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OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

March 23, 2016

MEMORANDUM 

Subject: Clarification of Generic Data Call-In for Products Containing Sodium Chlorate

Dear Registrant,

The purpose of this memorandum is to clarify certain data required by post-Reregistration 

Eligibility Decision (RED) GDCI-073301-30403 issued on December 31, 2015. Section I 

addresses data that are no longer required for GDCI-073301-30403, and Section II confirms data 

which are still required and provides clarification on data to be submitted as well as updated 

timeframes for when those data are due.

I. Status Change of Sodium Chlorate Post-RED Generic Data Call-In (GDCI) Data 

Requirements 

EPA (the Agency) has reviewed and made a determination that certain requirements associated 

with GDCI-073301-30403 are no longer required. Table 1 summarizes the previous and current 

status for select requirements and the associated rationale for each update. Note that studies 

listed in Table 1 are no longer required based on the Agency's current state of knowledge; if the 

need for a study becomes apparent upon review of additional information, this memorandum

does not preclude EPA from requiring these data in the future.
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Table 1. Data Requirements No Longer Required for GDCI-077301-30403

Study Requirement Status

Guideline Rationale

Number Name Previous Current

850.1300 Daphnid Chronic 

Toxicity Test Required Satisfied (Data Reviewed)

EPA has an acceptable study (MRID 

467313011) for this data requirement, 

and it is therefore no longer considered a 

data gap.

850.1400 Fish early-life

stage toxicity test Required Satisfied (Waived)

While current uses trigger the 40 CFR 

Part 158 criteria for requiring this study, 

EPA has determined this study is no 

longer needed based on the low chronic 

toxicity observed in available 

information. However, it continues to be 

a data gap. In the upcoming registration 

review process for inorganic chlorates, 

conservative assumptions may be used in 

the absence of data, if needed. 

850.4150

Terrestrial Plant 

Toxicity, Tier 1 

(vegetative vigor)

Required Satisfied (Waived)

There is no potential for exposure to 

plants from the currently registered 

antimicrobial use patterns for sodium 

chlorate and the Agency has determined 

no terrestrial assessment is necessary for 

the antimicrobial uses.

850.4225

Seedling 

Emergence, Tier 

II

Required Satisfied (Waived)

850.4400

Aquatic Plan 

Toxicity Test 

Using Lemna 

spp. Tiers I and II

Required Satisfied (Data 

Reviewed)

EPA has an acceptable study (MRID 

466876012) for this data requirement, it 

is therefore no longer considered a data 

gap. 

850.5400 Algal toxicity, 

Tiers I and II Required Satisfied (Data Reviewed)

The data under Guidelines 850.4500 and 

850.45503 are no longer needed because 

the registered sodium chlorate 

antimicrobial uses are all as chlorine 

dioxide generators. Therefore, chlorine 

dioxide is the compound to which aquatic 

plants would potentially be exposed 

from, and the Agency already has these 

data on chlorine dioxide.

 1

Thomas, P (2004) Chronic toxicity of Sodium Chlorate to Daphnia magna Under Semi-Static Conditions in a 21 Day 

Reproduction Test. Lab Project No. ICS-103 Final Research Report; CER F03043 T 02006 ODC. Unpublished study 

prepared by Akzo Nobel Chemicals Research Environmental Chemistry Department, Arnhem, the Netherlands. 2

Scheerbaum, D. (2003) Sodium Chlorate Aquatic Plant Toxicity Test, Lemna minor, Static, 7 days. Lab Project No. 

030724AT/TLA93762. Unpublished study prepared by Dr. U. Noack Laboratorien, Sarstedt, Deutschland. 3 In a Federal Register Notice dated June 27, 2012, EPA split the Public Draft OPPTS 850.5400 test guideline into 

two test guidelines: OCSPP 850.4500 and OCSPP 850.4550. See “Final Test Guidelines; OCSPP 850 Series; Notice of 

Availability” 77 FR 38282, June 27, 2012. http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-

0154-0028.
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II. Clarification of Data Requirements of Sodium Chlorate GDCI-077301-30403 

and Updated Data Submission Timeframes

The data requirements in Table 2 of GDCI-073301-30403 continue to be required. The Agency 

is clarifying that the test substance for the carcinogenicity study (guideline number 870.4200) is 

chlorine dioxide, not sodium chlorate. Since the registered antimicrobial uses of sodium chlorate 

are used to generate chlorine dioxide, the Agency intends to consider the chlorine dioxide 

toxicity endpoints as appropriate for these uses. A data gap for the carcinogenicity study is 

identified for the chlorine dioxide toxicity database and, therefore, is considered to be a data gap 

for the sodium chlorate uses that generate chlorine dioxide. The 90-day inhalation toxicity

(guideline number 870.3465), inhalation exposure – indoor (guideline number 875.1400), and 

description of human activity (guideline number 875.2800) studies continue to be required on the 

test substance sodium chlorate. Though the use of sodium chlorate to produce chlorine dioxide 

occurs in a closed system, handler exposure may occur when open pouring the product into 

premix tanks that feed into the system. This exposure was not assessed in the most recent 

assessment (D310653)4 that was done for the RED. Alternatively, if labels were amended to 

require closed loading and delivery systems, these exposure data would no longer be required.

Based on the changes described in this memorandum, EPA is giving additional time to comply 

with the DCI. Table 2 summarizes the previous and current status for those studies which 

continue to be required and provides updated study due dates. Additionally, EPA is extending the 

90-day response due date for GDCI-073301-30403 to June 23, 2016.

Table 2. Data Requirements of GDCI-077301-30403 and Updated Data Submission 

Timeframes

Study Requirement Status Test 

Substance

Data Submission Timeframe

Guideline 

Number Name Previous Current Previous Current

870.3465 90-Day Inhalation 

Toxicity Required Required Sodium chlorate

12-31-17 3-23-18-

870.4200 Carcinogencity Required Required Chlorine 

dioxide

12-31-19 3-23-20

875.1400 Inhalation Exposure -

Indoor Required Required Sodium chlorate

12-31-17 3-23-18

875.2800 Description of Human 

Activity Required Required Sodium chlorate

12-31-16 3-23-17

 4 Leighton, Tim. Sodium Chlorate: Occupational and Residential Exposure Assessment of Antimicrobial Uses for the 

Reregistration Eligibility Decision Document. December 14, 2004.