrine Disruptor Screening Program

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of the reregistration decisions for DTEA-HCl beginning in 1993, EPA 

reviewed these data yet never selected the most sensitive endpoints for relevant risk assessment 

scenarios from the existing hazard database presumably because the hazard database was very 

limited and only occupational exposure was expected. However, as required by FFDCA section 

408(p), DTEA-HCl is subject to the endocrine screening part of the Endocrine Disruptor 

Screening Program (EDSP). 

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 

2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, 

which contains 58 pesticide active ingredients and 9 inert ingredients. DTEA-HCl is not among 

the group of 58 pesticide active ingredients on the initial list to be screened under the EDSP. 

Accordingly, as part of registration review, EPA will issue future EDSP orders/data call ins, 

requiring the submission of EDSP screening assays for DTEA-HCl. 

For further information on the status of the EDSP, the policies and procedures, the list of 67 

chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our 

website: http://www.epa.gov/endo/. 

In this interim decision, EPA is making no human health or environmental safety findings 

associated with the EDSP screening of DTEA-HCl. Before completing this Registration Review, 

the agency will make an EDSP FFDCA section 408(p) determination.
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III. Proposed Interim Registration Review Decision

A. Risk Mitigation and Regulatory Rationale

Although there are no human health risks of concern, potential ecological risks of concern were 

identified. To address these concerns, the agency is proposing label amendments. 

The theoretical quantitative ecological risk assessment indicated exceedance of levels of concern 

for exposure of aquatic organisms for both federally threatened and endangered (listed) species 

in the water column and exceedance of levels of concern for aquatic benthic invertebrates. 

Aquatic food chain transfer and bioaccumulation of DTEA-HCl was identified to potentially 

pose risks to mammals and birds, but this risk is considered to be unlikely. The risk assessment 

did not model estuarine/marine water bodies; therefore, the agency does not know what the risk 

would look like (no data were available to do the modeling). Estuarine/marine water bodies are 

tidal in nature and thus similar or greater risk than the freshwater assessment was assumed.

The ecological risk assessment used conservative assumptions such as daily blowdown 

discharge, which is unlikely in practice. Additionally, the assessment indicated that frequency of 

use drives the risks of concern. The agency believes the following labeling changes will reduce 

the likelihood of exposure and risk if DTEA-HCl is marketed and used in the future in the U.S.:

• Add instructions to the Directions For Use to not discharge blowdown directly to bodies 

of water, such as:

o “Cooling water system blowdown must not be discharged to lakes, streams, 

ponds, estuaries, oceans or other waters unless in accordance with the 

requirements of a National Pollutant Discharge Permit (NPDES). Blowdown 

discharge must be sent to a secondary waste water treatment facility with 

activated sludge or be treated with a similar biological treatment process.”

o Currently, this language is partly addressed in the Hazard Statements section.

However, it must be in the directions for use section.

• Limit use of maintenance treatment of the intermittent or slug method to not more than 

every four days (96 hours).

• Add instructions to the Directions For Use for not discharging to esturine/marine water 

bodies, such as: 

o “Do not discharge to estuarine/marine water bodies.”

In addition, EPA understands that the use of DTEA-HCl may be effective at lower rates than 

currently indicated on labeling and believes that it is prudent to lower the rates on the labels 

accordingly. The following recommendations are being made: 

o Reduce the upper bound for dosage rates for initial treatment of both the 

intermittent/slug method and continuous feed method to 25 fluid ounces (oz.) per 

1,000 gallons of water.

 Current labels specify no more than 41 fluid oz.

o Reduce the upper bound for the dosage rate for maintenance treatment of the 

intermittent/slug method to 15 fluid oz. per 1,000 gallons of water.

 Current labels specify no more than 25 fluid oz.
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B. Proposed Interim Registration Review Decision

In accordance with 40 CFR Sections 155.56 and 155.58, the agency is issuing this proposed 

interim registration review decision document for DTEA-HCl. It does not cover the Endangered 

Species Act or the Endocrine Disruptor Screening Program component, and this interim decision 

is being proposed pending their evaluation. 

IV. Next Steps and Timeline

A. Interim Registration Review Decision

A Federal Register Notice will announce the availability of this proposed interim registration 

review decision for DTEA-HCl and allow a 60-day comment period. If there are no significant 

comments or additional information submitted to the docket during the comment period that 

leads the agency to change its proposed decision, EPA may issue an interim registration review 

decision for DTEA-HCl (case 5029). 

However, a final decision for DTEA-HCl may be issued without having previously issued an 

interim decision. A final registration review decision for the DTEA-HCl case will depend upon 

both the result of an ESA Section 7 Endangered Species consultation with the U.S. Fish and 

Wildlife Service, and an EDSP FFDCA section 408(p) determination. 

B. Implementation of Mitigation Measures

Once the Interim Registration Review Decision is issued in final form, registrants will be 

required to submit proposed amended labels that include ecological risk mitigation and submit 

them to the agency for approval within 60 days of such issuance. The mitigation measures and 

proposed label amendments are shown in Appendices A and B.
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Appendix A: Summary of Proposed or Completed Actions Taken for DTEA-HCl

 Summary of Proposed or Completed Actions Taken for DTEA-HCl

Registration Review Case#: 5029

PC Code: 128963

Chemical Type: Antimicrobial

Affected 

Population(s)

Source of 

Exposure

Route of 

Exposure

Duration 

of 

Exposure

Risk(s) of 

Concern

Action(s) 

Taken

Comment

Humans Occupational

handler

Inhalation, 

dermal

Acute Unassessed Label 

revisions to 

require 

closed 

delivery 

systems

Label 

amendment 

completed prior 

to risk 

assessment stage 

of registration 

review

Fishes

Aquatic 

invertebrates

Aquatic plants

Recirculating 

cooling 

water system 

blowdown

Uptake

through 

gills

Acute 

and 

Chronic

Acute and 

chronic 

toxicity

See 

proposed 

label 

revisions 

outlined in 

Appendix B
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Appendix B: DTEA-HCl Label Table

Summary of Proposed Labeling Changes for DTEA-HCl

Description Proposed Amended Labeling Language for DTEA-HCl

Products

Placement on Label

End Use Products

Reduce discharge 

blowdown directly to 

bodies of water

• Do not discharge blowdown directly to bodies of 

water and specify secondary waste water treatment 

with activated sludge or a similar biological 

treatment process; suggested labeling languages:

“Cooling water system blowdown must not be 

discharged to lakes, streams, ponds, estuaries, oceans or 

other waters unless in accordance with the requirements 

of a National Pollutant Discharge Permit (NPDES). 

Blowdown discharge must be sent to a secondary waste 

water treatment facility with activated sludge or be 

treated with a similar biological treatment process.”

Directions for Use

Limit use of 

intermittent or slug 

method

• Limit the use of the intermittent or slug method to 

not more than every four days (96 hours).

Directions for Use

Limit where there can 

be discharge

• “Do not discharge to estuarine/marine water bodies.” Directions for Use

Reduce certain use 

rates

• Reduce dosage rates for initial treatment of both the 

intermittent/slug method and continuous feed 

method to 25 fluid oz. per 1,000 gallons of water

• Reduce dosage rates for maintenance treatment of 

the intermittent/slug method to 15 fluid oz. per 1,000 

gallons of water.

Directions for Use