Pyrasulfotole

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 Jan - 13 Jul 2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Version / remarks:

adopted: 29 July 2016

Deviations:

no

GLP compliance:

yes

Remarks:

Ministerium für Arbeit, Gesundheit und Soziales des Landes Nordrhein-Westfalen, Düsseldorf, Germany

Analytical monitoring:

no

Vehicle:

yes

Remarks:

Acetone

Details on preparation and application of test substrate:

- Method of mixing into soil: The quartz sand-test item mixtures plus deionized water were thoroughly mixed into the artificial soil of each replicate using a laboratory mixer.
- Method of application to soil surface: Prior to the start of the test, a concentrated stock solution or the application solution of the highest test rate of the test item were prepared. The test item was diluted with acetone as homogeneously as possible. The stock solution or the application solution of the highest test rate were further diluted with acetone to obtain the desired rates of the application solutions. Uniform volumes of the application solutions were used for all test rates. Afterwards the test item solutions were applied on quartz sand, the solvent was evaporated (acetone) and finally mixed with deionized water again.
- Controls: deionized water quartz sand mixture; acetone-quartz sand mixture (solvent control)
- Chemical name of vehicle: Acetone
- Concentration of vehicle in test medium: 100% in the stock solution and application solution
- Evaporation of vehicle before use: Yes

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm
- Source: Forschungsanstalt für Landwirtschaft, Braunschweig, Germany
- Age at test initiation: 9 - 10 months (age differed not more than 4 weeks, 1st and 2nd run)
- Weight at test initiation (mean and range, SD): 0.32 to 0.39 g per earthworm (1st run) and 0.33 to 0.39 g per earthworm (2nd run)

ACCLIMATION
- Acclimation period: 1 d
- Acclimation conditions: Same as for the test
- Health during acclimation: Only healthy animals were used.

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Test temperature:

18.5 to 21.2 °C (1st run)
18.8 to 20.7 °C (2nd run)

pH:

5.4 - 6.16 (1st run)
5.36 - 5.87 (2nd run)

Moisture:

27.10 % - 27.74 % (1st run)
27.63 % - 30.56 % (2nd run)

Details on test conditions:

TEST SYSTEM
- Test container: Non-re-usable plastic boxes (length x width x height ca. 16.5 cm x 12 cm x 6 cm, area
approximately 200 cm2)
- Amount of soil or substrate: approximately 500 g (1st run) and 495 g (2nd run) artificial soil (dry weight)
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 8
- No. of replicates per vehicle control: 8

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition: Sphagnum peat (shredded): 10%; Kaolinite clay (content of Kaolinite = approx. 30%): 20%; Industrial quartz sand (Particle size: 0.20 mm – 0.05 mm = 85.0%) ̴70%
- Maximum water holding capacity: The WHCmax was calculated to be 72.28 g water/100 g dry artificial soil corresponding to 41.94 % soil moisture in the 1st run and 76.08 g water/100 g dry artificial soil corresponding to 43.21 % soil moisture in the 2nd run.
- Pretreatment of soil: The soil was premoistened with 3 L deionised water per 15 kg dry weight artificial soil.

OTHER TEST CONDITIONS
- Photoperiod: 16:8 h
- Light intensity: 534 – 621 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Mortality and abnormal behaviour or any other adverse effects of adult worms (after 28 d)
- Growth (after 0 d and 28 d) and reproduction of adults (after 56 d)
- Assessment of Food Consumption (at each feeding date)
VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Spacing factor for test concentrations: < 2

Nominal and measured concentrations:

Nominal test concentrations
- 1st run: 0, 18, 32, 56, 100, 178, 316, 562 and 1000 mg a.i./kg dry weight artificial soil (equivalent to 0.0, 18.5, 32.9, 57.6, 102.8, 182.9, 324.8, 577.6, 1027.7 mg test item/kg dry weight artificial soil);
- 2nd run: 0.0, 0.3, 0.5, 0.8, 1.5, 2.7, 4.7, 8.4 and 15 mg a.i./kg dry weight artificial soil (equivalent to 0.0, 0.31, 0.51, 0.82, 1.54, 2.77, 4.83, 8.63, 15.41 mg test item/kg dry weight artificial soil).

Reference substance (positive control):

yes

Remarks:

methyl 1H-benzimidazol-2-ylcarbamate (Carbendazim)

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

10.3 mg/kg soil dw

95% CI:

>= 3.2 - <= 21

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks on result:

other: Combined evaluation of run 1 and 2

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

18 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks on result:

other: Combined evaluation of run 1 and 2

Results with reference substance (positive control):

The change of body weight of the adult earthworms of the test concentration of 5.0 mg a.i./kg dry weight soil was statistically significant reduced in comparison to the control.
The number of juveniles per test vessel of the test concentrations 2.5 and 5.0 mg a.i./kg dry weight soil were statistically significant reduced in comparison to the control.
Therefore, the results of the reference test indicated that the test system was sensitive to the reference test item (according to the guideline significant effects should be observed between 1 and 5 mg a.i./kg dry weight artificial soil).

Reported statistics and error estimates:

Data for mortality were statistically evaluated by the means of a Fisher`s exact binominal test, one-sided greater, α = 0.05 (1st and 2nd run).
Data of growth were tested for normal distribution and homogeneity of variance using ShapiroWilk’s-Test and Leven’s -Test (α = 0.05) respectively. Data of growth were normally distributed, and homogeneity of variances was given. Therefore William´s t-test, two-sided, α = 0.05 (1st run) and Dunnett´s t-test, two-sided, α = 0.05 (2nd run) was used to determine NOEC and LOEC values.

Data of reproduction were tested for normal distribution and homogeneity of variance using Shapiro-Wilk’s-Test and Levene´s-Test (α = 0.05) respectively. Both was given. Therefore William´s t-test, onesided smaller, α = 0.05 (1st run) and Dunnett´s t-test, one-sided smaller, α = 0.05 (2nd run) was used to determine NOEC and LOEC values.
Therefore, the NOEC and ECx of the reproduction were calculated with the percent values corresponding to the solvent control of each test run. This approach enables the data analysis over all tested rates from both test runs combined. Data of reproduction were tested for normal distribution and homogeneity of variance using Shapiro-Wilk’s-Test and Levene´s-Test (α = 0.05) respectively. Data of reproduction were normally distributed, and heterogeneity of variances was given (combined data set of run 1 and 2). Therefore, a Sequentially-rejective Welsh-t-test after Bonferroni-Holm adjustment (onesided smaller, α = 0.05) was used to determine NOEC and LOEC values.

Table 1: Effects on mortality and growth of the adults after an exposure period of 28 days and the number of offspring per test vessel after 56 days (first run)

Test object	Eisenia fetida test item
Test item
mg a.s./kg dry weight artificial soil	control	Solvent control	18	32	56	100	178	316	562	1000
Mortality of adult earthworms [%] after 28 days	0	0	0	0	0	0	0	0	0	0
Significance (Mortality*)		---	-	-	-	-	-	-	-	-
Mean change of body fresh weight of the adults from day 0 to day 28 [%]	25.83	26.98	31.7	22.64	20.87	27.79	22.95	20.58	22.27	19.9
Standard Deviation	2.65	6.34	5.04	7.13	1.91	3.51	5.84	7.48	6.46	7.35
Significance (body fresh weight)**			-	-	-	-	-	-	-	-
Mean number of offspring per test vessel after 56 days	170.1	158.8	138	129.3	114.5	121.5	93	107	89.5	81
Standard Deviation	16.5	26.5	30.4	13.4	24.5	11.7	4.8	10.7	5.3	14.5
Coefficient of variance (%)	9.7	16.7	22.1	10.3	21.4	9.6	5.1	10	5.9	17.9
% of control		---	86.9	81.4	72.1	76.5	58.6	67.4	56.4	51
Significance (reproduction)***		---	+	+	+	+	+	+	+	+
	Adult Mortality				Growth			Reproduction
NOEC [mg a.s./kg dry weight soil]	≥1000				>1000			<18
LOEC [mg a.s./kg dry weight soil]	>1000				≥1000			≤18
* (Fisher`s Exact Binominal Test with Bonferroni Correction, two-sided, α = 0.05).
+ significant, - not significant
** (Dunnett t-test, two-sided. α = 0.05), + = significant, - = not significant
*** (Dunnett’s t-test, one-sided smaller, α = 0.05), + significant, - not significant
--- control was used for the statistical evaluation

 

Table 2: Effects on mortality and growth of the adults after an exposure period of 28 days and the number of offspring per test vessel after 56 days (second run)

Test object	Eisenia fetida test item
Test item
mg a.s./kg dry weight artificial soil	control	Solvent control	0.3	0.5	0.8	1.5	2.7	4.7	8.4	15
Mortality of adult earthworms [%] after 28 days	0	0	0	0	0	0	0	0	0	0
Significance (Mortality*)		---	-	-	-	-	-	-	-	-
Mean change of body fresh weight of the adults from day 0 to day 28 [%]	25.17	27.63	27.4	25.79	24.51	28.99	25.96	29.53	28.64	26.06
Standard Deviation	3.88	4.55	2.54	4.39	4.32	6.45	4.45	5.34	3.9	6.63
Significance (body fresh weight)**		---	-	-	-	-	-	-	-	-
Mean number of offspring per test vessel after 56 days	150.3	149.1	147.8	160.3	163.8	162.3	158.5	123	160	137
Standard Deviation	17.3	25	10.8	24.5	23.6	26.3	17	24.1	28.1	30.1
Coefficient of variance (%)	11.5	16.8	7.3	15.3	14.4	16.2	10.7	19.6	17.6	22
% of control		---	99.1	107.5	109.8	108.8	106.3	82.5	107.3	91.9
Significance (reproduction)***		---	-	-	-	-	-	-	-	-
	Adult Mortality				Growth			Reproduction
NOEC [mg a.s./kg dry weight soil]	≥15				≥15			15
LOEC [mg a.s./kg dry weight soil]	>15				>15			>15
* (Fisher`s Exact Binominal Test with Bonferroni Correction, two-sided, α = 0.05).
+ significant, - not significant
** (Dunnett t-test, two-sided. α = 0.05), + = significant, - = not significant
*** (Dunnett’s t-test, one-sided smaller, α = 0.05), + significant, - not significant
--- control was used for the statistical evaluation

Table 3: Survival and Mean weight of parental worms after 28d exposure to the test item (1^st run).

mg a.s./kg dry weight artificial soil	Box No.	Number of surviving worms Day 0	Number of surviving worms Day 28	Mean weight of worms [g] Day 0	Mean weight of worms [g] Day 28	weight change [%]
Control	1	10	10	0.36	0.46	28.09
	2	10	10	0.36	0.46	27.02
	3	10	10	0.36	0.45	26.97
	4	10	10	0.35	0.45	28.65
	5	10	10	0.36	0.45	25.41
	6	10	10	0.37	0.45	20.27
	7	10	10	0.34	0.42	24.34
	8	10	10	0.35	0.44	25.93
Mean standard deviation	±	10	10	0.36	0.45	25.83
		0	0	0.01	0.01	2.65
Solvent Control	1	10	10	0.36	0.48	34.65
	2	10	10	0.37	0.48	29.73
	3	10	10	0.36	0.44	23.68
	4	10	10	0.37	0.44	18.6
	5	10	10	0.37	0.46	23.18
	6	10	10	0.37	0.44	20.11
	7	10	10	0.35	0.47	33.62
	8	10	10	0.35	0.47	32.29
Mean standard deviation	±	10	10	0.36	0.46	26.98
		0	0	0.01	0.02	6.34
18	1	10	10	0.32	0.45	38.08
	2	10	10	0.36	0.46	28.69
	3	10	10	0.33	0.45	33.23
	4	10	10	0.35	0.45	26.78
Mean standard deviation	±	10	10	0.34	0.45	31.7
		0	0	0.02	0.01	5.04
32	1	10	10	0.35	0.44	27.59
	2	10	10	0.36	0.45	25.42
	3	10	10	0.37	0.41	12.05
	4	10	10	0.35	0.44	25.5
Mean standard deviation	±	10	10	0.36	0.44	22.64
		0	0	0.01	0.02	7.13
56	1	10	10	0.36	0.44	22.97
	2	10	10	0.35	0.43	22
	3	10	10	0.36	0.43	19.33
	4	10	10	0.37	0.44	19.19
Mean standard deviation	±	10	10	0.36	0.43	20.87
		0	0	0.01	0.01	1.91
100	1	10	10	0.37	0.46	23.53
	2	10	10	0.36	0.45	27.04
	3	10	10	0.35	0.46	32
	4	10	10	0.36	0.46	28.57
Mean standard deviation	±	10	10	0.36	0.46	27.79
		0	0	0.01	0.01	3.51
178	1	10	10	0.36	0.42	15.43
	2	10	10	0.34	0.43	29.55
	3	10	10	0.36	0.45	22.53
	4	10	10	0.35	0.44	24.29
Mean standard deviation	±	10	10	0.35	0.43	22.95
		0	0	0.01	0.01	5.84
316	1	10	10	0.34	0.44	28.78
	2	10	10	0.35	0.43	23.99
	3	10	10	0.39	0.44	11.48
	4	10	10	0.36	0.43	18.06
Mean standard deviation	±	10	10	0.36	0.43	20.58
		0	0	0.02	0.01	7.48
562	1	10	10	0.38	0.44	14.66
	2	10	10	0.36	0.43	19.94
	3	10	10	0.33	0.42	29.75
	4	10	10	0.36	0.45	24.72
Mean standard deviation	±	10	10	0.36	0.43	22.27
		0	0	0.02	0.01	6.46
1000	1	10	10	0.37	0.46	23.58
	2	10	10	0.34	0.43	27.43
	3	10	10	0.36	0.42	18.11
	4	10	10	0.36	0.4	10.5
Mean standard deviation	±	10	10	0.36	0.43	19.9
		0	0	0.01	0.02	7.35

 

Table 4: Survival and Mean weight of parental worms after 28d exposure to the test item (2nd run).

mg a.s./kg dry weight artificial soil	Box No.	Number of surviving worms Day 0	Number of surviving worms Day 28	Mean weight of worms [g] Day 0	Mean weight of worms [g] Day 28	weight change [%]
Control	1	10	10	0.36	0.43	18.13
	2	10	10	0.36	0.46	29.49
	3	10	10	0.35	0.45	28.99
	4	10	10	0.35	0.43	20.96
	5	10	10	0.35	0.44	26.36
	6	10	10	0.35	0.45	26.55
	7	10	10	0.37	0.46	24.52
	8	10	10	0.38	0.48	26.32
Mean standard deviation	±	10	10	0.36	0.45	25.17
		0	0	0.01	0.02	3.88
Solvent Control	1	10	10	0.37	0.45	22.34
	2	10	10	0.37	0.45	22.34
	3	10	10	0.33	0.42	26.35
	4	10	10	0.33	0.43	30.42
	5	10	10	0.35	0.45	27.51
	6	10	10	0.35	0.47	36.42
	7	10	10	0.34	0.44	26.82
	8	10	10	0.34	0.44	28.82
Mean standard deviation	±	10	10	0.35	0.44	27.63
		0	0	0.01	0.01	4.55
0.3	1	10	10	0.36	0.46	29.25
	2	10	10	0.36	0.45	25.21
	3	10	10	0.34	0.44	29.91
	4	10	10	0.35	0.43	25.22
Mean standard deviation	±	10	10	0.35	0.45	27.4
		0	0	0.01	0.01	2.54
0.5	1	10	10	0.36	0.45	24.51
	2	10	10	0.36	0.45	26.2
	3	10	10	0.37	0.48	31.51
	4	10	10	0.36	0.43	20.95
Mean standard deviation	±	10	10	0.36	0.45	25.79
		0	0	0	0.02	4.39
0.8	1	10	10	0.39	0.49	24.17
	2	10	10	0.36	0.44	21.17
	3	10	10	0.34	0.45	30.7
	4	10	10	0.37	0.46	21.98
Mean standard deviation	±	10	10	0.37	0.46	24.51
		0	0	0.02	0.02	4.32
1.5	1	10	10	0.35	0.46	33.62
	2	10	10	0.35	0.47	33.14
	3	10	10	0.35	0.46	29.46
	4	10	10	0.37	0.44	19.73
Mean standard deviation	±	10	10	0.35	0.46	28.99
		0	0	0.01	0.01	6.45
2.7	1	10	10	0.37	0.44	19.62
	2	10	10	0.35	0.45	29.48
	3	10	10	0.35	0.44	26.22
	4	10	10	0.36	0.46	28.53
Mean standard deviation	10	10	0.36	0.45	25.96	±
0	0	0.01	0.01	4.45
4.7	1	10	10	0.35	0.47	33.14
	2	10	10	0.37	0.46	22.73
	3	10	10	0.37	0.47	27.87
	4	10	10	0.35	0.47	34.38
Mean standard deviation	±	10	10	0.36	0.47	29.53
		0	0	0.01	0	5.34
8.4	1	10	10	0.37	0.48	28.65
	2	10	10	0.35	0.47	33.91
	3	10	10	0.36	0.45	24.59
	4	10	10	0.39	0.49	27.43
Mean standard deviation	±	10	10	0.37	0.47	28.64
		0	0	0.02	0.02	3.9
15	1	10	10	0.39	0.46	16.97
	2	10	10	0.38	0.51	32.89
	3	10	10	0.36	0.46	26.94
	4	10	10	0.38	0.49	27.42
Mean standard deviation	±	10	10	0.38	0.48	26.06
		0	0	0.01	0.02	6.63

Table 5: Reproduction of the earthworms after 56 d (1st run)

mg a.s./kg dry weight artificial soil	Control	Solvent Control	18	32	56	100	178	316	562	1000
Box No. 1	182	182	118	119	83	136	90	99	96	61
Box No. 2	165	152	115	134	129	118	88	97	83	81
Box No. 3	188	153	138	146	138	124	98	113	90	87
Box No. 4	176	191	181	118	108	108	96	119	89	95
Box No. 5	147	138
Box No. 6	174	179
Box No. 7	145	165
Box No. 8	184	110
Mean	170.1	158.8	138	129.3	114.5	121.5	93	107	89.5	81
SD	16.5	26.5	30.4	13.4	24.5	11.7	4.8	10.7	5.3	14.5
CV	9.7	16.7	22.1	10.3	21.4	9.6	5.1	10	5.9	17.9
% of control	---	---	86.9	81.4	72.1	76.5	58.6	67.4	56.4	51

 

Table 6: Reproduction of the earthworms after 56 d (2nd run)

mg a.s./kg dry weight artificial soil	Control	Solvent Control	0.3	0.5	0.8	1.5	2.7	4.7	8.4	15
Box No. 1	164	180	156	134	145	175	136	123	143	136
Box No. 2	137	152	153	187	197	191	169	156	197	95
Box No. 3	121	115	132	146	149	152	155	99	166	155
Box No. 4	156	125	150	174	164	131	174	114	134	162
Box No. 5	151	184
Box No. 6	153	134
Box No. 7	178	162
Box No. 8	142	141
Mean	150.3	149.1	147.8	160.3	163.8	162.3	158.5	123	160	137
SD	17.3	25	10.8	24.5	23.6	26.3	17	24.1	28.1	30.1
CV	11.5	16.8	7.3	15.3	14.4	16.2	10.7	19.6	17.6	22
% of control	---	---	99.1	107.5	109.8	108.8	106.3	82.5	107.3	91.9

 

Table 7: Validity criteria for OECD 222 (2016)

Criterion from the guideline to be satisfied in the controls	Outcome	Validity criterion fulfilled
Adult mortality over the initial 4 weeks of the test is ≤ 10%.	1st run: 0 % 2nd run: 0 %	Yes
Each replicate (containing 10 adults) produced ≥ 30 juveniles by the end of the test.	1st run: 110 -191 2nd run: 115 - 184	Yes
The coefficient of variation of reproduction is ≤ 30%.	1st run: 16.7 % 2nd run: 16.8 %	Yes

 

 

Validity criteria fulfilled:

yes

Remarks:

Please see Table 7 in "Any other information on results incl. tables".

Reference 2

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

19 Apr - 04 May 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium fur Umwelt, Raumordnung und Landwirtschaft des Landes Nordrhein-Westfalen, Düsseldorf, Germany

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil: Test item and quartz sand were transferred to a motar and thoroughly mixed with a pestle. This mixture was transferred separately to artificial soil (500 g dry weight) and mixed thoroughly using a laboratory mixer. Finally 50 mL of deionized water were added and mixed into each replicate to achieve between 40% and 60% of the maximum water holding capacity.
- Controls: 5 g of quartz sand (without test item) was mixed into the soil.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: earthworm
- Source: Prof Graff, Forschungsanstalt fur Landwirtschaft, 38104 Braunschweig, Germany
- Age at test initiation: >2 months old
- Weight at test initiation: 0.33 g (mean)

ACCLIMATION
- Acclimation period: 1 day
- Acclimation conditions (same as test or not): same as test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

20 ± 2 °C

pH:

6.37 to 6.40

Moisture:

23.9 to 24.9% in artificial soil

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1.5 liter preserving jars, covered with glass lids
- Amount of soil or substrate: 500 g dry weight test soil (equivalent to 625 g wet weight)
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4
- No. of replicates per vehicle control: 10

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition (if artificial substrate): Artificial soil was prepared by mixing Sphagnum peat (10%), Kaolinite Clay (20%), industrial quartz sand (69%), calcium carbonate (0.2 - 1%).
- Maximum water holding capacity (in % dry weigth): 59.1
- Pretreatment of soil: Soil was mixed with deionized water to achieve between 40 - 60% of holding capacity.

OTHER TEST CONDITIONS
- Photoperiod: constant light
- Light intensity: 400-800 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality was assumed when worms did not move when prodded and was measured at 14 days. Abnormal behavior, weight and observed symptoms were also determined.

VEHICLE CONTROL PERFORMED: no; not necessary

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 0.1, 1, 10, 100 and 1000 mg test substance/kg dry weight soil.
- Results used to determine the conditions for the definitive study: The LC50, NOEC and LOEC were at least 1000 mg/kg which was therefore the concentration used in the definitive test.

Nominal and measured concentrations:

nominal: control, 1000 mg/kg dw

Reference substance (positive control):

yes

Remarks:

Chloroacetamide

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

- Mortality at end of exposure period: The LC50 (14 d) was estimated to be > 1000 mg active ingredient/kg dry weight substrate
- Total mass of adults at beginning of test: 12.2 g
- Changes in body weight of live adults (% of initial weight) at end of exposure period: an increase of 5.7 % in body weight was observed
- Morphological abnormalities: None
- Behavioural abnormalities: None

Results with reference substance (positive control):

- Results with reference substance valid? The LC50 was within the correct concentration determined in international ring studies.
- Relevant effect levels: The LC50 (14 days) was calculated to be 16 mg chloroacetamide/kg dry soil weight.

Reported statistics and error estimates:

The LC50-values and the 95 percent confidence limits were calculated by Probit- Analysis according to "Maximum-Likelihood" Method
Pairwise Mann-Whitney U-Test (alpha = 0.05, one-sided smaller)

Description of key information

NOEC (56 d) 18 mg a.i./kg dry weight soil (Eisenia fetida, OECD 222)

EC10 (56 d) 10.3 mg a.i./kg dry weight soil (Eisenia fetida, OECD 222)

LC50 (14 d) > 1000 mg test item/kg dry weight soil (Eisenia fetida, OECD 207)

NOEC (14 d) ≥ 1000 mg test item/kg dry weight soil (Eisenia fetida, OECD 207)

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

1 000 mg/kg soil dw

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

10.3 mg/kg soil dw

Additional information

Two experimental studies are available investigating the toxicological effects of the test item to earthworms (M-822955-02-1 and M-075743-01-2). The first GLP- study was performed according to OECD 222. During two test runs, adult Eisenia fetida andrei were exposed for 28 d to nominal test item concentration as high as: 18, 32, 56, 100, 178, 316, 562 and 1000 mg a.i./kg dry weight artificial soil (run 1) and 0.3, 0.5, 0.8, 1.5, 2.7, 4.7, 8.4 and 15 mg a.i./kg dry weight artificial soil (run 2). Each run included a control and a solvent control. After these 28 d adult worms were removed and checked for survival and weight. Following another 28 d the emptied test containers were checked for the reproductive output of the removed adult worms. No statistical significant difference for survival and weight was observed for the tested concentrations. A 56-d NOEC of 18 mg a.i./kg dry weight soil was estimated based on a combined data evaluation (run 1 and 2) for reproduction. Further, a 56-d EC10 (reproduction) of 10.3 mg a.i./kg dry weight soil was calculated. The second study was performed according to OECD guideline 207 under GLP conditions. Adult Eisenia fetida andrei (4 x 10 animals per concentration, the overall average weight was 0.33 g) were exposed for 14 days in an artificial soil to the nominal concentration of 1000 mg a.i./kg dry weight soil. The artificial soil comprised 10% peat. No morphological and behavioral effects were observed. Related to weight alterations and symptoms, the NOEC was ≥ 1000 mg a.i./kg dry weight soil, the LOEC > 1000 mg test item/kg dry weight soil. No mortality was recorded resulting in a LC50 (14 d) of > 1000 mg a.i./kg dry weight soil.