### U. S. ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, DC 20460

OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES
PC Code No. 018301 DP Barcodes: D235437 D235434



### MEMORANDUM

SUBJECT: Waiver Review on Generic DCI Regarding Chlorporpham for Use on Easter Lilies and Ginkgo Trees.



### TO: Gary Mullins, PM Team Reviewer Jim Tompkins, Product Manager 25 Special Review and Re-registration Division



### PROM: Thomas M. Steeger, Ph.D., Senior Scientis Environmental Fate and Effects Division (7507C) /



### THROUGH: Betsy Behl, Branch Chief Environmental Risk Branch IV Environmental Fate and Effects Division \

The Environmental Fate and Effects Division (EFED) has reviewed the datawaiver request submittedin response to the generic data call-in (DCI) regarding chlorpropham (PC Code 018301)

use on Easter lilies and ginkgo trees. Based on the very limited use of chlorpropham on Easter lilies and ginkgo trees, the noncontiguous acreage (< 600 acres total) where it is applied, the existence of direct acute ecological effect data on chlorprofam, and the availability of data on a similarly structured compounds (propanil and propham), EFED is willing to waive all additional data requirements for the use of chlorprofam on 2,000 ginkgo trees in Washington DC, 400 acres of Easter lilies in Del Norte, California, and 150 acres of Easter lilies in Curry County, Oregon. According to the data package, approximately 300 pounds of active ingredient is applied for each use annually. EFEDYs willingness to concur with the current waiver requests should not be construed as a precedent for chemicals considered to be limited in use. The Special Review and Reregistration Division should recognize that waived data requirements introduce considerable uncertainty into characterizing the environmental fate and effects of any chemical. Furthermore, if additional uses are sought for chlorpropham, SRRD should report that EFED re-evaluate the need for additional data. Sincerough calculationsshowthat endangered species may be impactedby the proposed use of this chemical, any regulatory actions regarding chlorpropham use on Easter lilies and ginkgo trees should include the following language:

TheAgency has developed theEndangered Species Protection Program to identzfipesticides whose use may cause adverse impacts on endangered and threatened species, and to implement mitigation measures that address these impacts. TheEndangeredSpecies Act requires federal agencies to ensure that their actions arenot likely to jeopardize listedspecies or adverselymodzb designated critical habitat. To analyze the potential of registered pesticide uses to affect any particular species, EPA puts basic toxicity and exposure data developed for REDS into context for individual listed species and their locations by evaluating important ecologicalparameters, pesticide use information, the geographic relationship betweenspeciJicpesticidesuses and species locations, and biological requirements and behavioral aspects of the particular species. This analysis will include consideration oftheregulatory changes recommended in thisRED. A determination that there is a likelihood ofpotential impact to a listed species may result in limitations on use of the pesticide, other measures tomitigate anypotential impact, or consultations with the Fish and Wildlife Service and/orthe National Marine Fisheries Service as necessary.
Atpresent, the program is being implementedon an interim basis as described in aFederal Register notice (54 FR 27984-28008, July 3, 1989). Afinalprogram, which may be alteredfrom the interim program, will be proposed in a Federal Register notice scheduledforpublication in autumn of 2001.


### Attached please find a summary of the information used 

### by EFED in deciding whether to waive outstanding datarequirements for chlorprophamuse onEaster lilies in California and Oregon and on ginkgo trees in Washington DC.

### Summary

EFED has limited environmentalfate dataon chlorpropham (hydrolysis dataonly); ecological effect data are limited to acute toxicity data only for birds and aquatic animals; chronic toxicity data

are available on mammals only. Ecological effect data indicate that chlorpropham is practically nontoxictoterrestrialanimals and ismoderatelytoxic to aquatic animals on an acuteexposurebasis. Data exist for two similarly structured herbicides, 

### i.e.,propanil and propharn. Based on the very limited use of chlorpropham on Easter lilies and ginkgo trees, the noncontiguous acreage (< 600

acres total), the existence of direct acute ecological effect data on chlorprofam, and the availability of data on a similarly structured herbicides, i. e., propanil andpropham, EFED is willing to waive all additional data requirements for the use of chlorprofam on 2,000 ginkgo trees in Washington DC, 400 acres of Easter lilies in Del Norte, California, and 150 acres of Easter lilies in Curry County, Oregon. If additional uses are sought for chlorprofam, SRRD should report that EFED re-evaluate the need for additional environmental fate and ecological effects data particularly if the uses will be

on food-crops or turf. Thus 

### ,decisionsto waive data must remain on a case-by-case basis. EFED's willingness to concur with the current waiver requests should not be construed as a precedent for chemicals considered to be limited in use.
Background
Chlorprophamis a pre- and post-emergence herbicide that was originally registered in 1962 for use on a variety of terrestrial food crops, nonfood crops, and ornamentals to control broadleaf weeds and grasses, and sprouting inpotatoes. Chlorprophamis a herbicide andplant growthinhibitor used to controlmouseear chickweedin spinach and fi-uitingin ginkgo trees, reduce

### Botrytis infection in Easter lilies as well as assist in their floral bud removal, and inhibit sprouting in storepotatoes. By 1990,the primary registrantshad dropped all nationwide uses of chlorpropham except those for sproutcontrol on post-harvestpotatoes [indooruse]. However,an additional 1 1 registrations for use within a particular county or state [registered under FIFRA Section 24(c)] remained for use on spinach, Easter lilies, and ginkgo trees.

The proposed label for chlorpropham (Sprout NipB) indicates the product contains 36% active ingredient by weight. For applicationto Easter lilies,chlorpropham is applied at a maximum single application rate of 4 lbs. active ingredient per acre by ground boom or two applications of 2 lbs. a.i./A each separated by a 1-week interval.. For use on ginkgo tree in Washington DC, chlorpropham is applied at 0.02 lbs. a.i./gallon by mist blower and is applied to "near dripping point."
Following publication of the 1996 re-registration eligibility document (RED), the Platte Chemical Company and the Easter Lily Research Foundation requested a waiver from allremaining environmental fate and ecological effects studies required to supportthe continued [outdooruse] of the plant growth inhibitor on lily bulbs on up to 400 acres in Del Norte California and 150 acres in Curry County, Oregon. Additionally, Platte Chemical requested a waiver from the same studies to support the continued use of chlorprophamon approximately2,000 ginkgotrees in the Washington

Page 3 of 11DC area. In both cases, the Environmental Fate and EffectsDivision concurred with the request to waive 6 environmentalfate studies [photodegradationinwater (Guideline 16 1 -2),photodegradation

on soil (Guideline 16 1 -3), anaerobic soil metabolism (Guideline 162-2), laboratory volatility (Guideline 163-2), terrestrial field dissipation (Guideline 164-I), and bioaccumulation in fish (Guideline 165-4)]. The only environmental fate studiesrequired were an aerobic soil metabolism (Guideline 162-1) and an absorbtion/desorption study (Guideline 163-1). EFED alsoagreedto waive 8 ecological effect studies [seed germination /seedling emergence (Guideline 122-

### 1 a), vegetative vigor (Guideline 122-1 b), aquatic plant growth (Guideline 122-2), avian reproduction (Guidelines 71-4 a and b), fish early life stage (Guideline 72-4a), aquatic invertebrate life cycle (Guideline 

### 72- 4b), and fish full life cycle (Guideline 72-5). The only ecological effect studiesrequired by EFED

were an avian acute oral (Guideline 7 1 

### - 1

a) and a subacute dietary study (Guideline 7 1 -2b). The registrant has rejected EFED's request for any additional data based on their beliefthat the limited

use of chlorpropham in a very limited geographical area does not warrant any additional environmental fate or ecological effect data and in 1997,the registrant formally requested a waiver from the generic data call-in ((DB Barcodes D235437 and D235434).
The only environmental fate data available for chlorprophamfocus onhydrolysis;these data indicate that chlorpropham is stable to hydrolysis. The study concluded that chlorpropham does not hydrolyze or degrade in water at pH 4,7,9.
Acute toxicity testing (Table 

### 1) indicates that chlorpropham is practically nontoxic to mammals (LD50 =4,100 mglkg) and birds (LD50 > 2,000 mglkg) on an acute exposure basis and is alsopractically nontoxicto birds on an acute dietary exposure basis (LC50 

### > 5,620mglkg ofdiet. Chlorpropham is moderately toxic to freshwater fish (LC50 range 3.0 

### - 6.8 ma) and invertebrates (EC50 = 3.7 ma).

No ecological risk assessment was conducted forthe 1996 re-registration eligibilitydocument since the plant growth regulator was being re-registered for indoor use only and since no environmental fate datawere available for estimating environmental concentrations using available screening-level models.

In the absence of data on a particular compound, EFED will attempt to address data gaps (uncertainty) using informationfrom similarly structured chemicals. Figure 

### 1 shows the structure of chlorpropham and the similarly structured herbicides propanil (Figure 

### 2) and propham (Figure 3). Environmental fate data onpropanil indicate that the herbicide will not persist in the field as the compound is rapidly metabolized under aerobic or anaerobic conditions in a waterlsediment milieu (laboratoryt,,, = 2-3 days). Propanil metabolized rapidly in aerobic soil with a half-life of 0.5 days. However, similar to chlorpropham, propanil is stable to hydrolysis at pHs 5, 7, and 

### 9 in the laboratory. 

### A soil photolysis study also suggests that propanil is stable to photodegradation. Propanil is susceptible to biodegradation, yet stable to chemical degradative processes. Environmental fate data on propham is not as detailed as that for propanil; however, the compound is stable to hydrolysis but is not likely to persist due to biotic degradation (aerobic soil metabolism tl,, 

### < 14 days).

Page 4 of 11Additionally, based onmobility criteria(highly soluble, mediumKO, and K, values),propanil could possibly reach groundwater but due to its rapid metaboli,smin a waterlsoil matrix, it is not likely to persist for a significantamount oftime to leach in measurable quantities. Propham is also likely to be mobile 

### (K, range 0.27 

### - 2.7).
Comparison of ecological effect data on propanil 

### (Table 1) indicates the herbicide is practically nontoxic to birds (LC50 = range 2,311 

### - 5,627 mglkg of diet) on a subacute dietary exposurebasis but is slightly toxic mammals (LD50 = 1,080mglkg) and moderately toxic to birds (LD50 =20 1mglkg) on an acute exposure basis. Similarly,propham ispractically nontoxicto birds

on an acute exposurebasis (LD50 

### > 2,000 mglkg). Aquatic toxicity ofpropanil is roughly similar to that of chlorpropham for both freshwater fish (LC50 range: 2.3 

### - 5.4 mglL) and invertebrates (EC50 = 1.2mgh,); propham is roughly an order ofmagnitude less toxic with freshwaterfishLC50 valuesofapproximately29 mgh,.. Chronic toxicity dataare available forpropanil and indicate acute to chronic ratios for freshwater fish and invertebrates of 258 (LC50,,, = 2.3 mgL divided by NOEC,,,,,, = 0.009 mg/L) and 13,953 (EC50,,,,,, = 1,200 mg/L divided by NOEC,,,,,, = 0.086 mg/L), respectively. Additionally, data suggestthat similar to the degradation products ofpropanil (dichloroaniline), a likely degradation product of chlorpropham (monochloroanaline)is also toxic. Exposure to monochloroaniline (Fujitani et 

### al. 2001) has resulted in hematoxic effects similar to those observed in chronic toxicity tests with chlorpropham in rats (Fujitani et 

### al. 1997;Fujitani et 

### al. 2000).

There are no plant toxicity data available on either chlorpropham or propham. Terrestrial plant testing of propanil showed monocots (onions) to be the most sensitive (EC25 = 1.4 lbs a.i./Acre) plant group tested based on seedling emergence studies. Aquatic plant toxicity testing indicated that exposure levels ofpropanil at 0.11 mglL or greater may cause detrimental effects to the growth and reproduction of vascular aquatic plant species and that algae and diatoms may be affected from propanil exposure levels of 0.016 mg/L or greater.
Estimated environmental concentrations (EEC) (Appendix A) using the Generic Estimated Environmental Concentration (GENEEC2) model were derived for applications to Easter lilies based on the following input parameters: Kd= 0.27, solubility = 89 mglL, aerobic soil metabolism

= 14days, aerobic aquaticmetabolism =2 days. The estimatedpeak concentration in surface water is 197 ugh,. Based on this estimated concentration, the acute risk quotient (RQ = 0.066) for freshwater fish (EEC = 0.197 mglL divided by LC50,,, = 3 mglL) exceeds the acute endangered species level of concern (LOC). Additionally, the acute endangered species LOC is exceeded for 

### freshwater invertebrates (RQ = 0.05). Thus, based on a rough screening-level assessment of RQ values and the absence of chemical-specific environmental fate data, EFED concludes that the proposed use ofchlorpropham onEaster lilies may impact endangered speciesoffreshwaterfishand invertebrates.
Chronic RQ values for aquatic animals were derived by comparing the 21-day EEC (0.053 mg/L) to estimated no-observed effect concentrations (NOEC) for chlorpropham. Sinceno chronic toxicity data are availableon chlorpropham,NOEC values were estimated usingthe acuteto chronic

Page 5 of 11ratio (ACR) for propanil. Thus, the NOEC for fish is estimated to be 0.012 mg/L (LC50 = 3 mg/L divided by ACR = 258); the NOEC for freshwater invertebrates is estimated to be 0.27ug/L (EC50

=3.7mg/L dividedby ACR = 13,953). Based onthese estimated chronictoxicityvalues, the chronic RQ values for fish and invertebrates are 4.4 and 196, respectively, and exceed chronic levels of

concern. Appendix B lists threatened and/or endangered species located in Curray County, Oregon, and Madera County (Del Norte), California. There are three species of fish listed for the use sites: Lahontancutthroattrout (Oncorhynchusclarkihenshawi), Paiute cutthroattrout (0. clarki seleniris), and coho salmon (0. kisutch). Based on the suspected environmental fate properties of chlorpropham and the availableacute toxicity datafor freshwaterfish, the use ofchlorporphammay result in some mortality to these fish on an acute exposure basis. Additionally, chronic effects on these species are also likely.

Because ofthe existenceof environmental fate data on a similarly structured chemicals,the existence ofacute toxicity data on chlorpropham which is similar to that forpropanil andthe limited

use of chlorpropham onnoncontiguous acreage ofEaster lilies and ginkgotrees, EFED is willing to

reserve many of the required data for conducting an ecological risk assessment of chlorpropham. However,this action should notbe construed as setting a precedent for deminimous use compounds. Had a number of factors not have been in place (e.g. alternate data not or if the proposed use had been for a food-crop)EFED would likelyhave requiredthe sorption/desorption studyandthe aerobic soilmetabolism study. Additionally,had alternate chronic ecotoxicity data not been available,EFED would likely have required the chronic aquatic toxicity data identified in EFED's response to the 1996 waiver request.

Uncertainties

1 Within the past year, EPA has been requested to provide both environmental fate and ecological effects data on two chemicals spilt in the DC metro area and which resulted in incidents along Rock Creek Parkway. While the pesticides might have had limited use, spills require that sufficient data are available to address unusual exposure/toxicity circumstances. Bridging data should never be considered an ideal substitute for chemical specific data. Thus, the decision to waive data introduces significantuncertainty into EFED's ability to provide accurate environmental fate and ecological effect data should the need arise. Additionally, lily bulbs in Del Norte, California,have in the past been a use site resulting in groundwater contamination from aldicarb, a persistent, mobilepesticide. Although monochloroanilineis a degradate ofchlorpropham and there are data to indicate the degradate is toxic, the persistence and mobility of the degradate(s) are uncertain. EFED is uncertain to the degree to which the likely mobility of chlorprofam and its potential transformationto toxic degradates will impact groundwater. EFED has no direct plant data

on chlorpropham and has had to rely on plant toxicity data for propanil. The proposed application rate for Easter lilies (4 lbs. a.i./A) is roughly 2.8 times the EC25 of propanil for terrestrial plants. The potential effects of chlorpropham to nontarget terrestrial and aquatic plants are unknown. Finally, rough estimates of aquaticrisk quotientsindicate that acute endangered species and chronic

Page 6 of 11

### levels of concern are exceeded by the proposed use of chlorporpham on Easter lilies. Although the range of acute RQ values (0.53 to 0.66) is relatively low comparedto the trigger value (RQ = 

### 0.5), chronicRQ 

### values exceed LOCs by factors ranging from 4 

### to 196. EFED believes that the limited

use of chlorpropham in Madera County, California, and Curry County, Oregon, mitigates effects to endangered species;however, any regulatory document regarding the use of chlorpropham should containlanguage developedbythe Field and External Affairs Division regarding endangered species.

Table 1. Summary of acute and chronic toxicity data for chlorpropham and propanil (na =data not available).

Bobwhite quail LD50 = na LC50 > 5,620 mglkg diet LD50 = 201 mgkg LC50 =2,3 11mgkg diet

Mallard duck LD50 > 2,000 mgkg LD50 > 2,000 mglkg LD50 = na LC50 = na LC50 = 5,000 mgkg diet Laboratory rat LD50 > 5,620 mgkg NOEL > 1,000mgkg diet LD50 = 1,080 mgkg NOEL = 300 mgkg diet

Rainbow trout LC50 = 3.0 mg/L LC50 = 28 ma LC50 = 2.3 mg/L Bluegill sunfish LC50 = 6.8 mg/L LC50 > 29 mg/L LC50 = 5.4 mg/L

Fathead minnow LC50 =na NOEC =na
Water flea EC50 = 3.7 mg/L NOEC = na LC50 = na NOEC = 0.009 mg/L

EC50 = 1,200ma NOEC = 0.086 mdL



### Page 7 of 1

### 1Figure 

### 1. Chlorpropham [(3-chlorophenyl) carbamic acid 

### 1 -methylethyl ester]

Figure 

### 2. Propanil [N-(3,4-

-. dichlorophenyl)propanamide]



### 0 

# I I C-O- C-H

Figure 

### 3. Propham [phenylcarbamic acid 

### 1

-methylethyl ester]

Page 8 of 11References
Fujitani, T. Y. Tada, A. T. Noguchi, M, Yoneyama. 1997. Hematoxicity of chlorpropham (CIPC) in 

### F344 rats. Toxicology 123: 1 1 1 

### - 124.
Fujitani, T. Y. Tada, 

### A. Fujii, 

### M. Kimura, and 

### M. Yoneyama. 2000. Subchronic toxicity of chlorpropham (CIPC) in ICR Mice. Food and Chemical Toxicology 38: 617 

### - 625.
Fujitani, T. Y. Tada, A. T. Noguchi, M, Yoneyama. 2001. Effects of chlorpropham (CIPC) on the hemopoietic system of rats. Food and Chemical Toxicology 39: 253 

### - 259.

Page 9 of 

### 11APPENDIX A 

### GENEEC OUTPUT FILE

RUN No. 1 FOR chlorpropham ON Easter lil 

### * INPUT VALUES *

.................................................................... RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP

ONE (MULT) INTERVAL Kd (PPM) (%DRIFT) ZONE (FT) (IN)

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS)

.................................................................... METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) ( POND-EFF) ( POND) ( POND)

GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 May 1, 2001

.................................................................... PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC

Page 10 of 11

### APPENDIX B 

### ENDANGERED SPECIESLISTED FOR CURRY COUNTY (OREGON) AND MADERA COUNTY(CALIFORN1A).

CURRY OR

............................................................................ ............................................................................ SPECIES GROUP STATUS KNOWN

............................................................................ EAGLE, BALD BIRD T KNOWN GOOSE, ALEUTIAN CANADA BIRD T KNOWN MURRELET, MARBLED BIRD T/CH KNOWN OWL, NORTHERN SPOTTED BIRD TI CH KNOWN PELICAN, BROWN BIRD E KNOWN PLOVER, WESTERN SNOWY BIRD T KNOWN SALMON, COHO (SOUTHERN OR/NORTHERN CA COAST)FISH T KNOWN

SPECIES GROUP STATUS KNOWN

............................................................................ BEETLE, VALLEY ELDERBERRY LONGHORN INSECT TI CH KNOWN BIRD'S-BEAK, PALMATE-BRACTED PLANT E POSSIBLE EAGLE, BALD BIRD T KNOWN FOX, SAN JOAQUIN KIT MAMMAL E KNOWN GOLDEN SUNBURST, HARTWEG'S PLANT E KNOWN GRASS, HAIRY ORCUTT PLANT E KNOWN KANGAROO RAT, FRESNO MAMMAL El CH POSSIBLE LIZARD, BLUNT-NOSED LEOPARD REPTILE E KNOWN LUPINE, CLOVER PLANT E KNOWN OWL' S-CLOVER, FLESHY PLANT E KNOWN PUSSYPAWS, MARIPOSA PLANT T KNOWN ADOBE SUNBURST, SAN JOAQUIN PLANT E KNOWN TROUT, LAHONTAN CUTTHROAT FISH T KNOWN TROUT, PAIUTE CUTTHROAT FISH T KNOWN

Page 

### 11 of 11