EPA REGI STRATION DIVISION COMPANY NOTICE OF FILING FOR PESTI CI DE

PETI TI ONS PUBLISHED IN THE FEDERAL REGI STER Interregional Research Project Number 4 (IR - 4) Pesticide Petition (PP) #4E8264 EPA has received a pesticide petition , PP# 4E8264, from Interregional Research Project Number 4 (IR - 4), IR - 4 Project Headquarters, Rutgers, The State University of New Jersey , 500 College Road East, Suite 201 W, Princeton, NJ 08450 proposing, pursuant to section 408(d) of the Federal Food, Drug, and Cosmetic A ct (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180 by establishing a tolerance for residues of p rohexadione calcium in or on the raw agricultural commodit ies strawberry at 0.3 parts per million (ppm) and w atercress at 2.0 ppm . EPA has determined that the petition contains data or information regarding the elements set forth in section 408 (d)(2) of FDDCA; however, EPA has not fully evaluated the sufficiency of the submitted data at this time or whether the data supports granting of the petition. Additional data may be needed before EPA rules on the petition. A. Residue Chemistry 1. Plant metabolism. The metabolism of prohexadione calcium in plants peanuts and apples) is understood , the residue of concern is th e parent comp ound, prohexadione calcium
. 2. Analytical method. [ The method of anal ys is for strawberry i ncluded extraction and LC /MS/MS quantitation. T he limit of quantitation (L OQ) is 0.01 ppm. The method of anal ys is for watercress included extraction and GC
- MS quantitation. T he limit of quantitation (L OQ) is 0.1 ppm. ] 3. Magnitude of residues. [ A total of nine r esidue trials were conducted on strawberries grown in British Columbia, California, Florida, Michigan, New Jersey , Nova Scotia, Ontario, and Quebec in 20 10 . Strawberries were treated three times at a rate of 0. 032

– 0. 036 lbs prohexadione calcium per acre per application and 8

– 1 5 day s between applications. Whole strawberries were collected 1 6 to 2 5 day s after the last a pplication for anal ys is and anal yz ed by L C/MS/MS. R esidues ranged from 0.0 3 to 0. 16 ppm . A total of four residue trials were conducted on watercress grown in Florida and Maryland in 2009. W atercress was treated twice at a rate of 0.135

– 0.143 lbs prohexadione calcium per acre per application and 6

– 7 day s between applications per crop. Watercress leaves and stems were collected 3 days after the second application for anal ys is and anal yz ed b y GC
- MS. Residues ranged from 0.167 to 1.12 ppm. ] B. Toxicological Profile2

1. Acute toxicity. [ EP A has evaluated the tox icity database for prohexadione calcium and published assessment s in the Federal Register on May 3, 2000, FR Vol. 65, No. 86 pages 25655
- 25660 and on June 1, 2001 , FR Vol. 66, No. 106 pages 29705 through 29712 . The Agen cy determined that prohexadione calcium is of low acute toxicity . All tests showed the compound to toxicity category III or IV ] 2. Genotoxicty. [ Genotoxicity . Ames Test (1 Study ; point mutation): Negative; in vitro V79 Cells CH/HGPRT L ocus Mammalian Cell Mutation Assay (1 Study ; point mutation): Negative; in vitro CHO Cy togenetic Assay

(1 Study ; Chromosome Damage): Negative; in vivo Mouse Micronucleus (1 Study ; Chromosome Damage): Negative; in vivo Rat Bone Marrow Cy tog enetic Assay

(1 Study ; Chromosomal D amage): Negative; Rec Assay

(1 Study ; DNA damage and repair): Negative; in vitro Rat Hepatocy te (1 Study ; DNA damage and repair): Negative. Prohexadione calcium has been tested in a total of 7 genetic toxicology assay s consisting of in vitro and in vivo studies. Based on the results described above, it can be stated in summary

that prohexadione calcium did not show any mutagenic activity

when tested under the conditions of the studies mentioned above. Therefore, prohexadione calcium does not pose a mutagenic hazard to humans. ] 3. Reproductive and developmental toxicity. [ The reproductive and developmental toxicity of prohexadione calcium was investigated in a 2
- generation rat reproduction study as well as in rat and rabbit teratology studies. The 2
- generat ion rat reproduction study was conducted at dose levels of 0, 500, 5,000 and 50,000 ppm. There were no adverse effects on reproduction parameters seen even at the dose level of 50,000 ppm (5164 mg/kg bw for males and 5,600 mg/kg bw for females). The No Obs erved Adverse Effect Level (NOAEL) for parental sy stemic toxicity was 500 ppm (48 mg/kg bw for males and 51 mg/kg bw for females) and the NOAELfor developmental toxicity was 5,000 ppm (270 mg/kg bw for females). Stomach lesions were observed at 5,000 ppm. Two mid
- dose males and two males and one female of the high
- dose from the F0 died. Body weight and food consumption changes and slight transient reduction in offspring growth were noted at 50,000 ppm. No impairment of reproductive function was observed at an y of the dose levels tested. The reproductive and developmental studies are summarized below. A develop
mental study

was conducted via oral gavage in rats at dose levels of 0, 100, 300, and the 1,000 highest dose tested (HDT) mg/kg bw. The No Observed Adverse Effect Level (NOAEL) for developmental and maternal toxicity was 1,000 mg/kg bw, HDT. This was based on the fact that there were no signs of maternal toxicity , fetotoxicity or teratogenic effects. A developmental study was conducted via oral gava ge in rabbits at dose levels of 0, 40, 200, and 750 (HDT) mg/kg bw. The NOAELfor development toxicity was 40 mg/kg bw and the NOAEL for maternal toxicity was 40 mg/kg bw based on the following findings. Toxicity in the form of maternal mortality with valu es 16/20 and 4/20 was excessive in the mid
- and high
- dose group, respectively . Fetal deaths also occurred. Dose levels believed to exceed MTD; NOAELs for maternal and developmental effects are not considered reliable and useful for risk characterization. N o teratogenic effects were noted in this study
. i. Teratogenicity. Prohexadione calcium had no teratogenic potential at dose levels as high as 1,000 mg/kg bw in the rat and 350 mg/kg bw in the rabbit. The NOAEL for maternal toxicity

in the teratogenicity studies is 100 mg/kg bw (rabbit) and 1,000 mg/kg3

bw (rat), and the NOAEL for fetotoxicity in the teratogenicity studies is 350 mg/kg bw (rabbit) and 1000 mg/kg bw (rat). An additional teratology study in the same strain of rabbits was conducted at dose lev els of 0, 30, 75, and 150 mg/kg bw. The NOAEL for development toxicity

was 150 mg/kg bw and the NOAEL for maternal toxicity was 30 mg/kg bw based on the following findings. One low
- , two mid
- , and three high
- dose animals died prior to day 29, however, at the high dose group one died of gavage error and another pneumonia, and the reason for the other deaths could not be determined. No teratogenic or fetoxtoxic effects were noted in this study
. ii. Oral teratology

study . An oral range
- finding gavage teratolo gy study in the same strain of rabbits (5 animals/dose level) was conducted in another independent laboratory
. The dose levels selected were 0, 20, 100, 250, 500, and 1,000 mg/kg bw. This range finding study was conducted with a limited number of animals and a limited scope of examination. Based on these results the dose levels selected for the main study at this independent laboratory

were 0, 30, 100, and 350 mg/kg bw. The NOAEL for development toxicity

was 350 mg/kg bw and the NOAEL for maternal toxicity was 100 mg/kg bw based on the following findings. At the 350 mg/kg bw dose group transient body weight decreases and two abortions were observed. No teratogenic or fetotoxic effects were noted in this study
. iii. Conclusions from teratology studies. More than one definitive rabbit teratology

study was conducted because issues associated with exceeding the maximum tolerated dose (MTD) in the first study and spurious deaths, apparently not compound
related, in the second study confounded the determination of a NOAEL for maternal toxicity . There were no signs of teratogenic or fetotoxic effects in any study other than the first definitive study

in which maternal deaths above the MTD apparently occurred. It is BASF's opinion based on a thorough review of the teratology studies that the following overall NOAE Ls can be derived for the teratology studies: a. NOAEL maternal toxicity . 100 mg/kg body weight (rabbit) and 1,000 mg/kg body weight (rat). b. NOAEL prenatal toxicity . 350 mg/kg body weight (rabbit) and 1,0 00 mg/kg body weight (rat). The overall NOAEL of 100 mg/kg bw for maternal toxicity in rabbits is based on the last rabbit study , and is based on reduction of body weight gain and food intake at dose levels of 250 mg/kg body weight onwards. The NOAEL of 350 mg/kg bw for fetotoxic effects in the rabbit is also based on a reduction in body weight gain. Based on the overall study results, it is concluded that there are no developmental effects of concern. Based on preliminary discussions with EPA concerning the rabbit teratology studies, EPA concluded that the definitive NOAEL for maternal toxicity considering all of the studies ranges from 30 to 100 mg/kg/bw. Agency scientists further stated that they needed to review the studies in detail to ultimately dete rmine the definitive NOAEL for maternal toxicity . This uncertainty associated with maternal toxicity in the rabbit teratology

studies does not impact risk considerations since the risk assessment is based on a lower NOAEL (20 mg/kg bw) in the chronic dog s tudy
. ] 4. Subchronic toxicity
. [ The subchronic toxicity of prohexadione calcium was investigated in 90
- day

feeding studies with rats, mice and dogs. In all these studies, prohexadione calcium displayed low toxicity . Prohexadione calcium showed no signs of neurotoxicity

in a 90
- day neurotoxicity rat study . Additionally , the results seen in four4

week feeding range
- finding studies for rats and dogs were similar to the findings observed in the 90
- day

studies in the same animals. ] 5. Chronic toxicity
. [ Based on review of the available data, the Reference Dose (RfD) for prohexadione calcium will be based on a 1
- ye ar feeding study in dogs with a threshold No Adverse Effect Level (NOAEL) of 20 mg/kg/day . Using an uncertainty factor of 100, the RfD is calculated to be 0.2 mg/kg/day . The following are summaries of studies submitted to EPA. Prohexadione calcium was administered to Beagle dogs at dietary concentrations of 0, 20, 200, and 1,000 mg/kg bw for 12 months. Slight changes were observed for hematological and clinical chemical parameters and dilated basophilic renal tubules (without histopathological concurrence) at dose levels greater than 200 mg/kg bw. The NOAEL was 20 mg/kg bw for the males and female dogs. The 24
- month Fisher 344 rat chronic/carcinogenic feeding study was conducted at dose levels of 0, 400, 2,000, 10,000, and 20,000 ppm with 80 male and 80 female animals per dose group. After 26, 52, and 78 weeks, 10 animals were sacrificed (satellite groups). The remaining animals were autopsied after 10 4 weeks of diet administration. The NOAEL for chronic toxicity was 2,000 ppm for males (93.9 mg/kg bw) and 2,000 ppm for females (114 mg/kg bw). The following effects were observed in the 10,000 and 20, 000 ppm groups: i. Decreased body weights were obse rved in both male and female rats at the 20,000 ppm dose level; ii. Clinical chemical effects (i.e., lower potassium, bilirubin, and glucose levels) were observed in male and female rats at the 20,000 ppm dose level, in the 10,000 ppm dose level, reduced glucose levels were onl y seen in the males, and increased albumin/globulin ratios, sodium, chloride and calcium levels were observed only in the females; iii. Increased urine volumes and lower specific gravity were observed in the mid
high and high
- dose groups for both male and female rats; iv. Minor changes in organ weights were noted for animals of the high dose group only , which consisted of increased relative liver, adrenal and kidney weights, the latter also absolute in females only , at week 26; at the end of the study decreased liver weights and increased relative brain and testis weights were noted and these changes were considered to be associated with the decreased body weights; v. Macroscopic findings revealed an increase of pituitary nodules i n the high dose group for both male and female rats which was not confirmed histopathologically and submucosal ectopic tissue in the glandular stomach was found in both male and female rats in the highest dose levels that was confirmed by histopathology

wh ich showed an increase of squamous cell hy perplasia in males and of basal cell hy perplasia in the forestomach; vi. A higher incidence of cellular h yperplasia was observed in the th yroid in the mid
- high and high dose levels for male and female rats; and vii . No increased incidence of neoplasms occurred at any dose levels tested in this study
. In the 24
- month B6C3F1 mouse feeding study, conducted at dose levels of 0, 400, 2,000, 20,000, and 40,000 ppm with interim sacrifices at 52 and 78 weeks, prohexadione calcium was negative for oncogenicity. The NOAELfor chronic toxicity was 2,000 ppm5

for m ales (279 mg/kg bw) and 2,000 ppm for females (351 mg/kg bw). The following effects were observed in the 20,000 and 40,000 ppm groups: i. Statistically

significant decreases in body weights were observed in male mice at the 20,000 ppm dose level and in fe male mice at the 40,000 ppm dose level; ii. A variety

of changes in hematological parameters were noted in the respective investigations at weeks 52, 78, and 104, however, most of the changes were not dose related or consistent over time; iii. Increased absolute and/or relative heart, brain, testes, liver, ovary , and kidney weights were observed in the mid
- high and highest dose groups with a slight progression of severity to the highest dose group; iv. A higher incidence of splenomegaly was observed only in the male mice of the highest dose group; v. Histopathological examinations revealed an ectopic proliferation of the mucosal and glandular epithelium in the submucosal layer of the glandular stomach in male and female mice in the highest dose group tes ted, these changes were assessed to represent heteroplastic, ectopic proliferative changes accompanied by lumen dilatation and cy tological degeneration; vi. A higher incidence of hy perkeratosis of the forestomach was observed in both male and female mice and hy perplasia of the squamous epithelium of the forestomach of female male mice was observed in the highest dose group tested; vii. Vacuolic changes in the exocrine pancreas of the high dose female were observed; and viii. No increased incidence of neo plasms occurred at any dose levels tested in this study
. a. Threshold effects. Based on review of the available chronic toxicity data, BASF believes EPA will establish the Reference Dose(RfD) for prohexadione calcium at 0.20 mg/kg/day . This RfD for prohex adione calcium is based on the 1
- ye ar feeding study in dogs with a threshold NOELof 20 mg/kg/day in male and female dogs. Using an uncertainty factor of 100, the RfD is calculated to be 0.20 mg/kg/day. Based on the acute toxicity data BASF believes that p rohexadione calcium does not pose any dietary risks. b. Non
- threshold effects. Based on EPA Proposed Guidelines For Carcinogen Risk Assessment, BASF believes that prohexadione calcium will be classified as ``Not L ikely a Human Carcinogen''. Under the current assessment method BASF believes that EPA will classify

prohexadione calcium as Group E, no evidence of carcinogenicity based on studies in two spe cies. There was no evidence of carcinogenicity in mice and rat 24
- month feeding studies at the dosage levels tested. The doses tested were adequate for identifying a cancer risk. ] 6. Animal metabolism. [ The metabolism in animals (goats and poultry) is adequatel y understood. ] 7. Metabolite toxicology
. [] 8. Endocrine disruption
. [ No specific tests have been conducted with prohexadione calcium to determine whether the chemical may have an effect in humans that is similar to an effect produced b y a naturall y occurring estrogen or other endocrine effects. However, there were no significant findings in other relevant toxicity studies (i.e., subchronic and chronic toxicity , teratology and multi
- generation reproductive studies) which would suggest that prohexadion e calcium produces endocrine related effects. ]6

C. Aggregate Exposure 1. Dietary exposure. [ An assessment was conducted to evaluate the potential risk due to chronic dietary

exposure of the U.S. population and sub
- populations to residues of prohexadione calcium . Tolerance values for prohexadione calcium have previousl y been established and are listed in U.S. 40 CFR § 180.547. ] i. Food. [ BASF has conducted a prohexadione calcium dietary risk assessment for all currentl y registered crops and the propose d new tolerance s on strawberry at 0.3 ppm and watercress at 2.0 ppm . The assessment was conducted using 100 % crop treatment factors, tolerance level residues, and default processing factors of 1. The assessment included all food commodities and water at a concentration of 9.1 ppb. This water value was determined b y the US EPA during the most recent evaluation of a turf use for prohexadione calcium (US EPA, March 30, 2010, “Prohexadione Calcium. Proposed use on commercial and residential turf, golf courses, sod farms, and ornamental bedding plants and bedding plant plugs.” ). Acute Dietary

Exposure Assessment The EPA has determined that an acute assessment of prohexadione calcium is not required because there are no toxicological effects attributable to a single oral exposure
. Chronic Dietary

Exposure Assessment The most highl y exposed subpopulation was children 1
- 2 years of age. The % Chronic Population Adjusted Dose ( cPAD ) utilized was 16.6 %. Table 1 shows the exposure and % cPAD utilized by

all sub
- populations. Table 1. Results for P rohexadione Calcium Chronic Dietary E xposure (Food + Water) Anal ys is Considering all Current Tolerances and the New Proposed Tole rances for Strawberry and Watercress. Population Exposure Estimate %cPAD Subgroups (mg/kg b.w./day) US Population 0.00423 2.1 All infants (< 1 year) 0.02110 10.5 Children 1
- 2 years old 0.03317 16.6 Children 3
- 5 years old 0.01833 9.2 Children 6
- 12 years old 0.00711 3.6 Youth 13
- 19 years old 0.00256 1.3 Adults 20
- 49 years old 0.00177 0.9 Adults 50+ y

rs 0.00184 0.9 Females 13
- 49 years old 0.00194 1.0 cPAD = 0.2 mg/kg bw/day. * Exposure estimates based on tolerance values, default processing factor, and 100% crop treated values Results of the anal ys is show that for the U.S. population and all sub
- populations, the exposures are below a level of concern (< 100% cPAD). Additional refinements in the7

chronic dietary

risk assessment (i.e. utilizing anticipated residue values, process factors, percent crop treated values) would further reduce the estimated exposure values ] ii. Drinking water. [ The human exposure from drinking water was included in the dietary exposure . Acute Aggregate Exposure Acute aggregate exposure was not determined because the EPA has determine d that there is no toxicological effect resulting from a single oral dose of prohexadione calcium. Short
- and Intermediate Term Aggregate Exposure and Risk (food,water, and residential ) Short
- and intermediate
- term aggregate exposure takes into account residential exposure plus chronic exposure from food and water. Residential exposure is used to refer to non
occupational and non
- dietary exposure. Prohexadione calcium was registered fo r uses in 2010 which can result in post
- application exposure to the general population and children. The residential exposure value used in this risk assessment was previously determined b y the EPA ( US EPA, March 30, 2010, “Prohexadione Calcium. Proposed use on commercial and residential turf, golf courses, sod farms, and ornamental bedding plants and bedding plant plugs.”)
. The short
- term aggregate risk assessment is shown in Table 3 . The MOE values indicate that the aggregate risk from the use of pro hexadione calcium is acceptable.

Table 3. Short
- Term Aggregate Risk from the use of Prohexadione Calcium.

Sub
Populations Scenario Short term Aggregate Risk
Dietary MOE Dermal

MOE Oral hand to mouth MOE Total

Aggregate MOE General Population Res - post

app exp, 9466 11000 NA 5088 children 1
- 2 Res - post

app exp, 1206 14000 180000 1104 yo uth 13
- 19 Res - post

app exp 15645 7400 50248

Chronic Aggregate Exposure: Chronic aggregate expos ure includes exposure from food and drinking water . The dietary assessment conducted above includes food and water and therefore, is an aggregate exposure. The aggregate exposure to prohexadione calcium utilized less than 17 % of the cPAD for all subpopulations. ] 2. Non
- dietary exposure
. [ Residential exposure is used to refer to non
occupational and non
- dietary exposure. Prohexadione calcium was registered for uses in 2010 which can result in post
- application exposure to the general population and children. The residential exposure value used in this risk assessment was previously determined b y the EPA (US EPA, March 30, 2010, “Prohexadione Calcium. Proposed use on commercial and residential turf, golf courses, sod farms, and ornamental bedding plants and bedding plant plugs.”). The MOE values from the assessment are presented in the Table 3. Table 3. Residential Exposure and Risk Estimates for Post
- Application Uses for Prohexadione Calcium.
Population subgroup Scenario Dermal exp (mg/kg bw
day) Dermal

MOE Oral exp
-

hand to mouth (mg/kg bw

- day) Oral

MOE
Adult Post - App

golfer 0.00364 11000 NA yo uth Post - App

golfer 0.00541 7400 NA Toddler Post - App

Turf 0.00286 14000 0.00044 180001 ] D. Cumulative Effects [ BASF is aware of onl y one other registered compound, trinexapac
- eth yl4
- (cycloprop yl
- a - hydrox ymethylene)
- 3,5
- dioxocyclohexanecarbox yl ic acid ethyl ester, that has a structure similar to prohexadione calcium. However, BASF has no information that would indicate that the two compounds have a common mechanism o f toxicity . Further
more, trinexapac is registered for use onl y on turf. Therefore, even if the compounds were considered similar there would be no cumulative dietary exposure issue because of the differences in use patterns. In summary , dietary exposure t o prohexadione calcium should not result in cumulative toxicity with other known chemical compounds. ]9

E. Safety Determination 1. U.S. population. [ Based on this risk assessment, BASF concludes that there is a reasonable certainty

that no harm will resul t to the general population from the aggregate exposure to prohexadione calcium residues. ] 2. Infants and children
. [ Based on this risk assessment, BASF concludes that there is a reasonable certainty that no harm will result to infants or children from the aggregate exposure to prohexadione calcium residues ] F. International Tolerances [A maximum residue level (MRL) has not been established for prohexadione calcium in strawberries or watercress b y the Codex Alimentarius Commission.]