4-(4-isopropoxyphenylsulfonyl)phenol

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

Study period:

from 2003-10-22 to 2004-02-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1998

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: BB A 1994: 'Effects of pesticides on the reproduction and growth oí Eisenia fetida /Eisenia andrei.

Version / remarks:

In: BBA (Biologische Bundesanstalt für Land- und Forstwirtschaft, Bundesrepublik Deutschland), Richtlinie für die Prüfung von Pflanzenschutzmitteln im Zulassungsverfahren, Teil VI, Nr. 2-2; C. Kula

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Details on preparation and application of test substrate:

A stock solution was prepared by dissolving 4920 mg of the test item in 12 mL of acetone. A 1:3 dilution series was prepared by adding 10 mL of acetone to 5 mL of the stock solution or the respective dilution. The 5 mL of the stock solution or the respective dilution were added to 29 g of fine quartz sand. After evaporation of the solvent the test item blended sand was mixed into artificial soil to result in 2050 g dry weight to prepare the target nominal concentrations of the test item in the artificial soil:
Concentration [mg/mL acetone] / resulting concentration:
dilution 4: 5.1 / 12.3 mg/kg soil dry weight;
dilution 3: 15.2 / 37.0 mg/kg soil dry weight;
dilution 2: 45.6 / 111.1 mg/kg soil dry weight;
dilution 1: 136.7 / 333.3 mg/kg soil dry weight;
stock solution: 410.0 / 1000 mg/kg soil dry weight.
The control was treated with the same amount of acetone treated sand as the test item groups.
The artificial soil was mixed for about 5 min using a laboratory mixer. In the course of applying the test item the soil was ventilated and moistened with deionised water. The soil for each treatment was mixed in one batch then split into 4 replicates.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

- Taxonomic group: earthworms (Annelida: Oligochaeta)
- Species: Eisenia fetida andrei (Savigny 1826)
- Life stage: adults
- Age: ca. 5 months with well-developed clitellum, age range between test individuals not differing by more than 4 weeks
- Body weight: 350 - 550 mg, thus the body weight range did not differ by more than 200 mg
- Origin: bred under standardised conditions (in a breeding medium of cattle manure, peat, sand and straw, fed with cattle manure, stored at room temperature) by IBACON
- Acclimatisation: 3 days, in artificial soil, under test conditions

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Post exposure observation period:

28 d

Test temperature:

19 - 21 °C

pH:

6.2 - 6.5

Moisture:

Water content: at test initiation: 34.6 - 35.2 % (55.8 to 56.8 % of the water holding capacity)
at test termination: 35.9 - 38.6 % (57.9 to 62.3 % of the water holding capacity)

Details on test conditions:

Different concentrations of the test item were mixed homogeneously into the soil which was filled into plastic boxes before the earthworms were introduced on top of the soil; 5 concentrations; 4 replicates/concentration with 10 worms each. Assessment of worm mortality, behavioural effects and measurement of weight change was carried out after 28-d exposure of adult worms in treated artificial soil. After an additional 28 days, determination of number of offspring was conducted. The study was performed at 16 h light : 8 h dark regime with light intensity of 450 - 650 lux.

Nominal and measured concentrations:

Nominal concentrations: 0; 12.3; 37.0; 111; 333; 1000 mg test item/kg soil dry weight
No measured concentrations.

Reference substance (positive control):

yes

Remarks:

Carbendazim

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

333 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

LC0

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

56 d

Dose descriptor:

LC0

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Duration:

56 d

Dose descriptor:

LC0

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

food consumption

Details on results:

No mortality was observed at any treatment concentration of D-8. No effects on body weight of the earthworms, on feeding activity or any behavioural effects could be observed up to and including the highest concentration of 1000 mg test item/kg soil dry weight. The number of juvenile worms was not statistically different compared to the control up to and including the concentration of 333 mg test item/kg soil dry weight. At the highest concentration of 1000 mg test item/kg soil dry weight the reproduction rate was statistically reduced compared to the control.

Results with reference substance (positive control):

The most recent toxic standard test showed statistically significant effects on reproduction at a concentration of 1.0 mg carbendazim/kg artificial soil (dry weight). The EC50 for reproduction was calculated as 1.03 mg carbendazim/kg soil dry weight.

Reported statistics and error estimates:

Data of body weight changes and reproduction were tested for normal distribution and homogeneity of variance using Kolmogorov-Smirnov test and Cochran test.
Because data of body weight changes and reproduction were normally distributed and homogeneous Dunnett test was used (multiple comparison, alpha = 0.05, two-sided for weight changes, one sided smaller for reproduction).
The software used to perform the statistical analysis was EASY ASSAY, Multiple Testing, © SPiRiT, Version 4.0.

Mortality of the adult worms:

No mortality was observed in any treatment group.

Body weights of the adult worms:

None of the body weight changes observed at any treatment concentration was significantly different compared to the control (Dunnett test, α = 0.05).

Feeding activity:

In all treatment groups, food was consumed. The results show that the turnover of biomass of those earthworms exposed to the five different rates of the test item was comparable to the control.

The method used here only approximately assesses food consumption of Eisenia fetida, because any food remaining cannot be weighed again. However, it reflects roughly to what extent the ecological role of earthworms in decomposing organic material was affected.

Behavioural abnormalities:

No behavioural abnormalities were observed and all worms did burrow into the soil after introduction.

Reproduction (mean number of offspring worms per container):

The number juvenile worms in the test item treated groups was not statistically different compared to the control up to and including the concentration of 333 mg/kg soil dry weight. At the concentration of 1000 mg test item/kg soil dry weight the reproduction rate was statistically reduced compared to the control (Dunnett test, α = 0.05).

Table 1. Summary of Results

Test item:	D-8
Test species:	Eisenia fetida
Exposure:	Test item mixed into the soil
Test duration:	28 days for adult worms, additional 28 days for juvenile worms
	Control	D-8
		12.3 mg/kg	37.0 mg/kg	111 mg/kg	333 mg/kg	1000 mg/kg
Mortality (%)	0.0 ± 0.0	0.0 – ± 0.0	0.0 – ± 0.0	0.0 – ± 0.0	0.0 – ± 0.0	0.0 – ± 0.0
Body weight change (%)	27.8 ± 6.4	31.6 n.s. ± 2.5	32.6 n.s. ± 2.5	29.7 n.s. ± 8.4	32.4 n.s. ± 5.7	30.6 n.s. ± 6.8
Reproduction # of juveniles^1% of control	388 ± 65 -	415 n.s. ± 89 106.8	447 n.s. ± 48 115.2	453 n.s. ± 79 116.7	414 n.s. ± 38 106.6	264 * ± 71 67.9
Amount of food added (g)^1	25.0 ± 0.0	25.0 ± 0.0	25.0 ± 0.0	25.0 ± 0.0	25.0 ± 0.0	25.0 ± 0.0

1: mean ± Standard Deviation of 4 replicates; the results represent rounded values calculated on the exact raw data
-: not relevant
n.s.: not significantly different compared to the control, Dunnett test,α= 0.05
*: significantly different compared to the control, Dunnett test,α= 0.05
two sided for weight changes, one-sided smaller for reproduction

Validity criteria fulfilled:

yes

Conclusions:

D-8 was tested for toxicity to earthworms in a study according to ISO Guideline 11268-2. In this study no effects on mortality, growth and feeding activity of the earthworm Eisenia fetida were observed up to and including the concentration of 1000 mg D-8/kg soil dry weight. The reproduction rate of the earthworms was affected at the concentration of 1000 mg D-8/kg soil dry weight. Therefore, the overall no-observed-effect-concentration (NOEC) of D-8 was 333 mg /kg soil dry weight.

Executive summary:

D-8 was tested for toxicity to earthworms Eisenia fetida in a study according to ISO Guideline 11268-2. D-8 was tested for toxicity in concentrations of 0, 12.3, 37.0, 111, 333 and 1000 mg test item/kg soil dry weight. Artificial soil according to OECD 207 was prepared and mixed with the respectful amount test item to get each test concentration. Each concentration was tested in 4 replicated and in each replicate 10 adult earthworms were exposed for 28 days. For another 28 days the reproduction of the earthworms was observed. No mortality was observed at any treatment concentration of D-8. No effects on body weight of the earthworms, on feeding activity or any behavioural effects could be observed up to and including the highest concentration of 1000 mg test item/kg soil dry weight. The number juvenile worms was not statistically different compared to the control up to and including the concentration of 333 mg test item/kg soil dry weight. At the highest concentration of 1000 mg test item/kg soil dry weight the reproduction rate was statistically reduced compared to the control. Therefore, the overall no-observed-effect-concentration (NOEC) of D-8 was 333 mg /kg soil dry weight.

Description of key information

D-8 was tested for toxicity to earthworms in a 56-d study according to ISO Guideline 11268-2. In this study no effects on mortality, growth and feeding activity of the earthworm Eisenia fetida were observed up to and including the concentration of 1000 mg D-8/kg soil dry weight. The reproduction rate of the earthworms was affected at the concentration of 1000 mg D-8/kg soil dry weight. Therefore, the overall no-observed-effect-concentration (NOEC) of D-8 was 333 mg /kg soil dry weight.

Key value for chemical safety assessment

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

333 mg/kg soil dw

Additional information

D-8 was tested for toxicity to earthworms Eisenia fetida in a study according to ISO Guideline 11268-2. D-8 was tested for toxicity in concentrations of 0, 12.3, 37.0, 111, 333 and 1000 mg test item/kg soil dry weight. Artificial soil according to OECD 207 was prepared and mixed with the respectful amount test item to get each test concentration. Each concentration was tested in 4 replicated and in each replicate 10 adult earthworms were exposed for 28 days. For another 28 days the reproduction of the earthworms was observed. No mortality was observed at any treatment concentration of D-8. No effects on body weight of the earthworms, on feeding activity or any behavioural effects could be observed up to and including the highest concentration of 1000 mg test item/kg soil dry weight. The number juvenile worms was not statistically different compared to the control up to and including the concentration of 333 mg test item/kg soil dry weight. At the highest concentration of 1000 mg test item/kg soil dry weight the reproduction rate was statistically reduced compared to the control. Therefore, the overall no-observed-effect-concentration (NOEC) of D-8 was 333 mg /kg soil dry weight.