Methyl (R)-2-(4-(3-chloro-5-trifluoromethyl-2-pyridyloxy)phenoxy)propionate

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: BBA VI 2-2

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

EF-1400
Lot #: LF16150101
Purity/Active ingredient: 104 g a.e. Haloxyfop-methyl R/L

Analytical monitoring:

no

Vehicle:

yes

Remarks:

tap water

Details on preparation and application of test substrate:

The test substance dilutions were applied in a singular application according to agricultural practice with a laboratory spraying equipment onto the soil of the assigned trays. The inner sides of the test container walls were covered with filter paper to protect the inside walls. The filter paper was removed ultimately after spraying the trays.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm
- Source: Kraut & Ruben, Doris Haber, Zeilstraβe 40, D-64367 Muhltal
- Age: approximately 8 months, with clitellum, age range between test individuals not differing for >4 weeks
- Weight: 350-550 mg

ACCLIMATION
- Acclimation period: 2 days
- Acclimation conditions (same as test or not): Same as test conditions

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

8 wk

Test temperature:

18-23°C

pH:

5.5

Moisture:

60% (test start) to 77% (test end) of the total water holding capacity, deionized water was used

Details on test conditions:

TEST SYSTEM
- Test container (material, size): Plastic boxes (18.3 em x 13.6 em x 6 em) with perforated transparent lids
- Amount of soil or substrate: Approximately 500 g artificial soil
- No. of organisms per container (treatment): 10 per unit, i.e., 40 per treatment group
- No. of replicates per treatment group: 4
- No. of replicates per vehicle control: 4
- No. of replicates per toxic standard: 4

PROPERTIES OF SUBSTRATE
- 10% Sphagnum-peat, air-dried and finely ground
- 20% Kaolin clay
- Approximately 0.3% chalk (CaCO3) extra to adjust pH to 6.0 ± 0.5
- Approximately 69.8% fine quartz-sand

OTHER TEST CONDITIONS
- Photoperiod: 16 h light: 8 h dark
- Light intensity: 400-630 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Mortality: Number of dead adult earthworms at day 28 after application
- Behavioural abnormalities: Number of damaged adult earthworms (e.g. apathy, rigidity) at day 28 after application
- Food consumption: Approximated mean amounts of food added to each test container at each feeding date
- Mean body weights: Per test container estimated at start (day 0) and 28 days after application, same washing and weighing procedures as at test initiation
- Reproduction: Number of young worms 8 weeks after application

Nominal and measured concentrations:

1.5, 3.0, 7.5 L/ha

Reference substance (positive control):

yes

Remarks:

50% Benomyl

Key result

Duration:

8 wk

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: The test substance does not cause lethal or sublethal effects on the earthworm E. fetida if applied in amounts from 1.5 L/ha to 7.5 L/ha.

Details on results:

- Mortality at 4 weeks: The results of this study did not reveal any lethal effect
- Changes in body weight of live adults (% of initial weight): The body weights of the worms increased by about 16 to 38% in all treatment groups
- No. of offspring produced: Reproduction amounted to a mean of 219 ± 28 young worms in the control, 239 ± 34 in the containers treated with 1.5 L/ha rate of test substance, 202 ± 17 in the 3 L/ha rate, and 189 ± 24 in the containers treated with 7.5 L/ha rate. With these results reproduction of the worms exposed to the test substance was not reduced.
- Behavioural abnormalities: No behavioural abnormalities were observed
- Other biological observations: Feeding of those earthworms exposed to the four different rates of the test substance was comparable to that of the control

Results with reference substance (positive control):

None of the adult worms in the toxic standard treatment group died within the 4 weeks of experimental time. Statistically significant loss of body weight (-0.5%) was observed. There was a statistically significant reduction of reproduction (Dunnett-Test, α=0.05). A reduction of food consumption was observed

Validity criteria fulfilled:

yes

Conclusions:

The test substance does not cause lethal or sublethal effects on the earthworm E. fetida if applied in amounts from 1.5 L/ha to 7.5 L/ha.

Executive summary:

The effects of the test substance on the growth and reproduction of earthworms, Eisenia fetida, were investigated in a study lasting eight weeks according to ISO 11268 and BBA VI 2-2.

The results of this study show neither lethal nor sublethal effects of test substance on earthworms. Mortality, growth, reproduction and food consumption of the earthworms were not affected by exposing them to 1.5, 3.0 and 7.5 L/ha of test substance. The differences were not statistically significant (Dunnett-Test, α=0.05). In contrast to this, growth and reproduction were significantly lower in the test group treated with toxic standard (benomyl). The food consumption of the adult worms was also affected by the toxic standard substance. The conclusion ofthis study, consequently, is that the test substance does not cause lethal or sublethal effects on the earthworms if applied at rates of 1.5 to 7.5 L/ha.

Description of key information

8-week Eisenia fetida study, NOEC = 7.5 L/ha = 54.02 mg haloxyfop/kg dw exposed as a formulation (EF-1400). ISO 11268, 1995 and BBA 1994; GLP study; Reliability = 1.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:

54.02 mg/kg soil dw

Additional information

EF-1400 (10.49% w/w of Haloxyfop) does not cause lethal or sublethal effects on the earthworm E. fetida if applied for 8 weeks in amounts from 1.5 L/ha to 7.5 L/ha.

 

The NOEC in L/ha was converted to mg a.s./kg dw using the below information and assumptions:

 

EF-1400, 108 g a.s./L (104 g a.e./L density=1.03 g/mL)

Standard soil mass at 1 cm depth: 1.5 g/cm3 (1cm used since soil was sprayed on the surface rather than mixed into soil)