### 1 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460



### March 2 3 , 201 6

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 s tudies 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

.

### 2 

### Table 1. Data Requirements No Longer Required f or GDCI

- 077301

- 30403

Study Requirement Status Rationale Guideline Number Name Previous Current

850.1300 Daphnid Chronic Toxicity Test Required Satisfied ( Data Reviewed) EPA has an acceptable study (MRID 46731301 1 ) 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 t rigger 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. Tier s I and II Required Satisfied (Data Reviewed) EPA has an acceptable study (MRID 46687601 2 ) 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 850.4550 3 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 Rese arch 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, S arstedt, 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 Availabi lity” 77 FR 38282, June 27, 2012. http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0154

- 0028.

### 3 

### 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 i ntends 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 chlora te uses that generate chlorine dioxide

. The 90

- d ay i nhalation t oxicity (guideline number 870.346 5 ), i nhalation e xposure

– indoor (guideline number 875.1400 ), and d escription of h uman a ctivity (guideline number 875. 28 00 ) studies continue to be required on t he 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 clos ed 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 require d and provides updated study due dates

. Additionally, EPA is extending the 90

- day response due date for GDCI

- 073301

- 30403 to June 2 3
, 2016

.

Table 2

. Data Requirements of GDCI

- 077301

- 30403 and Updated Data Submission Tim e frame s

Study Requirement Status Test Substance Data Submission Timeframe
Guideline Number Name Previous Current Previous Current

870.346 5 90

- Day Inhalation Toxicity Required Required Sodium chlorate 12

- 31

- 17 3

- 2 3

- 18

-

870.4200 Carcinogencity Required Required Chlorine dioxide 12

- 31

- 19 3

- 2 3

- 20

875.1400 Inhalation Exposure

- Indoor Required Required Sodium chlorate 12

- 31

- 17 3

- 2 3

- 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.