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

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### MEMORANDUM

Date: 08-MA Y -14



### SUBJECT: Sulfentrazone; Review and generation of a Data Evaluation Record

PC Code: 129081 Decision No.: 485307 Petition No.: NA Risk Assessment Type: NA TXR No.: 0056843 MRID No.: 49253901, 49253902 DP Barcode: D416335 Registration No.: NA Regulatory Action: NA Case No.: NA 

### CAS No.: 122836-35-5 40 CFR: §180.498 Ver.Apr. 2010



### FROM: Anwar Y. Dunbar, Ph.D.

# ~**~ tJ~**  Pharmacologist, Risk Assessment Branch 1 / ' Health Effects Division (HED) (7509P)



### THROUGH: Charles W. Smith III, (__)

# ~...,;2-. Chief, Risk Assessment

## ~ Health Effects Division (HED) (7509P)



### TO: Bethany Benbow, Risk Review Manager Registration Division (7505P)



### I. CONCLUSIONS

RAB 1 has reviewed the 26-day inhalation exposure toxicity study and it is acceptable/nonguideline studies.



### II. ACTION REQUESTED

Please review this 26-day inhalation exposure toxicity study in rodents.

Page I of 1

### DATA EVALUATION RECORD

SULFENTRAZONE

STUDY TYPE: 26-DAY INHALATION TOXICITY STUDY - RAT; NON-GUIDELINE

MRID 49253902

Prepared for

Health Effects Division Office of Pesticide Programs U.S. Environmental Protection Agency One Potomac Yard 2777 S. Crystal Drive Arlington, VA 22202

Prepared by Summitec Corporation 9724 Kingston Pike, Suite 602 Knoxville, Tennessee

Task 6-83

Primary Reviewer:
H. T. Borges, Ph.D., M.T.(A.S.C.P.), D.A.B.T. Signature: Date: Secondary Reviewers: Thomas C. Marshall, Ph.D., DABT Signature: Date:

Robert H. Ross, M.S., Program Manager Signature: Date: Quality Assurance: Jennifer Goldberg, B.S. Signature: Date:

Disclaimer This review may have been altered subsequent to the contractor’s signatures above.

Summitec Corp. for the U.S. En vironmental Protection Agency under Contract No.EP-W-11-014SULFENTRAZONE / 129081 26-Day Inhalation Toxicity Study (2013) I Page 2 of 15 Non-guideline



### EPA Reviewer: Anwar Y. Dunbar, Ph.D. 

### Signature :

# ~ 

# J!.,**~** Risk Assessment Branch I, Health Effects Division (7509P) Date: (>(}-110/- 

## I £/'
EPA Secondary Reviewer: Ayaad Assaad, D.V.M

.. Ph.D. 

### Signature:**~;o::;""'T-l~~'='---** 

### Risk Assessment Branch IV, Health Effects Division (7509P) Date: -=.,.......,;.__-&:rl-l:t-7.r*'"tTXR#: 0056843



### DATA EVALUATION RECORD

STUDY TYPE: Subchronic Inhalation Toxicity-[Rats]; OPPTS 870.3465 [§82-4]; OECD 413.



### PC CODE: 129081 

### DP BARCODE: D 416335



### TEST MATERIAL (PURITY): Sulfentrazone Technical ( 91.7% a.i.)



### SYNONYMS: Sulfentrazone technical; N-(2, 4-dich1oro- 5-( 4 -( difl uoromethy 1)-4,5 -dihydro- 3-

me thy 1- 5-oxo-1 H -1 ,2, 4- triazol-1- y I )pheny I )methanesulfonamide



### CITATION: Koester

, A. (2013). 28-Day inhalation study ofsulfentrazone in rats with a 28- day recovery period. Battelle Toxicology West Jefferson, 1425 State Route 142 (Plain CityGeorgesville Road), West Jefferson, OH 43162

. Study Number 21621. October 2013. MRID 49253902. Unp ublished.



### SPONSOR: FMC Corporation, Agricultural Products Group, 701 Princetonsouth Corporate Center, Ewing

, NJ 08628



### EXECUTIVE SUMMARY:

In a subchronic inhalation toxicity study (MRID 49253902), sulfentrazone (purity 91.7%, Lot No.**PL12~0268)** was administered to groups of 5 male and 5 female Spragu e Dawley rats/group by nose only exposure at concentrations ofO, 0.085 (LCT), 0.256 (MCT), or 1.71 (HCT) mg!L, 6 hours/day for 26 days (calculated dose levels of20

, 60, and 400 mg/kg/day). An additiona15
rats /s ex were exposed either to 0 or 1.71 mg!L test material for 26 days followed by a 28-day
recovery period. At scheduled sacrifice after the 26 day exposure period or the 28-day recovery period, the rats were weighed, blood collected

, necropsied, and tissues and organs collected for microscopic examination.26-Day Inhalation Toxicity Study (2013) / Page 3 of 15 SULFENTRAZONE / 129081 Non-guideline



### There were no treatment-related effects on moribundity or mortality

.

There were no treatment re lated effects at 0.085 mg/L.

At 0.256 mg/L there were decreased the body weights in male and female rats ( ↓ 7 – 13%) during the treatment phase of the study. Statistically significant decreases were found in female rats treated for 26 days on mean corpuscular vo lume (MCV) and mean corpuscular hemoglobin (MCH) (both ↓ 6%).

At 1.71 mg/L there were increased incidences of excessive salivation in male and female rats from Day 17 through the end of the exposure phase. This observation ceased immediately during the recovery portion of the study. An increased incidence of squinting/shut eyes was also observed during the exposure phase. There we re decreased body wei ghts in both sexes ( ↓ 7 – 13%) during the treatment phase of the study. On day 26 in male rats there were decreases in numerous hematological parameters; hemoglobin ( ↓ 12%) , hematocrit ( ↓ 11%) , MCH ( ↓ 7%) , and the reticulocytes ( ↓ 80%) . On Day 26, females had statistica lly significant decreases in red blood cell count ( ↓ 15%) , hemoglobin ( ↓ 23%) , hematocrit ( ↓ 22%) , mean corpuscular volume ( ↓ 8%)

, and mean corpuscular hemoglobin ( ↓ 10%) relative to controls. Ex cept for mean corpuscular hemoglobin, which was statistically decreased on Day 54 but not on Day 26, these effects resolved during the recovery period. E xposure to the test material fo r 26 days increased the incidence of minimal nasal respiratory epithelial hyperplasia in male and female rats, as well as minimal laryngeal epithelial attenu ation in all test material exposure groups. These effects in the nasal passage and larynx were not resolved following the recovery period.

The systemic LOAEL is HTC or 1.71 mg/L base d on significant reduction in Red Blood Cell (RBC) parameters, including RBC count , HGB, hematocrit, MCV, MCH, and/or reticulocytes in male and female rats follow ing 26 days inhalation exposure to the test material. The NOAEL is 0.256 mg/L.

Port of entry LOAEL is HTC or 1.71 mg/L based on incidence of minimal nasal respiratory epithelial hyperplasia in male and female rats. Portal of entry NOAEL is 0.265 mg/L.

This study is classified as acceptable/non-guideline and satisfies the guideline requirement (OPPTS 870.3465; OECD 413) for a subchroni c inhalation study in the rat.

COMMENTS: Minor deficiencies were th e use of 5 male and 5 female rats for the LCT, MCT, or HCT groups 26-day exposure interval. Als o, the time to chamber equilibrium was not reported. A major deficiency is that findings in the lung, which is the target organ of the study, were not reported

COMPLIANCE: Signed and dated Quality Assurance, GLP, and Data Confidentiality statements were located in the study report.26-Day Inhalation Toxicity Study (2013) / Page 4 of 15 SULFENTRAZONE / 129081 Non-guideline



### I. MATERIALS AND METHODS:

A. MATERIALS:

1. Test material: Sulfentrazone Description: Technical, white powder Lot/batch #: PL12-0268 Purity: 91.7% a.i. Compound stability: Stable until December 18, 2014 CAS # of TGAI: 122836-35-5 Structure:



### 2. Vehicle and/or positive control: None

3. Test animals: Species: Rat Strain: Sprague Dawley Age/weight at study initiation: 9 -10 weeks / males 247.3 – 302.2 g; females 178.8 – 218.3 g Source: Charles River Laboratories, Portage, MI Housing: Individually in polycarbonate cage s containing hardwood bedding Diet: Certified Harlan Teklad Global Diet 2018C-Pellet, a d libitum (except during exposure)
Water: Municipal water, ad libitum Environmental conditions: Temperature: Humidity: Air changes: Photoperiod: 20.0 – 26.1°C 30 - 70% ≥ 10/hour 12 hours light/dark Acclimation period: 7 days



### B. STUDY DESIGN:

1. In-life dates: Start: April 1, 2013; End: Primary Phas e April 26, 2013; Recovery Phase May 24, 2013

2. Animal assignment: The rats were randomly assigned through a computer program to ensure similar group mean body weights (±20% of mean weight) to the test groups noted in Table 1.26-Day Inhalation Toxicity Study (2013) / Page 5 of 15 SULFENTRAZONE / 129081 Non-guideline

Table 1: Study design a Test group (Calculated Dose) Nominal (Target) conc. b (mg/L) Analytical conc. (mg/L) MMAD (μm) GSD No. Rats (males) No. Rats (females)

Control (0) 0.0 0.0 - - 10 10
Low (20 mg/kg/day) 0.085 0.094 2.1 2.0 5 5

Mid (60 mg/kg/day) 0.256 0.251 1.9 2.0 5 5

High (400 mg/kg/day) 1.71 1.93 2.3 1.9 10 10

Table was taken from page 21 and 30 of the study report

a Rats were exposed 6 hours/day for 26 consecutive days
b Based on 91.7% Sulfentrazone purity Five rats/sex in the control and HCT group, as well as the LCT and MCT ra ts were sacrificed on Day 26, while the remaining rats

were sacrificed on Day 54 (Recovery period).



### 3. Dose selection rationale: In a prior 7-day range-finding inhalation toxicity study (MRID 49253901), no adverse test material related findings were found in male rats exposed 6 hours/ day at concentrations of 0, 0.076, 0.229, or 0.764 mg/L. The NOAEL for the study was 0.764 mg/L. The Study Sponsor selected targ et sulfentrazone aerosol concentrations 0.085, 0.256, and 1.71 mg/L (target inhaled dose concentrations of 20, 60, and 400 mg/kg bw/day calculated inhaled Sulfentrazone, resp ectively) for the 26-day inhalation toxicity study.

4. Generation of the test atmosphere / chamber description: The rats were exposed to high efficiency particulate air (HEPA) or the te st material using Cannon-style rodent nose-only inhalation exposure systems. Four separate expo sure chambers were used to deliver either HEPA filtered air or Sulfentrazone technical aerosol. One-7 tier (56 ports) chamber was used to deliver HEPA filtered air to control group animals. Three separate 7 tier (56 port) chambers were used to deliver an aerosol of th e test material to the low-, mid- or high dose rats. The exposure system flow rates were se t to ~28 L/minute for all groups, which provided a test atmosphere flow rate of ~ 0.50 L/mi nute/exposure port. During exposures, the rats were restrained in polycarbonate exposure tube s. To promote better thermo-regulation, each tube contained a series of slots on the top portio n of the tube above the neck of each animal. Because of the "open" system, the exposure units were operated at a positive pressure relative to ambient atmosphere to prevent dilution of the test atmosphere with room air. The inhalation exposure chambers were exhausted at the required flow rate us ing a central vacuum pump system.

Dosage to the animals was controlled by vary ing the aerosol concentrations of the test material within each exposure plenum. Target test substance aerosol concentrations were calculated by estimating animal minute volumes using Bide's formula and an animal body weight of 0.250 kg (Bide et al, 2000) [0.499 x (group average body weight kg) 0.809 

### ] and a 360 minute exposure duration to achieve the intende d target dosage. The actual respiratory minute volumes were measured during exposures 1 day each week for each dose group and used to calculate the actual inhaled dose.26-Day Inhalation Toxicity Study (2013) / Page 6 of 15 SULFENTRAZONE / 129081 Non-guideline


### The aerosol generation and deliv ery system was designed to de liver a homogeneous exposure atmosphere, with respect to particle size dist ribution (PSD) and aerosol concentration, to the breathing zone of each rat. Aerosols of the test material powders for the low-, mid-, and high-dose groups were generated using a Wright Dust Feed me chanism at various operational speeds. Test material powders were packed in multiple layers with a hydraulic packing press. For the low- and mid-dose, the powders were packed at an applied load of 500 pounds while the high-dose was packed at 2000 pounds. Compressed air was supplied to each at 28.0 L/min. Percent oxygen, temper ature, and humidity of the atmosphere were measured a minimum of three times during each an imal exposure (all were unaffected).

Time to equilibrium was not located in the study report.

Analytical chemistry: Aerosol concentrations were m easured daily by collecting filter samples from each group during each exposure and analyzed gravimetrically. Selected aerosol concentration filter sample s collected at least weekly were used for chemical analysis by HPLC with UV detection (further details not located in study report). The estimated Sulfentrazone technical aerosol concentration was based on 91.7% test material purity.

Test atmosphere concentration: Daily sampling for aerosol concentrations was done using 25 mm glass fiber filters (Pall Corporation, Ann Arbor, MI). Prior to use, the filters were dried overnight in a vacuum desiccator before de termining filter tare weights. The filters were then placed into labeled Petri dishes until use. Before sampling, the filters were placed into in-line filter holders and attached via flexible tube to a sampling location in the breathing zone of the rats. A metered volume of test atmosphere was drawn across the filter at a rate of 0.5 L/minute for a specific time interval. The filter holder was removed from the sampling location, the filter removed and re-weighed to ob tain a post-sampling gross weight. The net gain of the dry filter mass was divided by the total volume of atmosphere sampled to calculate the total aerosol mass per liter of atmosphere. Results are in Table 2.

Table 2. Overall total mass aerosol concentration
Test Group Target (mg/L) Total mass aerosol concentration (mg/L) Average ± SD % RSD % Target Control 0.0 0.0 - - Low (LCT) 0.093 0.102 ± 0.015 15 109 Mid (MCT) 0.280 0.274 ± 0.029 11 98 High (HCT) 1.86 2.10 ± 0.473 23 113 Data from page 29 of MRID 49253902



### Particle size determination (PSD): PSD was measured a minimum of once per week per group (except for the air control group) using a nine stage Andersen style cascade impactor fitted with a 0.5 L/min isokinetic dilutor. The isokinetic dilutor allowed the impactor to operate at its nominal airflow ra te while allowing aerosol to be sampled at an airflow rate of 0.5 L/min . Results are in Table 1 above.

5. Statistics: Although various summary tables in the study re port indicated statistical analyses were done, the statistical methods used were not provided. The study pr otocol stated that appropriate quantitative in-l ife, clinical pat hology (hematology, serum chemistry, and coagulation), and post-mortem data were analyzed when N ≥ 3. According to the study protocol, data were analyzed by analysis of variance when considered homogenous by26-Day Inhalation Toxicity Study (2013) / Page 7 of 15 SULFENTRAZONE / 129081 Non-guideline


### Bartlett’s test. Tests for group differences were done using Dunnett's test. For nonhomogeneous data, pairwise differences between th e control and each of the comparison groups using Cochran and Cox's modified two-sample t- test were done. Statistical significance for all comparisons was p = 0.05.

C. METHODS:

1. Observations:

1a. Cageside observations: Cage-side clinical observations for morbidity and mortality were done at least three times daily begi nning on Day 1 of exposure. Observations were done once prior to each inhalation expos ure, at least once during the inhalation exposure, and 1 to 2 hours following exposur e. Observations were done once daily (on the weekends) during the 4-week exposure. Observations were also recorded at least weekly during the recovery period.

1b. Clinical examinations: Detailed clinical examina tions were not reported.

1c. Neurological evaluations: Neurological examinati ons were not reported.

2. Body weight: All rats were weighed before treatm ent for group assignment and on days 5, 8, 12, 15, 19, 22, and 25. The rats were also weighe d at necropsy (Days 26 or 54). During the 28 days of recovery, animals were weighed on Days 29, 36, 43, 50, and 53.

3. Food consumption: Individual animal food consumption was measured starting on day 8 of the study. Food was placed in the feed container for each animal and re-weighed after 1 week. Food efficiency was not calculated.

4. Ophthalmoscopic examination: Ophthalmoscopic examinations were not done.

5. Hematology and clinical chemistry: Rats necropsied on Day 26 were fasted only during exposure (~6 hours) and had blood collected at th e end of exposure. Rats necropsied following 28 days of recovery were fasted overnight before sample collection. The animals were anesthetized with CO 2 

### /O 2 

### and blood was collected from th e retro-orbital sinus for hematology and serum chemistry parameters, and vi a the posterior vena cava for coagulation parameters. The tubes for hematology contai ned EDTA while those for serum chemistry determinations did not contain an anticoagulant. Tubes for co agulation parameters contained sodium citrate. The CHECKED (X) parameters we re examined. Historical control data were provided.

a. Hematology:

X Hematocrit (HCT)* X Leukocyte differential count* X Hemoglobin (HGB)* X Mean corpuscular HGB (MCH)* X Leukocyte count (WBC)* X Mean corpusc. HGB conc.(MCHC)* X Erythrocyte count (RBC)* X Mean corpusc. volume (MCV)* X Platelet count* X Reticulocyte count X Platelet volume X Cell morphology Blood clotting measurements*26-Day Inhalation Toxicity Study (2013) / Page 8 of 15 SULFENTRAZONE / 129081 Non-guideline

X (Activated partial th romboplastin time) X (Fibrinogen) X (Prothrombin time)
* Recommended for subchronic inhalati on studies based on Guideline 870.3465



### b. Clinical chemistry:

X ELECTROLYTES X OTHER
X Calcium X Albumin* X Chloride X Creatinine* Magnesium X Urea nitrogen* X Phosphorus X Total Cholesterol* X Potassium* X Globu lins (Calculated) X Sodium* X Glucose*

X ENZYMES (more than 2 hepatic enzymes eg., *) X Total bilirubin

X Alkaline phosphatase* X Total serum protein (TP)* Cholinesterase (ChE) X Triglycerides X Creatine kinase (CK) Serum protein electrophoresis X Lactic acid dehydrogenase (LDH) X Albumin/globulin ratio (calculated) X Alanine aminotransferase (ALT/also SGPT)* X Aspartate aminotransfera se (AST/also SGOT)* Sorbitol dehydrogenase* Gamma glutamyl transferase (GGT)* Glutamate dehydrogenase
* Recommended for subchronic inhalati on studies based on Guideline 870.3465



### 6. Urinalysis : Urinalysis was not done.

7. Sacrifice and pathology: All rats were sacrificed by CO 2 

### inhalation followed by exsanguination. The necropsy included examination of the external surface of the body and all orifices; and the cranial, t horacic, abdominal, and pelvic cavities and contents. The CHECKED (X) tissues were collected for histol ogical examination and the (XX) organs, in addition, were weighed. Collected tissues we re placed in 10% neutral buffered formalin, with the exceptions. The testes were preser ved in Bouin's fixative, transferred to 70% ethanol, and subsequently transf erred to 10% neutral buffered formalin. The eyes with optic nerve were fixed in Davidson's fixative before transfer to 10% neutral buffered formalin. Bone marrow smears were fixed in methanol. The lungs were inflation fixed with 10% neutral buffered formalin via the trachea. All tissue preparations were stained withhematoxylin and eosin for microscopic examination. Only tissues from the control and highdose group were examined microscopically, with the exception of the la ryngeal tissue, which was examined in all animals.26-Day Inhalation Toxicity Study (2013) / Page 9 of 15 SULFENTRAZONE / 129081 Non-guideline

X DIGESTIVE SYSTEM X CARDIOVASC./HEMAT. X NEUROLOGIC X Tongue X Aorta, t horacic* XX Brain*+ X Salivary glands* XX Heart*+ X Peripheral nerve* X Esophagus* X Bone marrow* X Spinal cord (3 levels)* X Stomach* X Lymph nodes* XX Pituitary* X Duodenum* XX Spleen*+ X Eyes (optic nerve )* X Jejunum* XX Thymus*+ X GLANDULAR X Ileum* XX Adrenal gland*+
X Cecum* X UROGENITAL Lacrimal gland X Colon* XX Kidneys*+ XX Parathyroid* X Rectum* X Urinary bladder* XX Thyroid*
XX Liver*+ XX Testes*+ X OTHER

Gall bladder* (not rat) X Epididymid es*+ X Bone (sternum and/or femur) Bile duct* (rat) X Prostate* X Skeletal muscle X Pancreas* X Seminal vesicles* X Skin
X RESPIRATORY XX Ovaries*+ X Harderian glands
X Trachea* XX Uterus*+ X Nasal turbinates XX Lung* X Mammary gland* X A ll gross lesions and masses* X Nose* X Vagina X Pharynx* X Larynx*
* Recommended for subchronic rodent studies based on Guideline 870.3465

+ Organ weights required



### II. RESULTS:

A. OBSERVATIONS:

1. Clinical signs of toxicity: Treatment-related clinical si gns of toxicity included e xcessive salivation and squinting/ shut eyes for males and females in the high-exposure group. The observations of salivation occurr ed from Days 17 to 26 in 10/10 males and from Days 17 to 25 in 10/10 females. The squinting/shut eyes occurred from Days 3 to 19 in 7/10 males and from Days 3 to 23 in 9/10 females. No othe r clinical signs of toxi city were observed.

2. Mortality: All rats survived to scheduled sacrifice.

3. Neurological evaluations: Neurological examin ations were not done.

B. BODY WEIGHT AND WEIGHT GAIN:

The body weights of male and female rats expos ed to sulfentrazone by inhalation are shown in Table 3. Male group mean body weights were statistically d ecreased in the mid- and highexposure groups on Day 19 through Day 25 ( ↓ 11-13%). On Day 25, the last day of exposure, the male group mean body weights were decrease d 2, 11, and 13 percent, in the low-, mid-, and high-exposure groups, respectively, relative to the control group.

Female group mean body weights were statistica lly decreased in the mid- and high-exposure groups starting on Day 12 through 25 ( ↓ 7-13%, excluding Day 15). On Day 25, the female group mean body weights were decreased 4, 10, a nd 7 percent, in the low-, mid-, and highexposure groups, respectively, relative to the control group. Following the 28-day recovery period, male and female group mean body weights we re not statistically different than their26-Day Inhalation Toxicity Study (2013) / Page 10 of 15 SULFENTRAZONE / 129081 Non-guideline


### respective control groups.

TABLE 3. Mean (±SD) body weights during 26 days of trea tment with Sulfentrazone and 28 days of recovery via inhalation a

Day(s) Targeted concentration (mg/L)
0 0.085 0.256 1.71

Males Body Weights
1 277.7 ± 11.9 273.5 ± 9.5 269.1 ± 15.6 273.3 ± 7.6
8 308.3 ± 20.8 300.9 ± 17.6 286.4 ± 24.3 288.6 ± 9.2.8
15 329.0 ± 28.0 322.2 ± 25.9 301.9 ± 27.2 301.8 ± 12.2 22 353.2 ± 32.5 347.9 ± 29.0 313.7* ± 29.5 ( ↓ 11%) 311.9* ± 19.3 ( ↓ 12%) 25 357.7 ± 34.2 351.1 ± 32.1 317.1* ± 29.1 ( ↓ 11%) 312.3* ± 15.0 ( ↓ 13%)
29 362.2 ± 33.0 - - 338.7 ± 16.2
53 443.4 ± 37.9 - - 445.1 ± 42.4

Females Body Weights
1 200.7 ± 6.6 202.8 ± 12.4 196.7 ± 8.5 198.9 ± 9.9
8 200.8 ± 11.1 218.3 ± 7.6 209.0 ± 7.6 218.5 ± 9.0
15 238.1 ± 13.8 234.9 ± 12.5 222.0 ± 15.5 225.4 ± 9.1 22 252.0 ± 12.1 244.0 ± 10.7 232.9* ± 17.4 ( ↓ 8%) 238.5* ± 8.1 ( ↓ 7%) 25 254.3 ± 13.7 244.9 ± 12.1 228.7* ± 12.1 ( ↓ 11%) 237.1* ± 8.0 ( ↓ 7%)
29 266.9 ± 17.5 - - 234.6 ± 14.2
53 297.9 ± 20.0 - - 280.5 ± 6.5 Data from pages 44 – 47 of MRID 49253902



### C. FOOD CONSUMPTION:

1. Food consumption: The food consumption of HCT male a nd female rats was statistically decreased on Day 26 of exposure (16%, and 11%, respectively). No other significant effects on food consumption were noted during treatment or recovery.

2. Food efficiency: Food efficiency was not calculated.

D. OPHTHALMOSCOPIC EXAMINATION:

Ophthalmoscopic examinations were not done.

E. BLOOD ANALYSES:

1. Hematology: No treatment-related effects were noted on coagulation parameters. As shown in Table 4, treatment- and dose -related effects on RBC-related parameters were noted in MCT and HCT male and female treatment groups following 26 days of exposure. On Day 26, females in the HCT group had statistica lly significant decreases in RBC count ( ↓ 15%)

, HGB ( ↓ 23%) , hematocrit ( ↓ 22%) , MCV ( ↓ 8%) , and MCH ( ↓ 10%) relative to control females. Statistically signifi cant decreases were also found in MCT female rats treated for 26 days on MCV and MCH (both ↓ 6%) . Except for MCHC, which was statistically decreased on Day 54 but not on Day 26, these eff ects resolved during the recovery period. In26-Day Inhalation Toxicity Study (2013) / Page 11 of 15 SULFENTRAZONE / 129081 Non-guideline



### male rats, HGB ( ↓ 12%) , hematocrit ( ↓ 11%) , MCH ( ↓ 7%) , and the percen t reticulocytes ( ↓ 80%) were decreased in HCT rats following 26 days of treatment with the test material. All effects resolved during the 28-day recovery period in male rats. Other statistically significant effects were noted in WBC parame ters, but were considered unrelated to treatment due to a lack of dose-response. The treatment-related effects were consistent with protoporphyrinogen oxidase inhibition, which ha d been demonstrated in previous studies (FMC Report Nos. A90-3354 and A89-2881, data not provided).

Table 4. Selected group mean (± SD) hematology parameters of male and fema le rats treated with sulfentrazone Parameter / Group Males Females Day 26 Day 54 Day 26 Day 54 RBC (10 6 cells/μL) Control LCT MCT HCT 9.08 ± 0.50 9.38 ± 0.27 9.18 ± 0.51 8.58 ± 0.15 9.48 ± 0.36

-

- 9.15 ± 0.78 8.17 ± 0.37 8.51 ± 0.16 8.47 ± 0.55 6.95* ± 0.51

( ↓ 15%) 8.93 ± 0.24

-

- 9.19 ± 0.33

HGB (g/dL) Control LCT MCT HCT 16.6 ± 0.7 16.7 ± 0.1 15.8 ± 0.8 14.6* ± 0.5 ( ↓ 12%) 17.2 ± 0.8

-

- 16.1 ± 1.3 15.4 ± 0.6 15.8 ± 0.4 15.1 ± 0.7 11.9* ± 0.9 ( ↓ 23%) 16.9 ± 0.6

-

- 16.7 ± 0.3 HCT (%) Control LCT MCT HCT 50.7 ± 2.5 51.8 ± 0.7 49.3 ± 3.4 45.0* ± 1.6 ( ↓ 11%) 52.2 ± 2.3

-

- 50.6 ± 3.9 47.2 ± 2.4 47.9 ± 1.3 45.7 ± 2.7 36.9* ± 2.5 ( ↓ 22%) 50.4 ± 1.9

-

- 52.6 ± 2.2 MCV (fL) Control LCT MCT HCT 55.9 ± 2.7 55.2 ± 1.7 53.7 ± 1.6 52.4 ± 2.0 55.0 ± 1.9

-

- 55.4 ± 1.5 57.7 ± 1.0 56.3 ± 0.7 54.0* ± 1.1 ( ↓ 6%) 53.2* ± 0.8 ( ↓ 8%) 56.5 ± 1.4

-

- 57.2 ± 1.7 MCH (pg) Control LCT MCT HCT 18.3 ± 0.9 17.8 ± 0.5 17.3* ± 0.2 ( ↓ 5%) 17.1* ± 0.6 ( ↓ 7%) 18.1 ± 0.6

-

- 17.6 ± 0.8 18.9 ± 0.3 18.6 ± 0.1 17.8* ± 0.4 ( ↓ 6%) 17.1* ± 0.5 ( ↓ 10%) 18.9 ± 0.3

-

- 18.2 ± 0.4 MCHC (g/Dl) Control LCT MCT HCT 32.7 ± 0.8 32.2 ± 0.6 32.2 ± 0.7 32.5 ± 0.4 33.0 ± 0.4

-

- 31.8 ± 1.0 32.8 ± 0.4 33.1 ± 0.3 33.0 ± 0.7 32.1 ± 0.8 33.5 ± 0.4

-

- 31.7* ± 0.9 Reticulocytes (%) Control LCT MCT HCT 2.0 ± 0.3 1.9 ± 0.3 2.1 ± 0.4 0.4* ± 0.2 ( ↓ 80%) 2.4 ± 0.6

-

- 2.4 ± 0.8 2.2 ± 0.4 2.1 ± 0.3 1.8 ± 0.3 2.3 ± 3.8 2.2 ± 0.5

-

- 1.6 ± 0.5 Data from pages 155-162 of MRID 49253902 *p ≤ 0.05



### 2. Clinical chemistry: Although statistically significant e ffects were noted, all were within established normal ranges and none we re biologically relevant.

F. URINALYSIS:

Urinalysis was not done.

G. SACRIFICE AND PATHOLOGY:26-Day Inhalation Toxicity Study (2013) / Page 12 of 15 SULFENTRAZONE / 129081 Non-guideline



### 1. Organ weight: Although statistically signi ficant effects were noted on absolute and relative to body or brain organ weights, none were biologically or toxi cologically relevant and all lacked microscopic correlates.

2. Gross pathology: No treatment-related effects were noted at necropsy.

3. Microscopic pathology: Microscopic evaluation of the tis sues was only done for control and HCT animals, with the exception of laryngeal tiss ues which were examined from all rats. As shown in Table 5, microscopic findings in the nose of air control and the HCT group included respiratory epithelial hyperplasi a (increased number of cells), respiratory ep ithelial goblet cell hyperplasia (increased num ber of cells), olfactory epith elial metaplasia (change to respiratory epithelium), and respiratory epithelial inflammation (cellular infiltrate). The microscopic findings were gene rally of minimal severity. The hyperplasia was defined as increased cell thickness, increase d number of cells, disorganized cells, increased cytoplasmic basophilia, and/or intraepithelial cyst forma tion. The incidence of respiratory epithelial hyperplasia was increased in 4/5 male and fema le HCT rats following 26 days of treatment and was still increased in males, but not females, following the recovery period.

TABLE 5. Incidence of selected microscopic lesions in the nose a

Concentration Group Targeted concentration (mg/L)

Day 26 Males Day 54 b Males Day 26 Females Day 54 b Females

Air Control Microscopic Change Respiratory epithelium hyperplasia 2/5 1/5 3/5 1/5

Respiratory epithelium goblet cell hyperplasia 0/5 1/5 3/5 1/5

1.71 mg/L Respiratory epithelium hyperplasia 4/5 5/5 4/5 2/5

Respiratory epithelium goblet cell hyperplasia 2/5 3/5 2/5 2/5

a. Number with findings per number examined b. Recovery period was initiated on Day 27, t hus the final day of exposure was Day 26 From page 249 of MRID 49253902



### As shown in Table 6, microscopic findings inthe larynx consisted of submucosal mononuclear cell infiltrate (found in control and HCT rats at Days 26 and 54 recovery necropsy time points) and minimal epithelial attenuation (o bserved only in rats exposed to the test substance at all concentrations). The attenua tion was observed at the base of the epiglottis and consisted of a change from the expected cuboidal-to-transitional epithelium normally found to a more flattened morphology. Epithelia l attenuation remained evident in several HCT rats at the end of the recovery period.26-Day Inhalation Toxicity Study (2013) / Page 13 of 15 SULFENTRAZONE / 129081 Non-guideline

TABLE 6. Incidence of selected microscopic lesions in the larynx a

Concentration Group Targeted concentration (mg/L)

Day 26 Males Day 54 b Males Day 26 Females Day 54 b Females

Air Control

(mg/L) Microscopic Change Epithelial attenuation 0/5 0/5 0/5 0/5

Cellular infiltrate 1/5 1/5 1/5 2/5

0.085 Epithelial attenuation 1/5 No Recovery Animals 3/5 No Recovery Animals Cellular infiltrate 0/5 0/5

0.256 Epithelial attenuation 3/5 No Recovery Animals 4/5 No Recovery Animals Cellular infiltrate 0/5 0/5

1.71 Epithelial attenuation 3/5 3/5 4/5 1/5

Cellular infiltrate 1/5 0/5 3/5 2/5

a. Number with findings per number examined b. Recovery period was initiated on Day 27, t hus the final day of exposure was Day 26 From page 249 of MRID 49253902



### A few additional microscopic findings were spor adically observed in various air control and exposed rats and included panc reatic hyperplasia, pituitary gl and cyst, pituita ry gland hyperplasia, thyroid gland cellular in filtrate, liver cellular infiltrate, liver cytoplasmic vacuolization, Harderian gland cellular infiltrate, ly mphoid hyperplasia in the lung, alveolar macrophage focal infiltrates in the lung, and mandibular lymph node edem a. These results were of low incidence, minimal severity, sporadically ob served, and not related to dose. They were, therefore, considered unrelated to treatment.

III. DISCUSSION AND CONCLUSIONS:

A. INVESTIGATOR’S CONCLUSIONS:

The study author concluded th at treatment with sulfentr azone induced salivation and squinting of the eyes (HCT group), decr eased body weight (MCT and HCT groups), decreased food consumption (HCT group), a nd decreased RBC parameters (MCT and HCT groups). Nasal respiratory epithelial hyperpla sia at Day 26 in HCT groups was associated with administration of sulfentrazone for 28 days with incomplete recovery by Day 54. Laryngeal epithelial attenuation was noted in all sulfentraz one treatment groups after 28 days; possibly due to the potenti al slightly acidic characteristic of the test material. Laryngeal attenuation had decrea sed incidence and severity am ong HCT recovery rats which may suggest partial resolution. The laryngeal epithelial attenuati on was considered an adaptive response as a result of repetitive local ir ritation at the site during inhalation exposure. The study author stated the NOA EL for the study was the low-concentration,26-Day Inhalation Toxicity Study (2013) / Page 14 of 15 SULFENTRAZONE / 129081 Non-guideline


### 0.085 mg/L for male and female rats.

B. REVIEWER COMMENTS:

The reviewer generally agrees with the study author. Treatment with the test material increased the incidence of excessive salivati on in HCT male and female rats from Day 17 through the end of the exposure phase on Da y 26. This observation ceased immediately during the recovery portion of the study in HCT animals. An increased incidence of squinting/shut eyes was also observed from HC T rats during the exposur e phase of the study. These observations are likely a result of the acidi c nature of the test material and not due to systemic toxicity. Exposure to the test mate rial also decreased th e body weight of MCT and HCT male and female rats 7 – 13% du ring the treatment phase of the study.

Red Blood Cell (RBC) parameters, including RBC count, HGB, hematocrit, MCV, MCH, and/or reticulocytes were signi ficantly reduced in male and female rats following 26 days inhalation exposure to the test material. Th ese effects were primarily observed in HCT animals, and resolved by the end of the recove ry period. However, si gnificant decreases in MCH were observed in MCT male and female ra ts. As speculated by the study author, these effects were likely due to protoporphyrinogen oxidase inhibiti on that had been demonstrated in previous studies. No significant treatme nt-related effects were found on absolute and relative-to-body or brain organ weights. Exposur e to the test material for 26 days increased the incidence of minimal nasal respiratory epithelial hyperplasia in male and female rats in the HCT group, as well as minimal laryngeal ep ithelial attenuation in all test material
exposure groups.

The systemic LOAEL is HTC or 1.71 mg/L base d on significant reduction in Red Blood Cell (RBC) parameters, including RBC count , HGB, hematocrit, MCV, MCH, and/or reticulocytes in male and female rats follow ing 26 days inhalation exposure to the test material. The NOAEL is 0.256 mg/L.

Port of entry LOAEL is HTC or 1.71 mg/L based on incidence of minimal nasal respiratory epithelial hyperplasia in male a nd female rats. Portal of entry NOAEL is 0.265 mg/L.

This study is classified as acceptable/non-guideline and satisfies the guideline requirement (OPPTS 870.3465; OECD 413) for a subchroni c inhalation study in the rat.

C. STUDY DEFICIENCIES:

Minor deficiencies to the study we re the use of 5 male and 5 female rats for the LCT, MCT, or HCT groups 26-day exposure interval. Subchr onic guideline recommen dations state that 10 animals/sex/group be used. Also, the time to chamber equilibrium was not reported.

D. REFERENCES:26-Day Inhalation Toxicity Study (2013) / Page 15 of 15 SULFENTRAZONE / 129081 Non-guideline



### Bide, R.W., et al . (2000). Allometric resp iration/body mass data for animals to be used for estimates of inhalation toxicity to young adult humans. J. Appl. Toxicol. 20 :273-290.