Crop Application Rate lbs a. i./ A # app / interval, days Application method Emergence RQs Adjacent Areas1 Emergence RQs Semi aquatic Areas2 Drift RQs3 Monocot Dicot Monocot Dicot Monocot Dicot Corn 2 ( 1 / NA) Ground spray 2.40 > 60.0 20.4 > 510 0.4 > 3.3 Pineapple max 7.2 ( 1 / NA) Ground spray 8.6 > 216 73.4 > 1836 1.4 > 12.0 Sugarcane FL 1.2 ( 3 / 30) Ground spray 1.4 > 36 12.2 > 306 0.24 > 2.0 Aerial 1.9 > 8 8.4 > 210 1.2 > 10 HI 7.2 / 2.4 / 2.4 ( 3 / 30) Ground spray 8.6 > 16 73 > 836 1.4 > 12.0 Aerial 11.5 > 288 50.4 > 1260 7.2 > 60 LA 2 / 2.4 ( x4) ( 5 / 30) Ground spray 2.4 > 60 20.4 > 510 0.4 > 3.3 Aerial 3.2 > 80 14 > 350 2.0 > 16.7 PR 8 / 4 ( x2) ( 3 / 30) Ground spray 9.6 > 240 81.6 > 2040 1.6 > 13.3 Aerial 12.8 > 320 56.0 > 1400 8 > 66.7 TX 2 ( 3 / 30) Ground spray 2.4 > 60 20.4 > 510 0.4 > 3.3 Aerial 3.2 > 80 14.0 > 350 2.0 > 16.7 1 RQ = EEC/ Seedling Emergence NOAEC 2 RQ = EEC/ Seedling Emergence NOAEC 3 RQ = Drift EEC/ Vegetative Vigor NOAEC Also, 26 aquatic plant records report short term photosynthesis inhibition toxicity tests on various species of algae and diatoms with an EC 50 range of 10 to 135 µ g/ l. While these data are useful in characterizing potential non target effects of ametryn, none of the reported endpoints were as sensitive as the guideline study with the green algae, Pseudokirchneriella subcapitatum. However, the EC 50 values in many of these studies are well below the concentrations of ametryn that could be expected in surface water as modeled with PRZM EXAMS in both corn and sugarcane ( peak EEC range: 78   844 ppb). 53 Nontarget Aquatic Animals Surface water concentrations resulting from ametryn application to corn in North Carolina and sugarcane grown in Florida and Louisiana were predicted with the Tier II models PRZM EXAMS. Peak EECs were then compared to acute toxicity endpoints to derive acute risk quotients. The 21 day EECs were compared to chronic toxicity endpoints ( NOEC) to derive chronic risk quotients for freshwater invertebrates and 60 day EECs were compared to chronic toxicity endpoints for freshwater and estuarine/ marine fish ( Table 33). This risk assessment does not estimate risk to benthic organisms since no benthic invertebrate toxicity study was submitted to the Agency for ametryn.

For the current application rates modeled on corn in North Carolina and sugarcane in Florida and Louisiana where ametryn is applied, acute RQs for both freshwater fish and invertebrates were generally lower than the chronic RQs. Both sugarcane uses exceeded the acute endangered species LOC for freshwater fish. Chronic LOCs are exceeded for freshwater invertebrates in the Florida and Louisiana scenario and also fish in the Louisiana scenario. Acute RQ values ranged from 0.02   0.23 for freshwater fish and from 0.003  0.03 for freshwater invertebrates. Chronic RQ values ranged from 0.11   1.15 for freshwater fish and from 0.32   3.38 for freshwater invertebrates.

Table 33. Acute and chronic risk quotients for freshwater fish and invertebrates exposed to ametryn.

Crop Application Seasonal Rate (# of apps) EECs Acute Risk Quotients Chronic Risk Quotients Peak / 21 day Average 60 day Average ( µ g/ L) Freshwater Fish a LC 50 = 3600 µ g/ L Freshwater Invertebrateb LC 50 = 28000 µ g/ L Freshwater Fish a NOEC = 700 µ g/ L Freshwater Invertebrateb NOEC = 240 µ g/ L NC corn ( east) 84 82 80 0.02     0.003         0.11   0.34   NC corn ( west) 78 77 75 0.02     0.003         0.11   0.32   FL sugarcane 3.6 ( 3) 309 302 295 0.09e     0.01         0.42   1.2f   LA sugarcane 11.6 ( 5) 792 759 755 0.22d     0.03         1.1f   3.2f

a Rainbow trout ( Oncorhynchus mykiss) b Water flea ( Daphnia magna) c exceeds acute risk ( RQ

0.5), restricted use ( RQ

0.1) and endangered species level of concern ( RQ

0.05) d exceeds acute restricted use ( RQ

0.1) and endangered species level of concern ( RQ

0.05)

e exceeds acute endangered species level of concern ( RQ

0.05) f exceeds chronic level of concern ( RQ

1.0)

Acute endangered species LOCs for estuarine/ marine fish and invertebrates were exceeded in the Florida and Louisiana sugarcane ( Table 34). No data have been supplied by the registrant 54 demonstrating chronic toxicity for estuarine/ marine fish and invertebrates. Additionally, estuarine/ marine fish and invertebrates appeared to be similarly sensitive to ametryn when compared with their freshwater counterparts. As with the freshwater animals, both sugarcane uses exceeded the acute endangered species LOC for both acute estuarine/ marine fish and invertebrates. Acute RQ values ranged from 0.01   0.15 for estuarine/ marine fish and from 0.03  0.37 for estuarine/ marine invertebrates.

Table 34. Acute and chronic risk quotients for estuarine/ marine fish and invertebrates exposed to ametryn.

Crop Application Rate (# of apps) EECs Peak / 21 day Average 60 day Average ( ug/ L) Acute Risk Quotients Chronic Risk Quotients Estuarine/ marine Fisha LC 50 = 5800 µ g/ L Estuarine/ marine Invertebrateb LC 50 = 2300 µ g/ L Estuarine/ marine Fisha NOEC = 250 µ g/ Lg Estuarine/ marine Invertebrate NOEC = 20 µ g/ Lg NC corn ( east) 2 ( 1) 84 82 80 0.01     0.04         0.32   4.1f _

NC corn ( west) 2 ( 1) 78 77 75 0.01     0.03         0.3   3.9f _

FL sugarcane 1.2 ( 3) 309 302 295 0.05e     0.13d         1.2f   15.0f _

LA sugarcane 2.4 ( 5) 792 759 755 0.14d     0.34d         3. f   38.0f _

a Sheepshead minnow ( Cyprinodon variegatus) b Mysid shrimp ( Mysidopsis bahia) c exceeds acute risk ( RQ

0.5), restricted use ( RQ

0.1) and endangered species level of concern ( RQ

0.05) d exceeds acute restricted use ( RQ

0.1) and endangered species level of concern ( RQ

0.05) e exceeds acute endangered species level of concern ( RQ

0.05) f exceeds chronic level of concern ( RQ

1.0) g calculated value based on the assumption that the acute to chronic toxicity ratio for estuarine/ marine fish or invertebrates would be similar to that for freshwater fish or invertebrates There were no chronic toxicity studies available to assess the chronic toxicity of ametryn to estuarine/ marine fish or invertebrates. An estimated NOEC value of 250 ppb was derived for estuarine/ marine fish based on the assumption that the acute to chronic NOEC ratio for estuarine/ marine fish is the same as that for freshwater fish. Similarly, an estimated NOEC value of 20 ppb was derived for estuarine/ marine invertebrates based on the assumption that the acute to chronic NOEC ratio for estuarine/ marine invertebrates is the same as that for freshwater invertebrates. There is uncertainty associated with extrapolation from freshwater to estuarine/ marine chronic NOEC values, because quantifiable taxonomic sensitivity factors between the two broad categories of aquatic organisms do not exist. Chronic risk quotients calculated with these extrapolated toxicity endpoints suggest the potential for chronic risk to estuarine/ marine fish and invertebrates. The chronic risk quotient for 55 estuarine/ marine fish in the Florida sugarcane scenario equal to the LOC of 1.0, and the RQ of 3.2 for Louisiana sugarcane exceeds this LOC. Chronic risk quotients for estuarine/ marine invertebrates exceed the chronic LOC for all four corn and sugarcane scenarios, with an RQ range of 3.9 to 40.6.

Nontarget Aquatic Plants Surface water concentrations resulting from ametryn application to corn grown in North Carolina and sugarcane grown in Florida and Louisiana were predicted with the Tier II models PRZM EXAMS. Peak EECs were then compared to acute EC 50 and NOAEC toxicity endpoints to derive acute nonendangered and endangered species RQs, respectively. Acute non endangered and endangered species RQs for aquatic vascular and non vascular plants are summarized in Table 35. Acute non endangered RQs exceed the LOC for both vascular and non vascular plants ( RQ range: 8   84 ( vascular) and 21   230 ( non vascular)) in both the corn and sugarcane scenarios. There was no registrant submitted data for aquatic vascular plants; however, there were two records in the ECOTOX database that reported 7 day EC 50 ( a similar test to the registrant submitted non vascular plant study) endpoints of 10 and 52 µ g/ l for the vascular species of duckweed Lemna perpusilla and Spirodela polyrhiza, respectively. No NOAEC was reported. EFED used the Lemna perpusilla study ( EC 50 = 10 µ g/ l) to calculate an acute non endangered RQ for vascular plants. Acute endangered species RQs for nonvascular plants also exceed the LOC ( RQ range: 68   740).

Table 35. Acute non endangered and endangered species risk quotients for aquatic vascular and nonvascular plants exposed to ametryn.

Crop Application Rate (# of apps) EECs Acute Non Endangered Risk Quotients Acute Endangered Species Risk Quotients Peak ( µ g/ L) Vascular planta EC 50 = 10 µ g/ L Non vascular plantb EC 50 = 3.67 µ g/ L Vascular plant Non vascular plantb NOAEC = 1.14 µ g/ L NC corn ( east) 2 ( 1) 84 8c 23c   74c NC corn ( west) 2 ( 1) 78 8c 21c   68c FL sugarcane 1.2 ( 3) 309 31c 84c   271c LA sugarcane 2.4 ( 5) 792 79c 216c   695c a Duckweed ( Lemna perpusilla), from ECOTOX online database, reference # 8628, Liu, L. C., and A. Cendeno Maldonado, 1974, Effects of Fluometuron, Prometryne, Ametryne, and Diuron on Growth of Two Lemna Species, J. Agric. Univ. P. R. 63( 4): 483 488 b Green alga ( Selenastrum capricornutum) c exceeds acute risk ( RQ

1.0) and endangered species level of concern ( RQ

1.0)

RISK DESCRIPTION 56 Based on the results of the screening assessment described above, the use of ametryn on corn, sugarcane and pineapple poses a risk to non target terrestrial and aquatic plants. The predicted amount of exposure from drift alone would be greater than the amount which caused complete mortality for the most sensitive terrestrial plants tested in the seedling emergence study. The predicted amount of exposure also exceeded the amount of ametryn in the laboratory studies that caused reductions in dry weight in all test subjects of the most sensitive plant tested. This level of effect could potentially lead to risk to plant communities, and subsequent indirect effects to endangered herbivores. These levels of exposure extend to different distances from the treated field for the different ametryn use crops, but are predicted for all crops modeled.

Expected environmental concentrations ( EECs) in the screening assessment exceed acute levels of concern for mammals for all ametryn labeled uses. A 2 generation rat reproduction study resulted in a chronic NOAEL of 13 mg/ kg/ day, based on reduction in growth in the F2 generation. RQs exceed chronic LOCs for all feed items for all uses of ametryn ( RQ range = 2.3 to 160). A rat carcinogenicity study resulted in a NOAEL of 21 mg/ kg/ day, based on decreased body weights and gain effects and also histological changes in the testes, kidney and pituitary in males and in the liver and pancreas in females. The effects in the males indicate a potential for effects on organs involved in the endocrine system. Risk quotients calculated with the NOAEC from this study would also exceed chronic LOCs for all feed items for all uses of ametryn.

The potential for chronic risk to birds is indicated for all ametryn crops, based on the risk quotients described in the Risk Estimation section. However, because of the wide range of application rates for these crops, the certainty in this finding of risk is different for the different use scenarios. For instance, the chronic LOC for corn is exceeded for only the short grass feed item, and refinement of the exposure estimate with foliar dissipation data for ametryn could possibly bring the risk quotient of 1.6 below the LOC. The use of ametryn on sugarcane in Hawaii and Puerto Rico, however, would result in exceedence of the LOC at rates below those suggested on the product label.

The screening assessment for aquatic organisms indicated a possible chronic risk to freshwater invertebrates and endangered species concerns for freshwater fish from the use of ametryn on sugarcane. Due to the very different hydrology of the different sugarcane use areas, there is uncertainty that these risks extend beyond Florida and Louisiana, the scenarios modeled in the assessment. In addition, surface water monitoring in Florida, while not sufficiently extensive to establish potential acute concentrations, did not result in concentrations approaching those predicted by the model.

As described in the Exposure Characterization, there is some uncertainty in the results of the aquatic EECs since there are not sufficient data available describing the persistence of ametryn. As shown in Table 5, the aerobic soil metabolism half life used in the modeling was derived by multiplying the single available half life by a factor of three ( approximating the 90th percentile on the mean). Since aerobic aquatic metabolism data are not available for ametryn, the default model input was derived by multiplying the aerobic soil metabolism input by a factor of two. The resulting half lives used in the EEC modeling were 252 and 504 days, respectively. 57 Since outflow is not simulated from the standard pond as it is for the index reservoir for estimated drinking water concentrations, these long half lives result in an accumulation of ametryn in the standard pond over the 30 year simulation. Additional data on the aerobic soil metabolism and aerobic aquatic metabolism of ametryn would allow modeling of possible concentrations without the use of default input parameters for ametryn persistence. If the submitted half lives are shorter than the calculated default values, the predicted aquatic EECs could be significantly lower, and risk quotients might not exceed the LOCs as described in the Risk Estimation.

The surface water EECs derived with PRZM EXAMS are meant not only to represent the specific scenarios simulated, but to be screening assessment surrogates for ametryn crops in other states for which standard scenarios have not been developed. The EECs from the Florida and Louisiana sugarcane scenarios are recommended as screening surrogates for sugarcane in Texas and Hawaii, and for pineapple in Hawaii and Puerto Rico, since the higher concentrations from these scenarios make them more conservative surrogates than the corn scenarios, and because the high rainfall weather data for Louisiana and Florida should be better surrogates for Hawaii and Puerto Rico than data from North Carolina. There is some uncertainty involved with using individual scenarios as surrogates for crops in other parts of the nation, but the application rates on sugarcane in Texas are similar to those in Louisiana and Florida, and the rates on sugarcane or pineapple in Hawaii or Puerto Rico are significantly higher ( see Appendix A).

Risk to Terrestrial Organisms Risk To Terrestrial Plants The screening level assessment described above indicates a potential risk to plants at application rates well below those described on ametryn product labels. In fact, application rates as low as 0.4 lb ai/ acre ( lettuce) in the laboratory studies resulted in total test subject mortality. As a result, risk quotients calculated for exposure through spray drift and runoff, and from spray drift alone, exceed the LOC to a degree that mitigation of the risk could be difficult for some uses.

Refined exposure estimates with the spray drift model AgDrift give a better indication of the potential risk to plants. Tier 1 estimates of drift indicate the exposure that could be expected at varying distances from a treated field. ( see Tables 15 and 16). The greatest exposure should occur from application to sugarcane, which is the only crop for which aerial application is allowed on the label. Under the Tier 1 aerial application scenario for sugarcane in all five use states, the buffer distance that would be necessary to reduce spray drift to the EC25 for the most sensitive test plant in the vegetative vigor studies ( lettuce) is beyond the 999 ft limit in AgDrift.

Ametryn exposure from spray drift would pose a greater risk closer to sugarcane fields treated by aerial spray. Mortality would occur at both 4 and 8 lb ai/ acre. Table 36 details the distance from the edge of treated fields at which cabbage ( 1.0 lb ai/ acre), cucumbers ( 0.5 lb ai/ acre) and lettuce ( 0.4 lb ai/ acre) would be predicted to receive a dose equivalent to the lowest dose observed to cause mortality in all test subjects in the seedling emergence laboratory study.

These distances from the treated field were calculated from predicted spray drift for a single application only. If plants beyond these zones were to be exposed to ametryn through runoff or 58 drift from later treatments as well, the damage could be extended out further. If non target plants of similar sensitivity to cabbage, cucumbers or lettuce reacted similarly to the reaction of these crops in the laboratory, community effects might be possible which could alter the assemblage of plants adjacent to sugarcane fields. It is possible that complete mortality would not even be necessary for certain types of plants to be out competed by other less sensitive plants. In such an instance, these effects might occur at distances greater than that shown in the table below.

Table 36. Distance From Edge of Field ( feet) at which Ametryn ( lb ai/ acre) Would be Deposited at Rates which Caused 100% Mortality of Cabbage, Cucumbers and Lettuce in the Seedling Emergence Test Crop ( State) Max. Single Application Rate lbs. a. i./ A Maximum Distance From Edge of Field ( feet) at Which Ametryn Might Cause 100% Plant Mortality in Indicated Crop Cabbage Cucumber Lettuce Sugarcane ( FL) 1.2  7 13 Sugarcane ( HI) 7.2 69 138 171 Sugarcane ( LA) 2.4 7 30 56 Sugarcane ( PR) 8 75 154 184 Sugarcane ( TX) 2  23 33 Refined exposure estimates indicate that ametryn exposure from ground application would also exceed terrestrial plant LOCs far from treated fields sugarcane, corn and pineapple ( see Table 37). As shown below, spray drift exposure equal to the most sensitive EC 25 values calculated from the vegetative vigor and seedling emergence studies would be deposited hundreds of feet away from treated fields. The first distance shown for each scenario is that calculated by the Tier 1 terrestrial model assuming a very fine to fine spray. The values in parentheses which follow are calculated simulating fine to medium/ coarse droplets. For most scenarios, deposition equivalent to the toxicity endpoints would still be predicted hundreds of feet from the field in spite of the larger droplet size.

Table 37. Distance From Edge of Field ( feet) at which Ametryn ( lb ai/ acre) Would be Deposited at Rates Equal to the Most Sensitive EC25 Values for Vegetative Vigor and Seedling Emergence Crop ( State) Max. Single Application Rate lbs. a. i./ A Distance From Edge of Field ( ft) at Which Rate of Ametryn ( lb ai/ acre) Would be Deposited Equal to Tox Endpoint 0.002 lb ai/ acre 0.006 lb ai/ acre Sugarcane ( FL) 1.2 620 ( 351) 207 ( 85) Crop ( State) Max. Single Application Rate lbs. a. i./ A Distance From Edge of Field ( ft) at Which Rate of Ametryn ( lb ai/ acre) Would be Deposited Equal to Tox Endpoint 0.002 lb ai/ acre 0.006 lb ai/ acre 59 Sugarcane ( HI) 7.2 > 1000 (> 1000) > 1000 ( 741)

Sugarcane ( LA) 2.4 > 1000 ( 741) 423 ( 217)

Sugarcane ( PR) 8 > 1000 (> 1000) > 1000 Sugarcane ( TX) 2 971 ( 614) 351 ( 171)

Corn 2 971 ( 614) 351 ( 171)

Pineapple 7.2 > 1000 (> 1000) > 1000 ( 741)

If seeds of sensitive plants fail to emerge, or if a sufficient number of plants are damaged within a swath hundreds of feet from treated fields, community structure among those plants could change. Recent research on the effects of herbicides or herbicides plus fertilizer on plant community structure provide some evidence of this possibility ( Kleijn and Snoeijing, 1997 and Jobin, et al, 1997). A comparative study of the flora of hedgerows and woodland edges in southern Quebec, for instance, found a relatively greater proportion of annual and introduced species near fields that had recently been treated with herbicides in comparison to non cropped land, which had a higher proportion of native and perennial species ( Jobin, et al, 1997). The reduction of diversity within a plant community, either by direct damage or decreased ability to compete, could result in a loss of feed or habitat for endangered terrestrial animals.

The risk to non target terrestrial plants in much of the EAA in Florida appears to be reduced by the density of agriculture within most of this area. The percent cropped area in the EAA is nearly 100%, with non crop terrestrial plants located predominantly along the edges of drainage canals. The main risk would occur along the borders of wildlife preserves abutting the EAA. Spray drift from adjacent cropland could result in exposure of non target terrestrial plants in these areas.

The registrants of ametryn suggest mitigation measures that would help reduce exposure from aerial application to sugarcane. The labels state:

In order to assure that spray will be controllable within the target area when used according to label directions, make applications at a maximum height of 10 ft., using low drift nozzles at a maximum pressure of 40 psi, and restrict application to periods when wind speed does not exceed 10 mph. To assure that spray will not adversely affect adjacent sensitive nontarget plants, apply ( ametryn, eg Evik DF) alone by aircraft at a minimum upwind distance of 800 ft from sensitive plants, or apply ( a tank mix, eg Evik DF + Karmex) at a minimum upwind distance of 500 ft. from sensitive plants.

If sugarcane growers were to follow these recommendations, then both spray drift and runoff to adjacent fields would be reduced. However, the spray drift model AgDrift indicates that spray drift 60 to adjacent fields would still result in exposure above LOCs. Using default values for droplet size and wind speed in a Tier 1 assessment, but including an 800 ft buffer, results in an exposure through spray drift above the LOCs for both endangered and non endangered plants. As described above, the buffer distance that would be necessary to reduce spray drift to the EC25 for the most sensitive test plant in the vegetative vigor studies ( lettuce) is beyond the 1000 ft limit in AgDrift.

Even if spray drift were to be reduced to the point that spray drift alone would not exceed plant LOCs, runoff from field treated with ametryn could still be a concern. However, the likelihood of runoff from treated field to adjacent is different for each of the crop scenarios. For instance, the direction and amount of water flow is regulated by pumping water in and out of drainage canals in the Florida sugarcane areas, both for flood control and to depress the water table below the fields. When runoff is transported from sugarcane fields in Florida and Louisiana, however, it is dominantly captured in edge of field ditches and canals. This would greatly reduce the potential for the movement of runoff as sheet flow through adjacent non crop areas.

The discussion above also applies to risk to non endangered plants, for which EECs are compared to EC 25 values. Risk to endangered species is estimated by comparison to EECs to the NOAEL or EC 05, which were not determined for the most sensitive species tested. Since the spray drift data described above indicates that exposure above the non endangered LOC would occur hundreds of feet from fields treated with ametryn, and beyond the capacity of AgDrift to predict for aerial application to sugarcane, the endangered species is exceeded by default to an even greater, but unknown distance from the treated field.

Risk to Birds and Mammals Acute risk Ametryn is practically non toxic to birds on an acute exposure basis. Although 20 to 30% mortality was observed in the acute oral toxicity test ( LD 50 > 2250 mg/ kg bw), no mortality was observed in the subacute dietary toxicity study at the highest concentration tested. ( LC 50 > 5620 ppm). Mortality might occur at higher concentrations than that required by the guidelines. Based on the results of these studies, however, risk quotients are presumed not to exceed LOC's.

Ametryn is slightly toxic to mammals on an acute exposure basis, with an acute LD 50 for rats of 1162 mg/ kg diet. However, the maximum application rates are sufficiently high to result in RQs above acute risk LOCs for some crops, and endangered species LOC exceedences for other crops. Acute and acute endangered species LOCs for 15g and 35 g mammals are exceeded at maximum rates for pineapple and sugarcane in Hawaii, Louisiana, Puerto Rico and Texas. In addition, endangered species LOCs are exceeded for 15g and 35g mammals for the corn use, and for 1000g mammals at maximum application rates for pineapple and sugarcane in Hawaii, Louisiana, Puerto Rico and Texas. The acute restricted use LOC of 0.2 is exceeded for some feed items for all ametryn use crops.

Chronic Risk 61 The potential for chronic risk to birds is indicated for all ametryn treated crops. However, because of the wide range of application rates for these crops, the certainty in this finding of risk is different for the different use scenarios. For instance, the chronic LOC for sugarcane in Florida is exceeded for only the short grass and broadleaf feed items, with a maximum risk quotient of 1.78. If ametryn specific data were to indicate a foliar dissipation half life of 5 days or less ( instead of the default 30 days), these risk quotients would be below levels of concern. On the other hand, peak risk quotients for use on sugarcane at maximum rates in Hawaii and Puerto Rico exceed the chronic LOC for a single application; the risk quotients would exceed the LOC regardless of the foliar dissipation half life simulated.

The potential for chronic risk to mammals is also indicated for all ametryn treated crops. However, unlike the results of the screening assessment for birds, the chronic LOC for mammals exceeded on all feed items for all ametryn uses. In addition, the range of the RQ values ( 2.3 to 160) is greater than that for birds; refinement of the exposure estimate with foliar dissipation data for ametryn will not bring RQ's below the chronic LOC. The estimated concentrations from a single application at the 1.2 lb ai/ acre rate for Florida sugarcane range from 18 to 288 ppm, all of which result in risk quotients above the LOC.

Endocrine Disruption Potential Based on results of the chronic avian studies, ametryn may have the potential to affect endocrine disrupting processes in exposed animals. EPA is required under the FFDCA, as amended by FQPA, to develop a screening program to determine whether certain substances ( including all pesticide active and other ingredients) " may have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or other such endocrine effects as the Administrator may designate." Following the recommendations of its Endocrine Disruptor Screening and Testing Advisory Committee ( EDSTAC), EPA determined that there was scientific basis for including, as part of the program, the androgen and thyroid hormone systems, in addition to the estrogen hormone system. EPA also adopted EDSTAC's recommendation that the Program include evaluations of potential effects in wildlife.

For pesticide chemicals, EPA will use FIFRA and, to the extent that effects in wildlife may help determine whether a substance may have an effect in humans, FFDCA authority to require the wildlife evaluations. As the science develops and resources allow, screening of additional hormone systems may be added to the Endocrine Disruptor Screening Program ( EDSP). When the appropriate screening and/ or testing protocols being considered under the Agency's EDSP have been developed, ametryn may be subjected to additional screening and/ or testing to better characterize effects related to endocrine disruption.

Risk to Aquatic Organisms Risk to Aquatic Plants Based on modeling of maximum application rates for corn in North Carolina, and for sugarcane in Florida and Louisiana, exposure to ametryn through runoff would pose a risk to aquatic plants. 62 The exposure scenario simulated by PRZM/ EXAMS does not represent the managed hydrology of Florida sugarcane fields very well. Although levees around some drainage canals in Florida would retard runoff to the canals under most circumstances, ametryn could be directly introduced to drainage canals by intentional pumping during rain events for flood control, or to maintain the minimum required depth to the water table.

PRZM/ EXAMS scenarios are not available for Hawaii sugarcane or pineapple. Sugarcane in Hawaii, however, is grown under conditions which would appear to favor runoff. The sugarcane is grown on sloping (> 2%), uneven terrain on the islands of Maui and Kauai. Sugarcane production on Oahu ceased after the 1996 season ( Klasner and Mikami, 2003). More than 90% of sugarcane in Hawaii is drip irrigated to supplement the 10 to 60 inches of rain which falls annually. Unirrigated sugarcane areas receive 60 to 100 inches of rain a year. Since runoff from the fields could erode the soil, runoff diversion ditches have been installed in most fields. Information on the water bodies which receive this diverted water would allow better characterization of potential risk to aquatic plants and animals.

Spray drift modeling indicates a potential for risk to aquatic plants from spray drift exposure alone, as well. The most sensitive species, the green alga Pseudokirchneriella subcapitatum, has a laboratory EC 50 of 3.67 µ g/ l. As shown in Table 10, predicted concentrations of ametryn in a pond or wetland 100 feet from a sugarcane field treated aerially would exceed that value for all use states ( except for Florida, where that concentration would be estimated to occur at a distance of 92 feet). Concentrations in a wetland 100 feet from a treated field would also exceed the duckweed ( Lemna perpusilla) EC 50 of 10 µ g/ l obtained from the ECOTOX database. Since the LOC for aquatic plants is 1.0, this means the RQ for duckweed would exceed the LOC at 100 feet.

The EC 50 for vascular plants is equivalent to the EC 99 level for nonvascular plants. That is to say, the concentration of 10 µ g/ l corresponds to the dose in the Selenastrum capricornatum study at which the green alga suffered a 99% inhibition in cell count. An 87% inhibition occurred at 5 ug/ l. As shown in Table 10, this suggests that drainage ditches within 50 feet of treated fields ( based on the pond scenario) or wetlands beyond 100 feet could suffer almost total reduction in aquatic plants as sensitive as the Pseudokirchneriella test species. If sensitive plants were damaged by spray drift ( and runoff) of ametryn, endangered fish species which feed on such plants could suffer indirect effects. Additional data would be needed, however, on the potential of aquatic plants to recover from the effects of ametryn exposure.

The exposure estimates are based on instantaneous mixing to a pond with a 208.7 feet width and 6.56 ft ( 2 m) depth, and a wetland with the same width, but a 0.49 ft depth. These estimates could be refined with specific information on the width and depth of water bodies most likely to occur near sugarcane fields in each state. The AgDrift Tier 1 aquatic drift assessment does not take partitioning to the soil into account, but duckweed and algae at or near the surface of the water bodies could be expected to be exposed to spray drift hitting the water body before a small portion of the ametryn is partitioned to bottom sediment.

The confidence in the risk for Florida and Louisiana is increased by the presence of drainage ditches throughout the sugarcane use areas, and of bayous and/ or wetlands in and around southern Louisiana and the Everglades Agricultural Area. Surface water bodies are quite likely to be within 63 100 feet of treated fields in these areas. However, the possible risk in Louisiana and Florida drainage ditches should be considered in the context of local needs; drainage ditches in these areas are also treated to remove native or invasive aquatic plants which could clog the ditches and make them less effective for irrigation, flood control, etc.. Nearby natural wetlands and wildlife preserves, however, could also potentially be exposed.

Confidence in the potential risk to aquatic plants via spray drift from application to sugarcane in Hawaii and Puerto Rico stems more from the magnitude of the predicted exposure, which is about 7 times the Pseudokirchneriella EC 50 in a pond at 100 feet, or about 100 times for a wetland located at 100 feet from the treated field. The potential for additional exposure of aquatic plants from runoff increases the likelihood of risk.

Estimated concentrations of ametryn in adjacent water bodies from ground spray applications are significantly less than those from aerial application to sugarcane, as shown in Table 11. Nevertheless, the predicted concentrations for a wetland 100 feet from the treated field exceeds the EC 50 for green algae for all uses evaluated. The estimated concentrations for a pond directly adjacent to a treated field also exceed the EC 50 for green algae ( except for Florida sugarcane), which suggests that aquatic plants in adjacent drainage ditches would also be vulnerable.

Risk to Estuarine/ Marine Species Acute risk quotients indicate and exceedence of the endangered species LOC for estuarine/ marine fish for sugarcane in Louisiana, and for endangered estuarine/ marine invertebrates for sugarcane in Louisiana and Florida. There were no chronic toxicity studies available to assess the chronic toxicity of ametryn to estuarine/ marine fish or invertebrates. However, as described above, chronic risk quotients as high as 3.2 for estuarine/ marine fish and 40.6 for estuarine/ marine invertebrates were estimated by assuming that the acute to chronic ratio in toxicity studies for freshwater organisms is the same for their estuarine/ marine counterparts.

Chronic risk quotients calculated with these extrapolated toxicity endpoints suggest the potential for chronic risk to estuarine/ marine fish and invertebrates. However, there is uncertainty associated with extrapolation from freshwater to estuarine/ marine chronic NOEC values, because quantifiable taxonomic sensitivity factors between the two broad categories of aquatic organisms do not exist.

In addition, since PRZM/ EXAMS simulates runoff to a standard freshwater pond, there is some uncertainty in the use of these estimated concentrations for comparison with estuarine/ marine toxicity endpoints. This may be less of a concern in Louisiana, where much of the drainage from sugarcane fields is directed to estuarine rivers and bayous. However, as described above, the exposure scenario simulated by PRZM/ EXAMS does not represent the managed hydrology of Florida sugarcane fields very well, and most of the water leaving the Everglades Agricultural Area travels into and through the freshwater Everglades.

Since PRZM/ EXAMS modeling was not performed for sugarcane or pineapple in Hawaii, it isn't clear whether the chronic or endangered species LOCs would also be exceeded for these uses. However, there are currently no endangered fish listed for the State of Hawaii. There are, in fact, only five native fish species in the State. These five species ( four goby species and an eleotrid) are 64 less common in Hawaii streams than introduced species, but are not listed as endangered. The native fish spend their juvenile stage in the Pacific Ocean, but return to freshwater to reproduce. Native aquatic invertebrates include two species of shrimp ( one estuarine), and " a few native snails" ( again, one estuarine) ( Oki and Brasher, 2003).

ENDANGERED SPECIES The Agency's levels of concern for endangered and threatened freshwater fish and invertebrates, estuarine/ marine invertebrates, aquatic vascular and non vascular plants, birds, mammals, and non target terrestrial and semi aquatic plants are exceeded for the uses of ametryn discussed in this assessment. Appendix I provides a list of endangered/ threatened species and crop acreage at the state level for the taxonomic groups and crops of concern. Table 38 summarizes the number of species listed in states where each crop is grown. The Agency recognizes that there are no Federally listed estuarine/ marine invertebrates/ mollusks. The registrant must provide information on the proximity of Federally listed endangered species to the ametryn use sites. This requirement may be satisfied in one of three ways: 1) having membership in the FIFRA Endangered Species Task Force ( Pesticide Registration [ PR] Notice 2000 2); 2) citing FIFRA Endangered Species Task Force data; or 3) independently producing these data, provided the information is of sufficient quality to meet FIFRA requirements. The information will be used by the OPP Endangered Species Protection Program to develop recommendations to avoid adverse effects to listed species.

Table 38. Endangered and threatened species summary for the use of ametryn on corn, pineapple and sugarcane. This summary is based on LOC exceedances from RQ calculations in each taxonomic grouping in this risk assessment.

Use State Total species listed Taxonomic Grouping Bird Mammal Plant Amphibian Fish Clam Corn Florida 61 9 10 42       Georgia 28 5 4 19       Illinois 13 3 2 8       North Carolina 39 6 6 27       Ohio 7 2 1 4       South Carolina 25 4 3 18       Texas 33 12 3 18       Wisconsin 10 3 1 6       Pineapple Hawaii 154 18 2 134       Sugarcane Florida 35 9 5 13 1 2 5 65 Hawaii 75 13 2 60       Louisiana 9 4 1     2 2 Texas 11 6 2 3       The preliminary risk assessment for endangered species indicates that ametryn exceeds the endangered species LOCs for the following combinations of analyzed uses and species. The results for aquatic species are based on modeling for corn in North Carolina and for sugarcane in Louisiana and Florida. Because of the LOC exceedances from these representative use scenarios, endangered fish and invertebrates associated with use of ametryn on pineapple, or on corn and sugarcane in other states, are also included in the analysis below:

! Avian " chronic  corn   short grass  pineapple   short grass, tall grass, broadleaf plants/ small insects  sugarcane   short grass ( all states), tall grass ( HI, LA, PR, TX), broadleaf plants/ small insects ( all states)

! Mammals " acute  corn   short grass, tall grass, broadleaf plants/ small insects for 15 and 35 g classes  pineapple   short grass, tall grass, broadleaf plants/ small insects for all weight classes  sugarcane   short grass, tall grass, broadleaf plants/ small insects for 15 and 35 g classes ( all states), short grass for 1000 g class ( HI, LA, PR, TX), tall grass for 1000 g class ( PR), broadleaf plants/ small insects for 1000 g class ( PR), fruits/ pods/ large insects for 15 g class ( PR)

" chronic   exceedances in all uses for all weight classes ( RQ range: 2.3   160)

! Terrestrial plants " adjacent   exceedances for all uses ( RQ range: 1.5   640)

" semi aquatic   exceedances for all uses ( RQ range: 12   4080)

" drift  exceedances for all uses with dicot species  exceedances for monocots in pineapple and sugarcane ( except ground spray in FL and TX)

! Freshwater fish and invertebrates " Fish: LA sugarcane " Invertebrates: sugarcane ( FL and LA)

! Estuarine/ marine fish and invertebrates " sugarcane ( FL and LA) 66 ! Aquatic plants " exceedances in corn and sugarcane INDIRECT EFFECTS Pesticides have the potential to exert indirect effects upon listed organisms. Herbicides, for example, can disrupt primary productivity in aquatic habitats through their effects on both nonvascular and vascular plants while their potential effects on terrestrial plants can alter riparian habitat along streams, etc.. Thus, both decreased food availability and destruction of habitat can result as indirect effects.

In conducting a screen for indirect effects, the Agency uses the direct effect LOCs for each taxonomic group to make inferences concerning the potential for indirect effects upon listed species that rely upon non endangered organisms in these taxonomic groups as resources critical to their life cycle. For ametryn, acute risk LOCs are exceeded for mammals ( RQ range: 2.3 to 160 ) across all uses evaluated. Chronic LOCs are exceeded for freshwater fish ( RQ: 1.15 for Louisiana sugarcane) and invertebrates ( RQ range: 1.08 to 3.38) at maximum application rates used on sugarcane.

Consistent with ametryn's intended use as a herbicide, the screening assessment indicates that risk quotients for both aquatic and terrestrial plants exceed non endangered species LOCs by factors ranging up to three orders of magnitude and thus there is a potential for adverse effects to those species that rely either on a specific plant species ( plant species obligates) or multiple plant species ( plant dependent) for some important aspect of their life cycle. Additional analysis would be required to determine whether any of the listed species associated with the uses evaluated in this assessment are those for which plants are a critical component of their resource needs. If plant species obligates or dependent species may reside within the ametryn use area, the temporal and geographical nature of exposure and the scope of the effects data would have to be considered to determine if any potential effects are likely.

Additionally, since screening level chronic LOCs for birds exceed the endangered LOC by factors ranging as high as 6.9, there is a potential concern for indirect effects given the reduced growth and reproduction observed following chronic dietary exposure from most of the forage items evaluated ( small grass, tall grass, broadleaf plants and insects).

CRITICAL HABITAT In the evaluation of pesticide effects on designated critical habitat, focus is placed on the potential for effects on attributes of the critical habitat identified by the U. S Fish and Wildlife and National Marine Fisheries Services as principal critical elements of the habitat that are important to the conservation of the species. The evaluation of impacts to biologically based principle critical elements is accomplished using the screening level taxonomic analysis ( risk quotients, RQs) and 67 levels of concern ( LOCs) that are used to evaluate direct and indirect effects to listed and nonlisted organisms.

The screening level risk assessment has identified potential concerns for direct effects on birds, mammals, freshwater fish and invertebrates, and terrestrial and aquatic plants, and indirect effects on terrestrial and aquatic animals.

Available information at the screening level assessment does not allow a definitive geographical determination of the occurrence of pesticide use in areas designated as critical habitat at this time. Insofar that such critical habitat locations and pesticide use sites do occur in the same areas, there may be a potential concern for those critical habitats with designated principle critical elements that correspond to the taxa identified above as being of potential concern for direct and indirect effects.

References Bengston, R. and Selim, M., 2001 Herbicide Losses in Surface Runoff. Louisiana Agriculture, vol 44, no. 4. http:// www. getitgrowing. com/ Communications/ LouisianaAgriculture/ agmag/ 44_ 4_ articles/ herbici de. asp Hunt, CD, 2004. Ground Water Quality and its Relation to Land Use on Oahu, Hawaii, 2000 01. USGS WRIR 03 4305, Honolulu Hawaii, 76 pp.

Jobin, B., Boutin, C. and DesGranges, J L, 1997. Effects of Agricultural Practices on the Flora of Hedgerows and Woodland Edges in Southern Quebec. Can. J. Plant Sci. 77: 293 99.

Klasner, FL and Mikami, CD, 2003. Land Use on the Island of Oahu, Hawaii, 1998. USGS WRIR 02 4301, Honolulu, Hawaii, 20 pp.

Kleijn, D. and Snoeijing, G. I. J., 1997. Field Boundary Vegetation and the Effects of Agrochemical Drift: Botanical Change Caused by Low Levels of Herbicide and Fertilizer. J. Applied Ecol. 34: 1413 1425.

Oki, DS and Brasher, AMD, 2003. Environmental Setting and the Effects of Natural and Human Related Factors on Water Quality and Aquatic Biota, Oahu, Hawaii. USGS WRIR 03 4156, Honolulu Hawaii, 98 pp.

USDA, 2000. Crop Profile for Sugarcane in Hawaii.

USEPA, 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs, Endangered and Threatened Species Effects Determinations. 68 APPENDICIES APPENDIX A   USE CLOSURE MEMO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 69 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES MEMORANDUM TO: Ametryn Reregistration Eligibility Decision ( RED) Team Members FROM: Mark Howard, Chemical Review Manager Special Review and Reregistration Division ( 7508C) Reregistration Branch III SUBJECT: Use Closure Memo for Ametryn; PC Code: 080801; RED Case No.: 2010; CAS No.: 834 12 8 This memorandum was developed to summarize the results of communications between the RED team members and Syngenta Crop Protection, Inc., the technical registrant for the active ingredient ametryn, CAS name: 1,3,5 Triazine, 2( ethylamino) 4( isopropylamino) 6( methylthio) . This memorandum will serve as the Agency's record of common understanding on the uses of ametryn to be considered in risk assessments for its reregistration. This memo includes information on all registered products, agricultural uses, overall use patterns, and the status of the existing database. This memo was reviewed by RED team members, the US Department of Agriculture, and Syngenta, and comments were included as appropriate. Attachments include: The RED team members; Table A2 ( Food/ Feed Use Patterns Summary for Ametryn) as modified by the registrant ( Syngenta has voluntarily cancelled non Agriculture uses, so Table A3 is no longer relevant); a copy of the new ametryn product label; and a list of studies currently in review at EPA.

BACKGROUND:

Ametryn is an S Triazine herbicide used on terrestrial food and feed crops. The RED is scheduled to be completed in June of 2005. Ametryn will not be included in the cumulative risk assessment for atrazine, simazine, propazine, and their degradants ( desethyl s atrazine, desisopropyl s atrazine, diaminochlorotriazine) as determined by the Office of Pesticide Programs' Health Effects Division in its March 2002 report: " The Grouping of a Series of Triazine Pesticides Based on a Common Mechanism of Toxicity."

This memorandum serves primarily to clarify use information to be considered for the reregistration of ametryn. Data to support this memo derives from the Agency's Biological and Economic Analysis Division ( BEAD), current ametryn labels, and information provided by Syngenta at the August 22, 2003, SMART meeting. 70 71 Table 1. Formulations:

Registration # Company Name Product Name % Active Ingredient Formulation 100 579 Syngenta Crop Protection Ametryn Technical 90 Technical 100 786 Syngenta Crop Protection, EVIK 80 WDG 80* Water dispersible granule 48273 3 Marman USA Inc AMETRYNE 80W 80* Wettable powder 51036 105 Micro Flo Company LLC AMETRYNE 4FL 44 Flowable concentrate * These products are 76.0% Ametryn and 4.0% related compounds, equaling 80.0% active ingredients.

Use and Use Sites:

The technical registrant is supporting the continued use of ametryn in three terrestrial food crops: sugar cane, corn ( pop, field, and sweet), and pineapples. The technical registrant has agreed to voluntarily cancel all other registered uses including: bananas, plantains, and all general herbicidal uses ( industrial sites, rights of way, airports and landing fields, and uncultivated nonagricultural areas) in a November 10, 2003 letter to EPA. In the past, ametryn had been but since 1996, is no longer registered for use on oranges, grapefruit, and potatoes. The registrant has also indicated, they do not plan to support established regional residual tolerances for taniers, yams, and cassava roots.

SUPPORTED USES: UNSUPPORTED USES:

Corn Bananas ( and plantains) Pineapple Non crop land Sugarcane Taniers Yams Cassava roots Application Methods:

Ametryn products are not co formulated with any other pesticide active ingredient ( ai); however, ametryn may be used in tank mixes ( with other ais.). Ametryn can be applied by aerial equipment ( sugar cane only) and by ground boom sprayers. For corn ( pop, field, & sweet), ametryn is used as a directed spray for soil treatment post emergence. For sugar cane, ametryn is used as a band treatment ( ratoon), or as a broadcast spray ( pre emergence, ratoon, and postemergence For pineapple, ametryn is used as a blanket spray. 72 Relative Usage:

Corn: Mostly used in southeastern states, particularly North Carolina and South Carolina. Some use in Georgia and Texas. With small amounts used in Midwestern states as well. ( WI, OH, IL). Sugar Cane: Mostly Florida. Also some in Hawaii. Small quantities in Texas. Some use in Louisiana as well. Not currently used in Puerto Rico. Pineapple: Hawaii, some in Puerto Rico.

There are no current special local needs registrations of ametryn.

At the SMART meeting, the registrant reported 35,000 lbs of ametryn used per year with 75% on bananas and plantains and the remaining 25% used on root crops. Although it is not currently used on sugar cane, Syngenta has indicated it could be in the future.

Table 2. Overall Use Patterns Crop Max Single Rate ( Lbs/ ai/ A) Applications/ Yr Maximum Lbs / A/ Yr/ Lbs ai / year Percent Crop Treated Corn ( Field, Sweet, Pop) 2.0 1 2.0 200,000 < 2.5 Pineapple* 7.2 NS** 7.2 58,000** * Sugarcane ( state dependent) 8.0*** 5 16.0 90,000/ 30 State Use Programs: 124,000 FL 1.2 3 3.6 LA 2/ 2.4/ 2.4/ 2.4/ 2.4 5 11.6 TX 2/ 2/ 2 3 6.0 HI 7.2/ 2.4/ 2.4 3 12.0 PR 8/ 4/ 4 3 16.0 Sugarcane Retreatment Intervals: 30 days where specified.

* Pineapple Typical use in Hawaii, per Pineapple Growers Association of Hawaii, is a 1.6 lbs ai/ A application preplant or immediately postplant plus additional 1.6 lbs ai/ A applications prior to flower induction; Syngenta supports this practice within the 7.2 lbs ai/ A/ yr/ crop maximum.

NS = Not Specified on Labeling No EPA data on pineapple *** Maximum varies by Application and by state Sources registrant SMART meeting, Doane's, NCSU web site, BEAD 73 References:

Syngenta Crop Protection, Inc.; 2003; Proposed revised Evik DF EUP label. August, 2003.

Syngenta Crop Protection, Inc.; 2003; Ametryn Overview. Presentation by Syngenta at US EPA Ametryn SMART Meeting. August 26, 2003.

Syngenta Crop Protection, Inc.; 2003; Registrant Handwritten Notes to Table A2. Food/ Feed Use Patterns Summary for Ametryn. Presentation by Syngenta at US EPA Ametryn SMART Meeting. August 26, 2003.

Syngenta Crop Protection, Inc.; 2003; Ametryn, Chemical Code 080801, Case No. 2010 Voluntary Deletion of Certain Uses. Letter from registrant; September 11, 2003.

US EPA. OPPTS/ OPP/ BEAD; 2003, Usage Data Report  Screening Level Estimates of Agricultural Uses of Ametryn; April 17, 2003.

US EPA. OPPTS/ OPP/ BEAD; 2003; Table A2. Food/ Feed Use Patterns Summary for Ametryn & Table A3. Non Food/ Non Feed Use Patterns Summary for Ametryn; April 2, 2003.

US EPA. OPPTS/ OPP/ BEAD; 2003; RED Use Profile Report April 2, 2003.

EPA Office of Pesticide Programs Information Network ( OPPIN). 2003. Registration and Formulation information search for 080801; September 2003. 74 Status of Guideline Database:

Agency databases indicate there are six outstanding studies and 52 studies listed as in review. As study reviews are completed, DERs will be sent to the technical registrant. First outstanding studies and then studies listed as in review are listed below:

Outstanding Studies  No MRIDs available. Listed as No Decision/ Not Satisfied:

EPA does not have any waiver requests from the registrant or notations in CRMS indicating Agency intentions on these product chemistry studies.

63 14 Oxidizing/ Reducing Potential Registrant at SMART meeting indicated that in EPA's response to the ( ametryn) Phase Two submission this product specific requirement will be addressed in Phase Five.

63 15 Flammability 63 18 Viscosity 63 19 Miscibility 63 21 Dielectric Breakdown Voltage Registrant at the SMART meeting said the studies are not applicable because ametryn is not a liquid they would be addressed in Phase Five..

171 3 Directions for Use No information available about any submissions for this guideline.

Studies at EPA listed as In Review ( unless otherwise noted):

Guideline No. Name MRID Citation Reference 61 1 Chemical Identity 61 2( a) Description of Beginning Materials and Manufacturing Process 61 2( b) Discussion of Formation of Impurities 40844701 Lail, L. ( 1988) Product Chemistry: Technical Ametryn: Study No. PC 88 018. Unpublished study prepared by Ciba Geigy Corp. 205 p.

43335901 McCain, P. ( 1994) Technical Ametryn Product Chemistry ( Manufacturing Process): Addendum: Lab Project Number. Unpublished study prepared by Ciba Geigy Corp. 8 p. 75 62 1 Preliminary Analysis 62 2 Certification of limits 62 3 Analytical Method 41067901 Lail, L. ( 1989) Technical Ametryn: Product Chemistry: Study No. PC 89 002. Unpublished study prepared by Ciba Geigy Corp. 108 p.

63 2 Color 63 3 Physical State 63 4 Odor 63 5 Melting Point 63 7 Density 63 8 Solubility 63 9 Vapor Pressure 63 10 Dissociation Constant 63 11 Octonal/ Water Partition Coefficient 63 12 pH 63 16 Explodabilitiy 63 17 Storage Stability 63 20 Corrosion Characteristics 40877301 Lail, L. ( 1988) Technical Ametryn: Product Chemistry: Study No. PC 88 018. Unpublished study prepared by Ciba Geigy Corp. 136 p.

82 1( a) 90 Day Feeding Rodent 40349906 Hazelette, J.; Green, J. ( 1987) Ametryn: Combined Chronic Toxicity/ Oncogenicity Study in Rats: Laboratory Study No. 842119. Unpublished study prepared by Ciba Geigy Corp. 4305 p.

82 1( b) 90 Day Feeding Nonrodent 40349902 O'Connor, D. ( 1987) Ametryn: Chronic Toxicity Study in Dogs: Laboratory Study No. 842118. Unpublished study prepared by Ciba Geigy Corp. 665 p.

82 2 21 Day Dermal Rabbit/ Rat 41067902 Huber, K. ( 1989) Ametryn: 21 Day Dermal Toxicity Study in Rabbits: Study No. 882215. Unpublished study prepared by Ciba Geigy Corp. 326 p.

43407104 Sova, J. ( 1994) Submission of Additional Information To Upgrade The 21 Day Repeated Dose Dermal Toxicity Study In Rabbits: Prometryn Technical. Unpublished study prepared by Ciba Crop Protection. 7 p. 76 83 1( a) Chronic Toxicity Rodent 40349906 Hazelette, J.; Green, J. ( 1987) ibid.

83 1( b) Chronic Toxicity Nonrodent 40349902 O'Connor, D. ( 1987) ibid.

83 3 Teratogenicity  2 Species 153214 Infurna, R.; Youreneff, M.; Wallace, P.; et. al ( 1985) Ametryn Technical: A Teratology Study in Rabbits: Report 85063. Unpublished study prepared by Ciba Geigy Corp. 302 p.

153215 Infurna, R.; Wimbert, K.; Arthur, A. ( 1985) Ametryn Technical: A Teratology Study in Rats: Report 85140. Unpublished study prepared by Ciba Geigy Corp. 337 p.

83 4 2 generation reproductive study rat 40349905 Hummel, H.; Youreneff, M.; Yau, E. ( 1987) Ametryn Technical: Two generation Reproduction Study in Rats: Laboratory Study No. 852048. Unpublished study prepared by Ciba Geigy Corp. 1405 p.

84 2( b) Structural Chromosome Aberration study 41067903 Hertner, T. ( 1989) Ametry Technical: Structural Chromosomal Aberration Test: Micronucleus Test, Mouse: Study No. 881548. Unpublished study prepared by Ciba Geigy Limited. 38 p.

84 4 Other Genotoxic Effects.

41067904 Hertner, T. ( 1989) Ametryn Technical: Tests for other Genotoxic Effects: Autoradiographic DNA Repair Test on Rat Hepatocytes: Study No. 881549. Unpublished study prepared by Ciba Geigy Ltd. 98 p.

122 2 Aquatic plant growth 40995810 Hughes, J. ( 1989) Ametryn: The Toxicity of Ametryn Technical to Selenastrum capricornutum: Study No. 0267 42 1100 1. Unpublished study prepared by Malcolm Pirnie, Inc. 38 p.

123 1( b) Vegetative Vigor 40995809 Canez, V. ( 1989) Ametryn: Nontarget Phytotoxicity Test: Vegetative Vigor Tier 2: Study No. LR 88 55A. Unpublished study prepared by Pan Agricultural Labs, Inc. 281 p. 77 160 5 Chemical Identity Listed as No Decision/ Not Satisfied 40844701 Lail, L. ( 1988) Product Chemistry: Technical Ametryn: Study No. PC 88 018. Unpublished study prepared by Ciba Geigy Corp. 205 p.

162 3 Anaerobic aquatic metabolism Waiver Request was submitted and found Unacceptable 42861603 Skinner, W. ( 1993) Anaerobic Aquatic Metabolism of ( Carbon 14) Ametryn: Lab Project Number: 354W: 171 91. Unpublished study prepared by PTRL West, Inc. 167 p.

164 1 Terrestrial field dissipation Guideline status listed as No Decision/ Not Satisfied Several submissions for this guideline were determined by EPA to be Unacceptable.

43578501 Wiepke, T. ( 1995) Responses to the EPA EFGWB Review of Ametryn Terrestrial Field Dissipation Studies: MRID No. 418723 01, 418723 02, and 417524 02: Lab Project Number: ABR 95040. Unpublished study prepared by Ciba Geigy Corp. 36 p. ( No Decision)

41701601 Judy, D.; Jacobson, B. ( 1990) Ametryn: Terrestrial Field Dissipation for Evik 80W Bareground Application, Louisiana Site: Final Report: Lab Project Number: 37895. Unpublished study prepared by Analytical Bio Chemistry Laboratories, Inc. 219 p. ( In Review)

165 2 Field rotational crop CRMS listed this guideline as Data in Review. However there is a Phase 3 comment says this study is reserved based on a Nov 1994 letter but there is a 1999 submission from the registrant. 44783702 Lin, K. ( 1999) Ametryn Field Rotational Crops Following Bare Ground Application of Evik 80W: Final Report: Lab Project Number: 80 95: 102925: 80 95 A. Unpublished study prepared by Novartis Crop Protection, Inc. 107 p. { OPPTS 860.1900}

165 4 Bioaccumulation in fish 42061901 Dionne, E. ( 1991) Bioconcentration and Elimination of ( Carbon 14) Residues by ( Lepomis macrochirus) Exposed to Ametryn: Lab Project Number: 1781. 1090. 6264. 140: 91 5 3760: 155 90. Unpublished study prepared by Springborn Labs, Inc. and Ciba Geigy Corp. 156 p. 78 166 1 Small GW prospective Status is listed as Waiver Pending in CRMS but the Phase 3 Comment says a study and a protocol are required. Agency also notified registrant that field dissipation study would not satisfy this requirement nor would a atrazine/ simazine study. These are supposed to be for 166 2 Small GW  retrospective, Do these help with 166 1?

45629801 Yokley, R. ( 2002) FIFRA Section 6( a)( 2) Annual Ground Water Report for 2001. Unpublished study prepared by HAES Resources Department, Syngenta Crop Protection, Inc. 33 p.

45870401 Yokley, R. ( 2003) FIFRA Section 6( a) 2 Annual Ground Water Report for 2002: Final Report: Lab Project Number: 2240 02. Unpublished study prepared by Syngenta Crop Protection, Inc. 34 p.

171 2 Chemical Identity 40844701 Lail, L. ( 1988) Product Chemistry: Technical Ametryn: Study No. PC 88 018. Unpublished study prepared by Ciba Geigy Corp. 205 p.

43335901 McCain, P. ( 1994) Technical Ametryn Product Chemistry ( Manufacturing Process): Addendum: Lab Project Number. Unpublished study prepared by Ciba Geigy Corp. 8 p.

171 4( a) Nature of the Residue in Plants 44107901 Thalacker, F.; Ash, S. ( 1996) ( Carbon 14) Ametryn: Nature of the Residue in Bananas: Lab Project Number: HWI 6117 270: 318 94: 94.255. Unpublished study prepared by Hazleton Wisconsin, Inc. 141 p. 41397201 Yokley, R. ( 1990) Determination of Ametryn, Prometryn, and Metabolites by U. S. Food and Drug Administration Multiresidue Method Testing: Lab Project Number: ABR 89064: ABR 77060: 102065. Unpublished study prepared by Ciba Geigy Corp. 78 p.

171 4( b) Nature of Residue in Livestock 43931001 Wu, J. ( 1995) Ametryn: Storage Stability on Ametryn: Goat and Hen Metabolism: ( Supplement): Lab Project Number: RPT0023: RPT0024: 88085. Unpublished study prepared by Xenobiotic Labs, Inc. 27 p.

41662303 Liu, D. ( 1990) Ametryn: Metabolism of ? carbon 14| Ametryn in Laying Hens: Analysis and Quantitation of Metabolites in Eggs, Edible Tissues, and Excreta: Lab Project Number: RPT0024. Unpublished study prepared by Xenobiotic Laboratories, Inc. 350 p.

41662304 Lin, P. ( 1990) Metabolism Study in Laying Hens Feeding ? carbon 14| Ametryn: Lab Project Number: P01736. Unpublished study prepared prepared by Biological Test Center. 43 p.

41662305 Liu, D. ( 1990) Ametryn: Metabolism of ? carbon 14| Ametryn in Lac tating Goats: Analysis and Quantitation of Metabolites in Milk, Edible Tissues, and Excreta: Lab Project Number: RPT0023. Un published study prepared by Xenobiotic Laboratories, Inc. 142 p.

41662306 Lin, P. ( 1990) Metabolism Study in Lactating Goat Feeding ? carbon 14| Ametryn: Lab Project Number: P01734. Unpublished study pre pared by Biological Test Center. 53 p. 79 171 4( c) Residue Analytical Methods 44477701 Lin, K. ( 1997) Determination of Residues of Ametryn, GS 11354, GS 11355, and GS 26831 in Animal Tissue, Milk, and Egg: Lab Project Number: AG 649: 632 95: 102925. Unpublished study prepared by Novartis Crop Protection, Inc. 55 p. { OPPTS 860.1340}

44477702 Lin, K. ( 1997) Validation of Analytical Method AG 649 for Determination of Ametryn, GS 11354, GS 11355, and GS 26831 in Animal Tissues, Milk, and Poultry Eggs by Capillary Gas Chromatography: Lab Project Number: ABR 97127: 631 95: ANPHI 96003. Unpublished study prepared by Novartis Crop Protection, Inc. 133 p. { OPPTS 860.1340}

171 4( c) Magnitude of the Residue [ by commodity]

44477705 Hamilton, L. ( 1997) Ametryn Magnitude of the Residues in Meat and Eggs Resulting from the Feeding of Three Levels to Poultry: Lab Project Number: ABR 96110: 134 95: BIOL 95005. Unpublished study prepared by Novartis Crop Protection, Inc. 187 p. { OPPTS 860.1480}

44477706 Boyette, S. ( 1997) Ametryn Magnitude of the Residues in Meat and Milk Resulting from the Feeding of Three Levels to Dairy Cattle: Lab Project Number: ABR 96046: 144 95: BIOL 95006. Unpublished study prepared by Novartis Crop Protection, Inc. 186 p. { OPPTS 860.1480}

171 4( d) Residue Analytical Method Listed as in Review. No MRID, just an extension request with a due date of Dec 31, 1997 to submit by date.

171 4( e) Storage Stability 43931001 Wu, J. ( 1995) Ametryn: Storage Stability on Ametryn: Goat and Hen Metabolism: ( Supplement): Lab Project Number: RPT0023: RPT0024: 88085. Unpublished study prepared by Xenobiotic Labs, Inc. 27 p.

44477703 Hayworth, C. ( 1997) Stability of Ametryn and Selected Metabolites in Processed Fractions Under Freezer Storage Conditions: 6 Month Interim Report: Lab Project Number: ABR 97124: 213 96: 102925. Unpublished study prepared by Novartis Crop Protection, Inc. 107 p. { OPPTS 860.1380}

44477704 Hayworth, C. ( 1997) Stability of Ametryn and Selected Metabolites in Meat, Milk, and Eggs Under Freezer Storage Conditions: 14 Month Interim Report: Lab Project Number: ABR 97126: 222 96: 102925. Unpublished study prepared by Novartis Crop Protection, Inc. 98 p. { OPPTS 860.1380}

44783701 Hayworth, C. ( 1999) Stability of Ametryn and Selected Metabolites in Processed Fractions Under Freezer Storage Conditions: Final Report: Lab Project Number: 213 96. Unpublished study prepared by Novartis Crop Protection, Inc. 100 p. { OPPTS 860.1380} 80 171 4( j) Magnitude of residues in Meat/ Milk/ poultry 44477705 Hamilton, L. ( 1997) Ametryn Magnitude of the Residues in Meat and Eggs Resulting from the Feeding of Three Levels to Poultry: Lab Project Number: ABR 96110: 134 95: BIOL 95005. Unpublished study prepared by Novartis Crop Protection, Inc. 187 p. { OPPTS 860.1480}

44477706 Boyette, S. ( 1997) Ametryn Magnitude of the Residues in Meat and Milk Resulting from the Feeding of Three Levels to Dairy Cattle: Lab Project Number: ABR 96046: 144 95: BIOL 95006. Unpublished study prepared by Novartis Crop Protection, Inc. 186 p. { OPPTS 860.1480}

43931000 Ciba Geigy Corp. ( 1996) Submission of Residue Chemistry Data in Support of the Reregistration of Ametryn. Transmittal of 1 Study.

171 4( k) Corn 41909501 Selman, F. ( 1991) Ametryn: Magnitude of Residues in Field Corn For age, Fodder, Grain, and Processed Corn Grain Fractions Resulting From Applications of EVIK 80W: Lab Project Number: ABR 91001. Unpublished study prepared by Ciba Geigy Corporation. 507 p.

41662302 Detra, R.; Chib, J. ( 1990) Ametryn: Metabolism of Triazine? carbon 14| Ametryn in Corn: Lab Project Number: N/ 0963/ 1800. Unpublish ed study prepared by Battelle. 130 p.

171 4( k) pineapple 41909502 Wong, L. ( 1991) Ametryn: Pineapple Residue Study: Lab Project Num ber: 36 5294: PGA ES 91 5294: 96 20 26. Unpublished study prepared by Hawaiian Sugar Planters' Association. 208 p.

171 4( k) sugarcane 41662301 Detra, R.; Chib, J. ( 1990) Ametryn: Metabolism of Triazine ? carbon 14| Ametryn in Sugarcane: Lab Project Number: N/ 0963/ 1800. Un published study prepared by Battelle Columbus Div. 94 p.

41846601 Selman, F. ( 1991) Ametryn Magnitude of Residues in Sugarcane Forage , Stripped Cane, and Stripped Cane Processed Fractions Resulting from Applications of Evik 80W: Lab Project Number: ABR 91002. Unpublished study prepared by Ciba Geigy Corp. 417 p. 81 171 4( l) Corn 41909501 Selman, F. ( 1991) Ametryn: Magnitude of Residues in Field Corn For age, Fodder, Grain, and Processed Corn Grain Fractions Resulting From Applications of EVIK 80W: Lab Project Number: ABR 91001. Unpublished study prepared by Ciba Geigy Corporation. 507 p.

171 4( l) pineapple 41909502 Wong, L. ( 1991) Ametryn: Pineapple Residue Study: Lab Project Num ber: 36 5294: PGA ES 91 5294: 96 20 26. Unpublished study prepared by Hawaiian Sugar Planters' Association. 208 p.

171 4( l) sugarcane 41846601 Selman, F. ( 1991) Ametryn Magnitude of Residues in Sugarcane Forage , Stripped Cane, and Stripped Cane Processed Fractions Resulting from Applications of Evik 80W: Lab Project Number: ABR 91002. Unpublished study prepared by Ciba Geigy Corp. 417 p.

171 5 Reduction of Residues No MRID Guideline status listed as Research. Phase 3 comment suggests that concerns based on triazine ring may require additional ( at the table) data or other measures to reduce residues. Is this information still required?

202 1 Drift Field Evaluation No MRID See Spray Drift Task Force Submissions 82 US EPA Ametryn Team EFED Branch Chief Betsy Behl 1034C RAPL Kevin Costello 1021M Fate/ Transport Dirk Young 1034L Ecotoxicology John Ravenscroft 1008G HED Branch Chief Cathrine Eiden 821F Toxicologist Pam Hurley 806M Chemist/ risk assessor Will Donovan 821B ORE assessor Rob Travaglini 821E BEAD Economist ?

Label Data Cynthia Doucoure 911N Biologist Nicole Zinn 911F Other BEAD?

David Widawski Isty Yusuf Steve Jarboe Raefel Prieto Art Grube Gary Bangs/ DC/ USEPA/ US@ EPA,

Michelle Centra/ DC/ USEPA/ US@ EPA,

Danette Drew/ DC/ USEPA/ US@ EPA 83 Ametryn Synonyms:

[ 834 12 8]

1,3,5 Triazine, 2( ethylamino) 4( isopropylamino) 6( methylthio);

2 Ethylamino 4 isopropylamino 6 methylthio s triazine;

N ethyl N'( 1 methylethyl) 6( methylthio) 1,3,5 Triazine 2,4 diamine;

Ametrex;

Ametryne;

Ametryn ;

Cemerin;

Evik;

Evik 80W;

Gesapax;

N ethyl N'( 1 methylethyl) 6( methylthio) 1,3,5 Triazine 2,4 diamine; 84 APPENDIX B   ENVIRONMENTAL FATE SUMMARY Abiotic Degradation Hydrolysis Ametryn is stable to hydrolysis at environmentally relevant pH's and temperatures. Using sterilized aqueous buffered solutions at 25

C, ametryn did not hydrolyze at pH 5, 7, and 9 over the course of 30 days ( MRID 40885812). The submitted study was classified as acceptable and provides adequate data for the risk assessment.

Aqueous Photolysis Aqueous photolysis is not expected to be an important environmental fate process. The aqueous photodegradation half life for ametryn was calculated to range from 169 278 days at pH 7 when irradiated with outdoor sunlight ( MRID 41169601). The minor degradation products identified in this study were:

° 2,4 diamino 6 methylthio s triazine ( GS 26831),

° 2 amino 4 isopropylamino 6 methylthio s triazine ( GS 11354), 2 ethylamino 4 amino 6 methylthio s triazine ( GS11355),

° 2,4 diamino 6 methylthio s triazine ( GS 26831),

° 2 ethylamino 4 isopropylamino s triazine ( GS 32083), and ° 2 amino 4 isopropylamino s triazine ( GS 28304).

These degradation products were also noted in dark control samples suggesting that another degradation process may have been the fundamental degradation route and not photolysis. The submitted study was classified as acceptable and provided adequate data for the risk assessment.

Soil Photolysis Ametryn photodegrades slowly on soil surfaces with half lives in the range of 85 123 days. These halflives were calculated for ametryn applied at 10 ppm to sandy loams located in Florida and Maryland, and irradiated with outdoor sunlight ( MRID 41169602, 41169603). The half lives in the Florida soil were calculated as 85 and 112 days ( MRID 41169602), while the half lives in Maryland were 95 and 123 days ( MRID 41169603). The minor degradation products identified in these studies were GS 11354, GS 11355, GS 26831, GS 28304, GS 32083 and 2 amino 4 isopropylamino 6 hydroxy s triazine ( GS 17794). These degradation products were also noted in dark control samples suggesting that biodegradation may have been the fundamental degradation route and not photolysis. These studies were classified as acceptable and provide useful data for the risk assessment.

Metabolism 85 Aerobic Soil Metabolism Ametryn is metabolized slowly in soil under aerobic conditions. In a study classified as acceptable, [ 14C] ametryn, at 9.8 ppm, dissipated with a calculated half life of 84 days in an aerobic sandy loam that was incubated in the dark at 25 ± 1

C and at a moisture content of 75% of field capacity for 1 year ( MRID 41752401). The rate of degradation did not follow first order kinetics over the entire course of the experiment; the rate of degradation decreased significantly after the initial 90 days. Ametryn decreased from 88.4 89.1% of the initially applied radioactivity immediately following application, to 40.9 44.7% 31 days post treatment, and 2.9 3.0% 365 days post treatment. Using only the initial 92 days of the experiment, the registrant calculated half life was 41 days. The degradation products were GS 11354, GS 11355, and GS 32083. Partially resolved degradation products were 2 ethylamino 4 isopropylamino 6 hydroxy s triazine ( GS 34048) + 2 ethylamino 4 amino 6 hydroxy s triazine( GS 17791) and GS 26831 + GS 28304. Additional byproducts, 2 ethylamino 4 amino 6 hydroxy s triazine ( GS 17792) and GS 17794, were also isolated from a sample stored for seven months. Only GS 11355 was found to be present at > 10% of the initial amount applied. At 14 days post application, GS 11355 was detected at a maximum of 11.6 12.2% of the initially applied radioactivity. This study was classified as acceptable and provides a value that will be used in determining EEC's for the ecological risk assessment.

Anaerobic Soil Metabolism [ 14C] Ametryn, at 9.8 ppm did not undergo degradation in a flooded sandy loam soil incubated in foil wrapped ( dark) flasks and stored at 25 ± 1

C for 62 days following a 31 day incubation under aerobic conditions ( MRID 41752401). This study was classified as acceptable and provides adequate data for the risk assessment.

Mobility and Persistence Adsorption/ Desorption Based on soil adsorption coefficient ( Kd) values determined using Freundlich adsorption isotherms with batch equilibrium study data and the Koc values that were obtained by normalizing for the percentage of organic carbon content in the soils, ametryn is expected to have high to moderate mobility in sandy soils, sandy loams, and loam soils, while its mobility in clay soils is expected to be lower. The extent of adsorption does not appear to be dependent upon the percentage of organic matter, clay content, or cation exchange capacity ( CEC) of the soils tested.

Several mobility studies were submitted for the parent compound. Soil characteristics and the results of the soil adsorption experiments for one study ( MRID 40995813) are presented in Table B1. In this study, the adsorption of ametryn was studied in four soils ( 4 grams of soil) treated with 20 mL of [ 14C] ametryn at five concentrations ranging from 0.22 to 10.74  g/ mL. This soil slurry was shaken for four hours at 24 oC. After the equilibration period, the Freundlich adsorption coefficients were measured as 26.16, 1.09, 1.07, and 1.21 for a clay, sandy soil, sandy loam, and loam soil, respectively. This corresponded to Koc values of 86 927, 205, 96, and 257 for the clay, sandy soil, sandy loam, and loam soil, respectively. The Freundlich desorption K values were 27.77 for the clay, 3.02 for the sand soil, 3.43 for the sandy loam, and 4.66 for the loam soil. This study was classified as acceptable and provides adequate data on the parent compound for use in the risk assessment.

Table B1. Soil adsorption coefficients for ametryn in four soils. 1 Soil Property Soil Type Clay Sand Sandy loam Loam % Sand 25.2 95.6 63.2 44 % Silt 32.8 2.2 20 47 % Clay 42 2.2 16.8 9 % Organic matter 4.8 0.9 1.9 0.8 pH 5.9 6.5 7.5 6.7 % Field capacity 36 3.8 15.8 11.7 CEC ( meq/ 100 g) 24.3 1.8 6.1 4.3 Bulk density ( g/ mL) 1.22 1.65 1.38 1.55 Kd Koc 26.16927 1.09205 1.0796 1.21257 1 Data obtained from MRID 40995813.

In a second study ( MRID 41169604), adsorption was evaluated by studying the movement of ametryn in packed columns using four different soil types. Approximately 2 kg of sand, sandy loam, clay, or loam soils were packed to a depth of 12 inches in PVC tubing. The columns were immersed in water, removed, and allowed to dry to field capacity. Soil samples treated with [ 14C] ametryn at a concentration of 10.75 11.36 ppm were added to the top of the column and eluted with 20 inches ( 2317 mL) of distilled water at a rate of a < 1 inch per hour. In the sandy loam and loam soil columns, 2.65 6.34% of the radioactivity was recovered in the leachate. In the column containing the sandy soil, 0.29 0.50% of the radioactivity was recovered in the leachate, and in the clay column, 0.07 0.14% of the applied radioactivity was recovered in the leachate. Greater than 60% of the applied radioactivity remained in the upper 3 inches of the soil column for the sand, loam, and sandy loam; however, the rest of the remaining radioactivity was well distributed throughout the columns. Greater than 91% of the radioactivity remained in the upper 1 inch profile of the clay soil column suggesting a greater adsorption of ametryn in this soil.

In a third study that was considered scientifically sound, but not acceptable with respect to Subdivision N guidelines, it was determined that the degradation products of ametryn ( GS 11354, GS 11355, GS 32083, GS 26831, GS 17794 and GS 28304) were more mobile in a sandy loam soil than the parent compound ametryn. In this soil column leaching experiment, a greater portion of the ametryn degradation products 87 were detected in the leachate, and at deeper depths of the soil column than the parent compound leading to the conclusion that the degradation products have higher mobility in soil than ametryn.

Field dissipation studies have indicated that some degradation products of ametryn have great mobility in sandy soils and can leach deeper into soils than ametryn. GS 34048 leached to a depth of 6 12 inches in a field dissipation study using a sandy loam ( MRID 41752402), 12 18 inches in a sandy soil used to grow corn ( MRID 41872301), and up to 36 48 inches in an unvegetative ( bare ground) sandy soil ( MRID 41872302). Other degradation products generally did not leach below the 0 6 inch soil profile.

Laboratory Volatility Laboratory volatility studies for ametryn have been waived since this compound has a low vapor pressure ( 2.74x10 6 mm Hg at 25

C), resulting in an estimated airborne concentration of less than 3.3x10 5 mg/ L in the breathing zone of workers using this substance.

Field Volatility This data requirement ( Guideline # 163 3) was waived.

Terrestrial Field Dissipation Three separate studies were submitted, and each was classified as supplemental. In the first study ( MRID 41752402), ametryn and its degradates dissipated slowly in the 0 6 inch depth of a silty loam sugercane field in Louisiana following 2 applications spaced 1 month apart at an application rate of 2.5 lbs a. i./ A. In the upper 0 6 inch soil profile, ametryn averaged 1.1 ppm immediately after the first application, 0.83 ppm 15 days post application, and 0.29 ppm 31 days post application. Following the second application, the ametryn concentration was 1.3 ppm ( immediately after application), but 1.7 ppm 1 day post application. The concentration decreased to 0.89, 0.43, 0.35, 0.050, and 0.011 ppm 3, 6, 28, 60, and 422 days post application. Ametryn was detected only once at a depth greater than 6 inches. The average half life for ametryn was calculated using the data from 0 339 days following the second application and was calculated as 62 days ( r2 = 0.89 ). In the 0 6 inch profile, GS 34048 was detected at 0.044 ppm following the first application and 0.13 ppm following the second application. The level of GS 34048 was 0.21, 0.080, 0.040, and 0.013 ppm 6, 60, 90, and 330 days after the second application of ametryn. This degradate was detected below 6 inches on two occasions at levels of 0.014 0.015 ppm 20 and 60 days after the second application of ametryn. GS 17794 averaged 0.015 0.033 ppm at the 0 6 inch depth between 3 and 60 days following the second application of ametryn, and was not detected below 6 inches. GS 13354 averaged 0.015 0.026 ppm at the 0 6 inch depth at 2 and 15 days, respectively following the first application of ametryn, and 0.017 0.039 between days 0 28 following the second application. This degradation product was not detected below 6 inches.

A second supplemental study ( MRID 41872302) showed that ametryn and its degradation products, GS 34048, GS 17794, and GS 11354, dissipated slowly in a sandy soil used for growing corn in Illinois following a single application at 2 lbs a. i./ A. The dissipation of ametryn was considered bi phasic with fairly rapid dissipation over the first 30 days followed by much slower dissipation thereafter. In the 0 6 inch 88 depth profile, the ametryn concentrations were 1, 0.36, 0.12, 0.056, and 0.016 at 1, 6, 14, 28, and 154 days post application, respectively. In the 6 12 inch depth profile, the maximum concentration of ametryn was 0.026 ppm, which was observed 3 days post application. Ametryn was not detected at a depth greater than 12 inches. The overall half life of ametryn in the 0 6 inch core, calculated from concentrations on days 0 212, was 35 days ( r2 = 0.80 ). The maximum average concentration of GS 34048 was 0.21 ppm ( observed at day 6) in the 0 6 inch depth profile and was present at concentrations  0.012 ppm up to 330 days post application. This degradate was detected at all depths, including the deepest soil profile ( 36 48 inches) at a maximum concentration of 0.017 ppm. GS 17794 and GS 11354 were detected at maximum average concentrations 0.013 and 0.023 ppm, respectively, in the 0 6 inch core, but were not detected after 14 days post application, and were not detected deeper within the soil profile.

A third supplemental field dissipation study ( MRID 41872301) supported the conclusions of the other studies. Ametryn was applied once at 4 lbs a. i./ A to an unvegetative field in Illinois and its dissipation was monitored over time. The dissipation of ametryn was considered bi phasic with fairly rapid dissipation over the first 60 days followed by much slower dissipation thereafter. The half life during the initial 60 days was about 9 days. The overall dissipation half life ( using concentrations from day 0 to day 330) in the 0 6 inch core was calculated as 48 days ( r2 = 0.84). In the 0 6 inch depth profile, the ametryn concentrations were 1.7, 1.3, 0.29, 0.078, and ranged from 0.019 0.021 ppm at 1, 3, 14, 28, and 60 212 days, respectively, post application. In the 6 12 inch soil core, the maximum concentration ( 0.043 ppm) of ametryn was observed 14 days post application. Ametryn was not detected below the 6 12 inch soil profile. GS 34048 had a maximum average concentration of 0.22 ppm at day 14 in the 0 6 inch profile and was present at concentrations  0.014 ppm up to 270 days. GS 34048 was also detected at all depths sampled, including the deepest ( 36 48 inches) at 0.016 ppm. GS 17794 and GS 11354 were detected at maximum average concentrations 0.020 and 0.026 ppm, respectively, in the 0 6 inch core, but were not detected after 28 days post application. Neither of these degradation products were detected at any of the deeper levels.

Data from the three field dissipation studies are summarized in Table B2.

Table B2. Terrestrial field dissipation study results.

MRID Soil Texture ( 0 6 inch depth) Target Applic. Rate ( lb ai/ A) Site Plot Type Dissipation Half life ( or DT 50) in Soil ( days) Parent Max. Leaching Depth ( inches) Major Degradates1 & Max. Leaching Depth ( inches) Applic. Type/ Formulation 41752402 26% sand; 67% silt; 7% clay; 1% OM. 2.51 LA sugarcane field t 1/ 2 = 62 ( r2 = 0.89) 6 12 GS 34048 ( 6 12)

GS 17794 ( 0 6)

GS 11354 ( 0 6) spray applicator/ WP 41872302 93% sand; 3% silt; 4% clay; 1.6% OM. 2 IL corn field t 1/ 2 = 35 ( r2 = 0.80) 6 12 GS 34048 ( 36 48)

GS 17794 ( 0 6)

GS 11354 ( 0 6) spray applicator/ WP 41872301 93% sand; 3% silt; 4% clay; 1.6% OM. 4 IL bareground t 1/ 2 = 48 ( r2 = 0.84) 6 12 GS 34048 ( 36 48)

GS 17794 ( 0 6)

GS 11354 ( 0 6) spray applicator/ WP 1 2 ethylamino 4 isopropylamino 6 hydroxy s triazine ( GS 34048); 2 amino 4 isopropylamino 6 hydroxy s triazine ( GS 17794); 2 amino 4 isopropylamino 6 methylthio s triazine ( GS 11354)

2 Applied twice with an interval of one month. 89 Bioaccumulation A study ( MRID 42061901) has been submitted under Guideline # 165 4 ( Accumulation in Fish) and is under review.

APPENDIX C   PRZM   EXAMS OUTPUTS BY CROP 90 Corn   NC ( east)

Drinking water stored as dwcorn3. out Chemical: Ametryn PRZM environment: NCcornEC. txt modified Satday, 12 October 2002 at 17: 10: 28 EXAMS environment: ir298. exv modified Thuday, 29 August 2002 at 15: 34: 12 Metfile: w03812. dvf modified Wedday, 3 July 2002 at 09: 05: 50 Water segment concentrations ( ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1965 32.76 31.99 29.08 25.44 23.9 10.46 1966 50.75 49.72 46 39.95 35.55 16.17 1967 22.62 22.15 20.93 18.34 16.9 9.525 1968 16.86 16.48 15.06 12.98 11.88 6.671 1969 30.1 29.43 27.98 26.39 24.47 11.55 1970 9.139 8.961 8.374 7.546 7.288 5.44 1971 19.41 18.97 17.78 16.19 14.72 7.367 1972 58.21 56.83 53.29 44.99 39.88 17.24 1973 93.36 91.41 86.23 80.43 72.73 32.5 1974 52.58 51.42 49.28 42.52 37.87 19.89 1975 44.79 43.76 41.46 36.05 32.08 15.74 1976 47.61 46.56 42.66 35.95 32.52 15.7 1977 16.87 16.59 15.28 14.17 13 7.881 1978 27.46 26.83 24.87 22 19.49 9.015 1979 44.85 43.8 42.35 36.85 32.67 14.54 1980 53.53 52.48 48.98 42.52 37.97 17.45 1981 32.85 32.26 30.22 25.53 22.58 12.31 1982 24.33 23.79 21.68 20.41 18.84 9.717 1983 16.52 16.16 15.21 13.8 13.09 6.967 1984 38.09 37.31 34.07 30.05 26.77 12.03 1985 12.81 12.55 11.59 10.61 10.36 7.014 1986 19.65 19.2 17.95 15.08 13.68 7.691 1987 65.94 64.51 59.9 50.9 44.58 18.84 1988 11.62 11.43 10.86 9.793 9.076 7.428 1989 48.17 47.03 43.13 36.59 32.37 14.33 1990 24.3 23.76 22.14 20.39 18.75 10.17 Sorted results 91 Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.037037037037037 93.36 91.41 86.23 80.43 72.73 32.5 0.0740740740740741 65.94 64.51 59.9 50.9 44.58 19.89 0.111111111111111 58.21 56.83 53.29 44.99 39.88 18.84 0.148148148148148 53.53 52.48 49.28 42.52 37.97 17.45 0.185185185185185 52.58 51.42 48.98 42.52 37.87 17.24 0.222222222222222 50.75 49.72 46 39.95 35.55 16.17 0.259259259259259 48.17 47.03 43.13 36.85 32.67 15.74 0.296296296296296 47.61 46.56 42.66 36.59 32.52 15.7 0.333333333333333 44.85 43.8 42.35 36.05 32.37 14.54 0.37037037037037 44.79 43.76 41.46 35.95 32.08 14.33 0.407407407407407 38.09 37.31 34.07 30.05 26.77 12.31 0.444444444444444 32.85 32.26 30.22 26.39 24.47 12.03 0.481481481481481 32.76 31.99 29.08 25.53 23.9 11.55 0.518518518518518 30.1 29.43 27.98 25.44 22.58 10.46 0.555555555555556 27.46 26.83 24.87 22 19.49 10.17 0.592592592592593 24.33 23.79 22.14 20.41 18.84 9.717 0.62962962962963 24.3 23.76 21.68 20.39 18.75 9.525 0.666666666666667 22.62 22.15 20.93 18.34 16.9 9.015 0.703703703703704 19.65 19.2 17.95 16.19 14.72 7.881 0.740740740740741 19.41 18.97 17.78 15.08 13.68 7.691 0.777777777777778 16.87 16.59 15.28 14.17 13.09 7.428 0.814814814814815 16.86 16.48 15.21 13.8 13 7.367 0.851851851851852 16.52 16.16 15.06 12.98 11.88 7.014 0.888888888888889 12.81 12.55 11.59 10.61 10.36 6.967 0.925925925925926 11.62 11.43 10.86 9.793 9.076 6.671 0.962962962962963 9.139 8.961 8.374 7.546 7.288 5.44 0.1 60.529 59.134 55.273 46.763 41.29 19.155 Average of yearly averages: 12.4475384615385 Inputs generated by pe4. pl  8 August 2003 Data used for this run:

Output File: dwcorn3 Metfile: w03812. dvf PRZM scenario: NCcornEC. txt EXAMS environment file: ir298. exv Chemical Name: Ametryn Description Variable Name Value Units Comments Molecular weight mwt 227.3 g/ mol Henry's Law Const. henry atm m^ 3/ mol 92 Vapor Pressure vapr 2.74e 6 torr Solubility sol 1850 mg/ L Kd Kd mg/ L Koc Koc 371 mg/ L Photolysis half life kdp 368 days Half life Aerobic Aquatic Metabolism kbacw 546 days Halfife Anaerobic Aquatic Metabolism kbacs days Halfife Aerobic Soil Metabolism asm 273 days Halfife Hydrolysis: pH 7 0 days Half life Method: CAM 1 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 2.24 kg/ ha Application Efficiency: APPEFF .99 fraction Spray Drift DRFT .064 fraction of application rate applied to pond Application Date Date 18 04 dd/ mm or dd/ mmm or dd mm or dd mmm Record 17: FILTRA IPSCND 1 UPTKF Record 18: PLVKRT PLDKRT FEXTRC 0.5 Flag for Index Res. Run IR IR Flag for runoff calc. RUNOFF total none, monthly or total( average of entire run)

ECO stored as corneco. out Chemical: Ametryn PRZM environment: NCcornEC. txt modified Satday, 12 October 2002 at 17: 10: 28 EXAMS environment: pond298. exv modified Thuday, 29 August 2002 at 16: 33: 30 Metfile: w03812. dvf modified Wedday, 3 July 2002 at 09: 05: 50 Water segment concentrations ( ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1965 14.01 13.83 13.19 12.75 12.25 7.38 1966 28.63 28.41 27.68 26.84 25.99 19.07 1967 28.25 28.13 27.74 27 26.54 23.77 1968 28.61 28.5 28.06 27.37 26.94 25 1969 36.05 35.88 35.26 34.63 34.23 29.83 93 1970 30.66 30.61 30.42 30.16 30.01 29.37 1971 33.9 33.77 33.51 33.15 32.72 29.9 1972 50.66 50.3 49.69 47.92 46.78 38.24 1973 77.85 77.55 75.65 73.65 72.39 57.78 1974 76.4 76.07 75.29 73.68 72.36 65.17 1975 77.22 76.9 76.36 74.76 73.41 66.98 1976 80.43 80.13 78.91 76.73 75.38 69 1977 69.88 69.76 69.19 68.54 67.99 65.33 1978 69.29 69.08 68.36 67.32 66.27 61.71 1979 73.98 73.68 73 71.69 70.42 63.25 1980 79.06 78.77 77.7 75.93 74.47 66.46 1981 74.19 73.95 73.12 71.26 69.99 66.06 1982 69.37 69.21 68.43 67.95 67.25 63.42 1983 63.4 63.26 62.87 62.27 61.83 58.85 1984 68.09 67.82 66.88 65.87 64.78 58.94 1985 57.25 57.24 57.2 57.05 56.85 55.5 1986 57.17 57.02 56.51 55.19 54.41 52.44 1987 73.7 73.29 72.13 69.85 68.03 57.97 1988 59.6 59.58 59.52 59.35 59.14 56.38 1989 69.58 69.25 68.23 66.52 65.2 58.11 1990 62.98 62.8 62.25 61.68 60.98 57.43 Sorted results Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.037037037037037 80.43 80.13 78.91 76.73 75.38 69 0.0740740740740741 79.06 78.77 77.7 75.93 74.47 66.98 0.111111111111111 77.85 77.55 76.36 74.76 73.41 66.46 0.148148148148148 77.22 76.9 75.65 73.68 72.39 66.06 0.185185185185185 76.4 76.07 75.29 73.65 72.36 65.33 0.222222222222222 74.19 73.95 73.12 71.69 70.42 65.17 0.259259259259259 73.98 73.68 73 71.26 69.99 63.42 0.296296296296296 73.7 73.29 72.13 69.85 68.03 63.25 0.333333333333333 69.88 69.76 69.19 68.54 67.99 61.71 0.37037037037037 69.58 69.25 68.43 67.95 67.25 58.94 0.407407407407407 69.37 69.21 68.36 67.32 66.27 58.85 0.444444444444444 69.29 69.08 68.23 66.52 65.2 58.11 0.481481481481481 68.09 67.82 66.88 65.87 64.78 57.97 0.518518518518518 63.4 63.26 62.87 62.27 61.83 57.78 0.555555555555556 62.98 62.8 62.25 61.68 60.98 57.43 0.592592592592593 59.6 59.58 59.52 59.35 59.14 56.38 0.62962962962963 57.25 57.24 57.2 57.05 56.85 55.5 0.666666666666667 57.17 57.02 56.51 55.19 54.41 52.44 94 0.703703703703704 50.66 50.3 49.69 47.92 46.78 38.24 0.740740740740741 36.05 35.88 35.26 34.63 34.23 29.9 0.777777777777778 33.9 33.77 33.51 33.15 32.72 29.83 0.814814814814815 30.66 30.61 30.42 30.16 30.01 29.37 0.851851851851852 28.63 28.5 28.06 27.37 26.94 25 0.888888888888889 28.61 28.41 27.74 27 26.54 23.77 0.925925925925926 28.25 28.13 27.68 26.84 25.99 19.07 0.962962962962963 14.01 13.83 13.19 12.75 12.25 7.38 0.1 78.213 77.916 76.762 75.111 73.728 66.616 Average of yearly averages: 50.1284615384615 Inputs generated by pe4. pl  8 August 2003 Data used for this run:

Output File: corneco Metfile: w03812. dvf PRZM scenario: NCcornEC. txt EXAMS environment file: pond298. exv Chemical Name: Ametryn Description Variable Name Value Units Comments Molecular weight mwt 227.3 g/ mol Henry's Law Const. henry atm m^ 3/ mol Vapor Pressure vapr 2.74e 6 torr Solubility sol 1850 mg/ L Kd Kd mg/ L Koc Koc 371 mg/ L Photolysis half life kdp 368 days Half life Aerobic Aquatic Metabolism kbacw 504 days Halfife Anaerobic Aquatic Metabolism kbacs days Halfife Aerobic Soil Metabolism asm 252 days Halfife Hydrolysis: pH 7 0 days Half life Method: CAM 1 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 2.24 kg/ ha Application Efficiency: APPEFF .99 fraction Spray Drift DRFT .01 fraction of application rate applied to pond Application Date Date 18 04 dd/ mm or dd/ mmm or dd mm or dd mmm Record 17: FILTRA IPSCND 1 UPTKF Record 18: PLVKRT 95 PLDKRT FEXTRC 0.5 Flag for Index Res. Run IR Pond Flag for runoff calc. RUNOFF none none, monthly or total( average of entire run)

Corn   NC ( west)

Drinking water stored as dwcornw3. out Chemical: Ametryn PRZM environment: NCcornWC. txt modified Satday, 12 October 2002 at 17: 11: 14 EXAMS environment: ir298. exv modified Thuday, 29 August 2002 at 15: 34: 12 Metfile: w03812. dvf modified Wedday, 3 July 2002 at 09: 05: 50 Water segment concentrations ( ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1965 26.27 25.67 23.88 22.23 20.3 9.546 1966 43.65 42.8 40.26 38.36 34.88 17.26 1967 34.79 34.01 31.1 27.97 25.68 14.38 1968 21.25 20.78 19.03 17.87 17.52 10.62 1969 27.76 27.16 25.12 21.78 21.18 13.85 1970 16.08 15.73 14.71 12.78 11.44 8.177 1971 21.77 21.29 19.62 17.61 17.15 9.77 1972 43.07 42.13 38.5 35.25 34.58 17.16 1973 93.84 92.28 84.37 71.49 67.55 32.9 1974 39.35 38.52 36.98 33.01 30.43 18.45 1975 46.33 45.38 41.73 37.56 33.61 16.79 1976 55.61 54.44 50.05 44.36 39.67 19.45 1977 16.43 16.18 14.97 14.6 14.23 10.58 1978 27.7 27.08 24.92 22.35 20.13 11.66 1979 30.85 30.17 29.1 26.55 24.32 12.63 1980 38.33 37.61 35.09 32.97 30.6 15.16 1981 48.49 47.34 43.27 36.53 32.28 15.97 1982 22.12 21.71 20.83 19.52 19.32 12.33 1983 17.91 17.53 16.33 15.17 14.1 9.016 1984 36.9 36.05 33.06 31.26 28.91 14.34 1985 25.91 25.32 23.74 20.13 17.9 10.28 1986 23.61 23.21 21.85 19.69 17.99 11.56 1987 62.19 60.88 57.42 50.68 44.76 21.3 96 1988 13.72 13.56 12.91 11.61 10.74 9.327 1989 40.01 39.08 36.27 34.65 32.72 16.06 1990 25.39 24.85 22.95 20.95 20.39 13.46 Sorted results Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.037037037037037 93.84 92.28 84.37 71.49 67.55 32.9 0.0740740740740741 62.19 60.88 57.42 50.68 44.76 21.3 0.111111111111111 55.61 54.44 50.05 44.36 39.67 19.45 0.148148148148148 48.49 47.34 43.27 38.36 34.88 18.45 0.185185185185185 46.33 45.38 41.73 37.56 34.58 17.26 0.222222222222222 43.65 42.8 40.26 36.53 33.61 17.16 0.259259259259259 43.07 42.13 38.5 35.25 32.72 16.79 0.296296296296296 40.01 39.08 36.98 34.65 32.28 16.06 0.333333333333333 39.35 38.52 36.27 33.01 30.6 15.97 0.37037037037037 38.33 37.61 35.09 32.97 30.43 15.16 0.407407407407407 36.9 36.05 33.06 31.26 28.91 14.38 0.444444444444444 34.79 34.01 31.1 27.97 25.68 14.34 0.481481481481481 30.85 30.17 29.1 26.55 24.32 13.85 0.518518518518518 27.76 27.16 25.12 22.35 21.18 13.46 0.555555555555556 27.7 27.08 24.92 22.23 20.39 12.63 0.592592592592593 26.27 25.67 23.88 21.78 20.3 12.33 0.62962962962963 25.91 25.32 23.74 20.95 20.13 11.66 0.666666666666667 25.39 24.85 22.95 20.13 19.32 11.56 0.703703703703704 23.61 23.21 21.85 19.69 17.99 10.62 0.740740740740741 22.12 21.71 20.83 19.52 17.9 10.58 0.777777777777778 21.77 21.29 19.62 17.87 17.52 10.28 0.814814814814815 21.25 20.78 19.03 17.61 17.15 9.77 0.851851851851852 17.91 17.53 16.33 15.17 14.23 9.546 0.888888888888889 16.43 16.18 14.97 14.6 14.1 9.327 0.925925925925926 16.08 15.73 14.71 12.78 11.44 9.016 0.962962962962963 13.72 13.56 12.91 11.61 10.74 8.177 0.1 57.584 56.372 52.261 46.256 41.197 20.005 Average of yearly averages: 14.3086923076923 Inputs generated by pe4. pl  8 August 2003 Data used for this run:

Output File: dwcornw3 Metfile: w03812. dvf PRZM scenario: NCcornWC. txt 97 EXAMS environment file: ir298. exv Chemical Name: Ametryn Description Variable Name Value Units Comments Molecular weight mwt 227.3 g/ mol Henry's Law Const. henry atm m^ 3/ mol Vapor Pressure vapr 2.74e 6 torr Solubility sol 1850 mg/ L Kd Kd mg/ L Koc Koc 371 mg/ L Photolysis half life kdp 368 days Half life Aerobic Aquatic Metabolism kbacw 546 days Halfife Anaerobic Aquatic Metabolism kbacs days Halfife Aerobic Soil Metabolism asm 273 days Halfife Hydrolysis: pH 7 0 days Half life Method: CAM 1 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 2.24 kg/ ha Application Efficiency: APPEFF .99 fraction Spray Drift DRFT .064 fraction of application rate applied to pond Application Date Date 18 04 dd/ mm or dd/ mmm or dd mm or dd mmm Record 17: FILTRA IPSCND 1 UPTKF Record 18: PLVKRT PLDKRT FEXTRC 0.5 Flag for Index Res. Run IR IR Flag for runoff calc. RUNOFF total none, monthly or total( average of entire run)

ECO stored as cornecow. out Chemical: Ametryn PRZM environment: NCcornWC. txt modified Satday, 12 October 2002 at 17: 11: 14 EXAMS environment: pond298. exv modified Thuday, 29 August 2002 at 16: 33: 30 Metfile: w03812. dvf modified Wedday, 3 July 2002 at 09: 05: 50 Water segment concentrations ( ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1965 12.1 11.97 11.52 10.92 10.61 6.511 98 1966 26.88 26.66 26.23 25.4 24.94 19.04 1967 33.9 33.7 32.93 32.47 32.09 27.49 1968 35.28 35.22 34.95 34.25 34.18 31.58 1969 42.62 42.44 41.88 41.07 40.52 37.1 1970 40.41 40.27 39.88 39.14 38.63 37.88 1971 43.53 43.37 42.83 42.14 41.78 39.1 1972 55.54 55.29 54.3 52.81 51.98 45.9 1973 85.14 84.67 82.69 79.42 77.75 64.37 1974 77.23 76.98 76.4 75.45 74.7 70 1975 82.6 82.31 81.12 79.59 78.29 71.76 1976 88.3 87.98 86.7 85.3 83.9 75.97 1977 76.82 76.7 76.12 75.72 75.43 73.56 1978 77.35 77.14 76.4 75.36 74.37 70.8 1979 76.68 76.46 75.89 75.24 74.44 69.7 1980 78.4 78.21 77.05 76.52 75.68 69.92 1981 83.63 83.23 81.81 79.34 77.82 71.56 1982 73.94 73.75 73.28 72.86 72.76 70.41 1983 70.65 70.47 70.04 69.33 68.96 66.45 1984 75.33 75.1 74.04 73.56 72.89 67.29 1985 69.24 69.02 68.47 67.28 66.53 64.84 1986 66.74 66.6 66.11 65.45 64.98 63.54 1987 83.41 83.05 82.01 80.49 78.71 69.74 1988 71.3 71.28 71.2 70.98 70.73 67.71 1989 77.79 77.59 76.81 75.9 75.51 69.2 1990 73.35 73.13 72.34 71.5 71.51 69.1 Sorted results Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.037037037037037 88.3 87.98 86.7 85.3 83.9 75.97 0.0740740740740741 85.14 84.67 82.69 80.49 78.71 73.56 0.111111111111111 83.63 83.23 82.01 79.59 78.29 71.76 0.148148148148148 83.41 83.05 81.81 79.42 77.82 71.56 0.185185185185185 82.6 82.31 81.12 79.34 77.75 70.8 0.222222222222222 78.4 78.21 77.05 76.52 75.68 70.41 0.259259259259259 77.79 77.59 76.81 75.9 75.51 70 0.296296296296296 77.35 77.14 76.4 75.72 75.43 69.92 0.333333333333333 77.23 76.98 76.4 75.45 74.7 69.74 0.37037037037037 76.82 76.7 76.12 75.36 74.44 69.7 0.407407407407407 76.68 76.46 75.89 75.24 74.37 69.2 0.444444444444444 75.33 75.1 74.04 73.56 72.89 69.1 0.481481481481481 73.94 73.75 73.28 72.86 72.76 67.71 0.518518518518518 73.35 73.13 72.34 71.5 71.51 67.29 99 0.555555555555556 71.3 71.28 71.2 70.98 70.73 66.45 0.592592592592593 70.65 70.47 70.04 69.33 68.96 64.84 0.62962962962963 69.24 69.02 68.47 67.28 66.53 64.37 0.666666666666667 66.74 66.6 66.11 65.45 64.98 63.54 0.703703703703704 55.54 55.29 54.3 52.81 51.98 45.9 0.740740740740741 43.53 43.37 42.83 42.14 41.78 39.1 0.777777777777778 42.62 42.44 41.88 41.07 40.52 37.88 0.814814814814815 40.41 40.27 39.88 39.14 38.63 37.1 0.851851851851852 35.28 35.22 34.95 34.25 34.18 31.58 0.888888888888889 33.9 33.7 32.93 32.47 32.09 27.49 0.925925925925926 26.88 26.66 26.23 25.4 24.94 19.04 0.962962962962963 12.1 11.97 11.52 10.92 10.61 6.511 0.1 84.083 83.662 82.214 79.86 78.416 72.3 Average of yearly averages: 57.3277307692307 Inputs generated by pe4. pl  8 August 2003 Data used for this run:

Output File: cornecow Metfile: w03812. dvf PRZM scenario: NCcornWC. txt EXAMS environment file: pond298. exv Chemical Name: Ametryn Description Variable Name Value Units Comments Molecular weight mwt 227.3 g/ mol Henry's Law Const. henry atm m^ 3/ mol Vapor Pressure vapr 2.74e 6 torr Solubility sol 1850 mg/ L Kd Kd mg/ L Koc Koc 371 mg/ L Photolysis half life kdp 368 days Half life Aerobic Aquatic Metabolism kbacw 504 days Halfife Anaerobic Aquatic Metabolism kbacs days Halfife Aerobic Soil Metabolism asm 252 days Halfife Hydrolysis: pH 7 0 days Half life Method: CAM 1 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 2.24 kg/ ha Application Efficiency: APPEFF .99 fraction Spray Drift DRFT .01 fraction of application rate applied to pond Application Date Date 18 04 dd/ mm or dd/ mmm or dd mm or dd mmm 100 Record 17: FILTRA IPSCND 1 UPTKF Record 18: PLVKRT PLDKRT FEXTRC 0.5 Flag for Index Res. Run IR Pond Flag for runoff calc. RUNOFF none none, monthly or total( average of entire run)

Sugarcane   FL Drinking water stored as dwflsug4. out Chemical: Ametryn PRZM environment: FLsugarcaneC. txt modified Satday, 12 October 2002 at 16: 42: 14 EXAMS environment: ir298. exv modified Thuday, 29 August 2002 at 15: 34: 12 Metfile: w12844. dvf modified Wedday, 3 July 2002 at 09: 04: 30 Water segment concentrations ( ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1961 83.04 79.1 67.14 56.09 51.61 20.31 1962 96.83 92.25 78.45 72.05 64.67 26.24 1963 188 180 151 107 84.82 29.34 1964 153 147 131 119 100 36.61 1965 113 108 90.88 74.46 62.44 25.42 1966 88.72 84.58 72.87 59.59 51.81 29.83 1967 101 96.92 86.64 67.13 55.83 27.03 1968 163 155 144 109 90.3 34.29 1969 116 111 102 84.26 71.21 30.23 1970 165 159 134 99.16 98.32 42.65 1971 136 131 109 92.14 79.17 29.44 1972 250 239 211 168 139 48.53 1973 77.44 74.47 68.66 61.3 56.15 25 1974 50.75 48.44 42.95 36.45 33.75 17.99 1975 69.72 66.79 60.63 53.22 44.23 17.37 1976 125 120 101 79.91 67.19 28.92 1977 258 246 222 189 154 50.59 1978 83.39 79.84 68.38 59.5 52.76 23.04 1979 348 331 279 205 167 54.48 101 1980 104 99.57 87.11 68.26 60.69 28.15 1981 93.69 89.9 81.86 67.58 57.06 26.88 1982 252 244 211 180 156 55.5 1983 81.25 78.47 72.97 55.41 47.04 23.84 1984 154 147 124 98 99.08 41.58 1985 102 97.44 80.3 76.53 73.88 31.86 1986 66.32 64.32 56.89 46.63 38.78 20.8 1987 122 116 97.8 75.79 69.36 30.42 1988 150 144 124 116 101 39.85 1989 121 116 99.48 69.46 60.03 25.08 1990 89.54 85.46 74.97 62.13 52.26 22.51 Sorted results Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.032258064516129 348 331 279 205 167 55.5 0.0645161290322581 258 246 222 189 156 54.48 0.0967741935483871 252 244 211 180 154 50.59 0.129032258064516 250 239 211 168 139 48.53 0.161290322580645 188 180 151 119 101 42.65 0.193548387096774 165 159 144 116 100 41.58 0.225806451612903 163 155 134 109 99.08 39.85 0.258064516129032 154 147 131 107 98.32 36.61 0.290322580645161 153 147 124 99.16 90.3 34.29 0.32258064516129 150 144 124 98 84.82 31.86 0.354838709677419 136 131 109 92.14 79.17 30.42 0.387096774193548 125 120 102 84.26 73.88 30.23 0.419354838709677 122 116 101 79.91 71.21 29.83 0.451612903225806 121 116 99.48 76.53 69.36 29.44 0.483870967741936 116 111 97.8 75.79 67.19 29.34 0.516129032258065 113 108 90.88 74.46 64.67 28.92 0.548387096774194 104 99.57 87.11 72.05 62.44 28.15 0.580645161290323 102 97.44 86.64 69.46 60.69 27.03 0.612903225806452 101 96.92 81.86 68.26 60.03 26.88 0.645161290322581 96.83 92.25 80.3 67.58 57.06 26.24 0.67741935483871 93.69 89.9 78.45 67.13 56.15 25.42 0.709677419354839 89.54 85.46 74.97 62.13 55.83 25.08 0.741935483870968 88.72 84.58 72.97 61.3 52.76 25 0.774193548387097 83.39 79.84 72.87 59.59 52.26 23.84 0.806451612903226 83.04 79.1 68.66 59.5 51.81 23.04 0.838709677419355 81.25 78.47 68.38 56.09 51.61 22.51 0.870967741935484 77.44 74.47 67.14 55.41 47.04 20.8 0.903225806451613 69.72 66.79 60.63 53.22 44.23 20.31 102 0.935483870967742 66.32 64.32 56.89 46.63 38.78 17.99 0.967741935483871 50.75 48.44 42.95 36.45 33.75 17.37 0.1 251.8 243.5 211 178.8 152.5 50.384 Average of yearly averages: 31.4593333333333 Inputs generated by pe4. pl  8 August 2003 Data used for this run:

Output File: dwflsug4 Metfile: w12844. dvf PRZM scenario: FLsugarcaneC. txt EXAMS environment file: ir298. exv Chemical Name: Ametryn Description Variable Name Value Units Comments Molecular weight mwt 227.3 g/ mol Henry's Law Const. henry atm m^ 3/ mol Vapor Pressure vapr 2.74E 6 torr Solubility sol 1850 mg/ L Kd Kd mg/ L Koc Koc 371 mg/ L Photolysis half life kdp 368 days Half life Aerobic Aquatic Metabolism kbacw 546 days Halfife Anaerobic Aquatic Metabolism kbacs days Halfife Aerobic Soil Metabolism asm 273 days Halfife Hydrolysis: pH 7 0 days Half life Method: CAM 2 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 1.344 kg/ ha Application Efficiency: APPEFF .95 fraction Spray Drift DRFT .16 fraction of application rate applied to pond Application Date Date 15 02 dd/ mm or dd/ mmm or dd mm or dd mmm Interval 1 interval 30 days Set to 0 or delete line for single app.

Interval 2 interval 30 days Set to 0 or delete line for single app.

Record 17: FILTRA IPSCND 2 UPTKF Record 18: PLVKRT PLDKRT FEXTRC 0.5 Flag for Index Res. Run IR IR 103 Flag for runoff calc. RUNOFF total none, monthly or total( average of entire run)

ECO stored as amflfeb. out Chemical: Ametryn PRZM environment: FLsugarcaneC. txt modified Satday, 12 October 2002 at 16: 42: 14 EXAMS environment: pond298. exv modified Thuday, 29 August 2002 at 16: 33: 30 Metfile: w12844. dvf modified Wedday, 3 July 2002 at 09: 04: 30 Water segment concentrations ( ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 1961 46.07 45.67 44.82 43.22 42.03 30.61 1962 90.71 89.94 86.99 84.57 84.74 67.71 1963 147 145 141 134 129 100 1964 182 181 177 174 170 138 1965 178 177 173 171 168 148 1966 192 191 189 186 183 166 1967 199 198 197 192 188 170 1968 236 234 232 224 218 187 1969 230 229 227 226 223 198 1970 264 263 259 253 248 221 1971 252 251 248 244 242 216 1972 311 309 304 297 288 240 1973 250 249 247 243 241 224 1974 213 213 210 208 207 198 1975 197 196 194 192 189 176 1976 220 219 215 207 203 181 1977 291 290 284 274 267 216 1978 238 237 234 230 227 212 1979 327 324 318 308 301 244 1980 276 275 272 266 261 241 1981 254 253 250 246 241 225 1982 331 330 326 316 308 260 1983 268 267 266 259 255 239 1984 294 293 288 281 276 246 1985 273 272 269 265 264 242 1986 240 239 237 233 230 218 1987 249 248 243 237 234 211 104 1988 271 270 264 258 255 222 1989 248 247 243 235 232 211 1990 218 217 215 213 209 193 Sorted results Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly 0.032258064516129 331 330 326 316 308 260 0.0645161290322581 327 324 318 308 301 246 0.0967741935483871 311 309 304 297 288 244 0.129032258064516 294 293 288 281 276 242 0.161290322580645 291 290 284 274 267 241 0.193548387096774 276 275 272 266 264 240 0.225806451612903 273 272 269 265 261 239 0.258064516129032 271 270 266 259 255 225 0.290322580645161 268 267 264 258 255 224 0.32258064516129 264 263 259 253 248 222 0.354838709677419 254 253 250 246 242 221 0.387096774193548 252 251 248 244 241 218 0.419354838709677 250 249 247 243 241 216 0.451612903225806 249 248 243 237 234 216 0.483870967741936 248 247 243 235 232 212 0.516129032258065 240 239 237 233 230 211 0.548387096774194 238 237 234 230 227 211 0.580645161290323 236 234 232 226 223 198 0.612903225806452 230 229 227 224 218 198 0.645161290322581 220 219 215 213 209 193 0.67741935483871 218 217 215 208 207 187 0.709677419354839 213 213 210 207 203 181 0.741935483870968 199 198 197 192 189 176 0.774193548387097 197 196 194 192 188 170 0.806451612903226 192 191 189 186 183 166 0.838709677419355 182 181 177 174 170 148 0.870967741935484 178 177 173 171 168 138 0.903225806451613 147 145 141 134 129 100 0.935483870967742 90.71 89.94 86.99 84.57 84.74 67.71 0.967741935483871 46.07 45.67 44.82 43.22 42.03 30.61 0.1 309.3 307.4 302.4 295.4 286.8 243.8 Average of yearly averages: 194.710666666667 Inputs generated by pe4. pl  8 August 2003 105 Data used for this run:

Output File: amflfeb Metfile: w12844. dvf PRZM scenario: FLsugarcaneC. txt EXAMS environment file: pond298. exv Chemical Name: Ametryn Description Variable Name Value Units Comments Molecular weight mwt 227.3 g/ mol Henry's Law Const. henry atm m^ 3/ mol Vapor Pressure vapr 2.74E 6 torr Solubility sol 1850 mg/ L Kd Kd mg/ L Koc Koc 371 mg/ L Photolysis half life kdp 368 days Half life Aerobic Aquatic Metabolism kbacw 504 days Halfife Anaerobic Aquatic Metabolism kbacs days Halfife Aerobic Soil Metabolism asm 252 days Halfife Hydrolysis: pH 7 0 days Half life Method: CAM 2 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 1.344 kg/ ha Application Efficiency: APPEFF .95 fraction Spray Drift DRFT .05 fraction of application rate applied to pond Application Date Date 15 02 dd/ mm or dd/ mmm or dd mm or dd mmm Interval 1 interval 30 days Set to 0 or delete line for single app.

Interval 2 interval 30 days Set to 0 or delete line for single app.

Record 17: FILTRA IPSCND 2 UPTKF Record 18: PLVKRT PLDKRT FEXTRC 0.5 Flag for Index Res. Run IR Pond Flag for runoff calc. RUNOFF none none, monthly or total( average of entire run)

Sugarcane   LA Drinking water Louisiana Sugar DW for Ametryn 106 WATER COLUMN DISSOLVED CONCENTRATION ( PPB)

YEAR PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

1961 300.000 288.000 260.000 207.000 162.000 47.260 1962 290.000 279.000 249.000 196.000 163.000 88.490 1963 204.000 196.000 180.000 151.000 131.000 75.780 1964 316.000 304.000 259.000 212.000 208.000 108.000 1965 170.000 163.000 141.000 130.000 125.000 75.920 1966 185.000 180.000 174.000 164.000 145.000 67.410 1967 168.000 162.000 122.000 83.850 79.920 62.140 1968 258.000 248.000 219.000 161.000 134.000 74.030 1969 210.000 202.000 173.000 137.000 131.000 81.970 1970 248.000 239.000 177.000 130.000 121.000 81.370 1971 367.000 352.000 312.000 185.000 152.000 88.060 1972 293.000 282.000 259.000 210.000 177.000 97.550 1973 391.000 380.000 235.000 198.000 165.000 91.870 1974 382.000 368.000 328.000 264.000 220.000 93.920 1975 281.000 272.000 237.000 176.000 148.000 71.070 1976 212.000 203.000 187.000 138.000 107.000 63.380 1977 313.000 304.000 265.000 215.000 179.000 105.000 1978 239.000 230.000 200.000 162.000 138.000 81.750 1979 200.000 192.000 179.000 162.000 147.000 84.170 1980 275.000 264.000 240.000 185.000 158.000 83.120 1981 205.000 197.000 181.000 151.000 139.000 70.510 1982 554.000 536.000 462.000 256.000 190.000 92.150 1983 523.000 503.000 433.000 335.000 278.000 124.000 1984 430.000 412.000 363.000 283.000 233.000 108.000 1985 208.000 201.000 174.000 156.000 141.000 88.450 1986 292.000 281.000 232.000 178.000 143.000 76.420 1987 255.000 245.000 228.000 194.000 165.000 84.900 1988 305.000 294.000 231.000 197.000 182.000 105.000 1989 364.000 352.000 323.000 267.000 209.000 110.000 1990 285.000 278.000 258.000 225.000 190.000 91.100 SORTED FOR PLOTTING

PROB PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY        107 0.032 554.000 536.000 462.000 335.000 278.000 124.000 0.065 523.000 503.000 433.000 283.000 233.000 110.000 0.097 430.000 412.000 363.000 267.000 220.000 108.000 0.129 391.000 380.000 328.000 264.000 209.000 108.000 0.161 382.000 368.000 323.000 256.000 208.000 105.000 0.194 367.000 352.000 312.000 225.000 190.000 105.000 0.226 364.000 352.000 265.000 215.000 190.000 97.550 0.258 316.000 304.000 260.000 212.000 182.000 93.920 0.290 313.000 304.000 259.000 210.000 179.000 92.150 0.323 305.000 294.000 259.000 207.000 177.000 91.870 0.355 300.000 288.000 258.000 198.000 165.000 91.100 0.387 293.000 282.000 249.000 197.000 165.000 88.490 0.419 292.000 281.000 240.000 196.000 163.000 88.450 0.452 290.000 279.000 237.000 194.000 162.000 88.060 0.484 285.000 278.000 235.000 185.000 158.000 84.900 0.516 281.000 272.000 232.000 185.000 152.000 84.170 0.548 275.000 264.000 231.000 178.000 148.000 83.120 0.581 258.000 248.000 228.000 176.000 147.000 81.970 0.613 255.000 245.000 219.000 164.000 145.000 81.750 0.645 248.000 239.000 200.000 162.000 143.000 81.370 0.677 239.000 230.000 187.000 162.000 141.000 76.420 0.710 212.000 203.000 181.000 161.000 139.000 75.920 0.742 210.000 202.000 180.000 156.000 138.000 75.780 0.774 208.000 201.000 179.000 151.000 134.000 74.030 0.806 205.000 197.000 177.000 151.000 131.000 71.070 0.839 204.000 196.000 174.000 138.000 131.000 70.510 0.871 200.000 192.000 174.000 137.000 125.000 67.410 0.903 185.000 180.000 173.000 130.000 121.000 63.380 0.935 170.000 163.000 141.000 130.000 107.000 62.140 0.968 168.000 162.000 122.000 83.850 79.920 47.260 1/ 10 426.100 408.800 359.500 266.700 218.900 108.000 MEAN OF ANNUAL VALUES = 85.760 STANDARD DEVIATION OF ANNUAL VALUES = 16.525 UPPER 90% CONFIDENCE LIMIT ON MEAN = 90.240 ECO 108 Louisiana Sugarcane EECs for Ametryn WATER COLUMN DISSOLVED CONCENTRATION ( PPB)

YEAR PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

1961 196.000 194.000 183.000 139.000 109.000 30.550 1962 273.000 271.000 224.000 217.000 216.000 192.000 1963 340.000 338.000 330.000 300.000 279.000 263.000 1964 452.000 451.000 447.000 429.000 423.000 357.000 1965 466.000 465.000 459.000 454.000 449.000 424.000 1966 508.000 507.000 504.000 499.000 494.000 452.000 1967 488.000 485.000 473.000 462.000 462.000 442.000 1968 539.000 538.000 524.000 512.000 507.000 465.000 1969 532.000 530.000 525.000 519.000 519.000 491.000 1970 587.000 584.000 560.000 550.000 544.000 516.000 1971 637.000 634.000 629.000 573.000 569.000 536.000 1972 646.000 644.000 641.000 635.000 629.000 577.000 1973 714.000 713.000 647.000 619.000 615.000 581.000 1974 725.000 723.000 716.000 710.000 701.000 629.000 1975 691.000 690.000 683.000 669.000 662.000 605.000 1976 620.000 619.000 613.000 604.000 599.000 562.000 1977 678.000 676.000 671.000 642.000 623.000 592.000 1978 682.000 681.000 678.000 673.000 668.000 616.000 1979 683.000 682.000 678.000 672.000 667.000 619.000 1980 668.000 666.000 663.000 641.000 638.000 603.000 1981 689.000 688.000 683.000 673.000 665.000 610.000 1982 794.000 786.000 742.000 633.000 623.000 585.000 1983 795.000 792.000 781.000 770.000 760.000 688.000 1984 771.000 767.000 759.000 751.000 724.000 683.000 1985 761.000 760.000 756.000 755.000 751.000 697.000 1986 730.000 728.000 715.000 710.000 707.000 656.000 1987 742.000 741.000 736.000 728.000 723.000 660.000 1988 746.000 745.000 739.000 732.000 724.000 672.000 1989 770.000 760.000 755.000 740.000 724.000 679.000 1990 800.000 799.000 793.000 785.000 778.000 702.000 SORTED FOR PLOTTING    109 PROB PEAK 96 HOUR 21 DAY 60 DAY 90 DAY YEARLY

0.032 800.000 799.000 793.000 785.000 778.000 702.000 0.065 795.000 792.000 781.000 770.000 760.000 697.000 0.097 794.000 786.000 759.000 755.000 751.000 688.000 0.129 771.000 767.000 756.000 751.000 724.000 683.000 0.161 770.000 760.000 755.000 740.000 724.000 679.000 0.194 761.000 760.000 742.000 732.000 724.000 672.000 0.226 746.000 745.000 739.000 728.000 723.000 660.000 0.258 742.000 741.000 736.000 710.000 707.000 656.000 0.290 730.000 728.000 716.000 710.000 701.000 629.000 0.323 725.000 723.000 715.000 673.000 668.000 619.000 0.355 714.000 713.000 683.000 673.000 667.000 616.000 0.387 691.000 690.000 683.000 672.000 665.000 610.000 0.419 689.000 688.000 678.000 669.000 662.000 605.000 0.452 683.000 682.000 678.000 642.000 638.000 603.000 0.484 682.000 681.000 671.000 641.000 629.000 592.000 0.516 678.000 676.000 663.000 635.000 623.000 585.000 0.548 668.000 666.000 647.000 633.000 623.000 581.000 0.581 646.000 644.000 641.000 619.000 615.000 577.000 0.613 637.000 634.000 629.000 604.000 599.000 562.000 0.645 620.000 619.000 613.000 573.000 569.000 536.000 0.677 587.000 584.000 560.000 550.000 544.000 516.000 0.710 539.000 538.000 525.000 519.000 519.000 491.000 0.742 532.000 530.000 524.000 512.000 507.000 465.000 0.774 508.000 507.000 504.000 499.000 494.000 452.000 0.806 488.000 485.000 473.000 462.000 462.000 442.000 0.839 466.000 465.000 459.000 454.000 449.000 424.000 0.871 452.000 451.000 447.000 429.000 423.000 357.000 0.903 340.000 338.000 330.000 300.000 279.000 263.000 0.935 273.000 271.000 224.000 217.000 216.000 192.000 0.968 196.000 194.000 183.000 139.000 109.000 30.550 1/ 10 791.700 784.100 758.700 754.600 748.300 687.500 MEAN OF ANNUAL VALUES = 539.485 STANDARD DEVIATION OF ANNUAL VALUES = 158.595 UPPER 90% CONFIDENCE LIMIT ON MEAN = 582.482 110 APPENDIX D   SCI GROW OUTPUT SCIGROW VERSION 2.3 ENVIRONMENTAL FATE AND EFFECTS DIVISION OFFICE OF PESTICIDE PROGRAMS U. S. ENVIRONMENTAL PROTECTION AGENCY SCREENING MODEL FOR AQUATIC PESTICIDE EXPOSURE Corn   NC SciGrow version 2.3 chemical: Ametryn time is 9/ 9/ 2004 12: 48: 53

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

2.000 1.0 2.000 9.60E+ 01 91.0

groundwater screening cond ( ppb) = 2.60E+ 00 ************************************************************************

Pineapple SciGrow version 2.3 chemical: Ametryn time is 8/ 18/ 2004 12: 36: 33  111 Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

7.200 1.0 7.200 9.60E+ 01 91.0

groundwater screening cond ( ppb) = 9.36E+ 00 ************************************************************************

Sugarcane   FL SciGrow version 2.3 chemical: Ametryn time is 1/ 5/ 2004 9: 15: 42

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

1.200 3.0 3.600 2.31E+ 02 84.0

groundwater screening cond ( ppb) = 1.58E+ 00 ************************************************************************

SciGrow version 2.3 chemical: Ametryn time is 9/ 9/ 2004 12: 48: 13

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

1.200 3.0 3.600 9.60E+ 01 91.0

groundwater screening cond ( ppb) = 4.68E+ 00 ************************************************************************

Sugarcane   HI SciGrow version 2.3 chemical: Ametryn time is 9/ 9/ 2004 12: 56: 13  112 Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

2.400 5.0 12.000 9.60E+ 01 91.0

groundwater screening cond ( ppb) = 1.56E+ 01 ************************************************************************

Sugarcane   LA SciGrow version 2.3 chemical: Ametryn time is 1/ 5/ 2004 9: 14: 46

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

2.400 5.0 12.000 2.31E+ 02 84.0

groundwater screening cond ( ppb) = 5.27E+ 00 ************************************************************************

SciGrow version 2.3 chemical: Ametryn time is 1/ 5/ 2004 9: 15: 15

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

2.320 5.0 11.600 2.31E+ 02 84.0

groundwater screening cond ( ppb) = 5.09E+ 00 ************************************************************************

SciGrow version 2.3 chemical: Ametryn time is 9/ 9/ 2004 12: 47: 43

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

 113 11.600 1.0 11.600 9.60E+ 01 91.0

groundwater screening cond ( ppb) = 1.51E+ 01 ************************************************************************

Sugarcane   PR SciGrow version 2.3 chemical: Ametryn time is 8/ 18/ 2004 12: 39: 52

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

4.000 4.0 16.000 9.60E+ 01 91.0

groundwater screening cond ( ppb) = 2.08E+ 01 ************************************************************************

SciGrow version 2.3 chemical: Ametryn time is 8/ 18/ 2004 12: 40: 12

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days)

8.000 2.0 16.000 9.60E+ 01 91.0

groundwater screening cond ( ppb) = 2.08E+ 01 ************************************************************************

Sugarcane   TX SciGrow version 2.3 chemical: Ametryn time is 9/ 9/ 2004 12: 46: 47

Application Number of Total Use Koc Soil Aerobic rate ( lb/ acre) applications ( lb/ acre/ yr) ( ml/ g) metabolism ( days) 114

2.000 3.0 6.000 9.60E+ 01 91.0

groundwater screening cond ( ppb) = 7.80E+ 00 ************************************************************************

APPENDIX E   TERRESTRIAL EECs : ELL FATE and TERRPLANT SPREADSHEETS A first order decay assumption is used to determine the concentration at each day after initial application based on the concentration resulting from the initial and additional applications. The decay is calculated from the first order rate equation:

CT = Cie kT or in log transformed form:

ln ( CT/ Ci) =  kT Where:

CT = concentration at time T Ci = concentration in parts per million ( ppm) present initially ( on day zero) on the surfaces.

Ci is calculated based on Kenaga and Fletcher by multiplying the application rate, in pounds active ingredient per acre, by 240 for short grass, 110 for tall grass, and 135 for broad leaf plants/ insects and 15 for seeds. Additional applications are converted from pounds active ingredient per acre to parts per million ( PPM) on the plant surface and the additional mass added to the mass of the chemical still present on the surfaces on the day of application.

k= degradation rate constant determined from studies of hydrolysis, photolysis, microbial degradation, etc. Since degradation rate is generally reported in terms of half life, the rate constant is calculated from the input half life ( k = ln 2/ t ½ ) instead of being input directly. Choosing which process controls the degradation rate and which half life to use in terrestrial exposure calculations is open for debate and should be done by a qualified scientist. 115 T= time, in days, since the start of the simulation. The initial application is on day 0. The simulation is set to run for 365 days.

The program calculates concentration on each type of surface on a daily interval for one year. The maximum concentration during the year and the average concentration during the first 56 days are calculated.

EECs for LA, HI, and PR sugarcane were calculated using FATE. The current version of Ell FATE was unable to calculate the EECs due to the uneven application rates. The maximum EEC for both mean and maximum Kenaga residues during each run was used as exposure value.

Max residues using FATE 116 Sugarcane Use Regimes by State Max Single Rate Max Seasonal Ra Apps/ Yr FL 1.2 3.6 3 LA 2 2.4 2.4 2.4 2.4 11.6 5 TX 2 2 2 6 3 HI 7.2 2.4 2.4 12 3 PR 8 4 4 16 3 all values Tall Grass Short Grass Short Grass Tall Grass Broadleaf Broadleaf Seeds Seeds PPM Initial Conc 240 Initial Conc 110 Initial Conc 135 Initial Conc 15 FL RAN WITH ELLFATE RAN WITH ELLFATE RAN WITH ELLFATE RAN WITH ELLFATE MAX EEC 535 245 301 33 LA 480 264.9815 220 121.4498 270 149.0521 30 16.5613 840.9815 464.2594 385.4498 212.7855 473.0521 261.1459 52.5613 29.0162 1040.2594 574.2697 476.7855 263.2069 585.1459 323.0267 65.0162 35.8918 1150.2697 635.0003 527.2069 291.0418 647.0267 357.1877 71.8918 39.6875 1211.0003 555.0418 681.1877 75.6875 MAX EEC 1211 555 681 76 TX RAN WITH ELLFATE RAN WITH ELLFATE RAN WITH ELLFATE RAN WITH ELLFATE MAX EEC 891 408 501 56 HI 1728 953.9333 792 437.2195 972 536.5875 108 59.6208 1529.9333 844.5917 701.2195 387.1045 860.5875 475.0828 95.6208 52.787 1420.5917 651.1045 799.0828 88.787 MAX EEC 1728 792 972 108 PR 1920 1059.926 880 485.7994 1080 596.2083 120 66.2454 2019.926 1115.09 925.7994 511.0827 1136.2083 627.2378 126.2454 69.6931 2075.09 951.0827 1167.2378 129.6931 MAX EEC 2075 951 1167 130 MAX EECs FL LA TX HI PR Short Grass 535 1211 891 1728 2075 Tall Grass 245 555 408 792 951 Broadleaf 301 681 501 972 1167 Seeds 33 76 56 108 130 117 Sugarcane Use Regimes by State Mean Kenaga Residues Max Single Rate Max Seasonal Ra Apps/ Yr FL 1.2 3.6 3 LA 2 2.4 2.4 2.4 2.4 11.6 5 TX 2 2 2 6 3 HI 7.2 2.4 2.4 12 3 PR 8 4 4 16 3 all values Tall Grass Short Grass Short Grass Tall Grass Broadleaf Broadleaf Seeds Seeds PPM Initial Conc 85 Initial Conc 36 Initial Conc 45 Initial Conc 7 FL RAN WITH ELLFATE RAN WITH ELLFATE RAN WITH ELLFATE RAN WITH ELLFATE MAX EEC 189 80 100 16 LA 170 93.8476 72 39.7472 90 49.684 14 7.7286 297.8476 164.4252 126.1472 69.6389 157.684 87.0486 24.5286 13.5409 368.4252 203.3872 156.0389 86.1404 195.0486 107.6756 30.3409 16.7495 407.3872 224.896 172.5404 95.25 215.6756 119.0626 33.5495 18.5208 428.896 236.7698 181.65 227.0626 35.3208 MAX EEC 429 182 227 35 TX RAN WITH ELLFATE RAN WITH ELLFATE RAN WITH ELLFATE RAN WITH ELLFATE MAX EEC 316 134 167 26 HI 612 337.8514 259.2 143.09 324 178.8625 50.4 27.8231 541.8514 299.1262 229.49 126.69 286.8625 158.3609 44.6231 24.6339 503.1262 213.09 266.3609 41.4339 MAX EEC 612 259 324 50 PR 680 375.3904 288 158.9889 360 198.7361 56 30.9145 715.3904 394.9275 302.9889 167.2634 378.7361 209.0793 58.9145 32.5234 734.9275 311.2634 389.0793 60.5234 MAX EEC 735 311 389 61 MAX mean residue EECs FL LA TX HI PR Short Grass 189 429 316 612 735 Tall Grass 80 182 134 259 311 Broadleaf 100 227 167 324 389 Seeds 16 35 26 50 61 118 Chemical Name: Ametryn Use Corn Formulation foliar spray Inputs Application Rate 2 lbs a. i./ acre Half life 35 days Frequency of Application 1 days Maximum # Apps./ Year 1 Outputs Maximum 56 day Average Concentration Concentration ( PPM) ( PPM) Short Grass 480.00 292.92 Tall Grass 220.00 134.25 # days Broadleaf plants/ sm Insects 270.00 164.77 Exceeded Fruits/ pods/ lg insects 30.00 18.31 on short grass ( in first 56) Avian Acute LC50 ( ppm) 5620 0 Chronic NOAEC ( ppm) 300 24 Max Single Application which does NOT exceed Acute RQ Chronic RQ Avian Acute 23.417 ( Max. res. mult. apps.) Avian Chronic 1.250 ( lb a. i.) Short Grass 0.09 1.60 Tall Grass 0.04 0.73 # days Mammalian Acute 32.28 Broadleaf plants/ sm Insects 0.05 0.90 Exceeded Mammalian Chronic 0.05 Fruits/ pods/ lg insects 0.01 0.10 on short grass ( in first 56) Mammalian Acute LD50 ( mg/ kg bw/ d 1162 0 Rat Calculated LC50 ( ppm) 23240 Chronic NOAEL ( mg/ kg 13 56 Rat Calculated NOAEL ( ppm) 260 15 g mammal 35 g mammal 1000 g mammal Rat Acute Rat Chronic Acute RQ Acute RQ Acute RQ Dietary Dietary ( mult. apps) ( mult. apps) ( mult. apps) RQ RQ Short Grass 0.39 0.27 0.06 0.02 36.92 Tall Grass 0.18 0.12 0.03 0.01 16.92 Broadleaf plants/ sm insects 0.22 0.15 0.03 0.01 20.77 Fruits/ pods/ lg insects 0.02 0.02 0.00 0.00 2.31 Seeds ( granivore) 0.01 0.00 0.00 0.00 Length of Simulation 1 year Level of Concern 193.00 ( ppm)