### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON
, D.C. 20460



### MEMORANDUM

Date: J anuary 31, 2013 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### SUBJECT : Fenbuconazole

. Occupational Exposw;e Assessment to Support Use of a New Formulation on Peppers.

P

C Code: 1290 II DP Barcode: 0404874 Decision Nos.: 468478; 465307 Reg. Nos.: 62719-416; 62719-421 P

et iti on No.: 12F8304 Regulatory Action: Label Amendment Ri s k Assessment Type: ORE Case No.: 7012 TXR No.: N /A CAS No.: 114369-43-6 MRlD No.: N /A 40 CFR 180.480

From: Christ ina Swartz, Chief

# ~ R1 sk Assessme n t Branch II H ea lth Effec t s Division (7509P)

Throu gh:

To: Michael Doherty, Ph.D.
, Senior Scientist Risk Assessment Branch II Health Effects Division (7509P)

Erin Malone Fungicide Branch Registration Division (7505P)

BACKGROUND: Dow AgroSc iences LLC i s propos in g to bridge fenbuconazo l e residue data for peppers from a currently registered product to a new formulation. Residue data for Indar 75 WSP (EPA Reg. No. 62719

- 421) were provided to bridge to the produc t Enable ® 2F ( E PA Reg. No. 62719-416). Indar® 75 WSP is a wettable powder formulation packed in water-soluble pouches containing 75.0% active ingredient (ai)
, while Enable 2 F is a flowable concentrate containing 23.5% ai (2 lb ai/ gal). Although the use pattern for peppers is the same on the 2 label s, brid gi n g residue data indicated that an increased tolerance for peppers would be needed. HED has taken into consideration the findings of the pre v iou s risk assessment for peppers and the d ifferences in the 2 formulations, and has determined that a n ew occupational exposure and risk assessment is not needed to ensure adequate protection for occupational workers mixing, loadin g and applying the fungicide to peppers , or to tho se re-enter i ng treated areas.

COMPARISON OF USE PATTERN : lndar® 75 WSP is registered for use on pepper (includi n g bell, chili, cooking, pimento, and sweet varieties) at single and seasona l maximum app lication rates of
Page 1 of3

### Page 2 of 3 0.188 and 0.75 lb ai/A, respectively. The label al lows a maximum of 4 applications occurring at10-day intervals; however, the label prohibits more than 2 consecutive applications of fenbuconazole, in order to prevent development of re sistance. The pre-harves t interval (PHI) is 7 days after the last applicati on. The registrant is proposing the same use pattern for Enable ®

### 2F on pepper.
The personal protective equipment (PPE) specified on the Indar®

### 75 WSP label includes baseline clothing (long sleeved shirt, l ong pants and shoes with socks), chemical resistant gloves, and chemical resistant head gear for overhead exposure. The same PPE recommendations are specified on the proposed label for Enable ® 

### 2F. Both labels have the same restricted-entry interval (REI) of 12 hours, which is based on the acute toxicity of the technical active ingredient.

TOXICOLOGICAL DOSES AND 

### E NDPOINTS USED FOR 

### R ISK 

### A SSESSMENT 

### : Details of toxicological doses and endpoints for fenbuconazole are available in the 2008 risk assessment (D. Dotson, D350321, 6/12/2008). Dermal risks were not assessed quantitatively due to the lack of systemic toxicity via the dermal route and the absence of developmental or reproduc tive effects that would not have been assessed in the dermal study.

For inhalation assessment, HED previously select ed the dose and endpoint from a chronic oral study, in the absence of a route-specific inhalati on toxicity study. For the current action, a new occupational exposure assessment is not needed. In the 2008 assessment, the dose and endpoint (liver and thyroid effects) were selected from the chronic study in the rat; however, in the future HED will select the dose and endpoint from the 90-day rat study. Since the 90-day no-observedadverse-effects-level (NOAEL) and lowest-observed-adverse-eff ects-level (LOAEL) are higher than those seen in the chroni c study, HED’s risk estimates for inhalation exposure will be lower than those estimated in the 2008 assessment. In conjunction with the risk assessment supporting the tolerance amendment for peppers, HED’s HA SPOC determined that a subchronic inhalation toxicity study is not needed for fenbuconazole (TXR No. 0056540).

In the absence of additional uncertainty fact ors to account for missing data, HED’s level of concern (LOC) for occupational risk assessment is a margin of exposure (MOE) of 100, based on 10X interspecies and 10X intras pecies uncertainty factors.

HED has classified fenbuconazole as “Group C Carcinogen” with a cancer potency factor (Q 1 * 

### ) of 3.59 x 10 -3 

### (mg/kg/day) -1



### .

RESIDENTIAL EXPOSURES 

### : There are no registered resident ial uses for fenbuconazole including commercial/professional uses in residential areas.

OCCUPATIONAL EXPOSURES 

### : Long-term occupational exposure is not anticipated, either from dermal or inhalation routes. The conclusi ons regarding occupati onal handler and postapplication exposure and risk for Indar ®

### 75 WSP and Enable ®

### 2F are summarized below:

Occupational Handler Assessments Both product formulations were assessed for hand ler exposures, for similar scenarios. Indar ®

### 75 WSP was evaluated for use on pepper and other crops (S. Wan g, D345898, 5/28/2008) and

### Page 3 of 3 Enable ®

### 2F was assessed for use on cranberry, p eanut, and other crops (M. Collantes, D28908, 6/26/2006). Both assessments used the same singl e application rates (0.1 9 lb ai/A), equipment (ground and aerial foliar), timing (10 day interval ), and number of applications (4) as are currently proposed for the labe l amendment for peppers.

As stated previously, quantitative non-cancer derm al risk assessments were not needed due to the lack of toxicity via the dermal route. For Indar ®

### 75 WSP on pepper, the estimated short-term non-cancer inhalation risk for handlers was an MO E greater than or equal to 9,100 assuming the use of baseline PPE; the MOEs were greater than 100 and are therefor e not of concern. Combined dermal and inhalation cancer risk for occupational handlers was estimated to be at most 1.62 x 10 -7 

### . Given that the use patterns are similar, differences between risk estimates for the 2 formulations were driven by the unit expo sures for the various handler scenarios. In previous assessments for Enable 2F, the non-cancer inhalation MOE for Enable ®

### 2F was ≥2,600 assuming baseline PPE, and the estimated combined dermal and inhalation cancer risk was at most 3.0 x 10 -7



### . Occupational Post-Application Assessments HED did not quantitatively assess non-cancer pos t-application dermal exposure and risk for Indar ®

### 75 WSP or Enable ®

### 2F due to the lack of systemic toxi city via the dermal route. Cancer risk for post-application exposure via the dermalroute was estimated to be at most 9.9 x 10 -8



### . Since the use pattern has not changed, and no ne w assessment is needed for the current action, HED did not conduct an updated post-applicati on exposure assessment. A new assessment would address the following changes in the assumptions used: 1) increased body weight, from 70 to 80 kg; 2) increased life expectancy, from 70 to 78 years; and 3) increased transfer coefficient, from 1,000 to 1,900 cm2 

### /hour for high exposure activ ities. The use of these assumptions would increase estimated post-appl ication cancer risk to approximately 1.4 x 10 -7



### .
O VERALL 

### C ONCLUSIONS 

### : Both Indar ®

### 75 WSP and Enable ®

### 2F products were evaluated for similar occupational handler and post-application scenarios. Since the estimated handler MOEs for both formulations are greater than HED’s LOC of 100 (i.e., there are no risks of concern), a new occupational assessment is not needed in order to support the proposed amendment (i.e., adding pepper) to the Enable ®

### 2F label. The cancer risk associated with post-application exposure increased to approximately 1.4 x 10- 7 

### , with the increase being largely attributed to the increase in the transfer coeffi cient for high exposure activities.