15
3.5.1 ENVIRONMENTAL FATE AND BEHAVIOUR 3.5.1.1 Degradation in soil
Fluopyram is hydroxylated to form the metabolite fluopyram-7-hydroxy (max 4.2 % of applied radioactivity, AR). Fluopyram-7-hydroxy in turn is cleaved to form the metabolites pyridyl-carboxylic acid (max. 0.7 % AR), containing the pyridine ring, and benzamide (max.
1.1 % AR) containing the phenyl ring. The pyridyl-carboxylic acid is metabolised to methyl-sulfoxide (max. 1.0 % AR). Microbial breakdown of the phenyl ring leads to the formation of CO2.
The aerobic rate of degradation of fluopyram in the laboratory was best described with SFO kinetics in four of five soils, the last soil requiring the use of double first order in parallel (DFOP) kinetics. The degradation of fluopyram can be characterised as moderate to low with DT50 162-746 days (geometric (geo.) mean DT50: 290 days), DT90 538- >1000 days. DT50 values exceeded the study duration in all soils. Thus, estimated DT50 and also DT90 values must be regarded as highly uncertain. The degradation rate of the metabolite fluopyram-7-hydroxy was well described with SFO kinetics and its degradation rate was medium to high with DT50 5.8-18 days (geo. mean 11 days), DT90 16-59 days.
Bound residues reached levels of about 15% AR. Mineralisation to CO2 reached levels of 27
% AR.
Under anaerobic conditions the SFO DT50 of fluopyram was > 1000 days and fluopyram is, therefore, considered stable under anaerobic conditions in soil. No major transformation products were detected.
Photolysis on soil surfaces is not considered to be an important route of transformation of fluopyram.
The field dissipation of fluopyram from soil under European field conditions was investigated at six sites in bare soil plots in Burscheid, Germany (silt loam), Little Shelford, United
Kingdom (sandy loam), Staffanstorp, Sweden (loam), Vatteville, Northern France (silt loam), Vilobi d’Onyar, Spain (loam) and in Albaro, Italy (silt loam). Only the results from Germany, UK and Sweden are considered for Norway, as the other studies are not considered relevant.
Fluopyram was applied once pre-emergence at a rate of 250 g/ha, which is lower than the maximum dose according to the Norwegian GAP (1x300 or 2x250 g/ha). The DT50 values indicate that fluopyram has a moderate rate of dissipation, DT50 145-179 days (geo. mean 162 days). The DT90 values were > 1000 days in all the North European studies and
exceeded the study duration. Leaching might not be important at these sites, as there was no detection of residues below 30 cm.
Interim results from a soil accumulation study with sites in France and Germany indicated that fluopyram has potential for accumulation in soil under field conditions. However, the soils were not considered relevant for Norway due to a high sand content (only the German site) and low organic carbon content.
3.5.1.2 Sorption/mobility
The adsorption of fluopyram can be classified as medium, Kf: 2.94-6.82 L/kg (arithmetic mean 4.41 L/kg), Koc(ads): 233-400 L/kg (arithmetic mean 280 L/kg),1/n: 0.77-0.85
(arithmetic mean 0.83). The adsorption of fluopyram-7-hydroxy can be classified as moderate to medium, Kf(ads): 0.99-2.39 L/kg (arithmetic mean 1.52 L/kg), Koc(ads): 85-149 L/kg (arithmetic mean 103 L/kg), 1/n: 0.91-0.94 (arithmetic mean 0.93). The desorption Kd(des) of the 7-hydroxy metabolite ranged from 3.38 to 5.97L/kg (arithmetic mean 4.21 L/kg) and the Koc(des) values ranged from 237 to 373 L/kg (arithmetic mean 291 L/kg). Koc(des) values
16
were more than two times higher than the Koc(ads) values, indicating a strengthened binding of the test material once adsorbed to the soil (irreversible binding).
3.5.1.3 Degradation in water
Fluopyram is hydrolytically stable under acidic, neutral and alkaline conditions (pH 4, 7 and 9), and no major degradation products were detected.
Aquatic photolysis is not an important route of transformation for fluopyram in the aquatic environment and no major metabolites are expected to be formed in the natural
sediment/water systems.
Fluopyram is considered not readily biodegradable.
Aerobic degradation of fluopyram was studied in two pond water-sediment systems (sandy and clay). The half-life decline times were described by SFO kinetics for the total
sediment/water systems and by DFOP for the water phase. In the water phase the dissipation rate was medium, DT50 14-26 days. In the total system the dissipation rate was low, DT50
>648 days. Fluopyram partitioned significantly from water to the sediment under aerobic conditions. Extractable residues in sediment increased to 64 % AR in the first test system and to 69 % AR in the second test system during the study period (120 days). Residues in water decreased to 28 % AR in the first test system and to 21 % AR in the second test system. No major transformation products were detected in the water or sediment phases. Mineralization of fluopyram was low, with max 1.8 % AR as CO2 after 90 days. Non-extractable residues reached a maximum of 8.4 % AR.
An anaerobic water/sediment study also showed a rapid dissipation of fluopyram from water to sediment. Fluopyram did not degrade under anaerobic aquatic conditions. No
transformation products were detected. The dissipation rate of fluopyram from water was high, DT50 4.5 days, DT90 84 days. In the total system, the DT50 and DT90 values were greater than 1000 days. Mineralization of fluopyram was minimal, with 0.1 % AR as CO2 by the end of the study period. Non-extractable residues accounted for 6.1 % AR after 121 days.
3.5.1.4 Fate in air
Fluopyram does not absorb light at environmentally relevant wavelengths (>290 nm) and is not expected to undergo direct photolysis. The half-life of fluopyram in air was assessed using the Atkinson model (v. 1.91). A DT50 of 21 hours was estimated (assumes 12 hours day and 1.5∙106 OH¯/cm3). Fluopyram is not expected to partition to the atmosphere due to the low Henry’s Law constant and subsequently is not expected to be subjected to long range atmospheric transport.
3.5.2 EXPOSURE 3.5.2.1 Soil
The predicted environmental concentration of fluopyram in soil (PECsoil) was calculated by Mattilsynet with the Finnish PECsoil calculator, using the worst case application regime (crop: lettuce, 2x250 g a.i/ha/year, application interval 7 days, interception 25%/40%). Since none of the field studies can be considered as relevant for Norwegian conditions, PECsoil should be calculated by using the worst case SFO DT50 lab value, which is 276 days
(normalised geo. mean of the pyridyl and phenyl labels from the Laacherhof AXXa soil). This resulted in an initial PECsoil of 0.45 mg/kg and a PECsoil max of 2.09 mg/kg. The plateau level (background concentration) established during the 20 years run in the calculator seems to be at about 1.5-1.6 mg/kg. Based on these calculations, no accumulation in soil is expected.
17
3.5.2.2 Groundwater
For exposure assessment in groundwater both fluopyram and the 7-hydroxy metabolite were evaluated. The 7-hydroxy metabolite was included in the EU evaluation as part of a
precautionary approach. In addition to the EU FOCUS scenarios (modelled with
PEARL/PELMO) MACRO modelling with Swedish scenarios was performed by Mattilsynet according to the Norwegian GAP. The EU FOCUS scenarios indicated that fluopyram was not expected to leach to groundwater in concentrations >0.1 µg/L. The highest fluopyram value and fluopyram-7-hydroxy values of 0.05 µg/L and 0.02 µg/L, respectively, were found for the apple Piacenza scenario. However, results from modelling with MACROinFOCUS 5.5.3 and Swedish scenarios indicate that both fluopyram and the metabolite fluopyram-7-hydroxy have the potential to exceed 0.1 µg/L in groundwater for all crops, except peas.
3.5.2.3 Surface water
Models developed by EU’s working group FOCUS estimate predicted environmental concentrations in surface water and sediment for different scenarios. PECsw has been calculated up to Step 3 for all crops by the notifier and Mattilsynet. Step 4 calculations with spray drift mitigation (up to 30 m) and/or run-off mitigation (10-12 m) were performed by Mattilsynet using the Surface Water Assessment Enabler (SWAN) tool.
Max PECsw values for Step 3 calculations of pome fruit (4x100 g/ha), peas (2x250 g/ha) and strawberries (1x300 g/ha) were 2.6, 5.0 and 5.3 µg/kg, respectively (max PECsed: 10.0, 10.5 and 11.2 µg/kg, respectively).
Max PECsw in lettuce at Step 3 was 11.0 µg/L (max PECsed: 12.9 µg/L). As run-off was the main route of entry for the worst case scenario, drift buffers did not reduce the PECsw in Step 3. The introduction of a run-off buffer (10-12m) resulted in a max PECsw of 6.4 µg/L (max PECsed: 12.8 µg/kg).
Max PECsw in beans and strawberries at Step 3 was 15.7 µg/L (max PECsed: 40.6 µg/L). As drainage was the main route of entry for the worst case scenario, drift buffers and run-off buffers did not reduce the PECsw in Step 3. The PECsw and PECsed concentrations obtained in the worst case Step 3 scenario were higher than the concentrations obtained in the Step 2 calculations (PECsw:10.2 µg/L and PECsed: 28 µg/kg).
3.5.3 TERRESTRIAL ORGANISMS
Where there are indications that the plant protection product is more toxic than what can be explained by the content of the active substances (or studies are only conducted with the product), or identified metabolites are more toxic than the active substances, these calculations are included in the summary below. If this is not the case, these values and calculations are omitted.
3.5.3.1 Mammals
Fluopyram has low acute toxicity (LD50: >2000 mg/kg bw/d) to mammals. TERacute for the indicator species in orchards, strawberry, leafy vegetables/pulses are estimated as 86, 49 and 42, respectively. These values do not fall below the trigger (<10). The NOAEL from a two-generation reproduction study is 14.5 mg/kg bw/d.
In the first tier risk assessment for orchards, all estimated TERchronic values are above the trigger (<5) for the relevant generic focal species. In the first tier risk assessment, the TERchronic values for the generic focal species ‘small herbivorous mammal - vole’ are estimated to be 3.2 for strawberry, leafy vegetables, and pulses. This value falls below the trigger, thus prompting a higher tier assessment. However, ecotox colleagues have in the
18
Northern zone Guidance Document decided that the vole species is not considered relevant for these crops in the Northern zone.
3.5.3.2 Birds
Fluopyram has low acute toxicity (LD50: >2000 mg/kg bw/d) to birds. TERacute for the indicator species in orchards and strawberry/leafy vegetables/pulses are estimated as 251 and 36, respectively. These values do not fall below the trigger (<10). There are two long-term endpoints; the NOEC for reproduction (4.5 mg/kg bw/d) is used in the first tier risk
assessment and a population-relevant NOAEL (7.2 mg/kg bw/d) is used in the refined risk assessment.
In the first tier risk assessment for orchards, the TERchronic value for the generic focal species
‘small insectivorous bird – tit’ is estimated to be 2.2 which fall below the trigger and thus prompting a higher tier assessment. In the higher tier risk assessment, TERchronic are estimated to be 6.5 and 6.1 for the focal species blue tit and chaffinch, respectively. These values do not fall below the trigger (<5).
In the first tier risk assessment for strawberries, the TERchronic values for the generic focal species are estimated to be 2.2, 1.6, and 4.8 which fall below the trigger. In the higher tier risk assessment, TERchronic are estimated to be 5.7 and 5.8 for the focal species skylark and
starling, respectively. These values do not fall below the trigger (<5). In the higher tier risk assessment, the refined TERchronic value for the white wagtail is estimated to be 2.7, which is below the trigger (<5).
In the first tier risk assessment for leafy vegetables, the TERchronic values are below the trigger values for all the relevant generic focal species, thus triggering a higher tier assessment. In the higher tier risk assessment, the refined TERchronic values for the focal species skylark, white wagtail, and linnet are estimated to be 1.4, 3.3, and 2.1, respectively. These values are below the trigger (<5).
In the first tier risk assessment for pulses, the TERchronic values for the generic focal species
‘small insectivorous bird – wagtail’ is estimated to be 2.2 which fall below the trigger and thus prompting a higher tier assessment. In the higher tier risk assessment, the refined TERchronic value for the white wagtail is estimated to be 3.3, which is below the trigger (<5).
3.5.3.3 Bees
Fluopyram has low contact (LD50: >100 μg a.s./bee) and oral (LD50: >102 μg a.s./bee) toxicity to bees.
Hazard quotients for contact (Qhc) and oral exposure (Qho) are estimated to be <3.0 and <2.9, respectively. None of the hazard quotients exceed the trigger value (>50).
3.5.3.4 Non-target arthropods
In Tier 1 laboratory acute contact toxicity studies, formulations with 500 g fluopyram/L showed negligible effects on predatory mites and parasitoids. An extended lab study with the soil dwelling rove beetle did not show effects above the trigger effect level of 50 %. The LR50 is estimated to be > 2000mL product/ha which is more than 3 times the highest application rate.
3.5.3.5 Earthworms
Fluopyram has low acute toxicity (LC50: 1000 mg a.s./kg d.w. soil) to earthworms. TERacute is estimated to be 478. This value does not exceed the trigger (<10). In a chronic toxicity test, the NOEC is estimated to be 5620 mL product/ha which is 9 x the highest application rate.
19
3.5.3.6 Other soil macro organisms
Since the soil DT90 for fluopyram is >365 days, the toxicity of Luna Privilege has been tested on the springtail. Fluopyram has low chronic toxicity to Folsomia candida (NOEC:104 mg a.s./kg d.w. soil). TER is estimated to be 108, which is not below the trigger (<5).
3.5.3.7 Litter bag
A study on the effects on soil litter degradation showed no significant differences in litter mass loss between control (76 %) and treatment groups (77%) after 6 months.
3.5.4 AQUATIC ORGANISMS
Where there are indications that the plant protection product is more toxic than what can be explained by the content of the active substances (or studies are only conducted with the product), or identified metabolites are more toxic than the active substances, these calculations are included in the summary below. If this is not the case, these values and calculations are omitted.
The TER calculations below are based on maximum PEC-values from FOCUS surface water modelling and the lowest acute (LC50 or EC50) or chronic (NOEC) values for the different organism groups. A tiered approach is applied. Step 3 is calculated for all tested substances, and if the TER fails the triggers, higher steps are calculated. The EU triggers for TERacute and TERlong-term are >100 and >10, respectively.
3.5.4.1 Fish
Fluopyram is acutely toxic to fish (96h LC50: >0.98 mg a.s./L) and has moderate chronic toxicity (33 d NOEC: 0.135 mg a.s./L). Luna Privilege has low acute toxic to rainbow trout (96h LC50: >120 mg/L).
Acute TER calculations for fluopyram pass the EU trigger based on Step 3 FOCUS surface water scenarios for pome fruit, peas, and strawberries (single application). Based on Step 4 calculations, which includes 10 m drift buffer + 10-12 m run-off buffer, the acute TER pass the trigger for scenarios in lettuce. The acute TER (>62) for beans/strawberries fail the trigger.
The long-term TER calculations for fluopyram pass the EU trigger based on Step 3 FOCUS surface water scenarios for all crops other than beans/strawberries (TER is 9).
3.5.4.2 Invertebrates
Fluopyram has moderate acute toxicity (48h EC50: >0.5 mg a.s./L) and low chronic toxicity (21 d NOEC: 1.22 mg a.s./L) to aquatic invertebrates. Luna Privilege has low acute toxicity to Daphnia (48h EC50: >100 mg/L).
Acute TER calculations for fluopyram pass the EU trigger based on Step 3 FOCUS surface water scenarios for pome fruit and peas. Based on Step 4 calculations, which includes 10 m drift buffer + 10-12 m run-off buffer, the acute TER (>78) fail the trigger for scenarios in lettuce. Acute TER for strawberries (single applications) (>94) and beans/strawberries (>32) fail the trigger.
The long-term TER calculations for fluopyram pass the EU trigger based on Step 3 FOCUS surface water scenarios for all crops.
3.5.4.3 Sediment dwelling organisms
Fluopyram has low chronic toxicity to Chironomus riparius larvae (28 d NOEC: 1.4 mg a.s./L (spiked water)).
20
All TER calculations for fluopyram pass the EU trigger based on Step 3 FOCUS surface water scenarios.
3.5.4.4 Aquatic plants
Fluopyram is toxic to duckweed (14d EC50: 2.3 mg a.s./L). Luna Privilege is toxic to duckweed (14d EC50: 6.8 mg a.s./L).
TER calculations for fluopyram pass the EU triggers based on Step 3 calculations.
3.5.4.5 Algae
Fluopyram and Fluopyram-lactam are toxic to algae (72 h EC50:>1.1-9.4 mg a.s./L). Luna Privilege has moderate toxicity to algae (72h EC50: 16.1 mg/L).
All TER calculations for fluopyram pass the EU trigger based on Step 3 FOCUS surface water scenarios.
3.5.4.6 Microorganisms No information.
3.5.4.7 Microcosm/Mesocosm studies No information.
3.5.4.8 Bioaccumulation
Fluopyram has a low potential for bioaccumulation. The fish bioaccumulation study with bluegill sunfish indicated a low bioconcentration factor (whole fish = 18) and a very rapid clearance half life (1.8 to 3.4 days).