3-anilino-5-methyl-5-(4-phenoxyphenyl)-1,3-oxazolidine-2,4-dione;famoxadone (ISO)

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 November 1993 - 10 February 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.8 (Toxicity for Earthworms: Artificial Soil Test)

Version / remarks:

1979

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

1984

GLP compliance:

yes

Specific details on test material used for the study:

Purity: 97.4%
Batch: DPX-JE874-221

Analytical monitoring:

no

Vehicle:

yes

Remarks:

acetone

Details on preparation and application of test substrate:

Weighed amounts of DPX-JE874-221 were dissolved in acetone (60 ml range finding test and 120 ml definitive test) and added to the premixed soil on the day of the test (2 kg per concentration range finding test and 3 kg per concentration definitive test). This was then blended in a laboratory mixer for ca 5 min. The acetone was allowed to evaporate (ca 4 h) and the soil returned to the mixer. The soil was blended for a further 5-10 min, during which deionised water (316 ml range finding test and 464 ml definitive test) was slowly added to give a theoretical moisture content of 35%. Acetone alone was added to the solvent control soil and no acetone was added to the non-solvent control.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

Earthworms (Eisenia foetida andrei) at least 2 months old (with clitellum) and weighing between 300 and 600 mg were used for this study, and were obtained from Ecology Earthworms, Suffolk

Study type:

laboratory study

Substrate type:

artificial soil

Remarks:

Industrial sand: 70%; Kaolinite clay: 20%; Sphagnum moss peat: 10%. The pH of the soil was adjusted to 6.0 ± 0.5 by the addition of CaC03; the amount added during the tests was equivalent to 0.5% of the total dry weight.

Total exposure duration:

14 d

Test temperature:

19-23°С

pH:

6.2 - 6.5

Moisture:

Day 0: 29-33%
Day 14: 24-31%

Details on test conditions:

Moulded glass beakers of capacity ca 1 litre, and covered with perforated plastic film to retard evaporation, were used for this test. Test and control vessels each contained ca 750 g (wet weight) soil. Earthworms were added to the test and control soils approximately 5 h after the test
material was added to the premixed soil.
Rangefinding Study: A range finding test was conducted over a 14 day period at nominal concentrations of 0, 1, 10, 100, and 100 ppm. A non-solvent control was also prepared.
One vessel was prepared at each concentration, and 10 earthworms added per vessel.

Definitive Study: Four vessels were prepared at each concentration, and 10 earthworms added per vessel. The earthworms in the definitive test were observed daily throughout the test. Any abnormalities in behaviour (absence of burrowing, lethargy or colour change) and any deaths were noted. Mortalities were recorded after 7 and 14 days.

Nominal and measured concentrations:

Nominal: 0, 62.5, 125, 250, 500, and 1000 ppm

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

470 other: ppm

Basis for effect:

mortality

Duration:

7 d

Dose descriptor:

LC50

Effect conc.:

815 other: ppm

Nominal / measured:

nominal

Basis for effect:

mortality

Details on results:

Rangefinder: At the end of the 14 day period, 100% mortalities had occurred at 1000 ppm nominal, 10% mortalities at 100 ppm. and 10% at 0 ppm. (non-solvent). No mortalities occurred at 10 ppm., 1 ppm, and 0 ppm (solvent). Due to 100% mortality at 1000 ppm. nominal concentration DPX-JE874-221, a definitive test was conducted with a top nominal concentration of 1000 ppm.

In both the range finding and definitive tests, any worms not found in the soil were assumed to have decomposed and therefore counted as mortalities.

Definitive study: After 14 days, a 47% decrease in body weight had occurred at 1000 ppm, 29% at 500 ppm, 28% at 250 ppm, 22% at 125 ppm and 17% at 62.5 ppm. The worms in the solvent and non-solvent control vessels decreased in body weight by 6.6% and
8.9% respectively.
The intercept and dose response curve and hence LC50 were estimated by applying the standard technique of maximum likelihood estimation to the probit model.

7-day LC50 = 815 ppm (95% confidence limits of 656 to >1000 ppm)
14-day LC50 = 470 ppm (95% confidence limits of 389 to 581 ppm)

Definitive Test: All worms burrowed into soil within 5 min of addition to vessels. Worms were observed on the soil surface in test vessels at 1000, 500 and 250 ppm over the 7 day period. By Day 14, Worms were observed on the soil surface in test vessels at 1000, 500 and 250 ppm and one worm at 125 ppm over the 14 day period.

 

	% Mortality	% Mortality
	Day 7	Day 14
0 (non-solvent)	0%	0%
0 (solvent)	0%	0%
62.5	0%	0%
125	0%	5%
250	7.5%	155
500	35%	57.5%
1000	55%	77.5%

 

 

In both the range finding and definitive tests, any worms not found in the soil were assumed to have decomposed and therefore counted as mortalities.

Validity criteria fulfilled:

yes

Conclusions:

7-day LC50 = 815 ppm (95% confidence limits of 656 to >1000 ppm)
14-day LC50 = 470 ppm (95% confidence limits of 389 to 581 ppm)

Executive summary:

The acute toxicity (LC50) of DPX-JE874-221 to earthworms (Eisenia foetida andrei) was

determined over a 14 day period. The test was conducted according to OECD guideline 207 and EC Guideline, Annex V, Part C, Toxicity for Earthworms, Artificial Soil Test. Nominal concentration of 0, 62.5, 125, 250, 500, and 1000 ppm were tested. A non-solvent control was also prepared.

 

Forty earthworms were exposed at each concentration in the definitive test. The earthworms in the definitive test were observed daily throughout the test. Any abnormalities in behaviour (absence of burrowing, lethargy or colour change) and any deaths were noted. Mortalities were recorded after 7 and 14 days. Absence of burrowing was observed at 1000, 500, 250 and 125 ppm. No abnormalities in appearance were observed at any concentration. The 7-day LC50 was 815 ppm (95% confidence limits of 656 to >1000 ppm) and the 14-day LC50 was 470 ppm (95% confidence limits of 389 to 581 ppm).

Description of key information

14-day LC50 (earthworms, Eisenia foetida andrei) = 470 ppm, OECD 207 and EC Method C.8, Reliability = 1

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

470 mg/kg soil dw

Additional information

Famoxadone was tested in one earthworm study with a resultant 14-day LC50 of 815 ppm.