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

OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION

DP Barcode: 398130
PC Code: 555550

February 3, 2012

MEMORANDUM

SUBJECT: Cyflufenamid: Addendum to th e Ecological Risk Assessment on cucurbit vegetables (crop group 9), low growi ng berry (crop subgroup 12-07G) except cranberries, pome fruit (crop subgro up 11), outdoor landscape and outdoor nursery ornamentals, and small fruit vine climbing except fuzzy kiwifruit (crop subgroup 13-07F) for the treatment of powdery mildew (DP 360841, September 3, 2010).

TO: Mark Suarez, Product Manager 13 Samantha Hulkower, Risk Reviewer
Insecticide Branch Registration Division (7505P)

THROUGH: Dana S. Spatz, Chief Rosanna Louie-Juzwiak, Risk Assessment Process Leader
Environmental Risk Branch III
Environmental Fate and Effects Division (7507P)

FROM: Amy Blankinship, Chemist
Environmental Risk Branch III
Environmental Fate and Effects Division (7507P)

The Environmental Fate and Effects Division (EFE D) previously completed an ecological risk assessment (DPs 360841 and 366391, September 3, 2010) for the new fungicide, cyflufenamid, for use on cucurbit vegetables, low growing berry except cranberries , pome fruit, outdoor landscape and outdoor nursery ornamentals, and sm all fruit vine climbing except fuzzy kiwifruit for the treatment of powdery mildew.

The risk assessment identified several ecotoxicity and environmental fate data needs, which are
summarized in Table 1.2 Table 1. Ecological Effects and Environmental Fate Data Needs

Aquatic invertebrate life- cycle (freshwater) OPPTS 850.1300 Aquatic invertebrate life-cycle (saltwater) OPPTS 850.1350 Fish early-life stage (saltwater) OPPTS 850.1400 Aquatic plant growth (cyanobacteria and green algae) OPPTS 850.5400 Seedling emergence – Tier II for tomat o, cabbage, oat, and soybean OPPTS 850.4100 Chronic invertebrate whole sediment study using the TGAI (two freshwater species: a midge and an amphipod; one estuarine species: an amphipod)

Identification of VO C-2 from MRID 47620715

Additional characterization is provided below fo r each of the ecotoxic ity studies listed in Table
1 . Additionally, EPA has since received addition al information for consideration, specifically,
an OECD 219 sediment toxi city study using the midge, Chironomus riparius , tested using spiked
water as well as an acute toxi city study with the common carp ( Cyprinus carpio ). Although
there are several uncertainties associated with each of the previously iden tified ecological effects and environmental fate studies, based on the wei ght of evidence, EPA believes that risk to nontarget organisms is not expected for the propos ed uses. To confirm the conclusions reported in the previous ecological assessment, as well as the additional characterization presented in this memo, data are being requested as outlined below as confirmatory data.

Aquatic invertebrate life-c ycle (freshwater) OPPTS 850.1300

In the previous risk assessment (DP360841;366391) , chronic toxicity da ta for freshwater
invertebrates were not available as the submitte d study was classified as unacceptable due to excessive control mortality (MRID 47620704). The registrant submitted an additional chronic life-cycle toxicity test with Daphnia magna (MRID 48274002); however again, mortality in one of the control groups exceeded th e validity criteria. As such, as stand-alone studies, neither of these studies are adequate for use in a risk assess ment. However, when considered together, they present similar information on length, which is a sensitive endpoint . Given the current application rates and the calculated EECs, the NO AEC value of 0.0998 mg a.i./L (99.8 μg a.i./L) is approximately 217 times greater than the EEC. However, if in the future, an increase in application rate is proposed, then the use of this NOAEC value will need to be re-evaluated.

It does not appear that conducting an additional test would provide any added value for the risk assessment and therefore, the NOAEC for the da phnia chronic study of 0.0998 mg a.i./L can be used to assess the proposed uses. Th e MRID 48274002 study is classified as Supplemental

. Additionally, study #1 (MRID 47620704) will be upgraded to Supplemental . Further details of the review of these two studies are pres ented in the DER memo for 48274002 and the DER
addendum for 47620704.3 Aquatic invertebrate life-c ycle (saltwater), OPPTS 850.1350

Chronic toxicity data for estuarine-marine (saltw ater) invertebrates are no t available. Based on the risk assessment, acute risk to estuarine-marine invertebrates is not expected. The method of applying an acute-to-chronic ratio (ACR), using data from freshw ater invertebrates to estimate
chronic estuarine-marine toxi city cannot be used here as there was less than 50% immobility/mortality observed in the daphnia acute test, which was conducted at or above the limit of solubility (EC 50 > 1.73 mg a.i. (total)/L; 15% immobility at this concentration). As stated above, the NOAEC for the chronic freshwater invertebrates is 0.0998 mg a.i./L which is approximately 217 times greater than the chronic EEC. The acute EC/LC 50 values for estuarinemarine invertebrates are 0.16 mg a.i./L (160 μg a. i./L) (oyster) and 0.64 mg a.i. (total)/L (640 μg a.i. (total)/L) (mysid shrimp) which suggests that estuarine-marine invert ebrates appear to be
more sensitive than freshwater invertebrates on an acute basis. There is uncertainty in the mysid acute value as the study was conducted at the appare nt limit of solubility and did not measure the
dissolved fraction. For a chronic LOC exceedan ce for estuarine-marine invertebrates, the chronic toxicity NOAEC would have to be 0.46 μg a.i./L or lower which is approximately 348
times lower than the lowest acute estuarine-marine toxicity value. Given the magnitude between the EECs and the necessary chronic toxicity value for estuarine-marine invertebrates, as well as the observed differences for the chronic daphnia value and EECs, chronic risk to estuarinemarine invertebrates is not e xpected for the proposed uses.

Fish early-life stage (E LS) (saltwater), OPPTS 850.1400

Chronic (ELS) toxicity data for estuarine-marine (saltwater) fish are not available. The ACR approach, as described above, may also be used to estimate chroni c toxicity to estuarine-marine fish. Typically, the ACR is calculated using the acute and chronic freshwat er fish studies from the same species but there are no available acute toxicity study conducted on the fathead minnow, nor was a chronic rainbow trout study ava ilable. Additionally, the actual toxicity is
uncertain for the effects observed in the chroni c freshwater fish study because endpoints were based on total cyflufenamid (both dissolved and undissolved); the chronic NOAEC for the fathead minnow is 0.2 mg a.i. (total)/L (200 μg a.i.(total)/L) based on survival. However, to exceed the chronic LOC, the chronic NOAEC value fo r freshwater and/or estuarine-marine fish would have to be 0.22 μg a.i./L which is 913 times lower than the current chronic NOAEC for fathead minnow (based on total cyflufenamid concentrations). Acute toxicity values were
available for three freshwater fish (rainbow trout, bluegill an d common carp) and the estuarinemarine sheepshead minnow ( Table 2 ). Based on the available data, the LC 50 for warmwater fish appears to be greater than the limit of solub ility, and therefore testing the warmwater fathead minnow may also result in a non-definitive LC 50 value, which would preclude the ability to
conduct an ACR evaluation. In a ddition, as there was no mortality at the limit of solubility for sheepshead minnow, a comparison of toxicity to freshwater fish cannot be made. However, given the large difference between the observed toxicity in the chronic fathead minnow study and the EEC as well as the observed toxicity fo r warmwater fish, the un certainty in not having estuarine-marine chronic toxicity data is likely a minor issue in the overall risk conclusions for the proposed uses.4 Table 2 . Acute toxicity values for fish for cyflufenamid

Species LC 50 (mg a.i./L) MRID Comments

Rainbow trout 1.04 47620626 Acceptable

Bluegill sunfish >1.2 47620625 Supplemental due to
inversion of test concentrations; no mortality at highest concentration

Common carp >0.968 48715502 Preliminary review; no mortality at highest
concentration

Sheepshead minnow >0.20 47670702 Acceptable; no mortality at highest concentration
` Aquatic plant growth (cyanobacte ria and green algae), OPPTS 850.5400

Direct effects to non-vascul ar aquatic plants may result in indi rect effects to other taxa as an impact to their food source and/or habitat. Currently, there ar e no Federally listed nonvascular plant species.

As stated in the risk assessment, based on avai lable data, the RQs (based on toxicity to the freshwater diatom, Navicula ) for listed aquatic plants do not exceed the LOC for any of the proposed uses. For evaluation to non-listed plants, given that the available data resulted in no effect at the limit concentration (the EC 50 is a greater than value), RQ values were not calculated. However, the EECs for the proposed uses ( ≤ 0.85 ug ai/L) are at least 316 times less than the
limit concentration for Navicula (269 ug ai/L). Acceptable toxicity data were not available for two of the four required species ( i.e., cyanobacteria and green algae studies) and there was uncertainty about toxicity in the Skeletonema study because the measured concentrations are based on total (dissolved and undi ssolved) cyflufenamid and so toxicity may be underestimated.
In addition there is no available information on th e mode of action for this pesticide which could
be used to make inferences about toxi city to other alga l species from the Navicula and
Skeletonema studies. The submitted cyanobacteria a nd green algae studies were unacceptable because the use of a solvent may have promoted growth and therefore potentially mask effects of cyflufenamid. For the green algae, the promo tion of growth in the solvent control was 11% compared to the negative control. Based on the reported green algae NOAEC = 1.4 mg a.i./L (1,400 μg a.i./L) and the EEC (0.85 μg a.i./L), th e observed promotion of growth will likely not
influence the overall conclusions for non-vascul ar plants. For the cy anobacteria study, the reported NOAEC was 0.245 mg a.i./L (245 μg a.i. /L) which is approximately 288 times greater than the EEC. However, in this study, an ca. 70% promotion of growth was observed in the
solvent control and the dose-res ponse curve for the treatment groups is an inverted U-shaped curve (typically a relatively straight-line is optimal ), therefore it is difficu lt to make any adequate inferences about this study in relation to the EECs.

Evaluation of non-vascular aquatic plants is used to evaluate potential aquatic community effects due to a potential change in food source or habitat parameters. Based on the evaluation above, it appears that for three of the f our required test species, pote ntial direct adverse risk to non-5 vascular aquatic plants is notlikely. However, given the di fficulties in interpreting the cyanobacteria study, this study is re quested to confirm that there is no direct risk to non-vascular plants.

850.4225 - (referred to as 850.4100 in assessme nt which is Tier I study) Seedling Emergence, Tier II for Tomato, Cabbage, Oat, Soybean

As stated in the assessment, risk to non-listed terrestria l plants is not expect ed. In addition, risk to listed plants is also not expected ba sed on the vegetative vigor study (MRID 47620710) and six of the 10 requested plant species fo r the seedling emergence study (MRID 47620709). However, this assessment of risk to listed terres trial plants is based on an incomplete dataset. For the seedling emergence study, a NOAEC or EC 05 was not established for four plant species ( i.e ., tomato, cabbage, oat and soybean), and ther efore a Tier II seed ling emergence study was requested for these species to establish a NOAEC or EC 05 . In the seedling emergence study, two
concentrations were tested at application rates 1.6 to 2 times higher than the maximum proposed application rate, however, a dose- response relationship was not observed for all species, which makes it harder to make inferences about potential effects in relation to exposure concentrations.
The NOAEC or EC 05 is used to evaluate risk to listed te rrestrial plants and in turn any potential indirect effects to other taxa based on an oblig ate/dependant relationship to a listed plant. Overall, based on the available data, risk to listed plants is not expected, however, this conclusion is based on an incomplete dataset and data for the four remaining plant species are requested to confirm that listed plants are not expected to be at risk.

Chronic invertebrate whole sediment studies : (two freshwater species: a midge and an amphipod; one estuarine species: an amphipod)

Based on the fate and physical properties of cyfl ufenamid, it has the poten tial to bind to sediment and be persistent in the aquatic environment. A comparison of availabl e aquatic invertebrate acute toxicity data (i.e., EC 50 >1.73 mg a.i./L, Daphnia magna and LC 50 = 0.65 mg a.i./L, mysid shrimp, 0.16 mg a.i./L, Eastern oyster) to the sediment pore water peak EEC (0.132 μg/L) indicates that the pore water EEC is at least 1,200 times lowe r than the acute water-column toxicity data. A comparison of the chronic Daphnia NOAEC value (0.0998 mg a.i./L) to the 21- day pore water EEC (0.129 μg/L) indicates that the EEC is ca. 770 times lower than the chronic
value.

The registrant submitted a 28 day sediment invertebrate study using the midge, Chironomus riparius, which followed OECD Guideline 219, us ing spiked water (MRID 48715502). There were effects on emergence and developmental rate and time at the highest concentration tested (0.67 mg a.i./L, overlying water; 0.036 mg a. i./L, pore water; 7.64 mg/kg, sediment). The NOAEC was 0.37 mg a.i./L overlying water a nd 0.036 mg a.i./L pore water and 8.8 mg/kg sediment. This NOAEC value is expected to be an overestimation for the pore water and sediment concentrations as analytical measurem ents over the 28 day test period in the high and low treatment groups showed an increase (partitioning) to the se diment and pore water; however, pore water and sediment were only analyzed on Da y 28 for the other test concentrations, which
includes the concentration used to establish the NOAEC. In a ddition, per the test protocol, 20 immature midges were to be placed into each te st vessel; however, emergence of more than 206 organisms was observed for many of the vessels w ith numbers ranging from 21 to 27. Therefore, there is uncertainty in determining an effect on percent emergence if there is uncertainty in the actual number of organisms exposed. A comparison of the pore water NOAEC to the pore EEC (36 vs. 0.129 μg a.i./L) shows that the EEC is ca. 280 times lower than the NOAEC; this suggests risk may be low to Chironomus sp.

The original request for sediment toxicity data in the risk assessment asked for data on two freshwater organisms ( Chironomus tentans and Hyallela azteca ) and an estuarine-marine organism ( Leptochirus plumulosus ). If the results of the midge study above are representative of the Chironomus sp. sensitivity, then further testing with this Genus is not necessary. Also based on the results of the acute and chronic Daphnia a nd the sediment midge test, chronic testing may not be the appropriate first ste p. Therefore, a tiered approach is now recommended. It is recommended that first acute toxicity to the othe r two requested species be conducted to evaluate their sensitivity compared to the water column i nvertebrate and midge toxi city data, as well as a predicted EECs. Studies could be conducted following the 850.1020 acute amphipod guideline.
If it is deemed that further tes ting is warranted, then the next step may be to conduct subchronic testing using guidelines OPPT S 850.1735 and 850.1740 and then again evaluate to determine if further testing is warranted. However, if it is believed that chronic testing would be more suitable after analysis of the acute data, then go ing straight to chronic testing may be requested.