Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Soil macroorganisms except arthropods:

NOEC (56 d, reproduction) ≥ 1000 mg a.i./kg dw nominal (Eisenia fetida, OECD 222)

LC50 (14 d, mortality) > 869 mg/kg soil dw nominal (Eisenia fetida, OECD 207)

 

Terrestrial arthropods:

NOEC (28 d, reproduction) = 58.46 mg test a.i./kg soil dw nominal (Folsomia candida, OECD 232)

NOEC (14 d, reproduction) ≥ 185 mg a.i./kg soil dw nominal (Hypoaspis aculeifer, OECD 226)

 

Terrestrial plants:

NOEC (21 d) ≥ 0.2667 mg/kg soil dw nominal (Beta vulgaris, Brassica napus, Cucumis sativus, Glycine max, Helianthus annuus, Solanum lycopersicum, Allium cepa, Avena sativa, Triticum aestivum, Zea mays, OECD 208 limit test)

 

Soil microorganisms:

NOEC (28 d): ≥ 1.31 mg a.i./kg soil dw (OECD 216)

EC10 (28 d): > 1.31 mg a.i./kg soil dw (OECD 216)

NOEC (28 d): 0.265 mg a.i./kg soil dw (OECD 217)

EC10 (28 d): > 1.31 mg a.i./kg soil dw (OECD 217)

Additional information

Experimental studies on the toxicity of the test item are available for several trophic levels. All studies were performed according to international guidelines and GLP.

One study is available investigating the long-term toxicity to the earth worm Eisenia fetida according to OECD 222 (M-489574). In this long-term toxicity test adult earthworms were exposed to the test item for a period of 4 weeks (1st part). Thereafter, adults were removed from test vessels and cocoons and juveniles remained in test vessels for additional 4 weeks (2nd part). The test organisms were exposed to five concentrations in the ranging from 100 to 1000 mg/kg dry weight of soil (corresponding to 18.2 to 182 mg a.i./kg soil dw). Up to the highest test concentration no effect on growth and reproduction was observed. Therefore, the NOEC (28 d, growth) and NOEC (56 d, reproduction) is reported as ≥ 182 mg a.i./kg dry weight soil (the highest concentration tested).

One study is available investigating the short-term toxicity of the test item to the earthworm Eisenia fetida (M-469589-01-1). The study was performed according to OECD 207 (GLP). Adult earthworms were exposed in an artificial soil system over a period of 14 d to five concentrations up to 869 mg a.i./kg dry weight of soil. Mortality and biomass changes were determined after 14 d and were used to determine the effect concentrations. The LC50 (14 d) was > 869 mg a.i./kg dry weight soil (the highest concentration tested), the NOEC (14 d) was determined to be ≥ 869 mg a.i./kg dry weight soil.

Two further GLP studies testing the toxicity of the substance on terrestrial soil macroorganisms are available. The first study was conducted according to OECD 226 with adult soil mite Hypoaspis aculeifer exposed to nominal concentrations from 100 to 1000 mg test item/kg soil dw (corresponding to 18.5 to 185 mg a.i. mg/kg dw). After a period of 14 days, mortality rates were between 2.5 and 10.0 % in all exposure groups. Concerning the number of juveniles, no significant difference between control and the treatment groups was observed. Therefore, the NOEC for reproduction is ≥ 185 mg a.i./kg soil dw. In the second study (according to OECD 232), Folsomia candida was exposed to test item concentrations between 100 and 1000 mg/kg soil dw (corresponding to 18.5 to 185 mg a.i. mg/kg dw) for 28 days. Statistically significant differences were observed between the control and all treatment groups. The significant effects on reproduction at 104 and 185 mg/kg soil dw (22.2% and 23.1%) can be considered as biologically relevant while the observed statistically significant differences at 58.5, 104 and 185 mg a.i. mg/kg dw were very low and should not be regarded as biologically relevant. Furthermore, no dose-response relationship was observed. Therefore, a second test run was started, testing the same test concentrations and in addition 3 lower test concentrations ranging from 18 and 1000 mg/kg soil dw (corresponding to 3.33 to 185 mg a.i. mg/kg dw). No significant difference between control and any test item treatment group was observed in the second test run. Therefore, the overall NOEC for reproduction is 58.5 mg a.i./kg soil dw.

 

Two GLP studies were investigating the long-term toxicity of the test item on plants. Both studies were conducted as limit tests under controlled greenhouse conditions with ten crop plants species (6 dicotyledonous and 4 monocotyledonous species from 8 plant families) with a single application rate of 200 g a.s./ha (corresponding to 0.2667 mg a.s./kg soil dw).

In the key study (M-559339-01-1, according to OECD 208), final assessment after 21 days revealed no adverse or statistically significant effects on emergence, survival, visual phytotoxicity, growth stage development, shoot length and shoot dry weight.

In a second study (M-552710-01-1), a Vegetative Vigour Test according to OECD guideline 227 was performed. Final assessments were made for plant survival, visual phytotoxicity, plant growth stage, shoot length and shoot dry weight after 21 days. No adverse effects above the 25% effect level were observed. Slight growth retardation and significant shoot dry weight and length reductions were observed in Lycopersicon esculentum only.

 

The effects on soil microflora were studied in four experimental studies investigating the nitrogen (M-460650-01-1 and M-546745-01-1) and carbon transformation (M-460648-01-1 and M-546743-01-1). The studies were performed according to OECD 216 (nitrogen transformation) and 217 (carbon transformation) under GLP conditions using natural soil. Two application rates were tested (0.233 kg/ha and 1.116 kg/ha corresponding to test concentrations of 0.269 and 1.29 mg a.i./kg soil dw). The test design targets the requirements for plant protection products and they were not initially planned for the derivation of an EC10/NOEC. However, both test designs only differ in the selected concentrations but not in the number of replicates. For the assessment the NOEC/EC10 values were derived based on raw data. Test vessels were incubated under controlled conditions for 28 d. In the studies on nitrogen transformation no inhibition was recorded after 28 d. Thus, the EC10 and NOEC (28 d) values were derived to be > 1.31 mg a.i./kg soil dw and ≥ 1.31 mg a.i./kg soil dw, respectively. For carbon transformation a significant inhibition was recorded after 28 d at the concentration of 1.31 mg a.i./kg soil dw (maximum of 6%). Thus, the NOEC (28 d) was set to 0.265 mg a.i./kg soil dw and the EC10 (28 d) was derived to be > 1.31 mg a.i./kg soil dw.

Furthermore, five laboratory studies are available on the toxicity of the test item towards bees and bumblebees according to GLP.

In the first study (M-441758-01-1) effects on mortality of honeybees were determined after oral or contact exposure. The contact LD50 values (48, 72 + 96 h) of the test item were 1.25, 0.46 and 0.41 µg a.s./bee, respectively. Over the entire time of the test (96 hours) behavioural abnormalities (e.g. movement coordination problems and/or apathy) were observed in the 2.0, 1.0, 0.50 and 0.25 µg a.s./bee dose level groups (except after 96 hours in the 2.0 µg a.s./bee dose level). There was 3.3% mortality in the control group (water + 0.5% Adhaesit) and the solvent control group, respectively. The oral LD50 values (24 h, 48 h + 72 h) of the test item were 0.012, 0.010 and 0.010 µg a.s./bee, respectively. No mortality occurred in the water and solvent control groups, respectively.

 For the second study (M-548937-01-2) the acute oral toxicity of the test item to the bumblebee (Bombus terrestris) was tested. The 72 h oral LD50 value was 0.04 µg a.s./bumblebee. The 72 h oral NOED value was 0.013 µg a.s./bumblebee.

 For the third study (M-483352-01-3) the effects of the test item on the bumble bee (Bombus terrestris L.) after contact exposure was determined. During the 96 hour observation period, dead, affected, apathetic or moribund bumble bees were observed at the dose levels from 12.5 µg to 100 µg a.s./bumble bee. A mortality rate of 96.7% was observed at the highest dose level of 100 µg a.s./bumble bee at the final assessment after 96 hours. The 96 h contact LD50 value for the test item was determined to be 21.9 µg a.s./bumble bee. The 96 h NOED for mortality was determined to be 6.25 µg a.s./bumble bee.

For the fourth study (M-491456-01-1) the effects of the test item on honey bee larvae, Apis mellifera carnica, after a single exposure (feeding) event, using spiked diet on day +4 in an in vitro laboratory testing design were determined. Synchronised first instar larvae of Apis mellifera carnica, from three different honey bee colonies, each representing a replicate, were tested in an in vitro laboratory testing design, according to the OECD Draft Test Guideline on Honey Bee (Apis mellifera) Larval Toxicity Test and the current draft version of the Post–WNT25. The NOED for the larval mortality was determined to be 3.3 ng a.s./larva (based on nominal). The LOED for the larval mortality was determined to be 10 ng a.s./larva (based on nominal). The LD50 for the larval mortality was determined to be 17.2 ng a.s./larva until day +7 and 12.8 ng a.s./larva until day +8.

For the fifth study (M-571449-01-1) potential adverse effects of the test item on the development of honey bee larvae (Apis mellifera) to adulthood in an in vitro oral toxicity test over 22 days were assessed. The study was performed according to the OECD Draft Guidance Document for Testing Chemicals – Honey Bee (Apis mellifera) Larval Toxicity Test, Repeated Exposure (Revision following the April 2015 meeting, 20 July 2015), with modifications. Assessment endpoint was the emergence of adult honey bees until day 22. Overall, it can be concluded that the No Observed Effect Dose (NOED) on day +22, determined in this in vitro honey bee larvae study is 10 ng a.s. test item/larva and the Lowest Observed Effect Dose (LOED) is 30 ng a.s. test item/larva. Furthermore, 12.09 ng a.s. test item/larva was determined as LD50 value.

In addition seven experimental studies with birds are reported. Three studies investigate the oral toxicity to northern bobwhite quail (Colinus virginianus; M-522801-01-1, M-521692-01-1 and M-542825-02 -1), two studies were performed with mallard duck (Anas platyrhynchos, M-508260-01-1 and M-570069-02-1), one study was performed with canary (Serinus canaria, M-521691-01-1) and one with chicken (Gallus gallus domesticus; M-529716 -01-1). The key study (M-570069-02-01) was performed using eighteen pairs of adult mallard (Anas platyrhynchos) per treatment (approx. 25 weeks old). They were exposed to treated feed during a period of 20 weeks according to OECD 206 and US EPA OPPTS 850.2300. Nominal concentrations in feed were 0 (control), 111, 333 and 1000 mg a.s./kg feed, respectively. The achieved daily doses were 0, 14.1, 42.9 and 129.5 mg a.s./kg body weight per day. Birds were observed for mortality, abnormal behavior and signs of toxicity; adult body weight and feed consumption were measured; gross pathology was conducted; reproductive parameters, as well as hatchling health, growth and survival, were examined. The overall NOEC (20 weeks) for mallard exposed to the test item in the diet during the study was considered to be 42.9 mg a.s./kg/day (333 ppm). This study resulted in the lowest effect concentration. All results from the supporting studies were less sensitive. Five laboratory studies are available on the toxicity of the test item towards bees and bumblebees according to GLP (M-441758-01-1, M-548937-01-2, M-483352-01-3, M-491456-01-1, M-571449-01-1). Three studies were performed with honey bee (Apis mellifera) and two studies with bumblebee (Bombus terrestris). The studies were performed according to the OECD guidelines OECD 213, OECD 214 and US EPA OCSPP 850. Assessing the short-term effects mortality was determined after oral or contact exposure. The contact LD50 (72 h) was 0.41 µg a.i./bee whereas the oral LD50 (72 h) was 0.01 µg a.i./bee. In a larvae feeding study a LD50 of 0.0128 µg a.s./larva resulted.